Synthesis of [1,3,4]thiadiazino[2,3-b]quinazoline-3,6-diones

Department of Chemistry, Punjab University, Chandigarh-160 014

Manuscript received 7 April 1980, revised 8 September 1980, accepted 5 November 1980

2H, 6H-[1,3,4] thiadiazino [2,3-b] quinazoline-3,6(4H)-dione(Va) and 4-phenyl-2H, 6H-[1,3,4] thiadiazino [2,3 b] quinazoline-3,6(4H)-dione(Vb) have been synthesised by the condensation of chloroacetic acid(II) with 3-amino-2-mercaptoquinazoline-4(3H)- one(Ia) and 3-anilino-2-mercaptoquinazoline-4(3H)-one(Ib) respectively, followed by cyclisation with acetic anhydride in the presence of pyridine.