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An unexpected preparation of 4‐oxo‐2 H ‐1,3‐benzothiazines
Author(s) -
Golec Frederick A.,
Lee Paul,
Lloyd John R.
Publication year - 1983
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.5570200668
Subject(s) - chemistry , benzothiazine , hydrolysis , phenylene , sodium hydroxide , medicinal chemistry , organic chemistry , polymer
Treatment of compound N,N ‐(dithiobis(3‐chloro‐2,1‐phenylene)dicarbonylbis ( N ‐cyclopentylglycine)diethyl ester (3) with methanolic sodium hydroxide does not produce the expected hydrolysis product N,N ‐(dithiobis‐(3‐chloro‐2,1‐phenylene)dicarbonylbis ( N ‐cylcopentylglycine) (4) but yields a mixture of compounds 8‐chloro‐3‐cyclopentyl‐3,4‐dihydro‐4‐oxo‐2 H ‐1,3‐benzothiazine‐2‐carboxylic acid (6) and N ‐(3‐chloro‐2‐mercaptobenzoyl)‐ N ‐cyclopentylglycine (7). This unexpected observation has the potential of a new heterocyclic synthesis method for the 4‐oxo‐2 H ‐1,3‐benzothiazine class of compounds.