Pfizer’s PF 04991532 a Hepatoselective Glucokinase Activator Clinical Candidate for Treating Type 2 Diabetes Mellitus

PF 04991532
GKA PF-04991532
(S)-6-{3-cyclopentyl-2-[4-(trifluoromethyl)-1H-imidazol-1-yl]propanamido}nicotinic acid
(S)-6-(3-Cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanamido)nicotinic Acid
(S)-6-(3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanamido)nicotinic acid
MW 396.36, MF C₁₈ H₁₉ F₃ N₄ O₃
CAS 1215197-37-7
3-​Pyridinecarboxylic acid, 6-​[[(2S)​-​3-​cyclopentyl-​1-​oxo-​2-​[4-​(trifluoromethyl)​-​1H-​imidazol-​1-​yl]​propyl]​amino]​-
http://www.biochemj.org/content/441/3/881
Type 2 diabetes mellitus (T2DM) is a rapidly expanding public epidemic affecting over 300 million people worldwide. This disease is characterized by elevated fasting plasma glucose (FPG), insulin resistance, abnormally elevated hepatic glucose production (HGP), and reduced glucose-stimulated insulin secretion (GSIS). Moreover, long-term lack of glycemic control increases risk of complications from neuropathic, microvascular, and macrovascular diseases.
The standard of care for T2DM is metformin followed by sulfonylureas, dipeptidyl peptidase-4 (DPP-IV) inhibitors, and thiazolidinediones (TZD) as second line oral therapies. As disease progression continues, patients typically require injectable agents such as glucagon-like peptide-1 (GLP-1) analogues and, ultimately, insulin to help maintain glycemic control. Despite these current therapies, many patients still remain unable to safely achieve and maintain tight glycemic control, placing them at risk of diabetic complications and highlighting the need for novel therapeutic options.

Glucokinase (hexokinase IV) continues to be a compelling target for the treatment of type 2 diabetes given the wealth of supporting human genetics data and numerous reports of robust clinical glucose lowering in patients treated with small molecule allosteric activators. Recent work has demonstrated the ability of hepatoselective activators to deliver glucose lowering efficacy with minimal risk of hypoglycemia.
While orally administered agents require a considerable degree of passive permeability to promote suitable exposures, there is no such restriction on intravenously delivered drugs. Therefore, minimization of membrane diffusion in the context of an intravenously agent should ensure optimal hepatic targeting and therapeutic index.

Diabetes is a major public health concern because of its increasing prevalence and associated health risks. The disease is characterized by metabolic defects in the production and utilization of carbohydrates which result in the failure to maintain appropriate blood glucose levels. Two major forms of diabetes are recognized. Type I diabetes, or insulin-dependent diabetes mellitus (IDDM), is the result of an absolute deficiency of insulin. Type II diabetes, or non-insulin dependent diabetes mellitus (NIDDM), often occurs with normal, or even elevated levels of insulin and appears to be the result of the inability of tissues and cells to respond appropriately to insulin. Aggressive control of NIDDM with medication is essential; otherwise it can progress into IDDM.
As blood glucose increases, it is transported into pancreatic beta cells via a glucose transporter. Intracellular mammalian glucokinase (GK) senses the rise in glucose and activates cellular glycolysis, i.e. the conversion of glucose to glucose-6-phosphate, and subsequent insulin release. Glucokinase is found principally in pancreatic β-cells and liver parenchymal cells. Because transfer of glucose from the blood into muscle and fatty tissue is insulin dependent, diabetics lack the ability to utilize glucose adequately which leads to undesired accumulation of blood glucose (hyperglycemia). Chronic hyperglycemia leads to decreases in insulin secretion and contributes to increased insulin resistance. Glucokinase also acts as a sensor in hepatic parenchymal cells which induces glycogen synthesis, thus preventing the release of glucose into the blood. The GK processes are thus critical for the maintenance of whole body glucose homeostasis.
It is expected that an agent that activates cellular GK will facilitate glucose-dependent secretion from pancreatic beta cells, correct postprandial hyperglycemia, increase hepatic glucose utilization and potentially inhibit hepatic glucose release. Consequently, a GK activator may provide therapeutic treatment for NIDDM and associated complications, inter alia, hyperglycemia, dyslipidemia, insulin resistance syndrome, hyperinsulinemia, hypertension, and obesity.
Several drugs in five major categories, each acting by different mechanisms, are available for treating hyperglycemia and subsequently, NIDDM (Moller, D. E., “New drug targets for Type II diabetes and the metabolic syndrome” Nature 414; 821-827, (2001)): (A) Insulin secretogogues, including sulphonyl-ureas (e.g., glipizide, glimepiride, glyburide) and meglitinides (e.g., nateglidine and repaglinide) enhance secretion of insulin by acting on the pancreatic beta-cells. While this therapy can decrease blood glucose level, it has limited efficacy and tolerability, causes weight gain and often induces hypoglycemia. (B) Biguanides (e.g., metformin) are thought to act primarily by decreasing hepatic glucose production. Biguanides often cause gastrointestinal disturbances and lactic acidosis, further limiting their use. (C) Inhibitors of alpha-glucosidase (e.g., acarbose) decrease intestinal glucose absorption. These agents often cause gastrointestinal disturbances. (D) Thiazolidinediones (e.g., pioglitazone, rosiglitazone) act on a specific receptor (peroxisome proliferator-activated receptor-gamma) in the liver, muscle and fat tissues. They regulate lipid metabolism subsequently enhancing the response of these tissues to the actions of insulin. Frequent use of these drugs may lead to weight gain and may induce edema and anemia. (E) Insulin is used in more severe cases, either alone or in combination with the above agents.
Ideally, an effective new treatment for NIDDM would meet the following criteria: (a) it would not have significant side effects including induction of hypoglycemia; (b) it would not cause weight gain; (c) it would at least partially replace insulin by acting via mechanism(s) that are independent from the actions of insulin; (d) it would desirably be metabolically stable to allow less frequent usage; and (e) it would be usable in combination with tolerable amounts of any of the categories of drugs listed herein.
Substituted heteroaryls, particularly pyridones, have been implicated in mediating GK and may play a significant role in the treatment of NIDDM. For example, U.S. Patent publication No. 2006/0058353 and PCT publication Nos. WO2007/043638, WO2007/043638, and WO2007/117995 recite certain heterocyclic derivatives with utility for the treatment of diabetes. Although investigations are on-going, there still exists a need for a more effective and safe therapeutic treatment for diabetes, particularly NIDDM.

PATENT

US 20100063063
http://www.google.com/patents/US20100063063
SYNTHESIS CONSTRUCTION

6-aminonicotinic acid


BENZYL BROMIDE


FIRST KEY INTERMEDIATE

SECOND SERIES FOR NEXT INTERMEDIATE 

(R)-2-amino-3-cyclopentylpropanoic acid


(R)-methyl 3-cyclopentyl-2-hydroxypropanoic acid (I-1a)


(R)-methyl 3-cyclopentyl-2-hydroxypropanoate (I-1b)

Trifluoromethanesulfonic acid anhydride



(R)-methyl 3-cyclopentyl-2-(trifluoromethylsulfonyloxy)propanoate (I-1c)


CONDENSED WITH

4-Trifluoromethyl-1H-imidazole
TO  GIVE PRODUCT SHOWN BELOW


(S)-methyl 3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanoate (I-8a)




(S)-3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanoic acid (I-8b)



CONVERTED TO ACID CHLORIDE, (S)-3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanoyl chloride (I-8c)
AND CONDENSED WITH

WILL GIVE BENZYL DERIVATIVE AS BELOW


THEN DEBENZYLATION TO FINAL PRODUCT


Intermediate: (R)-methyl 3-cyclopentyl-2-hydroxypropanoic acid (I-1a)

To a stirred solution of (R)-2-amino-3-cyclopentylpropanoic acid (5.0 grams; Chem-Impex International, Inc., Wood Dale, Ill.) and 1 M H₂SO₄ (45.1 mL) at 0° C., was added a solution of NaNO₂ (3.12 g) in H₂O (15.6 mL) drop wise over 10 minutes. The reaction mixture was stirred for 3 hours at 0° C., then for 2 hours at room temperature. The solution was then extracted (3 times) with diethyl ether. The combined organic extracts were dried over MgSO₄, filtered, and the filtrate concentrated to afford 2.36 g of (I-1a). ¹H NMR (400 MHz, CDCl₃) δ 4.26-4.28 (1H), 1.99-2.07 (1H), 1.76-1.81 (4H), 1.60-1.62 (4H), 1.12-1.16 (2H); LCMS for C₈H₁₄O₃ m/z 157.1 (M−H)⁻.
Intermediate: (R)-methyl 3-cyclopentyl-2-hydroxypropanoate (I-1b)

