Reaction of Oximes with Dimethyl Carbonate: A New Entry to 3-Methyl-4,5-disubstituted-4-oxazolin-2-ones

Article abstract of DOI:10.1021/jo00073a041

The reaction of ketone oximes with dimethyl carbonate (DMC) carried out in an autoclave at 180-190 deg C and in the presence of K2CO3 yields 3-methyl-4,5-disubstituted-4-oxazolin-2-ones.The reaction can be applied to both aliphatic and aromatic ketone oximes, provided that a methylene group be present near the C=N bond.Nonoptimized yields range from 22 to 48percent.The reaction seems to be a <3,3> sigmatropic rearrangement where DMC plays a key role in causing the initial N-methylation of the oximes.