Patent ID: 6121444
Filing Date: 2000-09-19
Classification: C07D,D06L

Abstract:
A process for the preparation of compounds of the formula (I) in whichn is 0 or 1,M is an alkali metal ion or an ammonium ion of an optionally substituted amine, andX is N-alkylamino or N,N-dialkylamino, wherein the alkyl groups can be substituted with hydroxyl, cyano, carbamoyl, or sulfo groups, with the proviso that when X is N,N-dialkylamino, the two alkyl radicals, together with the N-atom to which they are bonded, can form a saturated 5- or 6-membered heterocycle which can be optionally interrupted by a hetero atom from the series O, N, and S, comprising(a) reacting cyanuric chloride with a 4,4'-diaminostilbene-2,2'-disulfonic acid salt of the formula (II) ##STR11## in which M is as defined above, in the molar ratio 2:1 to form a compound of the formula (III) ##STR12## in which M is as defined above, (b) reacting the compound of formula (III) with 2 equivalents of an aniline of the formula (IV) ##STR13## in which M and n are as defined above, to form a compound of the formula (V) ##STR14## in which M and n are as defined above, (c) subsequently reacting the compound of formula (V) with 2 equivalents of an amine of the formula XH (VI), in which X is as defined above,wherein in step (b) the reaction of the compound (III) with the aniline (IV) is carried out in the presence of the amine (VI) as an acid-absorber, said amine (VI) being metered in at a rate that maintains a pH in the range from 3.0 to 7.0, and in step (c) the protonated form of amine (VI) formed in step (b) is freed from its protonated form by adding a base for the reaction with compound (V) the amine (VI) is freed from the protonated form using a base for the reaction with compound (V).