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Synthesis of some 7‐substituted 3‐chloro‐3,4‐dihydro‐1‐hydroxycarbostyrils by the reduction cyclization of α‐chloro‐β‐(4‐substituted‐2‐nitrophenyl)propionic acids
Author(s) -
Mccord Tommy J.,
Warner Michael R.,
Shafer Paul L.,
Disher Rose M. Davis,
Davis Alvie L.
Publication year - 1985
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.5570220135
Subject(s) - chemistry , catalysis , hydrochloric acid , acetone , chloride , alkoxy group , medicinal chemistry , aqueous solution , organic chemistry , catalytic hydrogenation , alkyl
A new method was developed for the synthesis of some 7‐substituted 3‐chloro‐3,4‐dihydro‐l‐hydroxycarbostyrils 3c‐g in which α‐chloro‐β‐(4‐substituted‐2‐nitrophenyl)propionic acids 2c‐g were reductively cyclized by catalytic hydrogenation over platinum‐on‐carbon sulfided catalyst. In particular, this method was applied to α‐chloro‐β‐(2‐nitrophenyl)propionic acids bearing 4‐methyl 2c , 4‐ethyl 2d , 4‐ethoxy 2e , 4‐( n ‐butyl 2f and 4‐phenyl 2g substituents to afford good yields of the corresponding 7‐methyl 3c , 7‐ethyl 3d , 7‐ethoxy 3e , 7‐( n ‐butyl) 3f , and 7‐phenyl 3g substituted 3‐chloro‐3,4‐dihydro‐l‐hydroxycarbostyrils. The various 4‐substituted α‐chloro‐β‐(2‐nitrophenyl)propionic acids 2c‐q were synthesized by reacting the in situ diazotized salts of the appropriate 4‐substituted‐2‐nitroanilines in aqueous acetone with acrylic acid in the presence of cuprous chloride and hydrochloric acid. All compounds prepared in this study were characterized by microanalytical and ir and nmr spectral data.