Synthesis of novel 3-cyanopyridine-2(1H)-thiones, thieno[2,3-b]pyridines and pyrazolo[3,4-b]pyridines. Michael addition of ethyl 4,4,4-trifluoroacetate-3-oxobutanoate and 1,1,1-trifluoropentan-2,4-dione on arylmethylenecyanothioacetamides 1 in refluxing ethanol leads to the corresponding 3-cyano-pyridine-2(1H)-thiones 4 and 7. The synthesis of a new series of pyrazolo[3,4-b]pyridines 9 and thieno[2,3-b]pyridines 11 by alkylation and cycloaddition of the synthetized products 4 and 7 is reported. The structure of obtained products was determined on the basis of their IR and NMR data.
S. Askri, M.L. Efrit
arylidenecyanothioacetamides, pyridine-2(1H)-thiones, Thorpe-Ziegler reaction