Patent ID: 6555695
Filing Date: 2003-04-29
Classification: C07D

Abstract:
A process for the preparation of ethyl 2,3-dihydrobenzo[1,4]dioxin-2-carboxylate of Formula I, which comprises:a) reacting catechol with a base in a molar ratio of catechol to base in the range of about 1:1 to about 1:2 in a hydrocarbon solvent; b) removing the water by heating the reaction mixture at the reflux temperature of the solvent; c) adding polyethylene glycol as a phase transfer catalyst and 2,3-dibromopropionate to the reaction mixture and controlling the frothing by slowly adding alkali metal carbonate; d) stirring the resultant reaction mixture for a period of about 3 to about 10 hours at a temperature ranging from about 70 to about 150Â° C.; and e) filtering the reaction mixture and washing the filtrate followed by concentrating to obtain the desired product.