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Condensation of 3‐methylbenzoxazolinone with α,β‐unsaturated acids
Author(s) -
Merdji B.,
Lesieur D.,
Lespagnol C.,
Barbry D.,
Couturier D.
Publication year - 1981
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.5570180630
Subject(s) - chemistry , benzene , reactivity (psychology) , ring (chemistry) , condensation , nuclear magnetic resonance spectroscopy , medicinal chemistry , stereochemistry , organic chemistry , medicine , physics , alternative medicine , pathology , thermodynamics
The reaction between 3‐methylbenzoxazolinone and some unsaturated acids in PPA leads to mixtures of compounds, depending on the acid: 6‐crotonyl‐ (or cinnamoyl)‐3‐methylbenzoxazolinones, 2,3‐dihydro‐2,5‐(or 2,7)dioxo‐3‐methylcyclopenta[ f ]benzoxazoles and 6‐(3‐oxo‐indanyl)‐3‐methylbenzoxazolinones. The structure of the products was established by 13 C and 1 H nmr spectroscopy and (or) by independent synthesis. Possible mechanisms of the reaction are discussed; when competition is possible as in the last step of the cyclization, the benzene ring shows a higher reactivity than the aromatic nucleus of the benzoxazolinone; the contrary is observed when the benzene ring is p ‐chloro‐substituted.