1, 3-Oxazines and Related Compounds. V. N-Acylacetylation of Carboxamides with the Diketene-Halotrimethylsilane System or Acyl Meldrum's Acids

Abstract

Various aliphatic and aromatic carboxamides smoothly underwent N-acetoacetylation by means of the diketene-iodotrimethylsilane system to give the corresponding N-acetoacetyl derivatives. The diketene-bromotrimethylsilane system was found to be very efficient for N-acetoacetylation of unsaturated carboxamides such as acrylamide and methacrylamide. In addition, acyl Meldrum's acids proved effective for N-acylacetylation of carboxamides, especially heterocyclic carboxamides such as picolinamides.