| abstract |
wherein X is hydrogen, 5-fluoro or 5-chloro; Y is hydrogen, 6-fluoro or 6-chloro; and R 1 is benzyl, furyl, thienyl or thienylmethyl; provided that when X and Y are both hydrogen, R 1 is not benzyl, wherein the compound of formula reacts with an activated acid derivative of formula R 1 -C (= O) -OH such as its chloride, an anhydride of formula R 1 - (C = O) -O- (C = O) -R1, R1-C (= O) -O- (C = O) -R5 and R1- (C = O) -O- (C = O) -OR6 and simple alkyl esters of formula R1-C (= O) -OR6, wherein R5 is a branched lower alkyl group, such as t-butyl, and R6 is a lower alkyl group, at a temperature of -10 C to 25V ° C, in the presence of lower alkanol as solvent, preferably ethanol, and in the presence of an alkali metal salt of a lower alkanol solvent, preferably sodium methoxide. The process of claim 1, wherein X is 5-chloro, Y is hydrogen and R 1 is 2-thienyl. |