GB797046A - New complex chromium compounds of benzene-monoazo-pyrazolone dyestuffs and process for making them - Google Patents

Abstract

The invention comprises chromium complexes of dyestuffs of formula <FORM:0797046/IV (b)/1> where R1 is a benzene residue free from groups imparting solubility in water bound in the 1-position to the N atom of the pyrazolone ring and containing in the 2-position an alkyl group preferably of 1 or 2 carbon atoms, and nucleus I may contain substituents not imparting solubility in water. Preferably 1,2-complexes are formed. The dyestuffs are made by conventional chroming processes, including using a 1,1-complex as chroming agent, from the dyestuffs obtained by diazotizing appropriate anthranilic acids and coupling with the required pyrazolones. Advantageously R1 contains a halogen atom in the 6-position but particularly preferred products are obtained when this residue is, apart from the 2-alkyl group, unsubstituted. Indicated as substituents for I are nitro and alkoxy groups and halogen atoms. Specified pyrazolones are 1-(21-methyl- and -ethyl- and 21,41- and 21,61-dimethyl- and 21-methyl - 61 - chloro - and - methoxy - phenyl - 3 methyl - 5 - pyrazolones. Anthranilic acids specified are 4- and 5-nitro-, 4-methoxy- and 5-chloro-2-amino-benzene-1-carboxylic acids and anthranilic acid which is preferred. The dyestuffs dye animal materials such as silk, leather and especially wool and also dye synthetic fibres of superpoly-amides and -urethanes. Dyeings may be effected from weakly alkaline to weakly acid baths. In examples which illustrate the preparation of the dyestuffs and their use in dyeing processes the components used are certain of those specified above with the addition of 1-(21-n-propylphenyl)-3-methyl-5-pyrazolone.