NEW DATA ON THE ALKYLATION OF CYCLIC THIOUREAS WITH α-HALOCARBOXYLIC ACIDS AND THEIR ESTERS. 2. ALKYLATION OF TETRAHYDROPYRIMIDINE-2(1H)-THIONE AND 5,5-DIMETHYLTETRAHYDROPYRIMIDINE-2(1H)-THIONE

Abstract

In the absence of bases all the attempted variations for the alkylation of tetrahydropyrimidine-2(1H)-thione with  α-halocarboxylic acids gave only the bicyclic product – 2-R-6,7-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidin-3(2H)-one hydrohalide. However the hydrohalide of the "open" S-ethoxycarbonyl derivative of propyleneisothiourea can be obtained by treatment of tetrahydropyrimidine-2(1H)-thione with ethyl chloro- or bromoacetate in anhydrous acetone at room temperature. Alkylation of 5,5-dimethyltetrahydro-2(1H)-pyrimidinethione with chloro- or bromoacetic acid in anhydrous acetone at room temperature gave the hydrohalide of the "open" S-carboxymethyl derivative of dimethylpropyleneisothiourea. All remaining variations for the alkylation of this substrate with  α-halocarboxylic acids or their esters gave only the corresponding bicyclic compounds – the hydrohalide of 2-R-6,6-dimethyl-6,7-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidin-3(2H)-one – independently of the reaction conditions.

How to Cite
Kushakova, P. M.; Yulisova, A. I.; Ramsh, S. M.; Garabadgiu, A. V.  Chem. Heterocycl. Compd. 2006, 42, 520. [Khim. Geterotsikl. Soedin. 2006, 593.]

For this article in the English edition, see DOI 10.1007/s10593-006-0120-4