Rovatirelin Hydrate

Rovatirelin Hydrate, S-0373, 

Rovatirelin, RN: 204386-76-5
UNII: 9DL0X410PY

(4S,5S)-5-methyl-N-((2S)-1-((2R)-2-methylpyrrolidin-1-yl)-1-oxo-3-((1,3-thiazol-4-yl)methyl)propan-2-yl)-2-oxo-1,3-oxazolidine-4-carboxamide

(4S,5S)-5-methyl-N-((S)-1-((R)-2-methylpyrrolidin-1-yl)-1-oxo-4-(thiazol-4-yl)butan-2-yl)-2-oxooxazolidine-4-carboxamide4-Oxazolidinecarboxamide, 5-methyl-N-[2-(2-methyl-1-pyrrolidinyl)-2-oxo-1-(4-thiazolylmethyl)ethyl]-2-oxo-, [4S-[4α[R*(S*)],5α]]-

Phase III

A thyrotropin-releasing hormone potentially for the treatment of spinocerebellar ataxia.

CAS No.204386-76-5(Rovatirelin)

879122-87-9(Rovatirelin Hydrate)

C17H24N4O4S
Exact Mass: 380.1518

Rovatirelin is a novel synthetic agent that mimics the actions of thyrotropin-releasing hormone (TRH). Rovatirelin binds to the human TRH receptor with higher affinity (Ki=702nM) than taltirelin (Ki=3877nM). Rovatirelin increased the spontaneous firing of action potentials in the acutely isolated noradrenergic neurons of rat locus coeruleus (LC). Rovatirelin increased locomotor activity. Rovatirelin may have an orally effective therapeutic potential in patients with SCD.

Rovatirelin ([1-[-[(4S,5S)-(5-methyl-2-oxo oxazolidin-4-yl) carbonyl]-3-(thiazol-4-yl)-l-alanyl]-(2R)-2-methylpyrrolidine) is a novel synthetic agent that mimics the actions of thyrotropin-releasing hormone (TRH). The aim of this study was to investigate the electrophysiological and pharmacological effects of rovatirelin on the central noradrenergic system and to compare the results with those of another TRH mimetic agent, taltirelin, which is approved for the treatment of spinocerebellar degeneration (SCD) in Japan. Rovatirelin binds to the human TRH receptor with higher affinity (Ki=702nM) than taltirelin (Ki=3877nM). Rovatirelin increased the spontaneous firing of action potentials in the acutely isolated noradrenergic neurons of rat locus coeruleus (LC). The facilitatory action of rovatirelin on the firing rate in the LC neurons was inhibited by the TRH receptor antagonist, chlordiazepoxide. Reduction of the extracellular pH increased the spontaneous firing of LC neurons and rovatirelin failed to increase the firing frequency further, indicating an involvement of acid-sensitive K+ channels in the rovatirelin action. In in vivo studies, oral administration of rovatirelin increased both c-Fos expression in the LC and extracellular levels of noradrenaline (NA) in the medial prefrontal cortex (mPFC) of rats. Furthermore, rovatirelin increased locomotor activity. The increase in NA level and locomotor activity by rovatirelin was more potent and longer acting than those by taltirelin. These results indicate that rovatirelin exerts a central nervous system (CNS)-mediated action through the central noradrenergic system, which is more potent than taltirelin. Thus, rovatirelin may have an orally effective therapeutic potential in patients with SCD.

PATENT

WO 9808867

PATENT

WO 9945000 

PATENT

WO 2002017954

Example

Preparation of the compound represented by Example 1 set (IX)

The second step

Two

(First step)

Method described in the literature (Synth. Commun., 20, 3507 (1990)) synthesized N- in (tert- butoxide deer Lupo sulfonyl) one 3- (4 one-thiazolyl) one L Aranin (1, 21.79 g, 80 mmol) in Torifuruoro and the mixture was stirred acetic acid (80 ml) were added under ice-cooling for 2 hours and a half. Then stirred for 30 minutes at room temperature was added to the reaction mixture p- toluenesulfonic acid hydrate (15.22 g, 80 mmol). The reaction mixture was concentrated to dryness under reduced pressure. To remove excess Torifuruoro acetic acid by the obtained residue concentrated to dryness under reduced pressure by addition of water and methanol.Obtained obtained residue was collected by filtration crystals ether was added to precipitate the compound (2) 29.8 g (quantitative).

NMR (CD 3 OD): 9.01 (1H, d-, J = 1.8 Hz), 7.70 (2H ; yd), 7.46 (lH, d-, J = 1.8 Hz), 7.23 (2H, yd), 4.38 (1H, dd , J = 4.8 from and 3.8 from Hz), 3.45 (2H ; yd), 2.37 (3H, s).

(Second step)

I 匕合 product (2) 38.85 g E evening Nord (200 ml) of (112.8 mmol) – in THF (600 ml) solution, diphenyl di § zone methane while 攪袢 at room temperature (39 g, 201 mmol) in small portions over 30 minutes were added. The reaction mixture was stirred for 1 hour at room temperature, Ziv E sulfonyl di § zone methane (10 g, 51.5 mmol) was added and stirred for one hour. To the reaction mixture

After decomposing the excess reagent by the addition of acetic acid (0.1 ml), it was concentrated to dryness under reduced pressure and distilled off the solvent. The resulting residue (92 g) with ether (1 L) was crystallized to give compound (3) 49.05 g (96.1%).

mp: 139-140 ° C

[A] D = -34.7 ° (C = 1.006, CHC1 3) 23 ° C)

^ Cm IRCKB ” 1 : 1753, 1602, 1512, 1496, 1260, 1224, 1171, 1124, 1036, 1012. NMR (CD 3 0D): 8.92 (1H, D, J = 2 Hz), 7.70 (2H ; M ), 7.2-7.4 (13H, m) , 6.91 (1H, s), 4.62 (1H, t, J = 5.8 Hz), 3.47 (2H, d, J = 5.8 Hz), 2.36 (3H, s).

