摘要:
The indirect fluorination of some fluorocarbon nitrogen compounds has been investigated and reactions of the following functional groups have been determined under mild conditions: -N=C<, N C-, c-(-N = C<)(8), >N-H, >NCOF, -N = C = O, -NHCOF, -CONH2 and -CONHCO-. Fluorocarbon N-F compounds can be synthesized in certain cases by the action of silver difluoride on carbon-nitrogen unsaturation, by replacement of amine hydrogen or by cleavage of an acyl group from nitrogen. Rearrangement and coupling of the free radical intermediates are competitive with N-F bond formation, coupling becoming more important with progressively milder conditions. Volatile fluorocarbon isocyanates can be conveniently prepared from the corresponding amides by reaction with AgF2, and fluorocarbon azoalkanes, RFCF2N = NCF2RF, from nitriles by use of the same reagent. Similarity of the isocyanate synthesis to the Hofman and Curtius reactions is discussed.