To a stirred solution of 2.36 g of (I-1a) in anhydrous methanol (15 mL) at room temperature was added SOCl₂(1.64 mL). The resulting mixture was heated at reflux for 2 hours. It was then cooled and concentrated under reduced pressure. The residue was partitioned between ethyl acetate and aqueous saturated NaHCO₃ solution. The biphasic mixture was separated and the aqueous portion was extracted with ethyl acetate. The combined extracts were dried over MgSO₄, filtered, and the filtrate concentrated under reduced pressure. The resulting residue was purified by flash column chromatography (silica gel, heptanes/ethyl acetate) to afford 1.5 g of (I-1b) as a clear oil.¹H NMR (400 MHz, CDCl₃) δ 4.15-4.20 (1H), 3.77 (3H), 2.62-2.63 (1H), 1.97-2.05 (1H), 1.49-1.86 (8H), 1.06-1.17 (2H); LCMS for C₉H₁₆O₃ m/z 171.6 (M)⁺. Intermediate (I-1b) can alternatively be prepared by the method described below.
A 0.2M solution of Li₂CuCl₄ was prepared as follows: Anhydrous CUCl₂ (26.9 g, 200 mol) and anhydrous LiCl (17.0 g, 400 mmol) were dissolved in THF (1000 mL). The mixture required gentle heating to completely dissolve the solids. After cooling the solution is ready for use.
A solution of Li₂CuCl₄ (0.2 M in THF, 125 mL, 25.0 mmol) was added slowly to a suspension of cyclopentylmagnesium bromide (2 M in diethyl ether, 135 mL, 270 mmol; Aldrich Chemical Company, Inc., Milwaukee, Wis.) and THF (500 mL) at −50° C. over 2-3 mins. The pale grey/brown suspension was then allowed to warm slowly to −10° C. over 30 mins, by which time the color had developed to a dark grey. The mixture was re-cooled to −78° C. and (R)-methyl oxirane-2-carboxylate (25.0 g, 245 mmol; Aldrich Chemical Company, Inc., Milwaukee, Wis.) was added neat via syringe over 90 seconds. The reaction was then stirred at −78° C. for 20 mins, before removing the ice-bath and allowing to warm to approximately −50° C. over 30 mins. Saturated NH₄Cl (aq, 700 mL) was then added and the mixture stirred for 30 mins. The organic layer was collected and the aqueous layer extracted with diethyl ether (2×250 mL). The combined organics were washed with saturated NH₄Cl (aq, 350 mL), dried over MgSO₄, and evaporated. Distillation of the crude residue (68-70° C. at 0.8 mbar) yielded 65-70% of (I-1b) as a pale yellow oil. A small amount of less volatile material remained in the still pot. ¹H NMR (400 MHz; CDCl₃): δ 4.17(1H), 3.76 (3H), 2.67 (1H), 2.01 (1H), 1.48-1.88 (8H), 1.11 (2H).
Intermediate: (R)-methyl 3-cyclopentyl-2-(trifluoromethylsulfonyloxy)propanoate (I-1c)
Intermediate: (R)-methyl 3-cyclopentyl-2-(trifluoromethylsulfonyloxy)propanoate (I-1c
Intermediate (I-1b) (6.37 g, 37.0 mmol) was dissolved in dry dichloromethane (260 mL) and stirred under nitrogen in an ice bath. 2,6-Lutidine (9.0 mL, 77 mmol) was added. Trifluoromethanesulfonic acid anhydride (11 mL, 65 mmol) in dry dichloromethane (75 mL) was added dropwise. The reaction was stirred in the ice bath for 60 minutes, concentrated under reduced pressure, and taken up in 1N HCl and methyl t-butyl ether. The aqueous layer was separated, and the organic layer was washed with additional 1N HCl to insure the removal of all the lutidine. The combined organic layer was then washed with brine, dried over sodium sulfate, filtered, concentrated under reduced pressure, and dried under high vacuum to afford (I-1c) (11.3 g, 37 mmol, 100%), which was used immediately without further purification; ¹H NMR (400 MHz, CDCl₃) δ 5.10-5.14 (1H), 3.82 (3H), 2.02-2.12 (1H), 1.79-1.98 (4H), 1.51-1.66 (4H), 1.08-1.18 (2H).
Intermediate (I-1b) (6.37 g, 37.0 mmol) was dissolved in dry dichloromethane (260 mL) and stirred under nitrogen in an ice bath. 2,6-Lutidine (9.0 mL, 77 mmol) was added. Trifluoromethanesulfonic acid anhydride (11 mL, 65 mmol) in dry dichloromethane (75 mL) was added dropwise. The reaction was stirred in the ice bath for 60 minutes, concentrated under reduced pressure, and taken up in 1N HCl and methyl t-butyl ether. The aqueous layer was separated, and the organic layer was washed with additional 1N HCl to insure the removal of all the lutidine. The combined organic layer was then washed with brine, dried over sodium sulfate, filtered, concentrated under reduced pressure, and dried under high vacuum to afford (I-1c) (11.3 g, 37 mmol, 100%), which was used immediately without further purification; ¹H NMR (400 MHz, CDCl₃) δ 5.10-5.14 (1H), 3.82 (3H), 2.02-2.12 (1H), 1.79-1.98 (4H), 1.51-1.66 (4H), 1.08-1.18 (2H)
Intermediate: (S)-methyl 3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanoate (I-8a)

4-Trifluoromethyl-1H-imidazole (5.0 g, 37.0 mmol; Apollo Scientific Ltd., Bredbury, Cheshire, UK) was stirred in dry THF (180 mL) under nitrogen at room temperature. Lithium hexamethyldisilazide (1M in THF, 33.4 mL, 33.4 mmol) was added dropwise via addition funnel. The mixture was stirred at room temperature for 50 minutes and then chilled in an ice bath. A solution of (I-1c) (11.3 g, 37 mmol) in dry THF (45 mL), which had been chilled in an ice bath, was added in one portion. The reaction was allowed to warm to room temperature, stirred for 2 hours, quenched with saturated aqueous ammonium chloride solution (20 mL) and allowed to stir overnight. The aqueous layer was separated, and the organic layer was concentrated and then diluted with water and ethyl acetate. The organic layer was washed in series with dilute aqueous phosphoric acid, aqueous 10% potassium carbonate, and brine. The organic layer was then dried over sodium sulfate, filtered, and concentrated under reduced pressure to a brown oil. The crude material, containing the undesired regioisomer as a small impurity, was purified by chromatography on a 330 g pre-packed silica gel column, eluting with 10% ethyl acetate/heptane, linear gradient to 70% ethyl acetate/heptane. The product fractions were located by spotting on a silica TLC plate and visualizing with KMnO₄ stain. TLC (1:1 ethyl acetate/heptane, developed in potassium permanganate) located the pure and mixed fractions. The clean product fractions were combined, evaporated, and dried under high vacuum to afford (I-8a) as a clear oil (6.61 g, 22.4 mmol, 67%). ¹H NMR (400 MHz, CDCl₃) δ 7.57 (1H), 7.38 (1H), 4.71-4.74 (1H), 3.76 (3H), 2.01-2.14 (2H), 1.45-1.79 (7H), 1.03-1.18 (2H); m/z 291.4 (M+H)⁺.
Intermediate: (S)-3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanoic acid (I-8b
6N HCl (140 mL) was added to (I-8a) (6.61 g, 22.4 mmol) and the mixture was warmed to 95° C. for 16 hours and then allowed to cool. Solid potassium carbonate (58 g) was added in portions to bring the pH to about 4. A precipitate crashed out. Ethyl acetate was added, and the mixture was stirred until everything dissolved. The aqueous layer was extracted once with ethyl acetate. The combined organics were washed with brine, dried over sodium sulfate, filtered, concentrated under reduced pressure, and dried under high vacuum to afford (I-8b) as a clear glass (6.15 g, 21.9 mmol, 98%). ¹H NMR (400 MHz, CDCl₃) δ 7.73 (1H), 7.34 (1H), 6.85-7.15 (1H), 4.66-4.70 (1H), 1.98-2.17 (2H), 1.41-1.75 (7H), 1.01-1.19 (2H); m/z 277.4 (M+H)⁺.
Intermediate: (S)-3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanoyl chloride (I-8c)

To a suspension of intermediate (I-8b) (0.25 g, 0.9 mmol) in dichloromethane (5 mL) was added oxalyl chloride (0.35 g, 2.7 mmol) and N,N-dimethylformamide (1 drop) at room temperature. The mixture was stirred for 2 hours at room temperature. The reaction mixture was concentrated in vacuo, and the residue was chased with dichloromethane two times and concentrated in vacuo to afford (I-8c) (0.27 g, 100%) as an oil, which was used in the next step directly.
Intermediate: (S)-6-(3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanamido) nicotinoyl chloride (I-21a)

• 

  Thionyl chloride (225 mg, 1.89 mmol) was added to a solution of the compound of Example 48 (150 mg, 0.387 mmol) in dichloromethane (1.5 mL) and the reaction stirred at room temperature for 1 hour. LCMS of an aliquot in methanol showed ˜67% methyl ester. To the reaction mixture was added another 25 uL of thionyl chloride and this was stirred at room temp for another 30 minutes. Solvents were evaporated to afford 157 mg (100%) of (I-21a) as a grayish-white solid. LCMS in methanol to generate the methyl ester gave m/z 395.9 (M+H)⁺.