Elemental analysis (C 2E H 2S N 2 0 5 S 2 )

Calculated: C, 61.16; H, 5.13; N, 5.49; S, 12.56.

Measured value: C, 61.14; H, 5.32; N, 5.41; S, 12.46.

(Third step)

Cis-one L one 5-methyl-2-one O Kiso O Kisa ethylbenzthiazoline one 4-carboxylic acid 13.95 g (96.14 mmol), compound (3) 49.09 g (96.14 mmol ), N-hydroxybenzotriazole To Riazoru 2.6 g (19.23 mmol) and under ice-cooling in THF (1L) solution of Toryechiruamin 14.1 ml (lOlmmol), was added to the DCC (20.83g, 101 mmol). The cooling bath was removed after stirring for 10 minutes at the same temperature, and stirred for an additional 2 0 hours at room temperature. After removing the precipitated precipitate and the filtrate concentrated to dryness under reduced pressure an oily residue (82.7 g was obtained). The residue was filtered off and dissolved by heating to insoluble matter in acetic acid Echiru (700 ml). The filtrate was successively washed with sodium carbonate aqueous solution and water.After the addition of methanol (20 ml) the organic layer was dried with sulfuric acid mug Neshiumu, was concentrated to a small volume under reduced pressure.Precipitated collected by filtration and acetic acid E Ji Le crystals – ether (2: 3) washing to compound with a mixture (4) 35.69 g (79.8% ) was obtained. After addition was concentrated to dryness under reduced pressure of the mother liquor, and crystallized from acetic acid E Chiru ether mixture compound (4) 2.62 g (5.9% ) was obtained.

mp: 176-177 ° C

[A] D = -39.2 ° (C = 1.007, CHC1 3 , 24 ° C)

^ Cm IRiKB 1 : 1739, 1681, 1508, 1453, 1386, 1237, 1193, 1089.

NMR (CDC1 3 ): 8.71 (1H, d-, J = 1.8 Hz), 8.18 (lH, d-‘J = 3.9 from Hz), 7.2-7.4 (10H ; yd), 6.82 (1H, s), 6.66 (1H, d-, J = 1.8 Hz), 5.79 (1H, s), 5.12 (1H, yd), 4.94 (lH, yd), 4.35 (1H ; dd, J = 1.8 and 4.5 from Hz), 3.40 (1H ; dd, J 5.7 and 15 = Hz), 3.29 (1H ; dd, J = 4.5 of and 15 Hz), 1.27 (3H, d-, J = 6.3 Hz).

Elemental analysis (C 24 H 23 N 3 0 5 S)

Calculated: C, 61.92; H, 4.98; N, 9.03; S, 6.89.

Measured value: C ! 61.95; H, 5.01; N, 8.94; S ) 6.62.

(Fourth step)

Compound (4) 41.24 under ice-cooling to g (88.59 mmol), and the mixture was stirred Anisoru (240ml) and To Rifuruoro acetic acid (120 ml) and the mixture for 15 minutes. And the mixture was stirred for 2 hours 3 0 minutes further room temperature after removal of the cooling bath. The reaction mixture was added to the E one ether (500 ml) to the oily residue obtained by concentrated to dryness under reduced pressure was collected by filtration and pulverized. The resulting powder is water (50 ml) – was removed by filtration methanol (300 ml) warming dissolved insoluble matter in a mixture. The filtrate was concentrated to small volume under reduced pressure, and allowed to stand at room temperature for 3 days adding a seed crystal and methanol. The precipitated crystals were obtained Shi preparative filtration compound (5) 14.89 g (56.1%). The mother liquor was concentrated to dryness under reduced pressure, to give again further compound was crystallized from methanol one ether mixture of the (5) 10.3 g (38%). mp: 214-215 ° C

[]. -4.2 ° = (C = 0.5, H 2 0, 22 ° C)

^ Cm IRCKB 1 : 1753, 1707, 1655, 1548, 1529, 1409, 1343, 1264, 1236, 1102, 1092. NMR (DMS0-D6): 9.02 (1H, D, J = 1.8 Hz), 8.46 (1H, d-; J = 3.9 from Hz), 7.74 (1H, s),

7.38 (1H, d, J = 1.8 Hz), 4.77 (1H, dq, J = 6.6 and 8.7 Hz), 4.66 (1H, m), 4.21 (1H, d,

J = 8.7 Hz), 3.24 (IH, dd, J = 5.1 and 15 Hz), 3.13 (1H, dd, J = 8.4 and 15 Hz),

1.13 (3H, d, J = 6.6 Hz).

Elemental analysis (C U H 13 N 3 0 5 S)

Calculated: C ; 44.14; H, 4.38; N, 14.04; S ) 10.71.

Measured value: C, 43.94; H, 4.478; N, 14.09; S, 10.58.

(Fifth step)

Compound (5) 12.1 g, (40.48 mmol) and N- hydroxysuccinimide (4.66 g, 40,48 mM) under ice-cooling to THF (242 ml) suspension of,: DCC (8.35 g, 40.48 mmol) was added to 3 and the mixture was stirred for 10 minutes. The cooling bath was removed, and the mixture was further stirred at room temperature for 2 hours. The resulting compound N- hydroxysuccinimide ester solution of (5) was synthesized in a way described in the literature (Tetrahedron, 27, 2599 (1971 )) (R) – (+) – 2- Mechirupiro lysine hydrochloride (5.42 g) and Toryechiruamin (8.46 ml, was added at room temperature to THF (121 ml) suspension of 60.72 mmol). The reaction mixture was stirred for an additional 1 5 hrs. The filtrate after removal of the insoluble matter that has issued analysis was concentrated to dryness under reduced pressure. Residue (24.6 Ga) the insoluble material was removed by filtration was dissolved in water (150 ml). The filtrate was purified by gel filtration column chromatography one (MCI Gel CHP-20P, 600 ml). 4 0% aqueous methanol solution compound of the collected crude eluted cut off fractionated (IX) was obtained 8.87 g. Then after purification by silica gel column chromatography (black port Holm one methanol mixture), to give the compound was freeze-dried (IX) 5.37 g (35.7% ).

mp: 192-194 ° C

[A] D = -1.9 ° (C = 1.005, H 2 0, 25 ° C)

KB Cm- IR 1 : 1755, 1675, 1625, 1541, 1516, 1448, 1232, 1097.

