Thioxopyridinecarbonitrile as a precursor for thieno- and pyrazolopyridines

Pyridinethione 1 reacted with alkyl halides or with aliphatic alpha halocarbonyl to yield the corresponding alkylthio- derivatives 4[a-e], which underwent ring closure to form derivatives 5[a-e] Pyridinethione 1 reacted with bromomalononitrile, to give the thieno [2,3-b] pyridine-2,2-dicarbonitrile derivatives 6. Compound 1 reacted with bromomalononitrile to yield structure 7, which was elucidated by the reaction of bromomalononitrile with 8 to furnish compound 9. Treatment of each of 4[b] and 11[13] with hydrazine hydrate, respectively, afforded 3-amino-4-[4-chlorophenyl]-6-phenyl-1 H-pyrazolo [3,4-b] pyridine-5-carboxanilide [12] and ethyl 3-amino-4-[4-chlorophenyl]-6-methyl-lH-pyrazolo[3,4-b] pyridine-5-carboxylate [13], respesctively

new route for the synthesis of some quinazoline derivatives

S-methyl monothiomalonanilide hydroiodide 1 is a versatile compound for synthesizing the aimed quinazoline derivatives. Thus, compound 1 reacted with either anthranilic acid or ethyl anthranilate hydrochloride to yield 2. Also, polysubstituted pyranylquinazolinone was obtained by the reaction of quinazolin derivative 6 with p-chloro- alpha-cyano-cinnamonitrile 9. Chemical and spectroscopic evidences for the structures of the newly synthesized compounds were described