Patent ID: 6331638
Filing Date: 2001-12-18
Classification: C07D

Abstract:
A process for the preparation of the ester of 1,8-disubstituted 1,3,4,9-tetrahydropyrano(3,4-b)-indole-1-acetic acid of Formula I: ##STR4##wherein R.sub.1 is selected from the group consisting of hydrogen, lower alkyl and lower alkenyl, R.sub.2 is selected from the group consisting of lower alkyl and aralkyl, R.sub.3 is selected from the group consisting of lower alkyl, lower alkenyl, lower cyclohexyl, phenyl and benzyl, said process comprising reacting 7-alkyltryptophol of Formula II: ##STR5##with a .beta.-Ketoester of Formula III: ##STR6##in a hydroxylic solvent, comprising at least one alkanol system having 1-4 carbon atoms, containing hydrogen chloride gas, and subsequently recovering the ester of Formula I.