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Title: 3-Amino-2-carbamoyl-4,6-diphenyl-4,5- and -4,7-dihydrothieno-(2,3-b)pyridines

The treatment of piperidinium salts of 3-cyano-1,4-dihydropyridine-2-thiols with alkyl halides leads to 2-alkylthio-3-cyano-1,4-dihydropyridines. The authors have shown that alkylation of the piperidinium salt of 4,6-diphenyl-3-cyano-1,4-dihydropyridine-2-thiol with iodoacetamide gives carbamoylmethylthio derivative II, which, by the action of an equimolar amount of a base with heating to 50-60/sup 0/C, gives a mixture of 3-amino-2-carbamoyl-4,6-diphenyl-4,7-dihydrothieno(2,3-b)pyridine and 3-amino-2-carbamoyl-4,6-diphenyl-4,5-dihydrothieno(2,3-b)-pyridine in a ratio of 1:1. In the presence of excess base the principal product is IV. It was established by PMR spectroscopy that dihydropyridine II initially undergoes cyclization to 4,7-dihydrothienopyridine III, which then undergoes isomerization to 4,5-dihydrothienopyridine IV. Acidification of a solution of IV in d/sub 6/-DMSO gives rise to reverse isomerization.
Authors:
; ;
Publication Date:
OSTI Identifier:
7169314
Resource Type:
Journal Article
Resource Relation:
Journal Name: Chem. Heterocycl. Compd. (Engl. Transl.); (United States); Journal Volume: 23:4; Other Information: Translated from Khim. Geterotsikl. Soedin.; 23: No. 4, 563-564(Apr 1987)
Research Org:
Institute of Organic Synthesis, Riga (USSR)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 74 ATOMIC AND MOLECULAR PHYSICS; PYRIDINES; DEHYDROCYCLIZATION; ISOMERIZATION; NMR SPECTRA; ACIDIFICATION; ALKYLATION; AMINES; CHEMICAL SHIFT; COUPLING CONSTANTS; DEUTERATION; DEUTERIUM COMPOUNDS; DMSO; ISOTOPE EFFECTS; J-J COUPLING; ORGANIC SULFUR COMPOUNDS; SYNTHESIS; AZINES; CHEMICAL REACTIONS; COUPLING; HETEROCYCLIC COMPOUNDS; HYDROGEN COMPOUNDS; INTERMEDIATE COUPLING; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; SPECTRA; SULFOXIDES 400201* -- Chemical & Physicochemical Properties; 640302 -- Atomic, Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory