Convenient Preparation of N-Acylbenzoxazines from Phenols, Nitriles, and DMSO Initiated by a Catalytic Amount of (COCl)2

A convenient preparation method of N-acylbenzoxazines has been developed, in which phenols react with nitriles and dimethyl sulfoxide (DMSO) in the presence of a catalytic amount of (COCl)(2) in CH3CN or chloroform to afford the corresponding N-acylbenzoxazines in moderate-to-good yields. DMSO acts as a source of HCHO, which is generated in situ from the decomposition of a methoxydimethylsulfonium salt. A regeneration cycle of the methoxydimethylsulfonium salt is proposed, which is initiated by a catalytic amount of (COCl)(2).

Automated summary

The convenient preparation method involves the reaction of phenols with nitriles and DMSO in the presence of a catalytic amount of (COCl)2 to yield N-acylbenzoxazines in moderate-to-good yields in CH3CN or chloroform. DMSO acts as a source of HCHO generated from the decomposition of a methoxydimethylsulfonium salt, with a proposed regeneration cycle initiated by a catalytic amount of (COCl)2.