Isopropyl Acetate → 1H-Indole-6-carboxylic acid, 2-bromo-3-cyclopentyl-1-methyl-, 1-methylethyl ester
反応式
[CH:1]1([C:6]2[C:14]3[C:9](=[CH:10][C:11]([C:15]([O:17][CH:18]([CH3:20])[CH3:19])=[O:16])=[CH:12][CH:13]=3)[N:8]([CH3:21])[CH:7]=2)[CH2:5][CH2:4][CH2:3][CH2:2]1.C(OC(C)C)(=O)C.[Br:29]Br>>[Br:29][C:7]1[N:8]([CH3:21])[C:9]2[C:14]([C:6]=1[CH:1]1[CH2:2][CH2:3][CH2:4][CH2:5]1)=[CH:13][CH:12]=[C:11]([C:15]([O:17][CH:18]([CH3:19])[CH3:20])=[O:16])[CH:10]=2参加物
4
反応条件
- 温度
- -5 °C
実験手順
The mixture of isopropyl 3-cyclopentyl-1-methyl-1H-indole-6-carboxylate (84 g, 0.294 mol) and isopropyl acetate (1074 g) was cooled to between −10-0° C. Bromine (50 g, 0.312 mol) was added while the batch was maintained at −10-0° C. The resulting slurry was stirred at the same temperature for additional 30 min and quenched with a pre-cooled solution of sodium thiosulfate pentahydrate (13 g) and triethylamine (64.5 g) in water (240 g) while the temperature was maintained at 0-10° C. The mixture was heated to 40-50° C. and charged with methanol (664 g). After it was stirred at the same temperature for at least 0.5 h, the batch was cooled to 0-10° C. and stirred for another 1 hr. The precipitate was filtered, rinsed with 56 wt % methanol/water solution (322 g), and dried in vacuo (≦200 Torr) at 50-60° C. until the water content was ≦0.4% to give isopropyl 2-bromo-3-cyclopentyl-1-methyl-1H-indole-6-carboxylate as a beige solid (90-95 g, 80-85% yield).