ELECTROCHEMICAL PROCESS FOR PREPARING 4,4'-DINITROSTILBENE-2,2'-DISULFONIC ACID AND THE SALTS THEREOF

摘要

PURPOSE: To produce 4,4'-dinitrostilbene-2,2'-disulfonic acid or salts thereof by electrochemically treating PNTSA in an anode division of a partitioned electrolytic cell under a condition promoting oxidative condensation of the PNTSA. ;CONSTITUTION: An aq. alkali reaction medium containing about 3 to 35 wt.% p-nitrotoluene-2-sulfonic acid salt (PNTSA) is supplied to the anode division of the electrolytic cell and an aq. alkali soln. is added to a cathode division. Electrolysis is executed by making a current with current density of about 1 to 30 ASD flow through the electrolytic cell for a time and under a condition sufficient to cause oxidative condensation of the PNTSA. The aq. alkali soln. is prepared by blending water with a raw material of alkali metal or an alkali earth metal ion and a raw material of hydroxide ion (OH^-) (preferably one kind of hydroxide, etc., selected from among Na, K, Li). Thus, 4,4'- dinitrostilbene-2,2'-disulfonic acid or its salt is produced.;COPYRIGHT: (C)1993,JPO