NMR (CD 3 0D): 8.97 (1H, t, J = 2.1 Hz), 7.34 (1H, t, J = 2.1 Hz), 5.19 and 5.04 (total the IH, the each t, J = 7.5 Hz), 4.92 (1H , Dq, J = 6.6 And 8.7 Hz), 4.36 And 4.35 (1H, D, J = 8.7 Hz), 4.07 And 3.92 (Total IH, Eac M), 3.78 (1H ; M), 3.42 (1¾ M), 3.22 (2H, m), 1.5-2.0 ( 4H, m), 1.28 and 1.22 (total 3H, each d, J = 6.6 Hz), 1.21 and 1.02 (total 3H, each d, J = 6.6 Hz).

Elemental analysis (C 16 H 22 N 4 0 4 S H 2 0)

Calculated: C, 49.99; H, 6.29; N, 14.57; S, 8.34.

Measured value: C, 49.99; H, 6.29; N, 14.79; S, 8.36.

PATENT

WO 2006028277

Example

Example 1

B

Step 1 l-N-[N<tert-butoxycarbonyl)-3-(^^^

N.N-dicyclohexylcarbodiimide (10.83 g, 52.5 mmol), N-hydroxybenzotriazole (2.03 g, 15 mmol) and triethylamine (7.7 ml, 55.2 mmol) were added to a solution (130 ml) of N-(tert-butoxycarbonyl)-3-(thiazol-4-yl)-L-alanine (1) (13.62 g, 50 mmol) obtained by the method described in literatures (J. Am. Chem. Soc. 73, 2935 (1951) and Chem. Pharm. Bull. 38, 103 (1950)) and 2(R)-2-methylpyrrolidine p-toluenesulfonic acid (2) (12.79 g, 50 mmol) obtained by the method described in a literature (HeIv. Chim. Acta, 34, 2202 (1951)) in tetrahydrofuran. The mixture was stirred for 20 hours at room temperature. After the precipitates are filtered off, the obtained filtrate was concentrated under reduced pressure. Thus-obtained residue was dissolved in ethyl acetate (200 ml) and the solution were washed with an aqueous solution of sodium hydrogencarbonate and water, successively. The organic layers were dried over magnesium sulfate and concentrated under reduced pressure to give a title compound (3) (16.45 g, 100%) as oil.

NMR (CDCl3): OH 8.76 and 8.75 (1 H, each d, J=2.1Hz, Thia-H-2), 7.08 (1 H, d, J=2.fflz, thia-H-5), 5.45 (1 H, m, NH), 3.45-3.64 (1 H, m, AIa-CoH), 4.14 and 3.81 (1 H, each m, Pyr-CαH), 3.51 (1 H, m, PVr-NCH2), 3.1-3.4 (3 H, m, Pyr-CH2and AIa-CH2), 1.39 (9 H, s, BOC), 1.3-2.0 (4 H, m, PyT-CH2), 1.06 (3 H, d, J=6Hz, Pyr-Me)

Step 2 l-N-[3-(thiazol-4-yl)-L-alanyl]-(2R)-2-methylpyrroHdine di-p-toluenesulfcnate (4)

Compound (3) (33.77 g, 99.48 mmol) and p-toluenesulfonic acid hydrate (37.85 g, 199 mmol) were dissolved in ethyl acetate (101 ml) and the solution was cooled with ice. To the mixture, 4 mol/L solution of hydrogen chloride-ethyl acetate (125 ml) was added, and the mixture was stirred for 2 hours 45 minutes. After the mixture was concentrated under reduced pressure, methanol was added to the residue. The mixture was concentrated. Methanol-toluene (1: 1) was added to the residue and concentrated under reduced pressure to give crystalline residue. The residue was washed with acetone and filtered to give compound (4) as crystals (36 g, 62%). After the mother liquor was concentrated under reduced pressure, methanol and toluene were added to the residue and concentrated. Obtained crystalline residue was washed with acetone to give compound (4) (10.67 g, 18.4%). mp 188-189 0C [α]D 24 +2.2 (c, 1.0, MeOH) IR(KBr)Cm“1: 3431, 3125, 3080, 2963, 1667, 1598, 1537, 1497, 1451, 1364, 1229, 1198, 1170, 1123, 1035, 1011.

NMR (CD3OD): δH 9.04 and 9.03 (1 H, each d, J=2.1Hz, Thia-H-2), 7.70 (2 H, m, aromaticH), 7.46 (1H, d, J=2.1Hz, thia-H-5), 7.23 (2H, m, aromaticH), 4.49and4.46 (1 H, each d, J=6.9Hz, Ala-CαH), 4.14 and 3.75 (1 H, each m, Pyr-CαH), 3.51 (1 H, m, pyr-NCH2), 3.2-3.4 (3 H, m, PyT-CH2 and AIa-CH2), 2.36 (3 H, s, aromatic Me), 1.3-2.0 (4 H, m, pyr-CH2), 1.19 and 1.07 (3 H, each d, J=6.3Hz, Pyr-Me) Anal Calcd For C11H17N3OS 2C7H8O3S Calculated: C, 51.44%; H1 5.70%; N, 7.20%; S, 16.48%. Found: C, 51.36%; H, 5.69%; N, 7.23%; S, 16.31%.

