NEW THIENO COMPOUNDS .14. SYNTHESIS OF 4-AMINO-SUBSTITUTED THIENO[2,3-D]PYRIMIDINE-6-CARBOXYLIC ACID-DERIVATIVES

The combination of a basic and a carboxylic ester group in the thieno[ 2,3-d]pyrimidine structure could give interesting biological activitie s. Starting from the diester of 2-amino-4-methylthiophene-3,5-diacid t he ethylesters of -5-methyl-4-oxothieno[2,3-d]pyrimidin-6-carboxylic a cids were prepared by treatment with formamid or by nitril cyclization . With phosphorousoxychloride the corresponding 4-chloro derivatives w ere obtained. These 4-chloro derivatives react easily with amines. Und er appropriate conditions only the chloro atom is substituted.