
%0 Journal Article
%A Singh, H 
%A Singh, P 
%A Mehta, RK 
%T Synthesis of heterocyclics via enamines. VI. Acid-catalysed transformation of 4,6,6-Trimethyl-3,6-dihydropyrimidine-2-thiols. Functionalized cyclic enamines
%J Australian Journal of Chemistry
%D 1978/10/01
%V 31
%N 10
%P 2307-2312
%K 
%R https://doi.org/10.1071/CH9782307
%U https://www.publish.csiro.au/paper/CH9782307 
%X On heating with HCl or H2SO4, 4,6,6-trimethyl-3-phenyl-3,6- dihydropyrimidine-2-thiol (1; R = Ph) formed phenylthiourea and 4,6,6- trimethyl-2-phenylamino-6H-1,3-thiazine (3; R = Ph) and not 4,4,6- trimethyl-2-phenylamino-4H-1,3-thiazine (2; R = Ph) as reported by Ignatova. In a similar reaction, 4,6,6-trimethyl-3,6-dihydropyrimidine- 2-thiol gave thiourea, 2-amino-4,6,6-trimethyl-6H- 1,3-thiazine (3; R = H) and 4,6,6-trimethyl-4-(4',4',6'-trimethyl-1',4'-dihydropyrimidin-2'-ylthio)-tetrahydropyrimidine-2(1H)-thione (9). 
