DIAZIRIDINONES .4. FORMATION BY CONDENSATION OF ALKYL ISOCYANIDE WITH NITROSOALKANE . EVIDENCE FOR A CARBODIIMIDE N-OXIDE

Reaction of t-butyl isocyanide with 2-methyl-2-nitrosopropane, 5, at 70° (1:1, neat) affords di-t-butyldiaziridinone, 1a (90%), dl-t-butylcarbodiimide, 6a (10%), and 2-methyl-2-nitropropane, 7. The ratio of 6a: 1a increases with increasing concentrations of nitrosoalkane 5; products 6a and 7 are formed in comparable amounts over wide variation in the ratio of reactants. Reaction of t-butyl isocyanide with nitrosoalkane 5 in the presence of phenyl isocyanate affords two 1:1:1 adducts, 9 and 10. Reaction of isopropyl isocyanide and nitrosoalkane 5 affords 1-t-butyl-2-isopropyldiaziridinone, 1b, carbodiimide 6b, and nitroalkane 7 in the absence of phenyl isocyanate, and affords 1:1:1 adduct 8 in the presence of phenyl isocyanate. The results are discussed in terms of condensation of alkyl isocyanide with nitrosoalkane to afford carbodiimide N-oxide 3. This intermediate may rearrange (presumably via oxaziridinimine 2) to diaziridinone 1, may react with nitrosoalkane leading to carbodiimide 6 and nitroalkane 7, or may react with phenyl isocyanate to afford the 1:1:1 adducts. © 1969, American Chemical Society. All rights reserved.