Step 3 l-[N-[(4S,5S)-(5-methyl-2-oxooxazolidin-4-yl)carbonyl]-3-(thiazol-4-yl)-L-alanyl-(2R)-2- methylpyrrolidine trihydrate (I- 1) Step 3 (1) Method A

(4S, 5S)-5-methyl-2-oxooxazolidin-4-yl carboxylic acid (5) (1.368 g, 9.43 mmol) obtained by the method described in literatures (J. Chem. Soc. 1950, 62; Tetrahedron 48; 2507 (1992) and Angew. Chem. 101, 1392 (1989)), Compound (4) (5 g, 8.56 mmol) and N-hydiOxysuccinimide (217 mg, 1.89 mmol) were dissolved in N, N-dimethylformamide (10 ml), and tetrahydrofuran (65 ml) was added. After the mixture was cooled with ice in a cool bath, triethylamine (2.63 ml, 18.86 mmol) and N, N-dicyclohexylcarbodiimide (2.04 g, 9.89 mmol) were added with stirred and the mixture was stirred for additional 30 minutes. The cooling bath was removed and the mixture was stirred for 15 hours at room temperature. The precipitated were filtered off and the filtrate was concentrated under reduced pressure. Water (100 ml) was added to thus-obtained residue (9.95 g) and the mixture was stirred for 1.5 hours at room temperature. After insoluble substance was filtered off, the filtrate was concentrated until it was reduced to about half volume under reduced pressure. The small amount of insoluble substance was filtered off and the filtrate was concentrated until it was reduced to about 2O g under reduced pressure. After the mixture was allowed to stand in a refrigerator for 3 days, the precipitated crystals (2.98 g) were collected by filtration and washed with cold water. The filtrate was extracted twice with chloroform, dried over magnesium sulfate and concentrated under reduced pressure. Ethyl acetate (5 ml) was added to oil residue (1.05 g) and the mixture was stirred to give crystals (136 mg). The obtained crystals were combined and dissolved in purified water (45 ml) with heating. After the solution was allowed to cool to room temperature, the precipitated insoluble substance was filtered off The filtrate was concentrated under reduced pressure and allowed to stand at room temperature overnight. The mixture was cooled with ice, and the crystals were collected by filtration to give Compound (1-1, 2.89 g, 80.3%). mp 194-196 0C

[α]D 22 -2.0 ± 0.4 ° (c, 1.008, H2O), [α]365 +33.1 ± 0.7 ° (c, 1.008, H2O)

IR(Nujor)cm”1: 3517, 3342, 3276, 3130, 3092, 3060, 1754, 1682, 1610, 1551, 1465, 1442,

1379, 1235, 1089. NMR(CD3OD): δH 8.97 and 8.96 (total 1 H, d, J=2.1Hz, Thia-H-2), 7.34 and 7.33 (total 1

H, d, J=2.1Hz, Thia-H-5), 5.18 and 5.04 (total 1 H, each t, J=7.5Hz, Ala-CαH), 4.92 (1

H, dq, J=6.6 and 8.7Hz, Oxa-H-5), 4.36 and 4.35 (total 1 H, d, J=8.7Hz, Oxa-H-4), 4.07 and 3.92 (total 1 H, each m, Pyr-Cα-H), 3.78 (1 H, m, Pyr-NCH2), 3.42 (1 H, m, Pyr- 5 NCH2), 3.22 (2 H, m, AIa-CH2), 1.5-2.0 (4 H, m, Pyr-CH2), 1.28 and 1.22 (total 3 H, each d, J=6.6Hz, Oxa-5-Me), 1.21 and 1.02 (total 3 H, each d, J=6.6Hz, Pyr-2-Me)

Anal. Calcd For C16H22N4O4S 3H2O

Calculated: C, 45.00%; H, 6.71%; N, 13.33%; S, 7.63%.

Found: C, 45.49%; H, 6.60%; N, 13.58%, S, 7.88%. 10

Step 3 (2)

Method B

After Compound (1-2) (410 g, 1.119 mmol) was dissolved in purified water (6.3 L) with heating, the solution was concentrated until the total weight of the mixture was 15 reduced to 1370 g under reduced pressure. The concentrated solution was allowed to stand at room temperature overnight. The solution was cooled with ice for 1 hour and filtered to give the precipitated crystals. The obtained crystals were washed with cold water to give

Compound (T- 1) (448 g, 95.2%) as colorless crystals. Mother liquor was mixed with purified water (300 mL) with heating and the solution was concentrated to 55 g under reduced pressure. 20 After the concentrated solution was allowed to stand at room temperature overnight, the solution was filtered to give the precipitated crystals (T-1, 16.3 g, 3.5%, total amount 464.3 g, 98.7%). mp 194-196 0C

[α]D 22 -0.9 ± 0.4 ° (c, 1.007, H2O), [α]365 + 35.4 ± 0.8 ° (c, 1.007, H2O)

IR(NuJOr)Cm“1: 3511, 3348, 3276, 3130, 3093, 3060, 1755, 1739, 1682, 1611, 1551, 1465, 25. 1442, 1379, 1235, 1089.

AnalCalcdFor: C16H22N4O4S 3H2O

Calculated: C, 45.00%;H, 6.71%;N, 13.33%; S, 7.63%.

Found: C, 45.56%; H, 6.66%; N, 13.43%, S, 7.69%.