(I-8b
Intermediate: (S)-3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanoic acid (I-8b)
6N HCl (140 mL) was added to (I-8a) (6.61 g, 22.4 mmol) and the mixture was warmed to 95° C. for 16 hours and then allowed to cool. Solid potassium carbonate (58 g) was added in portions to bring the pH to about 4. A precipitate crashed out. Ethyl acetate was added, and the mixture was stirred until everything dissolved. The aqueous layer was extracted once with ethyl acetate. The combined organics were washed with brine, dried over sodium sulfate, filtered, concentrated under reduced pressure, and dried under high vacuum to afford (I-8b) as a clear glass (6.15 g, 21.9 mmol, 98%). ¹H NMR (400 MHz, CDCl₃) δ 7.73 (1H), 7.34 (1H), 6.85-7.15 (1H), 4.66-4.70 (1H), 1.98-2.17 (2H), 1.41-1.75 (7H), 1.01-1.19 (2H); m/z 277.4 (M+H)⁺.
(I-28a
Intermediate: benzyl 6-aminonicotinate (I-28a)

To a stirred suspension of 6-aminonicotinic acid (100 g, 0.72 mol; Aldrich Chemical Company, Inc., Milwaukee, Wis.) in N,N-dimethylformamide (700 mL) with brisk mechanical stirring was added potassium carbonate (150 g, 1.08 mol) and the reaction was stirred for 10 min before the portionwise addition of benzyl bromide (95 mL, 0.80 mol). The reaction was stirred at room temperature overnight, then the solids were filtered off and washed thoroughly with ethyl acetate, and the solvent was removed under vacuum. The filter cake was dissolved in water and extracted with ethyl acetate. The residue after evaporation of N,N-dimethylformamide was combined with the ethyl acetate extracts (total volume 2 L of ethyl acetate) and the combined organic extracts washed with brine (5×500 mL), dried (MgSO₄) and the solvent removed under reduced pressure. The crude product was refluxed with 1:1 diethyl ether:hexane for 30 min then the solids filtered off (warm), washed with diethyl ether:hexane (1:1), and dried. This solid was precipitated from hot toluene (hot filtration required to remove dibenzylated material) and dried to afford (I-28a) (107.2 g, 65%) as an off-white solid; ¹H NMR (DMSO-d₆): δ 8.50 (1H), 7.82 (1H), 7.34-7.29 (5H), 6.84 (2H), 6.43 (1H), 5.23 (2H); m/z 229.4 (M+H)⁺.
Example 47
(S)-benzyl 6-(3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanamido)nicotinate
Formula (1A-4) wherein R⁴ is

To Intermediate (I-8b) (16.28 g, 59.8 mmol) stirring in dry dichloromethane (400 mL) at room temperature under nitrogen was added 2 drops of DMF. Oxalyl chloride (11 mL, 130 mmol) was added dropwise. After the bubbling subsided the reaction was left stirring for 90 minutes and then concentrated under reduced pressure. Two successive portions of 1,2-dichloroethane were added and evaporated to remove all excess oxalyl chloride. The crude acid chloride was taken up in dichloromethane (150 mL) and stirred at room temperature. Intermediate (I-28a) (14.3 g, 62.5 mmol) and pyridine (10 mL, 130 mmol) were stirred in 400 mL dry dichloromethane. This was added to the acid chloride solution, using another 50 mL dry dichloromethane to complete the transfer. The mixture was left stirring at room temperature under nitrogen for 18 hours. The reaction was diluted with dichloromethane and water, and 1M aqueous phosphoric acid was added. The organic layer was separated and washed sequentially with dilute aqueous potassium carbonate, and brine. This was then dried over sodium sulfate, filtered, and concentrated under reduced pressure to a glass, which was taken up in hot ethyl acetate and stirred at room temperature. A precipitate appeared at about 30 minutes. The mixture was stirred for 16 hours and then filtered. The precipitate was washed with ethyl acetate and then diethyl ether and dried under high vacuum at 60° C. to afford the title compound as a white solid (17.8 g, 36.6 mmol, 61%). The mother liquor was evaporated and purified by silica gel chromatography on a 120 g pre-packed column, eluting with 40% ethyl acetate/heptane. The product fractions were combined, concentrated under reduced pressure, dried under high vacuum to a glass, and converted as previously described to additional product (3.5 g, 7.2 mmol, 12%, total yield 73%). ¹H NMR (400 MHz, DMSO-d₆) δ 11.50 (1H), 8.87-8.88 (1H), 8.29-8.32 (1H), 8.12-8.14 (1H), 7.93-7.94 (2H), 7.39-7.46 (2H), 7.30-7.37 (3H), 5.32 (2H), 5.21-5.25 (1H), 2.06-2.19 (2H), 1.26-1.63 (8H), 1.01-1.06 (1H); m/z 487.5 (M+H)⁺.
Example 48
(S)-6-(3-cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanamido)nicotinic acid
Formula (1A-4) wherein R⁴ is

The compound of Example 47 (4.07 g, 8.35 mmol) was added to a 500 mL Parr bottle, followed by ethyl acetate (50 mL) and ethanol (100 mL). The mixture was warmed until all of the solid dissolved, and then cooled to room temperature. 10% Pd/C (450 mg) was added, and the mixture was shaken under 50 psi hydrogen for 90 minutes. The reaction was filtered through a microfiber filter. The filtrate was concentrated under reduced pressure and dried under high vacuum at 50° C. to afford product as a glassy solid (3.0 g, 7.75 mmol, 90.6%). The glassy solid was stirred overnight in diethyl ether. The white solid precipitate was filtered, washed with diethyl ether, suction dried, and dried under high vacuum at 50° C. to afford the title compound as a white solid.
¹H NMR (400 MHz, DMSO-d₆) δ 13.10-13.25 (1H), 11.44 (1H), 8.83 (1H), 8.23-8.26 (1H), 8.09-8.12 (1H), 7.94-7.95 (2H), 5.22-5.26 (1H), 2.06-2.17 (2H), 1.29-1.64 (8H), 1.04-1.07 (1H);
m/z 397.3 (M+H)⁺.

THIS NMR IS FROM SUPPORTING INFO OF A JOURNAL



PAPER
Organic Process Research & Development (2012), 16(10), 1635-1645
http://pubs.acs.org/doi/abs/10.1021/op300194c

This work describes the process development and manufacture of early-stage clinical supplies of a hepatoselective glucokinase activator, a potential therapy for type 2 diabetes mellitus. Critical issues centered on challenges associated with the synthesis of intermediates and API bearing a particularly racemization-prone α-aryl carboxylate functionality. In particular, a T3P-mediated amidation process was optimized for the coupling of a racemization-prone acid substrate and a relatively non-nucleophilic amine. Furthermore, an unusually hydrolytically-labile amide in the API also complicated the synthesis and isolation of drug substance. The evolution of the process over multiple campaigns is presented, resulting in the preparation of over 110 kg of glucokinase activator.

(S)-6-(3-Cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanamido)nicotinic Acid (1)

Pressure Hydrogenation

 1 (89% yield) as a white solid:

mp 187–189 °C;

¹H NMR (400 MHz, d₆-DMSO) δ 13.23 (s, 1H), 11.49 (s, 1H), 8.86 (dd, J = 0.4, 2.4 Hz, 1H), 8.27 (dd, J = 2.4, 8.8 Hz, 1H), 8.13 (d, J = 8.8 Hz, 1H), 7.97–7.99 (m, 2H), 5.27 (dd, J = 5.6, 10.0 Hz, 1H), 2.20 (ddd, J = 6.0, 10.0, 14.0, 1H), 2.10 (ddd, J = 5.6, 8.4, 14.0, 1H), 1.27–1.69 (m, 8H), 1.03–1.12 (m, 1H);

¹³C NMR (100 MHz, d₆-DMSO) δ 168.8, 165.7, 154.3, 149.7, 139.6, 138.8, 129.9 (q, J_CF = 38 Hz), 122.6, 122.0 (q, J_CF = 265 Hz), 120.0 (q, J_CF = 4 Hz), 112.8, 60.0, 37.6, 36.2, 32.0, 30.8, 24.6, 24.4;

¹⁹F NMR (376 MHz, d₆-DMSO) δ −60.7.

