Premium
Synthesis and properties of 3‐chloro‐ and 3,7‐dichloro‐3,4‐dihydro‐1‐hydroxycarbostyrils and related heterocyclic compounds
Author(s) -
McCord T. J.,
DuBose C. E.,
Shafer P. L.,
Davis A. L.
Publication year - 1984
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.5570210303
Subject(s) - chemistry , catalysis , catalytic hydrogenation , platinum , hydrochloric acid , medicinal chemistry , organic chemistry
3‐Chloro‐ and 3,7‐dichloro‐3,4‐dihydro‐1‐hydroxycarbostyrils were synthesized by the catalytic hydrogenation of the α‐chloro‐ and α,4‐dichloro‐β‐( o ‐nitrophenyl)propionic acids in strong acidic solution over platinum‐on‐carbon sulfided catalyst. However, the catalytic hydrogenation of α‐bromo‐β‐( o ‐nitrophenyl)propionic acid yielded 3,4‐dihydro‐1‐hydroxycarbostyril under the same experimental conditions. The 3‐chloro‐3,4‐dihydro‐1‐hydroxycarbostyril and the α‐chloro‐β‐( o ‐nitrophenyl)propionic acid underwent facile dehydrochlorination in mild alkaline solution to give 1‐hydroxycarbostyril and o ‐nitrocinnamic acid, respectively. Selective reduction of 3‐chloro‐3,4‐dihydro‐1‐hydroxycarbostyril and 1‐hydroxycarbostyril to the corresponding lactams, 3‐chloro‐3,4‐dihydrocarbostyril and carbostyril, was effected by catalytic hydrogenation in hydrochloric acid over platinum black catalyst. The structures of the substituted carbostyril derivatives were correlated with their proton nmr spectra.