A Convenient and efficient method for the preparation of 6‐Acyl‐2(3H)‐benzoxazolones

Abstract

Benzoxazolinone derivatives have been found to exhibit various pharmacological properties and 6‐acyl‐2(3H)‐benzoxazolones are considered as key starting materials for the preparation of these compounds. Reported here are the optimal conditions for a regioselective acylation at the 6‐position of the benzoxazolinone ring. A general method leading to the expected products in excellent yields consists in using a mixture of aluminum chloride‐dimethylformamide as catalyst and acid anhydrides or chlorides as acylating agents.

Synthesis of Some New Mannich Bases of 6-Acyl-5-Chloro-2-Benzoxazolinones : Bazi Yeni̇ Mannich Bazi 6-Açi̇l-5-Kloro-2-Benzoksazolinonlarin Sentezleri̇

“…But these conditions presented some limitations for the preparation of a number of 6-acylbenzoxazolinones. For example, they were not applicable to dicarboxylic acids, or carboxylic acids containing a halogenoalkyl or heterocyclic moiety (15). In the light of this knowledge we prefer the first method.…”

Friedel-Crafts Acylation of 2(3H)-Benzoxazolone: Investigation of the Role of the Catalyst and Microwave Activation

“…The substrates become therefore highly deactivated. This problem can be alleviated to some extent using AlCl 3 -DMF as a catalyst [9]. In an effort to further substantiate the effect of the complexing agent on AlCl 3 we replaced dimethylformamide (DMF) by N-methylformamide (NMF), dimethylacetamide (DMA), pyrrolidone (PYR), and N-methylpyrrolidone (MPY).…”

4-(2-Carboxybenzoyl)-2(3H)-benzothiazolone

“…It seemed important to prepare the corresponding sulfur bioisosters, 6-benzoyl-2(3H)-benzothiazolones (Yous, Poupaert, Lesieur, Depreux & Lesieur, 1994;Follet-Houttemane, Boivin, Bonte & Lesieur, 1991), considering their greater chemical and metabolic stability. The development of synthetic compounds in this series (Taverne, 1995) led to 4-(2-carboxybenzoyl)-2(3H)-benzothiazolone (5% yield), as well as to the formation of 6-(2-carboxybenzoyl)-2(3H)-benzothiazolone (50% yield) under conditions previously described for 3H-benzoxazolone itself (Aichaoui, Lesieur & Henichart, 1992). 1H NMR spectroscopy, including nuclear Overhauser effect spectroscopy (NOESY) transfer experiments, ascertained an SE reaction resulting in these two isomers.…”