6‐Methyl‐2‐methylthio‐4‐oxopyrimidin‐3(4H)‐yl)acetohydrazide on heating in benzylamine undergo cyclization to 8‐methyl‐2H‐pyrimido[2,1‐c][1,2,4]triazine‐3,6(1H, 4H)‐dione, which under treatment with bromine in glacial acetic acid was converted to 7‐bromo substituted derivative and at reflux with Lawesson's reagent yielded 3‐thioxo compound. The latter reacted with primary and secondary amines to give 3‐amino substituted pyrimidotriazines and on alkylation—the corresponding S‐alkyl derivatives.

Synthesis and Functionalization of 8-Methyl-2H-pyrimido[2,1-c][1,2,4]triazine--3,6(1H,4H)-dione. -The title compound (II) is obtained by an intramolecular cyclization reaction of acetohydrazide (I). For further functionalization, compound (II) is treated with bromine in glacial acetic acid and with Lawesson reagent. -(JAKUBKIENE*, V.; CEPLA, V.; BURBULIENE, M. M.; VAINILAVICIUS, P.; J. Heterocycl. Chem. 49 (2012) 4, 737-741, http://dx.