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Synthesis of 4,10‐dihydro‐4,10‐dioxo‐1 H [1]benzothiopyrano[3,2‐ B ]pyridine and 7‐oxo‐7,13‐dihydro[1]benzothiopyrano[2,3‐ b ]‐1,5‐benzodiazepine
Author(s) -
Nakazumi Hiroyuki,
Endo Takashi,
Nakaue Toshiyuki,
Kitao Teijiro
Publication year - 1985
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570220123
Subject(s) - chemistry , sodium azide , pyridine , dimethyl acetylenedicarboxylate , medicinal chemistry , methanol , condensation , stereochemistry , organic chemistry , cycloaddition , catalysis , physics , thermodynamics
Abstract 3‐Amino‐4 H ‐1‐benzothiopyran‐4‐one (3‐aminothiochromone) was easily prepared by reaction of 3‐bromo‐thiochromen‐4‐one with sodium azide in methanol‐water. Condensation of 3‐aminothiochromone with diethyl ethoxymethylenemalonate and with dimethyl acetylenedicarboxylate gave intermediates, which were thermally cyclized to give 4,10‐dihydro‐4,10‐dioxo‐1 H [1]benzothiopyrano[3,2‐ b ]pyridinecarboxylates. 3‐Formyl‐thiochromone was condensed with o ‐phenylenediamine to give 7‐oxo‐7,13‐dihydro[1]benzothiopyrano[2,3‐ b ]‐1,5‐benzodiazepine.