30 Step 4 l-[N-[(4S)5S)-(5-methyl-2-oxooxazolidin-4-yl)carbonyl]-3-(thiazol-4-yl)-L-alanyl-(2R)-2- methylpyrrolidine (1-2)

Method A

After l-[N-[(4S,5S)-(5-methyl-2-oxooxazolidin-4-yl)carbonyl]-3-(thiazol-4-yl)-L- 35 alanyl-(2R)-2-methylpyrrolidine monohydrate (4.77 g) obtained by the method described in Patent Literature 8 was crushed in a mortar, it was dried under reduced pressure (66.5 Pa) at 100 0C for 15 hours to give 4.54 g of Compound (1-2). mp 194.5-196.5 0C [α]D 25 -2.1 +. 0.4 ° (c, 1.004, H2O), [α]365 +36.8 ± 0.8 ° (c, 1.004, H2O) Water measurement (Karl Fischer method): 0.27%

IR(NuJOr)Cm”1: 3276, 3180, 3104, 1766, 1654, 1626, 1548, 1517, 1457, 1380, 1235, 1102, 979. NMR(CD3OD):δH 8.97 and 8.96 (total 1 H, d, J 2.1 Hz, Thia-H-2), 7.34 and 7.33 (total 1 H, d, J 2.1 Hz, Thia-H-5), 5.19 and 5.04 (total 1 H, each t, J 7.5 Hz, Ala- CaH), 4.92 (1 H, dq, J 6.6 and 8.7 Hz, Oxa-H-5), 4.36 and 4.35 (total 1 H, d, J 8.7 Hz, Oxa-H-4), 4.07 and 3.92 (total 1 H, each m, Pyr-Cα-H), 3.78 (1 H, m, Pyr-NCH2), 3.42 (1 H, m, Pyr-NCH2), 3.22 (2 H, m, AIa-CH2), 1.5-2.0 (4 H, m, Pyr-CH2), 1.28 and 1.22 (total 3 H, each d, J 6.6 Hz, Oxa-5-Me), 1.21 and 1.02 (total 3 H, each d, J 6.6 Hz, Pyr-2-Me). Anal Calcd For: C16H22N4O4S

Calculated: C, 52.44%; H, 6.05%; N, 15.29%; S, 8.75%. Found: C, 52.24%; H, 5.98%; N, 15.27%, S, 8.57%.

Method B

After Compound (1-1) (17.89 g, 47.3 mmol) was crushed in a mortar, it was dried under reduced pressure (66.5 Pa) at 100 °C for 14 hours to give Compound (1-2, 17.31 g). mp 193-194 0C [α]D 25 -1.9 ± 0.4 ° (c, 1.002, H2O), [α]365 +37.2 ± 0.8 ° (c, 1.002, H2O)

Water measurement (Karl Fischer method): 0.22%

IR(NuJOr)Cm“1: 3273, 3180, 3111, 1765, 1685, 1653, 1626, 1549, 1516, 1456, 1346, 1331,

1277, 1240, 1097, 980.

Anal Calcd For C16H22N4O4S Calculated: C, 52.44%; H, 6.05%; N, 15.29%; S, 8.75%.

Found: C, 52.19%; H, 5.98%; N, 15.42%, S, 8.74%.

REFERENCES

1: Ijiro T, Nakamura K, Ogata M, Inada H, Kiguchi S, Maruyama K, Nabekura J,
Kobayashi M, Ishibashi H. Effect of rovatirelin, a novel thyrotropin-releasing
hormone analog, on the central noradrenergic system. Eur J Pharmacol. 2015 Aug
15;761:413-22. doi: 10.1016/j.ejphar.2015.05.047. Epub 2015 Jul 2. PubMed PMID:
26142830.

////////Rovatirelin Hydrate, S-0373, Rovatirelin, 204386-76-5, clinical, phase 3

C[C@@H]1CCCN1C(=O)[C@H](Cc2cscn2)NC(=O)[C@@H]3[C@@H](OC(=O)N3)C

Flow synthesis of fluoxetine

Scheme 1: Flow synthesis of fluoxetine (46).

One of the early published examples of industry-based research on multi-step flow synthesis of a pharmaceutical was reported in 2011 by scientists from Eli Lilly/UK and detailed the synthesis of fluoxetine 46, the API of Prozac[1]. In this account each step was performed and optimised individually in flow, with analysis and purification being accomplished off-line. The synthesis commences with the reduction of the advanced intermediate ketone 47 using a solution of pre-chilled borane–THF complex (48) to yield alcohol 49 (Scheme 1).

Conversion of the pendant chloride into iodide 51 was attempted via Finckelstein conditions, however, even when utilising phase-transfer conditions in order to maintain a homogeneous flow regime the outcome was not satisfactory giving only low conversions. Alternatively direct amination of chloride 49 utilising high temperature flow conditions (140 °C) allowed the direct preparation of amine 50 in excellent yield.

Flow processing using a short residence time (10 min) at the elevated temperature allowed for a good throughput; in addition, the handling of the volatile methylamine within the confines of the flow reactor simplifies the practical aspects of the transformation, however, extra precautions were required in order to address and remove any leftover methylamine that would pose a significant hazard during scaling up.

 

The final arylation of 50 was intended to be performed as a S_NAr reaction, however, insufficient deprotonation of the alcohol 50 under flow conditions (NaHMDS or BEMP instead of using a suspension of NaH as used in batch) required a modification to the planned approach. To this end a Mitsunobu protocol based on the orchestrated mixing of four reagent streams (50, 54 and reagents 52 and 53) was developed and successfully applied to deliver fluoxetine (46) in high yield.

Overall, this study is a good example detailing the intricacies faced when translating an initial batch synthesis into a sequence of flow steps for which several adaptations regarding choice of reagents and reaction conditions are mandatory in order to succeed.

