Patent ID: 9242942
Filing Date: 2016-01-26
CPC Classification: C07D

Claim Text:
1. A process for purifying an impure aryltriazole obtained by the diazotization reaction of an ortho-phenylenediamine with a nitrite, said impure aryltriazole containing dark and colored impurities, consisting of the steps: 1) dissolving at a temperature of 50 to 100° C. said impure aryltriazole with an aqueous solution of at least 1 equivalent of a 10-20% aqueous solution of strong acid to form two liquid phases, one phase of said two liquid phases comprising the cationic form of said aryltriazole in an aqueous solution and other phase of said two liquid phases comprising substantially all of the dark and colored impurities; 2) separating the one phase of the said two liquid phases comprising said cationic form of said aryltriazole in an aqueous solution from the other phase of the liquid mixture comprising substantially all of the dark and colored impurities; 3) neutralizing said one phase of the said two liquid phases comprising said cationic form of said aryltriazole in an aqueous solution with a base thereby forming two new phases, one phase being the purified impure aryltriazole and the other phase being a salt solution; 4) separating said purified impure aryltriazole from said salt solution.