NOVEL PROCESS FOR THE PREPARATION OF NARATRIPTAN HYDROCHLORIDE

摘要

Present invention provides a novel and improved process for the preparation of N- methyl-1H-indole-5-ethanesulfonamide of formula (I). Compound of formula (I) is a key intermediate used in the synthesis of naratriptan hydrochloride of formula (II). Hydrazone derivative of formula (XL) derived from the corresponding hydrazine and pyruvate ester is reacted with an acid catalyst to get the indole-2-carboxylate derivative of formula (XLI). Hydrolysis of this ester and decarboxylation gave the compound of formula (I). Naratriptan hydrochloride (Amerge) is widely used as anti-migraine drug in the market.