Method for synthesizing benzoxazole through microwave radiation of benzamide compound in water phase

Abstract

The invention discloses a method for synthesizing benzoxazole through microwave radiation of a benzamide compound in a water phase. The benzamide compound is added into the water phase under the microwave condition to be subjected to a cyclization reaction for generating the benzoxazole under the alkali condition, and the method for preparing the benzoxazole is environmentally friendly, easy and convenient to operate, safe, low in cost and efficient. Compared with the prior art, the method can be applied to a large number of functional groups, the yield is high, the number of by-products is small, and the method is easy to operate, safe, low in cost and environmentally friendly. (Please see the specifications for the formula).

Description

technical field [0001] The invention belongs to a method for synthesizing benzoxazole by using a benzamide compound under microwave conditions in an aqueous phase. Background technique [0002] Benzoxazoles are a very important class of nitrogen-containing fused heterocyclic compounds, which are important precursors and precursors for organic synthesis. Important role Currently reported methods for synthesizing benzoxazole compounds are rare. Generally speaking, there are two synthetic methods: one is to use nitrobenzene as an oxidant, and o-aminophenol and benzaldehyde are heated and refluxed. The method has high temperature, low yield and many by-products, which limit its development; the other is that in the presence of a dehydrating agent, o-aminophenol and carboxylic acid are condensed. This method uses a large amount of dehydrating agent, and the post-processing is more troublesome. . [0003] Since the concept of "green chemistry" was put forward in 1991, the greeni...

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Problems solved by technology

In traditional organic synthesis, it is usually necessary to maintain a high temperature, a long reaction time, and use toxic and poorly biodegradable organic reagents as solvents. This process will undoubtedly impose a huge burden on energy and the environment.

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