HRMS-ESI m/z: [M + H]⁺ calcd for C₁₈H₁₉F₃N₄O₃, 397.1482; found, 397.1481.

Achiral HPLC: rt 4.6 min. Chiral SFC: rt 4.1 min (1), 3.1 min (ent-1).

NMR……..http://pubs.acs.org/doi/suppl/10.1021/op300194c/suppl_file/op300194c_si_001.pdf

PAPER

Journal of Medicinal Chemistry (2012), 55(3), 1318-1333
http://pubs.acs.org/doi/abs/10.1021/jm2014887

Glucokinase is a key regulator of glucose homeostasis, and small molecule allosteric activators of this enzyme represent a promising opportunity for the treatment of type 2 diabetes. Systemically acting glucokinase activators (liver and pancreas) have been reported to be efficacious but in many cases present hypoglycaemia risk due to activation of the enzyme at low glucose levels in the pancreas, leading to inappropriately excessive insulin secretion. It was therefore postulated that a liver selective activator may offer effective glycemic control with reduced hypoglycemia risk. Herein, we report structure–activity studies on a carboxylic acid containing series of glucokinase activators with preferential activity in hepatocytes versus pancreatic β-cells. These activators were designed to have low passive permeability thereby minimizing distribution into extrahepatic tissues; concurrently, they were also optimized as substrates for active liver uptake via members of the organic anion transporting polypeptide (OATP) family. These studies lead to the identification of 19 as a potent glucokinase activator with a greater than 50-fold liver-to-pancreas ratio of tissue distribution in rodent and non-rodent species. In preclinical diabetic animals, 19 was found to robustly lower fasting and postprandial glucose with no hypoglycemia, leading to its selection as a clinical development candidate for treating type 2 diabetes.

(S)-6-(3-Cyclopentyl-2-(4-(trifluoromethyl)-1H-imidazol-1-yl)propanamido)nicotinic Acid (19)

 afford 19 as a white solid (3.22 g, 71%).

¹H NMR (400 MHz, DMSO-d₆) δ 11.47 (s, 1H), 8.86 (d, J = 1.95 Hz, 1H), 8.27 (dd, J = 2.24, 8.68 Hz, 1H), 8.13 (d, J = 8.78 Hz, 1H), 7.97 (d, J = 4.88 Hz, 2H), 5.27 (dd, J = 5.37, 9.66 Hz, 1H), 2.04–2.26 (m, 2H), 1.38–1.72 (m, 7H), 1.26–1.37 (m, 1H), 1.08 (td, J = 7.88, 11.75 Hz, 1H);

LCMS m/z 397.5 (M + H)⁺.

HPLC purity (method A): t_R = 7.690 min, 100%.

PAPER

Bioorganic & Medicinal Chemistry Letters (2013), 23(24), 6588-6592
http://www.sciencedirect.com/science/article/pii/S0960894X13012638

Figure 1.

Structure of Hepatoselective GKA PF-04991532 (1).

References

Drug Metabolism & Disposition (2015), 43(2), 190-198
PLoS One (2014), 9(5), e97139/1-e97139/9,
Journal of Biological Chemistry (2012), 287(17), 13598-13610
Drug Discovery Today (2012), 17(9-10), 528-529
Biochemical Journal (2012), 441(3), 881-887.

///////////

Figure 1. Representative structures of glucokinase activators.

TARANABANT

Taranabant ( MK-0364)
701977-09-5
N-[3-(4-Chlorophenyl)-2(S)-(3-cyanophenyl)-1(S)-methylpropyl]-2-methyl-2-[5-(trifluoromethyl)pyridin-2-yloxy]propionamide
N-[(2S,3S)-4-(4-chlorophenyl)-3-(3-cyanophenyl)butan-2-yl]-2-methyl-2-[5-(trifluoromethyl)pyridin-2-yl]oxypropanamide
Taranabant (codenamed MK-0364) is a cannabinoid receptor type 1 inverse agonist being investigated as a potential treatment forobesity due to its anorectic effects.^[1][2] It was discovered by Merck & Co.
In October 2008, Merck has stopped its phase III clinical trials with the drugs due to high level of central side effects, mainlydepression and anxiety.^[3][4][5][6]
The compound had also been in clinical evaluation in chronic cigarette smokers as an aid for smoking cessation.

Paper

.
http://pubs.rsc.org/en/content/articlelanding/2013/cs/c2cs35410a#!divAbstract

PATENT

WO 2003077847
http://www.google.co.in/patents/WO2003077847A2?cl=en

PAPERS

Convenient total synthesis of taranabant (MK-0364), a novel cannabinoid-1 receptor inverse agonist as an anti-obesity agent
Tetrahedron 2007, 63(52): 12845
Wallace, D.J.; Campos, K.R.; Shultz, S.; Klapars, A.; et al.
New efficient asymmetric synthesis of taranabant, a CB1R inverse agonist for the treatment of obesity
Org Process Res Dev 2009, 13(1): 84
Lin, L.S.; Lanza, T.J. Jr.; Jewell, J.P.; Liu, P.; Shah, S.K.; Qi, H.; Tong, X.; Wang, J.; Xu, S.S.; Fong, T.M.; Shen, C.P.; Lao, J.; Xiao, J.C.; Shearman, L.P.; Stribling, D.S.; Rosko, K.; Strack, A.; Marsh, D.J.; Feng, Y.; Kumar, S.; Samuel, K.; Yin, W.; Ploeg, L.H.; Goulet, M.T.; Hagmann, W.K.
Discovery of N-[(1S,2S)-3-(4-Chlorophenyl)-2- (3-cyanophenyl)-1-methylpropyl]-2-methyl-2- [[5-(trifluoromethyl)pyridin-2-yl]oxy]propanamide (MK-0364), a novel, acyclic cannabinoid-1 receptor inverse agonist for the treatment of obesity
J Med Chem 2006, 49(26): 7584
Cole, P.; Serradell, N.; Rosa, E.; Bolos, J.  Taranabant Drugs Fut 2008, 33(3): 206

PAPER

Chen, C.-Y.; Frey, L.F.; Shultz, S.; et al.   Catalytic, enantioselective synthesis of taranabant, a novel, acyclic cannabinoid-1 receptor inverse agonist for the treatment of obesity
Org Process Res Dev 2007, 11(3): 616
http://pubs.acs.org/doi/abs/10.1021/op700026n

Chiral amide 1 (MK-0364, taranabant) is a potent, selective, and orally bioavailable cannabinoid-1 receptor (CB-1R) inverse agonist indicated for the treatment of obesity. An asymmetric synthesis featuring a dynamic kinetic resolution via hydrogenation for the preparation of the bromo alcohol 5 is disclosed. Conversion of the alcohol intermediate to the chiral amide 1 is accomplished in good overall yield.

N-[(1S,2S)-3-(4-Chlorophenyl)-2-(3-cyanophenyl)-1-methylpropyl]-2-methyl-2-{[5-(trifluoromethyl)pyridin-2-yl]oxy}propanamide (1, MK-0364). hemisolvate (approximately 94 wt %, 94% isolated yield from amine salt).

¹H NMR (CDCl₃):  δ 8.35 (s, 1H), 7.83 (dd, J = 2.38, 8.70 Hz, 1H), 7.45 (d, J = 7.57 Hz, 1H), 7.31 (t, J = 7.99 Hz, 1H), 7.24 (m, 2H), 7.07 (d, J = 8.34 Hz, 2H), 6.88 (d, J = 8.63 Hz, 1H), 6.72 (d, J = 8.33 Hz, 2H), 5.88 (d, J = 8.95 Hz, 1H), 4.34 (m, 1H), 3.13 (dd, J = 3.04, 12.72 Hz, 1H), 2.82 (m, 2H), 1.76 (s, 3H), 1.72 (s, 3H), 0.87 (d, J = 6.72 Hz, 3H).

