Iodine-catalyzed aromatization of tetrahydrocarbazoles and its utility in the synthesis of glycozoline and murrayafoline A: a combined experimental and computational investigation
A new protocol for the aromatization of tetrahydrocarbazoles has been achieved using a catalytic amount of iodine. The role of iodine has been explained by DFT, and its scope is extended to the total synthesis of glycozoline and murrayafoline A.
[EN] METHOD FOR PREPARING AN OPTICALLY ACTIVE FROVATRIPTAN<br/>[FR] PROCÉDÉ DE PRÉPARATION DE FROVATRIPAN OPTIQUEMENT ACTIF
申请人:NATCO PHARMA LTD
公开号:WO2010073253A1
公开(公告)日:2010-07-01
Disclosed Process for the preparation of optically active Frovatriptan or a salt comprising of : (i) Combining the racemic 6-cyano-3-N-methylamino- 1,2,3,4- tetrahydrocarbazole of formula (I) with D-Pyroglutamic acid as the resolving agent in a Resolution solvent and crystallizing from the said mixture the diastereomeric salt of compound of formula (II) with optically pure D- Pyroglutamic acid; (ii) Separation of desired (+)-6-cyano-3-N-methylamino-l,2,3,4- tetrahydrocarbazole of the formula (III) from the diastereomeric salt (II) using simple filtration technique; (iii) Hydrolyzing compound of formula (III) with phosphoric acid to get R-(+)-6-carboxamido-3-N-methylamino-l,253,4-tetrahydrocarbazole (frovatriptan) of the formula (IV).