PROCESS FOR THE PREPARATION OF 5-SUBSTSITUTED INDOLE DERIVATIVE

摘要

The present invention relates to an improved and industrially advantageous process for preparation of eletri tan of formula I,or pharmaceutically acceptable salts thereof from bromo indole intermediate of formula II, through isolation of N-acetylated bromo indole intermediate of formula III, to elude carrying forward of impurities to next stage. The present invention relates to process for the preparation of 5-bromo-3-[(R)-l-methyl-pyrrolidin-2- lmeth l -lH-indol of formula II, a key intermediate for the synthesis of eletriptan or pharmaceutically acceptable salts thereof, through novel keto carbamate intermediate. The present invention also relates to novel process for the preparation of a-form of eletriptan hydrobromide.