¹³C NMR (CDCl₃):  δ 173.4, 163.9, 144.5 (q, J = 4.30 Hz), 142.4, 137.5, 136.3 (q, J = 3.02 Hz), 133.0, 132.2, 132.0, 130.7, 130.0, 129.3, 128.5, 123.7 (q, J = 271.45 Hz), 121.1 (q, J = 33.32 Hz), 118.6, 112.7, 112.6, 82.1, 53.6, 48.6, 38.2, 25.4, 25.1, 18.4.
Anal. Calcd for C₂₇H₂₅ClF₃N₃O₂:  C 62.85; H 4.88; N 8.14. Found:  C 62.95; H 4.74; N 8.00.

References

1.  Armstrong HE, Galka A, Lin LS, Lanza TJ Jr, Jewell JP, Shah SK, et al. "Substituted acyclic sulfonamides as human cannabinoid-1 receptor inverse agonists." Bioorganic & Medicinal Chemistry Letters. 2007 Apr 15;17(8):2184-7. PMID 17293109. doi:10.1016/j.bmcl.2007.01.087
2.  Fong TM, Guan XM, Marsh DJ, Shen CP, Stribling DS, Rosko KM, et al. "Antiobesity efficacy of a novel cannabinoid-1 receptor inverse agonist, N-[(1S,2S)-3-(4-chlorophenyl)-2-(3-cyanophenyl)-1-methylpropyl]-2-methyl-2-[[5-(trifluoromethyl)pyridin-2-yl]oxy]propanamide (MK-0364), in rodents." Journal of Pharmacology and Experimental Therapeutics. 2007 Jun;321(3):1013-22. PMID 17327489.doi:10.1124/jpet.106.118737
3.  "Press release by Merck". Retrieved October 2008.
4.  Aronne LJ, Tonstad S, Moreno M, Gantz I, Erondu N, Suryawanshi S, Molony C, Sieberts S, Nayee J, Meehan AG, Shapiro D, Heymsfield SB, Kaufman KD, Amatruda JM (May 2010). "A clinical trial assessing the safety and efficacy of taranabant, a CB1R inverse agonist, in obese and overweight patients: a high-dose study". International Journal of Obesity (2005) 34 (5): 919–35. doi:10.1038/ijo.2010.21.PMID 20157323.
5.  Kipnes MS, Hollander P, Fujioka K, Gantz I, Seck T, Erondu N, Shentu Y, Lu K, Suryawanshi S, Chou M, Johnson-Levonas AO, Heymsfield SB, Shapiro D, Kaufman KD, Amatruda JM (June 2010). "A one-year study to assess the safety and efficacy of the CB1R inverse agonist taranabant in overweight and obese patients with type 2 diabetes". Diabetes, Obesity & Metabolism 12 (6): 517–31. doi:10.1111/j.1463-1326.2009.01188.x. PMID 20518807.
6.  Proietto J, Rissanen A, Harp JB, Erondu N, Yu Q, Suryawanshi S, Jones ME, Johnson-Levonas AO, Heymsfield SB, Kaufman KD, Amatruda JM (August 2010). "A clinical trial assessing the safety and efficacy of the CB1R inverse agonist taranabant in obese and overweight patients: low-dose study". International Journal of Obesity (2005) 34 (8): 1243–54. doi:10.1038/ijo.2010.38. PMID 20212496.

Radiolabeled cannabinoid-1 receptor modulators [US7754188]	2006-06-01	2010-07-13
Combination therapy for the treatment of obesity [US2006270650]	2006-11-30
CERTAIN CRYSTALLINE DIPHENYLAZETIDINONE HYDRATES, PHARMACEUTICAL COMPOSITIONS THEREOF AND METHODS FOR THEIR USE [US8003636]	2009-08-13	2011-08-23
NOVEL DIPHENYLAZETIDINONE SUBSTITUTED BY PIPERAZINE-1-SULFONIC ACID AND HAVING IMPROVED PHARMACOLOGICAL PROPERTIES [US2009264402]	2009-10-22
Arylaminoaryl-alkyl-substituted imidazolidine-2,4-diones, process for preparing them, medicaments comprising these compounds, and their use [US7759366]	2009-08-27	2010-07-20
COMPOUNDS WITH A COMBINATION OF CANNABINOID CB1 ANTAGONISM AND SEROTONIN REUPTAKE INHIBITION [US8138174]	2008-09-04	2012-03-20
Substituted imidazoline-2,4-diones, process for preparation thereof, medicaments comprising these compounds and use thereof [US2011112097]	2011-05-12
Novel phenyl-substituted imidazolidines, process for preparation thereof, medicaments comprising said compounds and use thereof [US2011178134]	2011-07-21
HETEROCYCLIC COMPOUNDS, PROCESSES FOR THEIR PREPARATION, MEDICAMENTS COMPRISING THESE COMPOUNDS, AND THE USE THEREOF [US2011183998]	2011-07-28
Cyclic pyridyl-N-[1,3,4]-thiadiazol-2-yl-benzene sulfonamides, processes for their preparation and their use as pharmaceuticals [US2011224263]	2011-09-15

Taranabant

Systematic (IUPAC) name
N-[(2S,3S)-4-(4-chlorophenyl)-3-(3-cyanophenyl)-2-butanyl]-2-methyl-2-{[5-(trifluoromethyl)-2-pyridinyl]oxy}propanamide
Clinical data
Routes of administration	Oral
Identifiers
CAS Number	701977-09-5
ATC code	A08AX
PubChem	CID: 11226090
UNII	X9U622S114
Chemical data
Formula	C27H25ClF3N3O2
Molecular mass	515.95 g/mol

///////////CC(C(CC1=CC=C(C=C1)Cl)C2=CC=CC(=C2)C#N)NC(=O)C(C)(C)OC3=NC=C(C=C3)C(F)(F)F
C[C@@H]([C@@H](CC1=CC=C(C=C1)Cl)C2=CC=CC(=C2)C#N)NC(=O)C(C)(C)OC3=NC=C(C=C3)C(F)(F)F

New route for Expensive drug Ivacaftor synthesis from CSIR-NCL, Pune, India

IVACAFTOR

Breaking and Making of Rings: A Method for the Preparation of 4-Quinolone-3-carb­oxylic Acid Amides and the Expensive Drug Ivacaftor

1. N. Vasudevan^†,
2. Gorakhnath R. Jachak^† and
3. D. Srinivasa Reddy^*

Article first published online: 3 NOV 2015

DOI: 10.1002/ejoc.201501048

http://onlinelibrary.wiley.com/doi/10.1002/ejoc.201501048/abstract
SUPPORTING INFO……….http://onlinelibrary.wiley.com/store/10.1002/ejoc.201501048/asset/supinfo/ejoc_201501048_sm_miscellaneous_information.pdf?v=1&s=2b5b6ac6456ec88f478c07a692e49254e7239f80

Abstract

A simple and convenient method to access 4-quinolone-3-carboxylic acid amides from indole-3-acetic acid amides through one-pot oxidative cleavage of the indole ring followed by condensation (Witkop–Winterfeldt type oxidation) was explored. The scope of the method was confirmed with more than 20 examples and was successfully applied to the synthesis of the drug Ivacaftor, the most expensive drug on the market.

REFERENCES

N. Vasudevan, Gorakhnath R. Jachak And D. Srinivasa Reddy, Breaking and Making of Rings: A Method for the Preparation of 4-Quinolone-3-carb­oxylic Acid Amides and the Expensive Drug Ivacaftor, Eur. J. Org. Chem., , 0000 (2015), DOI:10.1002/ejoc.201501048.
http://academic.ncl.res.in/publications/index/select-faculty/2015/ocd

Breaking and Making of Rings: A Method for the Preparation …

onlinelibrary.wiley.com › … › Early View

6 days ago – European Journal of Organic Chemistry … 20 examples and was successfully applied to the synthesis of the drug Ivacaftor, the most expensive …

European Journal of Organic Chemistry – Wiley Online Library

onlinelibrary.wiley.com › … › European Journal of Organic Chemistry

European Journal of Organic Chemistry ….. examples and is successfully applied to the synthesis of the drug Ivacaftor, the most expensive drug on the market.

Breaking and making – Wiley Online Library

onlinelibrary.wiley.com › … › Early View › Abstract

6 days ago – … for the Preparation of 4-Quinolone-3-carboxylic Acid Amides and the Expensive Drug Ivacaftor … European Journal of Organic Chemistry.

