Preparation and Beckmann rearrangement of O-(chlorooxalyl)oximes

Article abstract of DOI:10.1055/s-1990-27112

Oximes 1 react with phosgene or oxalyl chloride to give O-(chloroformyl)- 2, or O-(chlorooxalyl)oximes 8, which undergo Beckmann rearrangement with antimony pentachloride to afford nitrilium hexachloroantimonates 3 in high yields. With di- or triphosgene (4 of 6) oximes 1 form mixtures of O-(chloroformyl)-2 and O-(trichloromethoxyformyl)oximes 5. The O-(chlorooxalyl)oximes 8 are further characterized as esters 10 and amides 11. With N,N-dimethylformamide the nitrilium salts 3 react to give N-acyl formamidinium salts 12.