METHOD OF OBTAINING STILBENIC COMPOUNDS

A process for the preparation of a 4,4'-bis-(triazinylamino)-stilbene-2,2'-disulphonic acid compound of formula (1) is disclosed, characterized in that (a) in a first reaction step cyanurchloride is reacted with the disodium salt of 4,4'-diaminostilbene-2,2'-disulfonic acid to give the intermediate of formula (2); (b) in a second reaction step the compound of formula (2) is reacted with a compound of formula R1-H and/or R2-H to give the compound of formula (3); (c) in a third step the compound of formula (3) is reacted with the compound of the formula R3H, and reaction step (a) and/or (c) are carried out in a medium consisting of a mixture of water and a polyglycol to give the compound of formula (1), wherein R1, R2 and R3, independently, are phenylamino; phenylamino substitued by C1-C3alkyl, halogen, cyano, COOR or COR; CONH-R; SO2NH-R; NH-COR; mono- or disulphonated phenylamino; morpholino; piperidino; pyrrolidino; -NH2; -NH(C1-C4alkyl); -N(C1-C4alkyl)2; -NH(C2-C4hydroxyalkyl); -N(C2-C4hydroxyalkyl)2; -N(C1-C4alkyl)(C2-C4hydroxyalkyl); NHC2-C4 alkylsulphonic acid; -OC1-C4alkyl; an aminoacid or aminoacid amide residue from which a hydrogen atom on the amino group has been removed; R1 and R2 may further independently represent hydrogen; C1-C4alkyl; phenyl; naphthyl; phenyl or naphthyl substituted by C1-C4alkyl, C1-C4alkoxy, halogen, C2-C5alkanoyl-amino, nitro, sulpho or C1-C4alkylated amino; R is hydrogen; or C1-C3alkyl; and M is H, Na, Li, K, Ca, Mg, ammonium, or ammonium that is mono-, di-, tri- or tetrasubstituted by C1-C4alkyl, C2-C4hydroxyalkyl or a mixture thereof.