A facile and convenient method for the preparation of macrocyclic diamides

A number of macrocyclic diamides have been synthesized from the reaction of a diacid dicarboxylic dichloride with primary diamino compound in the pres ence of magnesium oxide-silica gel at room temperature in good yields. Usin g urea and thiourea as well as diamines to produce the corresponding macroc ycles in the range of 52-56% yields are also included in this paper. One of the major advantages of this method is simple regeneration of inorganic so lid and its reuse through several cycles without a decrease in activity.