A one-pot strategy for regioselective synthesis of 6-aryl-3-oxo-2,3-dihydropyridazine-4-carbohydrazides

A simple and efficient method for the synthesis of 6-aryl-3-oxo-2,3-dihydropyridazine-4-carbohydrazide derivatives was developed. The synthesis was achieved via one-pot multicomponent reaction of arylglyoxals, dialkylmalonates, and hydrazine hydrate in pyridine at room temperature. This procedure features high regioselectivity, generally good to excellent yields, the use of easily available starting materials, and operational simplicity. This chemistry provides an efficient and promising synthetic strategy for diversity-oriented construction of the 6-arylpyridazinone skeleton.Ar = C6H5, 4-ClC6H4, 4-BrC6H4, 4-FC6H4, 4-CH3OC6H4, 4-NO2C6H4, 3,4(CH3O)2C6H3, 3,4(OCH2O)C6H3, 4-OH-3-CH3OC6H3, 3-BrC6H4, 3-CH3OC6H4 R = CH3, CH2CH3