( Therefore, the reaction mechanism of the conversion of aldoxime to nitrile or amide should be described as follows: the hydroxyl of oxime attacks triphosgene and forms O-((trichloromethoxy)carbonyl) oxime as intermediate as well as phosgene and HCl as byproducts, which reacts nucleophilically with phosgene or HCl and undergoes the same path to form O-chlorocarbonyl oxime or amino oxonium. Soon, the deprotonation of the carbonyl oxime and amino oxonium convert to the final nitrile. Besides, the transformation of aldoxime into amide undergoes Beckman Rearrangement. However, Part of the oxime raw material will be hydrolyzed to aldehyde and ketone result in the lower selectivity and yield, shown in Scheme 2. Scheme 2. Proposed reaction mechanism of oximes with triphosgene.