PROCESS FOR PREPARING SUBSTITUTED 4,4'-DIAMINOSTILBENE-2,2'-DISULPHONIC ACID SALTS

摘要

PCT No. PCT/EP96/03357 Sec. 371 Date Jan. 22, 1999 Sec. 102(e) Date Jan. 22, 1999 PCT Filed Jul. 31, 1996 PCT Pub. No. WO98/05653 PCT Pub. Date Feb. 12, 1998In the preparation of substituted 4,4'-diaminostilbene-2,2'-disulfonic acid salts a clear increase in the reaction rate may be achieved by carrying out the reaction of the tetrachlorine derivative (III) with the aniline (IV) in the presence of the amine (VI) as acid-absorber.