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The synthesis and reactions of certain 3‐substituted‐2,1‐benzisothiazoles
Author(s) -
Albert Anthony H.,
O'Brien Darrrell E.,
Robins Roland K.
Publication year - 1978
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.5570150401
Subject(s) - chemistry , nucleophilic substitution , medicinal chemistry , ring (chemistry) , potassium , hydrogen peroxide , nitro , sulfide , hydrogen sulfide , nucleophile , organic chemistry , hydrogen chloride , catalysis , sulfur , alkyl
A new and general synthesis of 2,l‐benzisothiazolin‐3‐ones ( 2 ) is described from the corresponding isatoic anhydride ( 3 ) and potassium hydrogen sulfide which gives the thioanthranilic acid ( 4 ) which is readily oxadized and ring closed to 2 with hydrogen peroxide. Phosphorus oxy‐chloride converted 3‐hydroxy‐2,1‐benzisothiazole to 3‐chloro‐2,1‐benzisothiazole which gave a number of different 3‐substiluted 2,1‐benzisothiazolesby nucleophilic substitution of the 3‐chloro group. Rleetrophilie substitution of 1‐methyl‐2,1 ‐benzisothiazoIin‐3‐one ( 2i ) proceeded readily to give the corresponding 5‐bromo‐, 5‐nitro‐, and 5‐chlorosulfonyl‐1‐methyl‐2,1‐benzisothiazolin‐3‐one. This appears to be a good synthetic route to such 2,1‐benzisothiazole derivatives.