Synthesis and reactions of some pyridopyrimidine and thienopyridine derivatives for antiviral evaluation

Compounds 6-amino-4-[4-chlorophenyl]-2-thien-2-ylpyridine5-carbonitrile [2] and 4-[4-chlorophenyl]-6-thioxo-2-thien-2-yll,6-dihydropyridine-5-carbonitrile [9] were prepaied using 3-[4-chlorophenyl]-l-thien-2-ylpropenone [I] and malononitrile or cyanothioacetamide, respectively. Pyridine derivative 2 was in turn used as a precursor for preparation of some pyridopyrimidine and fused pyridopyrimidine derivatives 3-8. On the other hand, the pyridine derivative 9 was used in preparation of thienopyridine derivatives 10 and 11. Moreover, fusion of compound 11 with excess of benzoyl chloride ' afforded 4-[4-chlorophenyl]-2-phenyl-7-thien-2-yl-3H-pyrido [3,2:4,5] thieno[3,2-d] pyrimidin-4-one [12]