Sulfuric Acid → Ethylene Oxide

Participants

Reaction Steps

20.1 parts of 5-amino-4-cyano-3-phenylisothiazole in a mixture of 150 parts by volume of a 17:3 glacial acetic acid/propionic acid mixture and 70 parts of 80% strength sulfuric acid are stirred, and 32 parts of nitrosylsulfuric acid (11.5% of N2O3) are added slowly at 15°-20° C. The mixture is stirred for 3 hours at this temperature and in the presence of an excess of nitrous acid, and stirring is then continued for a further 15 minutes in the presence of 5 parts of urea. The resulting diazo solution is then run into a solution of 34 parts of 2-(2-methoxyphenylamino)-3-cyano-4-methyl-6-cyclohexylaminopyridine in 300 parts by volume of glacial acetic acid and 150 parts by volume of dimethylformamide, and stirring is continued at 15° C. until coupling is complete, which takes about 30 minutes. Filtration under suction and washing with 300 parts by volume of glacial acetic acid and with hot water give the dye of the formula: ##STR16## as an aqueous paste (λmax.=533 nm). A union fabric consisting of 63 parts of polyester and 37 parts of cotton is impregnated, at pH 6, with a formulation consisting of 6 parts (based on dry substance) of this dye, 80 parts of polyethylene glycol having a molecular weight of 1,500, 20 parts of a reaction product obtained from 1 mole of hexamethylenediamine and 15 moles of ethylene oxide and 894 parts of water. The impregnated fabric is dried at 110° C. and then treated with hot air at 215° C. for 5 minutes. It is washed with cold water, and the dyeing is treated with a commercial detergent at 100° C. A very lightfast, washfast, brilliant bluish red dyeing which is fast to solvents and to crocking is obtained in this manner.

Provenance & Evidence