Process of substituted 4,4'-diaminostilbene-2,2'-disulfonic acids

摘要

Preparation of 4,4'-bis(2-amino-4-(sulpho)anilino-1,3,5-triazin-6-yl-amino)-stilbene- 2,2'-disulphonic acids and salts (I) of formula (A; X = Y) involves reacting the corresponding 2-chloro-triazinyl compound (II) of formula (A; X = Cl) with an amine of formula Y-H (III) at pH 5-10, optionally in the presence of an acid acceptor (IV) other than (III). The novel features are that (i) (II) is added to an aqueous medium with a temperature NOTLESS 40 degrees C and (III) and optionally (IV), independently of one another, are added before, during and/or after addition of (II); in which n = 0, 1 or 2; M = H, an alkali metal ion or an optionally substituted ammonium ion; and Y = anilino, N-alkylamino or N,N-dialkylamino, in which the alkyl groups may have an O, N or S hetero-atom in the chain and N,N-dialkylamino may = a saturated 5- or 6-membered heterocycle.