Synthesis and investigation of merocyanine dyes

New merocyanine dyes — derivatives of 1-unsubstituted, 1-methyl-, and l-phenyl-3,4-pyrroline-2,5-diones — were synthesized by the reaction of quaternary salts of 2-methyl — substituted heterocyclic nitrogen bases with the appropriate 3,4-dihalopyrrolinedione and sodium benzenesulfinate or with 3-phenylamlno-4-phenylsulfonylpyrroline-2,5-diones.The effect of substituants attached to the nitrogen atom of 3,4-dihalo-3,4-pyrroline-2,5-diones on the nature of the products formed by reaction with aniline and sodium benzene-sulfinate was investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1387–1390, October, 1971.