A PROCESS FOR PREPARING 5-BROMO-3-[(R)-1-METHYL-PYRROLIDIN-2-YLMETHYL]-1H-INDOLE

摘要

The invention encompasses a process for preparing 5-bromo-3-[(R)-1-methyl-pyrrolidin-2-ylmethyl]-1H-indole comprising reacting (R)-2-(5-bromo-1H-indole-3-carbonyl)-pyrrolidine-1-carboxylic acid benzyl ester with a reducing agent selected from the group consisting of sodium dihydro-bis(2-methoxyethoxy)aluminate, lithium tris[(3-ethyl-3-pentyl)oxy]aluminohydride, lithium tri-tert-butoxyaluminum hydride and diisobutylaluminium hydride. 5-bromo-3-[(R)-1-methyl-pyrrolidin-2-ylmethyl]-1H-indole is a key intermediate for preparing eletriptan and its salts thereof F(I)