1. Ahmed-Omer, B.; Sanderson, A. J. Org. Biomol. Chem. 2011, 9, 3854–3862. doi:10.1039/C0OB00906G
   
   Paper

   Preparation of fluoxetine by multiple flow processing steps

   Batoul Ahmed-Omer^a and   Adam J. Sanderson*^a  

    

   *Corresponding authors

   ^aEli Lilly and Co. Ltd., Lilly Research Centre, Erl Wood Manor, Windlesham, Surrey, UK

   Org. Biomol. Chem., 2011,9, 3854-3862

   DOI: 10.1039/C0OB00906G
   http://pubs.rsc.org/en/Content/ArticleLanding/2011/OB/c0ob00906g#!divAbstract

Microflow technology is established as a modern and fashionable tool in synthetic organic chemistry, bringing great improvement and potential, on account of a series of advantages over flask methods. The study presented here focuses on the application of flow chemistry process in performing an efficient multiple step syntheses of (±)-fluoxetine as an alternative to conventional synthetic methods, and one of the few examples of total synthesis accomplished by flow technique.

1 The general method set-up of flow process used for the synthesis of (±)- fluoxetine.

Scheme 1 Synthesis of (±)-fluoxetine in flow: (i) BH3·THF, r.t., 5 min (77%); (ii) NaI, toluene: water, 100 °C, 20 min (43%); (iii); MeNH2 (aq), ...

//////////Flow synthesis, fluoxetine

Setipiprant

Setipiprant, KYTH-105

CAS  866460-33-5

2-(2-(1-naphthoyl)-8-fluoro-1,2,3,4-tetrahydropyrido[4,3-b]indol-5-yl)acetic acid

2-[8-fluoro-2-(naphthalene-1-carbonyl)-3,4-dihydro-1H-pyrido[4,3-b]indol-5-yl]acetic acid

5H-Pyrido(4,3-b)indole-5-acetic acid, 8-fluoro-1,2,3,4-tetrahydro-2-(1-naphthalenylcarbonyl)-

MF C24H19FN2O3

MW 402.4176632

IND FILED BY ALLERGAN FOR Alopecia

ACT-129968, a CRTH2 receptor antagonist, had been in phase II clinical trials at Actelion

Setipiprant; UNII-BHF20LA2GM; ACT-129968; 866460-33-5;

Setipiprant is a prostaglandin D2 (PGD2) antagonist. Essentially, it inhibits PGD2 receptor activity

KYTH-105 had previously been studied as a potential allergic inflammation treatment and had undergone eight clinical trials, resulting in a safety database of more than 1,000 patients. Treatment in all studies was well tolerated across all treatment groups.

Intellectual Property
KYTHERA acquired exclusive worldwide rights to KYTH-105, as well as certain patent rights covering the use of PGD2 receptor antagonists for the treatment of hair loss (often presenting as male pattern baldness, or androgenic alopecia).

Next Steps
KYTHERA plans to file an Investigational New Drug (IND) application and initiate a proof-of-concept study to establish the efficacy of KYTH-105 in male subjects with androgenic alopecia (AGA).

In 2015, Allergan acquired Kythera.

2-(2-(1-Naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic Acid

mp 224.0 °C.

LC(1)/ESI-MS t_R = 0.83 min; m/z [M + H⁺] = 403.09.

¹H NMR (DMSO-d₆), 65:35 mixture of two rotamers, δ: 8.02 (m, 2 H), 7.76 (d, J = 7.8 Hz, 0.65 H), 7.72 (m, 0.35 H), 7.49–7.64 (m, 3.35 H), 7.35–7.49 (m, 2.35 H), 6.98 (ddd, J_H–F = 9.3 Hz, J₁ = 9.3 Hz, J₂ = 2.4 Hz, 0.65 H), 6.88 (m, 0.65 H), 4.85–5.14 (m, 3.3 H), 4.42 (m, 0.35 H), 4.32 (m, 0.7 H), 4.06 (m, 0.35 H), 3.50 (t, J = 5.5 Hz, 1.3 H), 2.95 (m, 0.70 H), 2.68 (m, 0.65 H), 2.58 (m, 0.65 H).

¹³C NMR (DMSO-d₆) δ: 170.7, 169.2, 157.7 (d, J_C–F = 232 Hz), 157.4 (d, J_C–F = 233 Hz), 137.1, 136.2, 135.1, 134.9, 134.0, 133.8, 133.5, 129.6, 129.5, 129.4, 129.3, 128.9, 128.8, 127.5, 127.4, 127.0, 126.9, 126.0, 125.9, 125.7 (d, J_C–F = 10 Hz), 125.2, 125.1, 125.0, 124.1, 123.9, 110.9 (d, J_C–F = 10 Hz), 110.8 (m), 109.3 (d, J_C–F = 26 Hz), 109.1 (d, J_C–F = 26 Hz), 106.7 (m), 103.3 (d, J_C–F = 23 Hz), 103.0 (d, J_C–F = 23 Hz), 44.73, 44.70, 44.5, 44.4, 39.5, 39.3, 23.1, 22.3.

HRMS (ESI): m/zcalcd for C₂₄H₂₀N₂O₃F [M + H⁺] 403.1458, found 403.1458.

SYNTHERSIS

Setipiprant (INN) (developmental code names ACT-129,968, KYTH-105) is a drug originally developed by Actelion which acts as a selective, orally available antagonist of the prostaglandin D₂ receptor 2 (DP₂).^[1] It was initially researched as a treatment for allergies and inflammatory disorders, particularly asthma, but despite being well tolerated in clinical trials and showing reasonable efficacy against allergen-induced airway responses in asthmatic patients,^[2][3] it failed to show sufficient advantages over existing drugs and was discontinued from further development in this application.^[4]

However, following the discovery in 2012 that the prostaglandin D₂ receptor (DP/PGD₂) is expressed at high levels in the scalp of men affected by male pattern baldness,^[5] the rights to setipiprant were acquired by Kythera with a view to potentially developing this drug as a novel treatment for baldness, with a previously unexploited mechanism of action.^[6] While it is too early to tell whether setipiprant will be an effective treatment for this condition, the favorable pharmacokinetics and relative lack of side effects seen in earlier clinical trials mean that fresh clinical trials for this new application can be conducted fairly quickly.^[7]

Prostaglandin D2 is a known agonist of the thromboxane A2 (TxA2) receptor, the PGD2 (DP) receptor and the recently identified G-protein-coupled "chemoattractant receptor- homologous molecule expressed on Th2 cells" (CRTH2).

