SYNTHESIS OF PYRAZOLE DYES

摘要

NOVEL SYNTHESIS OF PYRAZOLE DYES A process for preparing a l-alkyl-3-secondary or tertiary alkyl-4-cyano-pyrazol-5-yl azo dye or a 1alkyl-3-aryl-4-cyano-pyrazol-5-yl azo dye comprising: a) reacting a 3-secondary or tertiary alkyl-4- cyano-5-amino pyrazole or a 3-aryl-4-cyano-5-amino pyrazole with a diazotizing reagent to form a pyrazol-5-yl diazonium salt; b) allowing said diazonium salt to react with an aromatic coupling component to form a 3secondary or tertiary alkyl-4-cyano-pyrazol-5-yl azo dye or a 3-aryl-4-cyano-pyrazol-5-yl azo dye; and c) reacting the product of step b) with an alkylating agent in the presence of a base to form a l-alky1-3-secondary or tertiary alkyl4-cyano-pyrazol-5-yl azo dye or a 1-alkyl-3-aryl-4-cyano-pyrazol-5-yl azo dye.