formula ii is generally adjusted to ph 4 5 5 with acetic acid and admixed with one or more disperse dyes according to the depth of shade and the liquor ratio the liquor is then preferably introduced into the dyeing machine together with the material to be treated this is preferably followed by heating to 130 u00b0 c over 30 to 60 minutes under pressure and dyeing at 130 u00b0 c for 60 to 90 minutes the dyeing is customarily followed by a reductive aftertreatment with 2 g l of sodium hydrosulfite at 75 85 u00b0 c for 20 minutes use of the compound of the formula i according to the invention provides excellent fastness it is likewise possible to use further customary auxiliaries such as dispersants leveling agents carriers and aftertreatment agents in the dyeing the compounds of the formula i according to the invention can be used in pure form or in the form of aqueous solutions with or without customary solvents such as glycol or polyglycol a preferred form is the aqueous solution of compounds of the formula i in a concentration of 10 to 90 by weight preferably 70 to 30 by weight particularly preferably 45 to 35 by weight the solutions can be prepared for example by mixing the compounds of the invention with solvents in suitable stirred apparatuses for example at room temperature or with heating the.