Unusual ring-opening reaction of 4-benzyl-5-methyl-2-aryloxazole N-oxides with POCl3

Several 2-aryl-4-benzyl-5-methyloxazole N-oxides have been synthesized. It has been shown that the action of the POCl3 does not lead to the formation of the product of the known deoxygenation-chlorination reaction, but proceeds with the opening of the oxazole ring. As a result, a series of (Z)-N-(3-oxo-1-phenylbut-1-en-2-yl)arylamides was obtained with yields of 25-92%. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A series of (Z)-N-(3-oxo-1-phenylbut-1-en-2-yl)arylamides was obtained with yields of 25-92% by the action of POCl3, which does not lead to the formation of the product of the known deoxygenation-chlorination reaction.