Pyrrolidinone and Piperidinone Isocyanides from Isocyano Esters

The alkylation of isocyano esters with 1,2- and 1,3-dibromoalkanes affords bromo isocyanides. Under treatment with various amines the latter form new isocyano-substituted lactams, which can be further used in Passerini or Ugi reactions.