REACTIONS OF 3,4-DICHLORO-N-R-MALEIMIDES WITH SUBSTITUTED 2-THIOURACILS
Keywords:
7-R-2-R2 -3-R1 -7,8-dihydro-4H,6H-pyrrolo[3',4':4.5][1,3]thiazolo[3,2-a]pyrimidine-4,6,8-triones, N2 -R-6-R1 -5-oxo-5H[1,3]thiazolo[3,2-a]pyrimidine-2-carboxamide, nucleophilic substitution in 3,4-dichloro-N-R-maleimidesAbstract
Reactions of 3,4-dichloro-N-R-maleimides with substituted thiouracils at 40°C gave a 1:1 mixture of isomers of pyrrolothiazolopyrimidinetriones. Under conditions of thermodynamic control (100°C, 5 h) only pyrrolo[3',4':4,5]thiazolo[3,2-a]pyrimidine-4,6,8-triones were formed, hydrolysis of which followed by decarboxylation gave 5-oxo-5H-thiazolo[3,2-a]pyrimidine-2-carboxamide. The structure of N2-phenyl-6-methyl-5-oxo-5H-thiazolo[3,2-a]pyrimidine-2-carboxamide was confirmed by X-ray crystallography. Analogous cyclization of 3,4-dichloro-N-R-maleimides with 2-thioxoquinazol-4-one also gave a mixture of two isomers which were successfully separated by fractional crystallization.
How to Cite
Volovenko, Yu. M.; Dubnina, G. G.; Chernega, A. N. Chem. Heterocycl. Compd. 2004, 40, 94. [Khim. Geterotsikl. Soedin. 2004, 100.]
For this article in the English edition, see DOI 10.1023/B:COHC.0000023775.37226.f1