Abstract :
4-IMINO-3N- (substituted) -5-(thiophen-2-yl) -3,4,dihydro-thieno [2,3-d] pyrimidine-2(1H) (2) was used as precursor for the preparation of some novel 1-(2,3-dihydro-3-methyl-5-(thiophen-2-yl)-2-thioxothieno[2,3-d] pyrimidine – 4 (1H)-ylidene) -3-methyl or phenylthiourea (3a,b) and also for the preparation of 2-Hydrazinyl -3-methyl-5- (thiophen-2-yl)- thieno [2,3-d] pyrimidin-4(3H-imine) (5) which was reacted with methyl and phenylisothiocyanat at room temp. to give compounds 6a,b. Also, 5 was reacted with methylisothiocyanate, and / or formic acid to give the triazolopyrimidines 7 and 8. Also, 5 was reacted with nitrous acid to give the 2-azido thienopyrimidine 9.