The response to allergen exposure in a previously sensitized host results in a cascade effect involving numerous cell types and release of a number of cytokines, chemokines, and multiple mediators. Among these critical initiators are the cytokines interleukin (IL)-4, IL-13, and IL-5, which play critical roles in Th2 cell differentiation, immunoglobulin (Ig)E synthesis, mast cell growth and differentiation, upregulation of CD23 expression, and the differentiation, recruitment, and activation of eosinophils. The stimulated release of the array of mediators, causes end-organ damage, including constriction and hyperresponsi- veness, vascular permeability, edema, mucous secretion, and further inflammation.

Because of the number of responses targeted, corticosteroids have proven to be the most effective therapy. Rather than antagonizing these specific responses in a directed way, another approach is to alter the immune response, that is, to change the nature of the immunological response to allergen. CRTH2 is preferentially expressed on Th2 cells and is a chemoattractant receptor for PGD2 that mediates PGD2-dependent migration of blood Th2 cells. Chemoattractants are responsible for the recruitment of both Th2 cells and other effector cells of allergic inflammation, which can provide the conceptual basis for the development of new therapeutic strategies in allergic conditions.

So far, few compounds having CRTH2 antagonistic activity have been reported in the patent literature. Bayer AG claims the use of Ramatroban ((3R)-3-(4-fluorobenzene- sulfonamido)-l,2,3,4-tetrahydrocarbazole-9-propionic acid) for the prophylaxis and treatment of allergic diseases, such as asthma, allergic rhinitis or allergic conjuvatitis

(GB 2388540). Further, (2-tert.-butoxycarbonyl-l, 2, 3, 4-tetrahydro-pyrido[4,3-b]indol-5- yl)-acetic acid and (2-ethoxycarbonyl-l, 2, 3, 4-tetrahydro-pyrido[4,3-b]indol~5-yl)-acetic acid are disclosed by Kyle F. et al in two patent applications (US 5817756 and WO 9507294, respectively).

Furthermore, oral bioavailability of the Ramatroban and its ability to inhibit prostaglandin D2-induced eosinophil migration in vitro has been reported (Journal of Pharmacology and Experimental Therapeutics, 305(1), p.347-352 (2003)).

Description of the invention:

It has now been found that compounds of the general Formulae (I) and (II) of the present invention are CRTH2 receptor antagonists. These compounds are useful for the treatment of both chronic and acute allergic/immune disorders such as allergic asthma, rhinitis, chronic obstructive pulmonary disease (COPD), dermatitis, inflammatory bowel disease, rheumatoid arthritis, allergic nephritis, conjunctivitis, atopic dermatitis, bronchial asthma, food allergy, systemic mast cell disorders, anaphylactic shock, urticaria, eczema, itching, inflammation, ischemia-reperfusion injury, cerebrovascular disorders, pleuritis, ulcerative colitis, eosinophil-related diseases, such as Churg-Strauss syndrome and sinusitis, basophil- related diseases, such as basophilic leukemia and basophilic leukocytosis.

The compounds of general Formulae (I) and (II), especially those mentioned as being preferred, display high selectivity towards the CRTH2 receptor. No antagonistic effects (IC₅₀ >10 μM) are observed on e.g. prostaglandin D2 receptor DPI; PGI2 receptor (IP), PGE2 receptors (EPl, EP2, EP3, EP4), PGF2 receptor (FP), thromboxane receptor A2 (TxA2), leukotriene receptors (CysLTl, CysLT2, LTB4), complement receptor (C5a), angiotensin receptors (ATI, AT2) or serotonin receptor 5HT2c.

The solubility of compounds of general Formulae (I) and (II) in buffer at pH 7 is generally >800 μg/ml.

In vitro assays with rat and dog liver microsomes, or with rat and human hepatocytes revealed high metabolic stability for compounds of general Foπnulae (I) and (II), especially for those compounds mentioned as being preferred.

The compounds of general Formulae (I) and (II), especially those mentioned as being preferred, do not interfere with cytochrome P-450 enzymes, e.g. they are neither degraded by, nor do they inhibit such enzymes.

Excellent pharmacokinetic profiles have been observed for compounds of general Formulae (I) and (II), especially for those compounds mentioned as being preferred, after oral administration (10 mg/kg) to rats and dogs (bioavailability 20-80%, T_max 30 min, C_max 2000- 6000 ng/ml, low clearance, T_{] 2}4-8 h). The compounds of general Formulae (I) and (II), especially those mentioned as being preferred, are efficacious in vitro, inhibiting PGD2-induced migration of eosinophils or other CRTH2 expressing cells in a cell migration assay. A number of techniques have been developed to assay such chemotactic migration (see, e.g., Leonard et al., 1995, "Measurement of α- and β-Chemokines", in Current Protocols in Immunology, 6.12.1- 6.12.28, Ed. Coligan et al, John Wiley & Sons, Inc. 1995). The compounds of the present invention are tested using a protocol according to H. Sugimoto et al. (J Pharmacol Exp Ther. 2003, 305(1), 347-52), or as described hereinafter: Purified eosinophils are labeled with a fluorescent dye, i.e. Calcein-AM and loaded in BD Falcon FluoroBlock upper inserts. Test compounds are diluted and incubated with eosinophils in the BD Falcon

FluoroBlock upper inserts for 30 min at 37 °C in a humidified CO₂ incubator. A constant amount of PGD2 is added to BD Falcon FluoroBlock lower chamber, at a concentration known to have a chemotactic effect on CRTH2 cells. As a control, at least one aliquot in the upper well does not contain test compound. The inserts are combined with the chambers and are incubated for 30 min at 37 °C in a humidified CO₂ incubator. After an incubation period, the number of migrating cells on the lower chamber is counted using a fluorescent reader, i.e. an Applied Biosystems Cyto Fluor 4000 plate reader. The contribution of a test compound to the chemotactic activity of PGD2 is measured by comparing the chemotactic activity of the aliquots containing only dilution buffer with the activity of aliquots containing a test compound. If addition of the test compound to the solution results in a decrease in the number of cells detected in the lower chamber relative to the number of cells detected using a solution containing only PGD2, then there is identified an antagonist of PGD2 induction of chemotactic activity of eosinophils.

