Regioselective alkylation of the lower rim of p-tert-butylthiacalix[4]arene with N-(p-nitrophenyl)-alpha-bromoacetamide

The preparation of partially substituted thiacalix[4]arenes 2-6 has been accomplished by conducting the reaction of the thiacalixarene 1 with N-(p-nitrophenyl)--bromoacetamide in acetone or acetonitrile in the presence of M2CO3 (M=Na, K and Cs). The influence of the reaction conditions (temperature, time, solvent, ratio of the reagents and the nature of the alkali metal carbonate) on regio- and stereoselectivity of this reaction is described.