Reactions of carbonyl diisocyanate with amides and acids

Carbonyl diisocyanate ( 1 ) reacts with primary amides to give 1‐acylated isocyanuric acids ( 5,6 ). With secondary amides, 1 affords the rather instable oxadiazinediones 4 , which for certain substituents rearrange to give triazines ( 5,10 ). With nucleophiles, compounds 4 give oligourets, e.g. with ureas pentaurets ( 11,12 ) were obtained. Carbonyl diisocyanate reacts with hydrogen halides to afford the crystalline urea‐1,3‐dicarbonyl halides 13a – c . Diverse products ( 16,17,24,26 ) were obtained with carboxylic acids. In most cases oxadiazinediones ( 26 ) were isolated, which can be transformed with nucleophiles into acyl ureas 30,31 , biurets 32 , and triurets 33 . Acetylation of 26 leads to the reactive heterocycles 34 .