PAPER

Journal of Medicinal Chemistry (2013), 56(12), 4899-4911

http://pubs.acs.org/doi/abs/10.1021/jm400122f

Identification of 2-(2-(1-Naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic Acid (Setipiprant/ACT-129968), a Potent, Selective, and Orally Bioavailable Chemoattractant Receptor-Homologous Molecule Expressed on Th2 Cells (CRTH2) Antagonist

Heinz Fretz*, Anja Valdenaire, Julien Pothier, Kurt Hilpert, Carmela Gnerre, Oliver Peter, Xavier Leroy, and Markus A. Riederer

Drug Discovery Unit, Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland

J. Med. Chem., 2013, 56 (12), pp 4899–4911

DOI: 10.1021/jm400122f

Herein we describe the discovery of the novel CRTh2 antagonist 2-(2-(1-naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid 28 (setipiprant/ACT-129968), a clinical development candidate for the treatment of asthma and seasonal allergic rhinitis. A lead optimization program was started based on the discovery of the recently disclosed CRTh2 antagonist 2-(2-benzoyl-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid 5. An already favorable and druglike profile could be assessed for lead compound 5. Therefore, the lead optimization program mainly focused on the improvement in potency and oral bioavailability. Data of newly synthesized analogs were collected from in vitro pharmacological, physicochemical, in vitro ADME, and in vivo pharmacokinetic studies in the rat and the dog. The data were then analyzed using a traffic light selection tool as a visualization device in order to evaluate and prioritize candidates displaying a balanced overall profile. This data-driven process and the excellent results of the PK study in the rat (F = 44%) and the dog (F = 55%) facilitated the identification of 28 as a potent (IC₅₀ = 6 nM), selective, and orally available CRTh2 antagonist.

PAtent

WO 2005095397

http://www.google.co.in/patents/WO2005095397A1?cl=en

Formula 6.

Scheme 1

Step a)

Step b)

Scheme 2

Formula (I).

References

1.  Fretz H, Valdenaire A, Pothier J, Hilpert K, Gnerre C, Peter O, Leroy X, Riederer MA. Identification of 2-(2-(1-naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid (setipiprant/ACT-129968), a potent, selective, and orally bioavailable chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) antagonist. J Med Chem. 2013 Jun 27;56(12):4899-911. doi: 10.1021/jm400122f PMID 23721423
2.  Sidharta PN, Diamant Z, Dingemanse J. Single- and multiple-dose tolerability and pharmacokinetics of the CRTH2 antagonist setipiprant in healthy male subjects. Fundam Clin Pharmacol. 2014 Dec;28(6):690-9. doi: 10.1111/fcp.12079 PMID 24734908
3.  Diamant Z, Sidharta PN, Singh D, O'Connor BJ, Zuiker R, Leaker BR, Silkey M, Dingemanse J. Setipiprant, a selective CRTH2 antagonist, reduces allergen-induced airway responses in allergic asthmatics. Clin Exp Allergy. 2014 Aug;44(8):1044-52. doi: 10.1111/cea.12357 PMID 24964348
4.  Norman P. Update on the status of DP2 receptor antagonists; from proof of concept through clinical failures to promising new drugs. Expert Opin Investig Drugs. 2014 Jan;23(1):55-66. doi: 10.1517/13543784.2013.839658 PMID 24073896
5. Garza LA, et al. Prostaglandin D2 inhibits hair growth and is elevated in bald scalp of men with androgenetic alopecia. Science Translational Medicine, 21 March 2012; 4(126):126ra34. doi: 10.1126/scitranslmed.3003122
6.  George Cotsarelis, Garret Fitzgerald, Luis Garza. Compositions and methods for regulating hair growth. US Patent application 2015/0072963
7.  Pipeline KYTH-105 (setipiprant)
8. http://files.shareholder.com/downloads/AMDA-MFNLA/4023632629x0x817836/4E5AC47A-B9EE-4296-9D97-631C0F6B7C97/KYTH-105_setipiprant_.pdf

Patent ID	Date	Patent Title
US2015072963	2015-03-12	COMPOSITIONS AND METHODS FOR REGULATING HAIR GROWTH
US2014328861	2014-11-06	Combination of CRTH2 Antagonist and a Proton Pump Inhibitor for the Treatment of Eosinophilic Esophagitis
US2010234396	2010-09-16	Tetrhydropyridoindole Derivatives
US7714132	2010-05-11	Tetrahydropyridoindole derivatives

S etipiprant

Systematic (IUPAC) name
2-[8-fluoro-2-(naphthalene-1-carbonyl)-3,4-dihydro-1H-pyrido[4,3-b]indol-5-yl]acetic acid
Clinical data
Administration	Oral
Identifiers
CASRN	866460-33-5
ATC code	none
PubChem	CID 49843471
Chemical data
Formula	C24H19FN2O3
Molar mass	402.417 g/mol

///////Setipiprant, KYTH-105, 866460-33-5, ALLERGAN,  Alopecia, KYTHERA

c15ccccc5cccc1C(=O)N(CC3)Cc2c3n(CC(O)=O)c(cc4)c2cc4F