A convenient one-pot synthesis of 3-amino-2, 5-dihydropyridazine and pyrimidine derivatives in the presence of high surface area MgO as a highly effective heterogeneous base catalyst.

A new and efficient method for the preparation of 3-amino-2,5-dihydropyridazines from three-component reactions of (phenyl-hydrazono)-propan-2-one, aldehydes, and malononitrile or ethyl cyanoacetate in the presence of magnesium oxide (MgO) as a highly effective heterogeneous base catalyst is presented. Also, the three-component reactions of aldehydes, amidine systems, and malononitrile or ethyl cyanoacetate for the formation of 4-amino-5-pyrimidine carbonitrile and pyrimidinone derivatives, respectively, are investigated. The salient features of these methods include high conversions, short reaction times, cleaner reaction profiles, and the use of inexpensive and readily available catalyst.