READ ABOUT DR SRINIVASA REDDY at…………

ONE ORGANIC CHEMIST ONE DAY BLOG……..LINK

Dr. Srinivasa Reddy of CSIR-NCL bags the

prestigious Shanti Swarup Bhatnagar Prize

sept 2015…………..http://www.biospectrumindia.com/biospecindia/news/222486/

dr-srinivasa-reddy-csir-ncl-bags-prestigious-shanti-swarup-bhatnagar-prize

The award comprises a citation, a plaque, a cash prize of Rs 5 lakh

The Shanti Swarup Bhatnagar Prize for the year 2015 in chemical sciences has been awarded to Dr. D. Srinivasa Reddy of CSIR-National Chemical Laboratory (CSIR-NCL), Pune for his outstanding contributions to the area of total synthesis of natural products and medicinal chemistry.

This is a most prestigious award given to the scientists under 45 years of age and who have demonstrated exceptional potential in Science and Technology. The award derives its value from its rich legacy of those who won this award before and added enormous value to Indian Science.

Dr. Reddy will be bestowed with the award at a formal function, which shall be presided over by the honourable Prime Minister. The award, named after the founder director general of Council of Scientific & Industrial Research (CSIR), Dr. Shanti Swarup Bhatnagar, comprises a citation, a plaque, a cash prize of Rs 5 lakh.

Dr. Reddy’s research group current interests are in the field of total synthesis and drug discovery by applying medicinal chemistry. He has also been involved in the synthesis of the agrochemicals like small molecules for crop protection. The total synthesis of more than twenty natural products has been achieved in his lab including a sex pheromone that attracts the mealy bugs and has potential use in the crop protection. On the medicinal chemistry front significant progress has been made by his group using a new concept called “Silicon-switch approach” towards central nervous system drugs. Identification of New Chemical Entities for the potential treatment of diabetes and infectious diseases is being done in collaboration with industry partners.

His efforts are evidenced by 65 publications and 30 patents. He has recently received the NASI-Reliance industries platinum jubilee award-2015 for application oriented innovations and the CRSI bronze medal. In addition, he is also the recipient of Central Drug Research Institute award for excellence in the drug research in chemical sciences and scientist of the year award by the NCL Research Foundation in the year 2013. Dr. Reddy had worked with pharmaceutical companies for seven years before joining CSIR-NCL in 2010.

AN INTRODUCTION

Ph.D., University of Hyderabad, 2000 (Advisor: Professor Goverdhan Mehta).
Post-doctoral with Profs. Sergey A. Kozmin(University of Chicago, USA) and Prof.

Jeffrey Aubé (University of Kansas, USA)
Experienced in leading drug discovery programs (Dr. Reddy’s & TATA Advinus – 7

years of pharma experience)
Acquired skills in designing novel small molecules and lead optimization
Experienced in planning and execution of total synthesis of biologically active

molecules with moderate complexity
One of the molecules is currently in human clinical trials.

MYSELF WITH HIM

DEC2014 NCL PUNE INDIA

DR ANTHONY MELVIN WITH DR SRINIVASA REDDY

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DC_AC50, selective way of blocking copper transport in cancer cells

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DC_AC50
3-amino-N-(2-bromo-4,6-difluorophenyl)-6,7-dihydro-5H- cyclopenta [b] thieno [3,2-e] pyridine-2-carboxamide
licensed DC_AC50 to Suring Therapeutics, in Suzhou, China
INNOVATORS  Jing Chen of Emory University School of Medicine, Hualiang Jiang of the Shanghai Institute of Materia Medica of the Chinese Academy of Sciences, Chuan He of the University of Chicago, and coworkers

COPPER TRANSPORT

Chaperone proteins (green) transfer copper ions to copper-dependent proteins (lilac) via ligand exchange between two cysteines (-SH groups) on each protein. DC_AC50 binds the chaperone and inhibits this interaction.

Credit: Nat. Chem.

Inhibition of human copper trafficking by a small molecule significantly attenuates cancer cell proliferation

• Jing Wang,
• Cheng Luo,
• Changliang Shan,
• Qiancheng You,
• Junyan Lu,
• Shannon Elf,
• Yu Zhou,
• Yi Wen,
• Jan L. Vinkenborg,
• Jun Fan,
• Heebum Kang,
• Ruiting Lin,
• Dali Han,
• Yuxin Xie,
• Jason Karpus,
• Shijie Chen,
• Shisheng Ouyang,
• Chihao Luan,
• Naixia Zhang,
• Hong Ding,
• Maarten Merkx,
• Hong Liu,
• Jing Chen,
• Hualiang Jiang
• & Chuan He

Nature Chemistry, (2015)

doi:10.1038/nchem.2381

Jing Chen of Emory University School of Medicine, Hualiang Jiang of the Shanghai Institute of Materia Medica of the Chinese Academy of Sciences, Chuan He of the University of Chicago, and coworkers have now developed a selective way of blocking copper transport in cancer cells (Nat. Chem. 2015, DOI: 10.1038/nchem.2381). By screening a database of 200,000 druglike small molecules, the researchers discovered a promising compound, DC_AC50, for cancer treatment. They zeroed in on the compound by testing how well database hits inhibited a protein-protein interaction leading to copper transport and reduced proliferation of cancer cells.

Scientists had already found a molecule, tetrathiomolybdate, that interferes with copper trafficking and have tested it in clinical trials against cancer. But tetrathiomolybdate is a copper chelator: It inhibits copper transport in cells by nonselectively sequestering copper ions. Sometimes, the chelator snags too much copper, inhibiting essential copper-based processes in normal cells and causing side effects.

In contrast, DC_AC50 works by inhibiting interactions between proteins in the copper-trafficking pathway: It prevents chaperone proteins, called Atox1 and CCS, from passing copper ions to enzymes that use them to run vital cellular processes. Cancer cells are heavy users of Atox1 and CCS, so DC_AC50 affects cancer cells selectively.

The team has licensed DC_AC50 to Suring Therapeutics, in Suzhou, China, for developing anticancer therapies. The group also plans to further tweak DC_AC50 to develop more-potent versions.

Thomas O’Halloran of Northwestern University, who has studied tetrathiomolybdate, comments that “the challenge in drug design is hitting one of these copper-dependent processes without messing with housekeeping functions that normal cells depend upon. DC_AC50 appears to block the function of copper metallochaperone proteins without interacting directly with their cargo, copper ions. As the first member of a new class of inhibitors, it provides a new way to interrogate the physiology of copper trafficking disorders and possibly intervene.”

PATENT
http://www.google.com/patents/WO2014116859A1?cl=en



COMPD IS LC-1 COMPD 50

Scheme 1 (Compounds LCI -LCI 9):

Experimental procedure for Scheme 1 :
Step a: To 1 equivalent of sodium metal in anhydrous diethyl ether is added 1-2 equivalents of ethyl formate and 1-2 equivalents of cyclopentanone. The resulting mixture is stirred overnight. The mother liquor is filtered by suction filtration to obtain crude intermediate 2.
Step b: To a solution of intermediate 2 in an organic solvent, is added 0.1 to 1 equivalent of glacial acetic acid. The reaction is stirred at 50-100 °C, then 2′ and 0.1 to 1 equivalent of glacial acetic acid are added. The resulting reaction mixture is refluxed for 1-5 hours, filtered and recrystallized to produce product 3; the said organic solvent may optionally be tetrahydrofuran, ether, dimethylformamide, ethyleneglycol dimethyl ether, ethylene glycol diethyl ether, dioxane, ethanol, methanol, ethyl acetate, or dichloromethane. Step c: To a solution of compound 3 in an organic solvent, is added 1 equivalent of methyl bromoacetate and an appropriate amount of base. The reaction mixture is stirted at room temperature to produce intermediate 4. The said organic solvent may optionally be tetrahydrofuran, aether, dimethylformamide, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dioxane, ethanol, methanol, ethyl acetate, or dichloromethane. The said base may optionally be potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, cesium carbonate, and their aqueous solution in various concentrations.
Step d: The base described in Step c is added to a solution of compound 4 in an organic solvent. The reaction mixture is stirred and heated to produce intermediate 5. Step e: An appropriate amount of di-tert-butyl dicarbonate and alkali are added to a solution of compound 5 in an organic solvent. The reaction is stirred to produce intermediate 6.
Step f: An appropriate amount of base is added to a solution of compound 6 in an organic solvent, which is then hydro lyzed to produce intermediate 7.
Step g: 3′ and a stoichiometric amount of condensing agent are added to a solution of compound 7 in an organic solvent. The reaction mixture is stirred until 3′ reacts completely to produce the final product. The said organic so ί vers t may optional iy be tetrahydrofuran, aether, dimethyl formamide, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dioxane, ethanol, methanol, ethyl acetate, or dichloromethane. The said condensing agent may optionally be DCC, EDO, HOBt, and GDI. Step h: To a solution of compound 7 in an organic solvent is added aqueous hydrochloric acid or trifluoroacetic acid. The reaction mixture is stirred vigorously to yield the BOC- deprotected final product.

