Synthesis and pharmacological activity of annelated pyrimidine derivatives

A series of 2,3-diglycosylpyrimidine 4, annelated pyrimidine derivatives, pyrazolo-[3,4-d]pyrimidine 8, ditetrazolo[1,5-a;1',5'-c]pyrimidine 9, 2,9a,10-triazaanthracene 12, thieno-[2,3-d]pyrimidine 14, 9-thia-1,3,5,7-tetraazafluorene-8-one-15, 7-oxa-9-thia-1,3,5-triazafluorene-8-one 16, and 5-oxa-9-thia-1,3-diazafluorene 21a,b derivatives have been synthesized via a sequence of heterocyclization reactions of suitably functionalized 6-[5-(4-bromophenyl)oxazol4-yl]-1,2,3,4-tetrahydro-2-thioxo-4-oxopyrimidine-5-carbonitrile (2) with different electrophiles and nucleophiles. The new compounds were prepared with the objective to study their pharmacological properties.