PRODUCTION OF 2,6-DIAMINOBENZO-(1,2-D:4,5-D')-BISTHIAZOLE

摘要

PURPOSE:To obtain the titled compound in high purity in a relatively short reaction time without using organic solvent, by carrying out the oxidative cyclization of p-phenylenebis(thiourea) in sulfuric acid in the presence of bormine or hydrogen bromide. CONSTITUTION:The objective compound can be produced by the oxidative cyclization of p-phenylenebis(thiourea) in sulfuric acid (preferably having a concentration of 55-100wt%) in the presence of bromine and/or hydrogen bromide (or a hydrobromide salt producing hydrogen bromide in sulfuric acid), preferably at 80-90 deg.C for 3hr. The amount of sulfuric acid is preferably 5-9pts. wt. per 1pt.wt. of p-phenylenebis(thiourea). USE:Intermediate for dyes and pigments, etc., or a raw material of 2,5-diamino-1,4- benzenethiol.