M. Salman, S. J. Babu, P. C. Ray
Jan 26, 2002
Citations
0
Influential Citations
8
Citations
Journal
Organic Process Research & Development
Abstract
This report describes an efficient and commercially viable synthesis of 3-ethoxy-4-ethoxy-carbonyl-phenylacetic acid (1), a key intermediate for the preparation of repaglinide, an oral hypoglycemic agent, from 2-hydroxy-4-methylbenzoic acid in two steps. Thus, 2-hydroxy-4-methylbenzoic acid was first alkylated with ethyl bromide in a polar aprotic solvent and in the presence of an inorganic base to afford ethyl 2-ethoxy-4-methylbenzoate; deprotonation with lithium diisopropylamide (LDA) and quenching the resulting carbanion with carbon dioxide provided the desired compound with improved yield and excellent purity. This procedure is significantly better than a previously published synthesis which involves five steps and requires use of expensive and hazardous reagents.