A convenient synthesis of 5-deaza nonclassical antifolates: Reaction of cyanothioacetamide with sodium salts of 2-(hydroxymethylene)-1-cycloalkanones

Condensation of cyanothioacetamide with sodium salts of 2-(Hydroxymethylene)-1-cycloalkanones afforded the corresponding pyridine-2(1H)-thiones 4. Compounds 4 served as a key intermediates for the synthesis of condensed 2,4-diaminopyrido[2,3-d]pyridines 7. Compounds 7 were of interest as potential inhibitors of dihydrofolate reductase.