| 93% |
at 0 - 130℃; for 1.00 h; Inert atmosphere; Microwave irradiation |
1H-pyrrole-3-carboxylic acid 24 (2.0 mmol) was placed in a 35 mL microwave vessel and dissolved in ethanol (10 mL) under nitrogen atmosphere. The vessel was placed in an ice bath to reach 0°C and thionyl chloride (10.0 mmol) was added slowly while stirring. After 5 minutes the vessel was placed in a microwave reactor and the reaction carried out with the following method in dynamic mode: 130°C, 60 min, 80W. After completion the reaction mixture was transferred to a round bottom flask, methanol was added to destroy remaining thionyl chloride and the solvent evaporated under reduced pressure. The crude product was dissolved in ethyl acetate and washed 3 times with 20percent K2CO3. The organic phase was dried over anhydrous Na2SO4, and the solvent evaporated in vacuum to obtain the product (yield 93percent) which needed no further purification. Note: the product is sensitive to light and heat. 1HNMR (CDCl3) δ 9.71 (s, 1H), 8.80 (bs, 1H), 7.53 (s, 1H), 6.82 (s, 1H), 6.52 (s, 1H), 4.19 (q, J = 7.0 Hz, 2H), 1.28 (t, J = 7.0 Hz, 3H) ppm. |
| 81% |
With dmap; dicyclohexyl-carbodiimide In tetrahydrofuran at 60℃; for 10.00 h; |
Ethanol (3.2 mL, 54 mmol) and 4-dimethylamino pyridine (DMAP) (54 mg, 0.45 mmol) were added to a mixture of pyrrole-3-carboxylic acid (500 mg, 4.5 mmol) and dicyclohexylcarbodiimide (1.11 g, [5.] 4 mmol) (Aldrich, Milwaukee, WI) in tetrahydrofuran (THF) (15 mL). After heating at 60 [°C] for 10 hours, the reaction was cooled. The precipitate was filtered off, washed with ethyl acetate, the combined filtrate was concentrated and purified on a silica gel column to give 500 mg (81percent) of [LH-PYRROLE-3-CARBOXYLIC] acid ethyl ester as a colorless oil. [APOS;HNMR] (400 MHz, DMSO-d6) 8 [11.] 40 (br s, [1H,] NH), 7.37 (s, 1H), 6.78 (s, [1H),] 6. [38] (s, [1H),] 4.13 (q, J = 7 Hz, 2H), 1.22 (t, [J=] 7 Hz, 3H). Ms m/z 138 [M-1]. A solution of 2-chloronicotinoyl chloride (493 mg, 2.8 mmol) in benzene (1 mL) was added to a mixture of [LH-PYRROLE-3-CARBOXYLIC] acid ethyl ester (390 mg, 2. [8] mmol) in benzene (3 mL), followed by a dropwise addition of tin (IV) chloride (0.5 [ML).] The mixture was stirred at room temperature under nitrogen for overnight. The reaction was treated with 2N HCl and extracted with ethyl acetate. The combined ethyl acetate was washed, dried and concentrated to give 390 mg (50percent) [OF 5-(2-CHLORO-PYRIDiNE-3-CARBONYL)-LH-PYRROLE-3-] carboxylic acid ethyl ester as a white solid. 'HNMR (400 MHz, DMSO-d6) 8 12.92 (br s, 1H, NH), 8.57 (s, 1H), 8.05 (d, 1H), 7.80 (s, 1H), 7.57 (m, 1H), 6.78 (s, 1H), 4.16 (q, J= 7 Hz, 2H), 1.21 (t, J= 7 Hz, 3H). MS [M/Z] 279 [[M++IL.] A mixture of 5-(2-chloro-pyridine-3-carbonyl)-1H-pyrrole-3-carboxylic acid ethyl ester (1.2 g, 4.32 mmol) and hydrazine hydrate (6.27 mL) in ethanol (50 mL) was heated at 80 °C for 24 hours. The reaction was concentrated and the residue was neutralized to pH 7 with 1N [HC1,] extracted with ethyl acetate. The combined ethyl acetate was dried, concentrated and purified on a silica gel column to give the titled compound as a white solid. [IHNMR] (400 MHz, DMSO-d6) 8 13.70 (s, 1H, NH), 12.16 (br s, [1H,] [NH),] 8.52 (m, 2H), 7.46 (s, [1H),] 7.21 (m, [1H),] 7.04 (s, 1H), 4.2 (q, 2H), 1. [28] (t, 3H). MS [M/Z] 257 [[M++1].] |
| 74% |
for 72.00 h; Reflux |
Example No.144(7aS,9R,11aS)-11a-Benzyl-9-ethyl-9-hydroxy-N-(2-methylpyridin-3-yl)-6,7,7a,8,9,10,11,11a-octahydro-5H-benzo[c]pyrrolo[1,2-a]azepine-2-carboxamide; compound with (7aR,9S,11aR)-11a-benzyl-9-ethyl-9-hydroxy-N-(2-methylpyridin-3-yl)-6,7,7a,8,9,10,11,11a-octahydro-5H-benzo[c]pyrrolo[1,2-a]azepine-2-carboxamide (187, R2=Benzyl, R4=Methyl, R6=2-Methylpyridin-3-yl)Step No.1: Ethyl 1H-pyrrole-3-carboxylate (176)A solution of 1H-pyrrole-3-carboxylic acid (175) (10 g, 90 mmol) in EtOH (450 mL) was treated with H2SO4 (0.48 mL, 9.0 mmol) and the resulting solution was stirred at reflux for about 3 days. The reaction mixture was then concentrated under reduced pressure and the residue was then partitioned between saturated aqueous NaHCO3 (250 mL) and EtOAc (250 mL). After separating the layers, the organic phase was washed with saturated aqueous NaCl (200 mL), dried over Na2SO4, filtered, and concentrated under reduced pressure. The sample was purified on silica gel (220 g) using a gradient of 0-50percent EtOAc in heptane to yield ethyl 1H-pyrrole-3-carboxylate (176) (9.2 g, 74percent). LC/MS, method 3, Rt=1.71 min, MS m/z 140 (M+H)+. 1H NMR (400 MHz, CDCl3) δ 8.66-8.43 (bs, 1H), 7.45-7.41 (m, 1H), 6.78-6.74 (m, 1H), 6.68-6.64 (m, 1H), 4.29 (q, J=7.1 Hz, 2H), 1.34 (t, J=7.1 Hz, 3H). |
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