Abstract Various reactions of 2-oxo (or thioxo)-1, 2, 3, 4-tetrahydropyrimidine-5-carboxylic acid derivatives (Biginelli-compounds) were investigated. The site of methylation and acylation on 6-methyl-4-phenyl-2-thioxo-1, 2, 3, 4-tetrahydropyrimidine-5-carboxylic acid ethyl ester 1a and its 2-oxo derivative 9a was studied. The synthesis of pyrimido [2, 3-b] thiazines and thiazolo [3, 2-a] pyrimidines was accomplished by condensation of 1a with 1 ...
![ETHYL 2,7-DIMETHYL-3-OXO-5-PHENYL-2,3-DIHYDRO-5H-[1,3]THIAZOLO[3,2-A]PYRIMIDINE-6-CARBOXYLATE Structure](https://image.chemsrc.com/caspic/364/123044-04-2.png)