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The synthesis of [1]benzothieno[2,3‐ c ]quinolines, [1]benzothieno[2,3‐ c ][1,2,4]triazolo[4,3‐ a ]quinoline, and [1]benzothieno[2,3‐ c ]tetrazolo[1,5‐ a ]quinoline
Author(s) -
McKenney J. Dew,
Castle Raymond N.
Publication year - 1987
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.5570240606
Subject(s) - quinoline , chemistry , formic acid , ring (chemistry) , medicinal chemistry , thiophene , stereochemistry , organic chemistry
Photocyclization of 3‐chloro‐ N ‐phenylbenzo[ b ]thiophene‐2‐carboxamide 10 afforded [1]benzothieno[2,3‐ c ]‐quinolin‐6(5 H )‐one 11 which was chlorinated to 6‐chloro[1]benzothieno[2,3‐ c ]quinoline 12 followed by dechlorination to give [1]benzothieno[2,3‐ c ]quinoline 5 . A series of 6‐substituted alkoxy and thioalkoxy[1]benzothieno[2,3‐ c ]quinoline derivatives were prepared along with the N ‐methyl quaternary salt 13 of 5 . 6‐Chloro[1]‐benzothieno[2,3‐ c ]quinoline 12 was converted into 6‐hydrazino[1]benzothieno[2,3‐ c ]quinoline 23 which upon treatment with formic acid yielded [1]benzothieno[2,3‐ c ][1,2,4]triazolo[4,3‐ a ]quinoline 6 . Treatment of 23 with nitrous acid resulted in [1]benzothieno[2,3‐ c ]tetrazolo[1,5‐ a ]quinoline 7 . Compounds 6 and 7 are novel heterocyclic ring systems.