1. Field of the Invention
The present invention relates to hydrazone pigments and their preparation. More particularly, the present invention relates to mono-azo/hydrazone or bis-azo/hydrazone pigments derived from 2-aryl-3-alkoxycarbonyl-5-pyrrolinones and 2-aryl-5-pyrrolinones intermediates.
2. Description of the Prior Art
Lovren et al., 47 Pharmazie 773–776 (1992) discloses the synthesis of azo/hydrazones where 2-methyl-3-carboethoxy-5-pyrrolinones are reacted with aromatic aldehydes and aryldiazonium (azo) salts.
USPTO Backgrounds
USPTO Backgrounds