2-Hydrazinopyiimidines as precursors for azolopyrimidines and pyrimidotriazines expected antimicrobial activity

ABSTRACT

Reaction of 2-hydrazino derivatives 2a,b with aromatic aldehydes afforded the arylhydrazone derivatives 3a-c which cyclized into triazolo derivatives 4a-c. Furthermore 2a,b reacted with aliphatic acids namely formic acid and acetic acid to yield the corresponding triazolo derivatives 5a-c and with nitrous acid to give the tetrazolo derivatives 6a,b. Compounds 6a,b were reduced by zinc dust to yield amines 7a,b. Also, compounds 2a,b reacted with carbon disulphide to yield the 3-triazolothione derivatives 8a,b. On the other hand, 2-hydrazino compounds 2a,b condensed with ethyl acetoacetate to afford 2-ethylacetoacetatdiydrazon derivatives 9a,b. Compound 9a cyclized by heating in ethanolic sodium ethoxide to yield 2-[l-pyrazolyl] derivative 10. Furthermore, compounds 2a,b reacted with phenacyl bromide to give triazinone derivative 11 and condensed with pentane-2, 4-dione to yield pyrazolyl derivatives 12a,b. Newly synthesized compounds 2b,5b,6b,7b and 9b exhibited promising biological activity