PROCESS FOR THE MANUFACTURE OF BIS- BENZOXAZOLYL-STILBENE COMPOUNDS

摘要

Process for the manufacture of bis-benzoxazolyl-stilbene compounds which comprises the chlorination in an inert organic solvent of benzoxazolyl-stilbene carboxylic acid, addition of a solution of an aminophenol in an aprotic, dipolar solvent to the acid chloride thus obtained and subsequent cyclization in the presence of an acid catalyst of the acyl compound obtained. The improved process provides products of high purity in a one-stage process so that the products may be directly used as optical brighteners without previous purification by recrystallization.