Synthesis of α, β-unsaturated diketones and derivatives of 2-pyrazoline from 2, 5-diformylthiophene

The crotonic condensation of 2, 5-diformylthiophene with various aromatic and heterocyclic methyl ketones has given 15 , -unsaturated diketones. By the reaction of the latter with phenylhydrazine, ten 2, 5-di(1-phenyl-3-R-²-pyrazolin-5-yl)thiophenes possessing a bright blue-violet or green luminescence have been synthesized.