Scheme 2 (Compounds LCI -LCI 9)

LCI ~LC39
Experimental procedure for Scheme 2(Compounds LC1-LC19):
Step a: Dissolve 1 equivalent of sodium in anhydrous ether, which shall be added slowly under an ice bath and rapid stirring condition. Add 1 equivalent of ethyl formate and 1 equivalent of cyclopentanone in a constant pressure dropping funnel, add 0.5 ml ethanol as an initiator, after 1 hour of stirring in ice bath, and stir overnight at room temperature until the reaction of sodium is finished. Perform suction filtration, wash with absolute ether to produce crude product for the following steps of reaction.
Step b: Dissolve the product in above steps directly in ethanol and control its amount, add an appropriate amount of glacial acetic acid, and stir and reflux under 70°C. Add cyano- sulfamide into the reaction solution, and add an appropriate amount of glacial acetic acid, react and reflux for about 3 hours. Recrystallize with ethanol to produce crude product.
Step c: Add 1 equivalent of the appropriate aniline or phenol and 2 equivalents of potassium carbonate solid in a round-bottomed flask that is placed in ice bath, add anhydrous THF to fully dissolve the solid, add 1.5 equivalents of bromoacetyl bromide into a constant pressure dropping funnel and dilute with THF, which is slowly dropped into the former said round- bottomed flask that is moved to room temperature in 10 min late and react for 1 hour; extract and dry with anhydrous sodium sulfate, filtrate by suction, and perform rotary evaporation to remove the solvent, and the crude product is obtained, which is to be used directly in the next step of reaction.
Step d: Dissolve the product from Step 2 into DMF under normal temperature by mixing, add 3 equivalents of 10% KOH solution, which is then transferred to an oil bath of 70°C and react, and add I equivalent of the product from step 3. Stir for about 3 hours and then extract directly with ethyl acetate, and recrystallize the crude product with ethanol to produce pure end product.
Steps a and b: Intermediate 3 is prepared in accordance with the method outlined in Scheme 1. Step c: 3′ and bromoacetyl bromide are condensed in the presence of a suitable base to produce intermediate 9. The said base may optionally be potassium hydroxide, sodium hydroxide, sodiumcarbonate, potassium carbonate, cesium carbonate, and their aqueous solution in various concentrations.
Step d: An appropriate amount of base is added to a solution of compound 3 in an organic solvent, and the reaction mixture is heated to 40-100 °C. Intermediate 9 is added, and the heated solution is stirred for 1-10 hours to yield the final product. The said organic solvent may optionally be tetrahydrofuran, aether, dimethylformamide, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dioxane, ethanol, methanol, ethyl acetate, or dichloromethane. The said base may optionally be potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, cesium carbonate, and their aqueous solution in various concentrations.
NMR and mass spectral data: LC-1 (Compound 50)- 3-amino-N-(2-bromo-4,6-difluorophenyl)-6,7-dihydro-5H- cyclopenta [b] thieno [3,2-e] pyridine-2-carboxamide

1H NMR (CDCI3, 400 MHz) δ 9.15 (s, 1H), 7.61 (s, 1H), 7.13(m, 1H), 6.60 (m, 1H), 6.27 (s, 2H), 3.20 (t, 2H), 2.98 (t, 2H), 2.39 (m, 2H); ESI-MS (EI) m/z 422 (M⁺)





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AMG-319

AMG-319
N-((1S)-1-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine, WO2008118468
(S)-N-(1-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine

 CAS 1608125-21-8

Chemical Formula: C21H16FN7
Exact Mass: 385.14512

Phosphoinositide-3 kinase delta inhibitor
AMGEN, PHASE 2

PI3K delta isoform selective inhibitor that is being investigated in human clinical trials for the treatment of PI3K-mediated conditions or disorders, such as cancers and/or proliferative diseases
Useful for treating PI3K-mediated disorders such as acute myeloid leukemia, myelo-dysplastic syndrome, myelo-proliferative diseases, chronic myeloid leukemia, T-cell acute lymphoblastic leukemia, B-cell acute lymphoblastic leukemia, non-Hodgkins lymphoma, B-cell lymphoma, or breast cancer.
Amgen is developing AMG-319, a small molecule PI3K-δ inhibitor, for treating lymphoid malignancies and solid tumors including, head and neck squamous cell carcinoma.
AMG-319 is a highly selective, potent, and orally bioavailable small molecule inhibitor of the delta isoform of the 110 kDa catalytic subunit of class IA phosphoinositide-3 kinases (PI3K) with potential immunomodulating and antineoplastic activities. PI3K-delta inhibitor AMG 319 prevents the activation of the PI3K signaling pathway through inhibition of the production of the second messenger phosphatidylinositol-3,4,5-trisphosphate (PIP3), thus decreasing proliferation and inducing cell death. Unlike other isoforms of PI3K, PI3K-delta is expressed primarily in hematopoietic lineages. The targeted inhibition of PI3K-delta is designed to preserve PI3K signaling in normal, non-neoplastic cells.

PATENT

http://www.google.com/patents/WO2008118468A1?cl=en

PATENT

WO2013152150
http://www.google.com/patents/WO2013152150A1?cl=en

PATENT

WO-2015171725

Example 4: Method of making N-((lSM-(7-fluoro-2-(2-pyridinyl)- 3-quinolinyl)ethyl)-9H-purin-6-amine
N-((l S)- 1 -(7-Fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine (4) is synthesized in four steps beginning with (S)-l-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethanamine hydrochloride (1). A nucleophilic aromatic substitution between coupling partners 1 and purine 5 affords the penultimate intermediate 2. Cleavage of the p-methoxybenzyl (PMB) group leads to the isolation of the desired butyl acetate solvate 3. A crystalline form change is induced through an aqueous-acetone recrystallization to afford the target hydrate 4.
Synthetic Scheme

Step 1. Preparation of PMB protected pyridylpurinamine tosylate (2)
(S)- 1 -(7-Fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethanamine is prepared similar to that described in US20130267524. The (S)-l-(7-fluoro-2-(pyridin-2-
yl)quinolin-3-yl)ethanamine hydrochloride (1) is coupled to PMB-chloropurine (5, prepared similar to that described in J. Med. Chem. 1988,31, 606-612) in the presence of K₂CO₃ in IPA. Upon reaction completion the K₂CO₃ is removed via filtration and the product is crystallized by the addition of /?-toluenesulfonic acid (pTSA). Isolation of the PMB-protected pyridylpurinamine tosylate (2) is conducted via filtration.

