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Rearrangement of some chlorosubstituted 3‐amino‐3,4‐dihydro‐1‐hydroxycarbostyrils in hydrogen halide acids
Author(s) -
Mccord Tommy J.,
Kelley Stephen F.,
Rabon James A.,
Gage Larry D.,
Maples Larry L.,
Davis Alvie L.
Publication year - 1976
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.5570130531
Subject(s) - chemistry , halide , nucleophile , bromide , halogenation , chloride , medicinal chemistry , hydrogen bromide , ion , hydrochloric acid , bicarbonate , amino acid , hydrogen chloride , hydrogen halide , organic chemistry , halogen , bromine , catalysis , biochemistry , alkyl
The general conditions and results of rearrangement studies of the 5‐, 6‐, 7‐, and 8‐chloro‐substituted 3‐amino‐3,4‐dihydro‐1‐hydroxycarbostyrils in concentrated hydrochloric and hydro‐bromic acids to the corresponding dihalosubstituted 3‐amino‐3,4‐dihydrocarbostyrils have been described. The 5‐, 7‐ and 8‐chlorocarbostyrilhydroxamic acids undergo nucleophilic displacement by either chloride or bromide ion preferentially at the 6‐position to form the respective 5,6‐, 6,7‐ and 6,8‐dihalolactams. However, with the 3‐amino‐6‐chloro‐3,4‐dihydro‐1‐hydroxycarbo‐styril where the 6‐position is blocked, nucleophilic displacement by halide ions occurs at the 8‐position to afford the 6,8‐dihalolactams. The 6,8‐dichloro‐ and 6,8‐dibromolactams were also prepared by alternative halogenation procedures for purposes of comparison with the rearrangement products.