Preparation of solutions of azo methine basic dyestuffs
AssigneeBayer Aktiengesellschaft
InventorRoderich Raue
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Abstract
Stable concentrated solutions of basic dyestuffs of the formula ##STR1## wherein R denotes the remaining part of a 5- or 6-membered heterocyclic ring, R.sub.1 denotes optionally substituted alkyl, alkenyl, cycloalkyl, aralkyl or aryl, R.sub.3 denotes alkyl and A denotes an aromatic or heterocyclic radical are prepared by reacting bases of the formula ##STR2## with dialkyl sulphates of the formula (R.sub.3 -O-).sub.2 SO.sub.2 in organic solvents which are completely or partially miscible with water and which do not react with the dialkyl sulphates or react with these more slowly than the dye bases.
Claims1
Process for the preparation of a solution of the basic dyestuff of the formula ##STR9## wherein R is the remaining part of a 5-membered or 6-membered heterocyclic ring;
- R.sub.1 is alkyl, alkenyl, cycloalkyl, aralkyl, aryl, haloaryl, C.sub.1 -C.sub.4 -alkaryl, C.sub.1 -C.sub.4 -alkoxyaryl, or alkyl substituted by halogen, hydroxyl, cyano, C.sub.1 -C.sub.4 -alkoxy, phenoxy, or acetoxy;
- R.sub.3 is alkyl;
- and
- A is phenyl, naphthyl, or either of phenyl or naphthyl substituted 1-3 times with alkyl, alkoxy, aralkyl, aralkoxy, halogen, carboxyl, carboxylic acid esters, carbonamide, amino, acylamino, aryl, acyl, acyloxy, aryloxy, or nitro;
- the process comprising reacting a dye base of the formula:
- ##STR10## with a dialkyl sulphate of the formula
- (R.sub.3 -O-).sub.2 -SO.sub.2
- in glycerol triacetate, methylglycol acetate, ethylglycol acetate, ethylene glycol diacetate, .beta.-methoxypropionitrile, .beta.-hydroxypropionitrile, .gamma.-butyrolactone, ethylene glycol carbonate, or propylene glycol carbonate.
Dependencies are inferred from the claim text.