DIAZIRIDINONES (2,3-DIAZACYCLOPROPANONES) .2. SYNTHESIS, PROPERTIES, AND REACTIONS

Reaction of 1-chloro-1,3-di-t-alkylurea with potassium t-butoxide in t-butyl alcohol effects ring closure to a diaziridinone 1, a new three-membered ring heterocycle. Spectral data indicate a trans orientation for the substituents attached to the nitrogen atoms. The diaziridinones are reactive toward acids, only moderately reactive toward a range of nucleophiles, and function as mild oxidizing agents toward thiols, phenols, enols, and some hydrazines. The acids studied include hydrogen chloride, picric acid, benzoic acid, and formic acid with resultant ring opening of diaziridinone and formation of substituted carbazates 8a, c-e. A second method of formation of diaziridinones is found in the regeneration of 1a by the action of potassium i-butoxide on 2,3-di-t-butylcarbazyl chloride 8a. Studies of the action of nucleophiles on dl-t-butyldiaziridinone include t-butoxide, t-butyl alcohol, methoxide, and methanol (ring opening to alkyl carbazates 8b and 8f), isopropylamine (ring opening to substituted semicarbazide 10), and hydrazine (ring opening and conversion to carbohydrazide). Di-t-butyldiaziridinone is reduced by benzylthiol (or ethanethiol) to 1,3-di-t-butylurea and benzyl disulfide (or ethyl disulfide). Diaziridinone la is reduced to the urea rapidly by ascorbic acid and by phenylhydrazine and, more slowly, by phenol and by 2,4,6-tri-t-butylphenol. t-Butylhydroxylamine reacts with la both by nucleophilic attack at carbonyl carbon with ring opening giving carbazate 17, and by oxidation-reduction giving di-t-butylurea and 2-methyl-2-nitrosopropane. The reactions described here constitute a new method for the formation of a nitrogen-nitrogen bond, hydrazo, and azo compounds. They also provide new routes to substituted carbazates and semicarbazides. Of special interest in the chemistry of diaziridinones is the balance between nucleophilic ring opening with cleavage of the carbonyl carbon-nitrogen bond and oxidation-reduction ring opening with reductive cleavage of the nitrogen-nitrogen bond. © 1969, American Chemical Society. All rights reserved.