Abstract The synthesis of 1, 2-disubstituted perhydropyridazine-3, 6-diones in high yield is described. The reaction of succinic anhydride and 1, 2-dialkylhydrazines leads to N, N′- dialkyl-3-carboxypropionhydrazides which are converted to 1, 2-dialkylperhydropyridazine- 3, 6-diones in refluxing xylene or polyphosphoric acid. The reaction of 1, 2-diarylhydrazines with 3-carbomethoxypropionyl chloride and hydrolysis of the resulting N, N′-diaryl-3- ...