105753-08-0Relevant articles and documents
Preparation method of 2-aminobenzoxazole compound
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Paragraph 0040-0041; 0043-0044; 0046-0047, (2022/01/20)
The present invention relates to a method for preparing a 2-aminobenzoxazole compound. Comprising the following steps: (1) condensation reaction: taking o-aminophenol and nitrobenzoyl chloride compounds as raw materials, synthesizing amide intermediates in an alkaline solution system. The highly selective double-base combination system does not react with the raw material and can neutralize the acid gas generated by the reaction; (2) Cyclization reaction: acid is added to the condensation reaction solution as a catalyst, and 2-nitrobenzoxazole compounds are generated after dehydration. The solid super acid catalyst used is efficient and easy to separate and recycle; (3) hydrogenation hydrogenation reaction: 2-nitrobenzoxazole compounds are catalyzed to obtain 2-aminobenzoxazole compounds. The bi-alkali system and solid super acids used in the present invention are highly selective, product quality and yield are high. The operation is safe and simple, the raw material cost is low, in line with the green and environmentally friendly production concept, which is conducive to industrial production.
Eine einfache Methode zur Herstellung von Benzoxazolen
Seha, Zdenek,Weis, Claus D
, p. 413 - 419 (2007/10/02)
The preparation of benzoxazoles by a facile one-pot reaction is reported.The reaction of carboxylic acids with 2-chloro-N-methyl-Δ1-pyrrolinium chloride in an excess of N-methyl-2-pyrrolidone afforded carboxylic acid chlorides which were converted subsequently to their 2-hydroxyanilides by addition of 2-aminophenols.Cyclization of the 2-hydroxy-anilides at elevated temperatures furnished the benzoxazoles in high yield and purity.
