Trimethyl orthoacetate, orthopropionate or orthobenzoate in contrast to orthoformiate do not undergo a three component condensation with anilines and cyclic sixmembered active methylene compounds to the corresponding N-substituted aminomethylene derivatives; they do react, however, with five membered ring compounds. The reaction proceeds smoothly with primary aliphatic or aromatic amines, whilst secondary amines give no or only low yields. In comparison to other synthetic routes to β,β-diacyl-enamines the condensation described has the following advantages: a) The products thus obtained have previously often required a two step procedure, b) the only reaction product besides the aminoalky lidene derivative is an alkohol, c) the usually mild conditions allow the preparation of compounds so far not available by employing more drastic alternative method
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