Dry 100 L reactor under nitrogen. Set the temperature to 20 ± 5 °C. Charge (l S)-N-chloro-l-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethanamine HCl salt (1) to the reactor. Then 9-(4-methoxybenzyl)-6-chloro-9H-purine (5) is added. Potassium carbonate is added to the reactor. Isopropyl alcohol is added to the reactor and the mixture is heated to 80 °C and stirred for 24 hours. Additional isopropyl alcohol is added to the reactor and the mixture is cooled to 20 °C. The mixture is filtered through Celite and the solid is washed with isopropyl alcohol and the isopropyl alcohol solutions containing 9-(4-methoxybenzyl)-N-((S)- 1 -(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine are collected.
The 9-(4-methoxybenzyl)-N-((S)- 1 -(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine isopropyl alcohol solution is heated to 50 °C. /^-Toluene sulfonic acid monohydrate is dissolved in isopropyl alcohol and added to the 9-(4-methoxybenzyl)-N-((S)-l-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine in portions. The mixture is slowly cooled to 20 ± 5 °C over 6 ± 2 hrs. The crystalline 9-(4-methoxybenzyl)-N-((S)- 1 -(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)- 9H-purin-6-amine toluene sulfonic acid salt is collected, rinsed with isopropyl alcohol and dried with vacuum.
Example 5: Method of Making the Crystalline Hydrate Form of N-((1S)-1- (7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine Step 1: Isolation of a Butyl Acetate (BuOAc) Solvate of N-((lS)-l-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine (3)
To a 2 L jacketed reactor equipped with a condenser, a mechanical stirrer, and a bubbler, under an atmosphere of N₂, was added N-((l S)-l-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9-(4-methoxybenzyl)-9H-purin-6-amine (2, 100.0 g, 0.148 mol), followed by acetic acid (AcOH; 240 mL) and 1 -dodecanethiol (71.1 mL, 0.295 mol). The vessel was evacuated and back-filled with nitrogen three times. Methanesulfonic acid (MSA; 28.7 mL, 0.443 mol) was added to the vessel over 10 minutes. Then, the reaction was heated to 80 °C and stirred for 20 hrs. The reaction was then cooled to ambient temperature, after which toluene (1000 mL) and water (700 mL) were sequentially added. The solution was then stirred for 30 minutes. The phases were separated by removing the organic phase, adding another charge of toluene (1000 mL) to the aqueous phase, and the mixture was stirred for another 30 minutes. After removing the organic phase again, the aqueous phase was charged to a jacketed 5 L reactor equipped with a mechanical stirrer followed by n-butyl acetate (1500 mL,) and heated to 50 °C. The aqueous phase was neutralized to pH 6.3 with 10 N NaOH (350 mL). The organic (BuOAc) phase was azeotropically dried to 600 ppm water, while keeping a constant volume. The dried organic phase was polish filtered at 50 °C to remove salts, which were subsequently washed with hot BuOAc (285 mL). The BuOAc was charged back into the 2 L jacketed reactor equipped with a mechanical stirred and distillation apparatus, and then concentrated to 54 mg/g of N-((l S)-l-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine in solution. The solution was then seeded with 1 wt% seed of the BuOAc solvate of N-((l S)- 1 -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine. The slurry was further concentrated to 300 mL total volume and cooled to ambient temperature over 1 hour. Heptane (460 mL) was added dropwise to the solution, and the solution was aged overnight. The supernatant concentration was checked, and determined to be 5.3 mg/g of N-((l S)-l-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine. The supernatant was filtered and the resulting solid cake was washed with 1 : 1 BuOAc:heptane (280 mL), followed by heptane (280 mL). The washed cake was then
allowed to dry on the filter. The BuOAc solvate of N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine was obtained as a white solid (59.5 g, 99.6 LCAP, 86.3 wt%, 90 % corrected yield). ^!H NMR (400 MHz, CDC1₃) δ 13.72 (s, 1H), 8.80 (s, 1H), 8.37 (s, 1H), 8.31 (s, 1H), 8.09 (d, J = 7.8 Hz, 1H), 7.92 (d, J = 18.8 Hz, 2H), 7.76 (t, J = 1 1.6 Hz, 2H), 7.39 (s, 1H), 7.31 (td, J = 8.7, 2.5 Hz, 1H), 6.15 (s, 1H), 4.06 (t, J = 6.7 Hz, 1H), 2.04 (s, 1H), 1.65 – 1.44 (m, 3H), 1.39 (dt, J = 14.9, 7.4 Hz, 1H), 1.33 – 1.20 (m, 2H), 0.93 (t, J = 7.4 Hz, 1H), 0.88 (t, J = 6.8 Hz, 1H); ¹³C NMR (101 MHz, CDC1₃) δ 152.28 (s), 148.46 (s), 138.10 (s), 137.22 (s), 135.58 (s), 129.47 (s), 124.80 (s), 123.53 (s), 1 13.24 – 1 13.09 (m), 1 12.89 (d, J = 20.3 Hz), 64.40 (s), 48.60 (s), 31.91 (s), 30.67 (s), 29.05 (s), 22.72 (s), 19.15 (s), 14.15 (s); IR: 3193, 3087, 2967, 2848, 1738, 1609, 1493, 1267, 1242, 1 143, 933, 874, 763, 677, 646, 627, 606, 581 , 559, 474 cm^“1; exact mass m/z calcd for C₂iH₁₆FN₇, (M + H)⁺386.1451 , found 386.1529; MP = 144 °C.
Step 2: Isolation of the Crystalline Hydrate of N-((lS)-l-(7-fluoro-2-(2-pyridinvn-3-quinolinyl)ethyl)-9H-purin-6-amine 4
To a 100 L reactor with its jacket set to 20 °C, 1.206 kg butyl acetate solvate of N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine 3 was charged, followed by 6.8 L of acetone and 6.8 L of water. The resulting mixture was stirred at 90 rpm under nitrogen for 13 minutes to ensure complete dissolution of all solids. During these charges, the reactor contents increased in temperature that maximized at 26 °C. The solution was then transferred to another clean 100 L reactor through a 5 μιη filter, and stirred at 85 rpm under nitrogen. The solution was heated to 45 °C, and water (14.8 L) was added to reach a water content (by Karl Fischer, KF) of 75 wt%. The reactor solution was assayed by HPLC and shown to contain 42 mg/g N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine. The solution was seeded with a slurry of 1 13 g of the crystalline hydrate of N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine in 1 L water, and the seed slurry was rinsed into the reactor with an additional 1 L water. The reactor contents were cooled to 0 °C over 16 h and held at that temperature for 1 h. The supernatant was then assayed, and found to contain 7.6 mg/g of N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine. Next, 10 L of water was added to the reactor over 38 min and aged for 1 h. The supernatant was assayed at 4.9 mg/g, and the solids were isolated by filtration. The solids were washed with an acetone/water solution (140 mL acetone in 2.7 L water), then 4 L water, and dried under nitrogen on the filter for 68 h. The crystalline hydrate of N-((l S)-l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine was isolated as an off-
white solid (1.12 kg, 616 ppm acetone, 3.73 wt% water, 99.56 LCAP, 95.88 wt%). This material was co-milled at 3900 rpm using a 0.024″ screen to yield an off-white powder (1.09 kg, 99.7 LCAP, 95.4 wt%, 75% yield). Calculated losses were 212 g (18%) to liquors, 5.5g (0.5%) to washes, and 23 g (2%) to fouling. ¾ NMR (400 MHz, DMSO) δ 12.86 (s, 1H), 8.69 (s, 1H), 8.64 (s, 1H), 8.27 (s, 1H), 8.10 (s, 1H), 8.06 – 7.91 (m, 4H), 7.76 (dd, J = 10.4, 2.4 Hz, 1H), 7.50 (ddd, J = 19.2, 9.5, 3.6 Hz, 2H), 6.03 (s, 1H), 3.38 (s, 2H), 1.63 (d, J = 6.6 Hz, 3H). ¹³C NMR (101 MHz, DMSO) δ 163.58, 161.12, 158.36, 157.94, 151.99, 147.98, 146.49, 146.36, 136.82, 134.07, 130.24, 130.14, 124.69, 124.65, 123.30, 1 17.36, 1 17.1 1, 112.10, 1 1 1.90, 46.02, 22.01. HRMS m/z Calcd. for C₂iH₁₇FN₇ (M + H): 386.15295. Found: 386.15161.

PAPER
1: Cushing TD, Hao X, Shin Y, Andrews K, Brown M, Cardozo M, Chen Y, Duquette J, Fisher B, Gonzalez-Lopez de Turiso F, He X, Henne KR, Hu YL, Hungate R, Johnson MG, Kelly RC, Lucas B, McCarter JD, McGee LR, Medina JC, San Miguel T, Mohn D, Pattaropong V, Pettus LH, Reichelt A, Rzasa RM, Seganish J, Tasker AS, Wahl RC, Wannberg S, Whittington DA, Whoriskey J, Yu G, Zalameda L, Zhang D, Metz DP. Discovery and in vivo evaluation of (S)-N-(1-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine (AMG319) and related PI3Kδ inhibitors for inflammation and autoimmune disease. J Med Chem. 2015 Jan 8;58(1):480-511. doi: 10.1021/jm501624r. Epub 2014 Dec 3. PubMed PMID: 25469863.
http://pubs.acs.org/doi/abs/10.1021/jm501624r

The development and optimization of a series of quinolinylpurines as potent and selective PI3Kδ kinase inhibitors with excellent physicochemical properties are described. This medicinal chemistry effort led to the identification of 1 (AMG319), a compound with an IC₅₀ of 16 nM in a human whole blood assay (HWB), excellent selectivity over a large panel of protein kinases, and a high level of in vivo efficacy as measured by two rodent disease models of inflammation.

(S)-N-(1-(7-Fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine (1)

 ¹H NMR (400 MHz, [D₆]DMSO) δ ppm 12.76 (1 H, br s), 8.69 (1 H, br s), 8.63 (1 H, s), 8.21 (1 H, br s), 7.96–8.12 (4 H, m), 7.93 (1 H, s), 7.76 (1 H, dd, J = 10.4, 2.5 Hz), 7.45–7.57 (2 H, m), 6.00 (1 H, d, J = 1.2 Hz), 1.61 (3 H, d, J = 6.7 Hz). Mass spectrum (ESI) m/e = 386.0 (M + 1).

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