GB498241A - The manufacture of azodyestuffs - Google Patents

Abstract

Azo dyestuffs are manufactured by coupling an o-diazophenol with an acylaminonaphthol of the general formula <FORM:0498241/IV/1> where X is a halogenated aliphatic radicle containing more than one carbon atom, the components being so selected that the azo dyestuff formed contains at least one sulphonic acid group. Alternatively an o-diazophenol is coupled with an aminonaphthol and the resulting aminoazo dyestuff is treated with the chloride or anhydride of a halogenated fatty acid containing more than two carbon atoms, including the commercial mixtures obtained by the action of chlorine or bromine on propionic or butyric acid chloride. The products may be converted on the fibre into metal compounds. Examples describe the production of the following dyestuffs: (1) 4-methyl-6-nitro-2-aminophenol --> 2-(b -chloropropionylamino)-8-naphthol-6-sulphonic acid; the product dyes wool from an acid bath reddish-violet shades becoming reddish-grey on after-chroming; the diazo component may be replaced by 4-chloro-6-nitro-2-aminophenol; (2) 4-chloro-5-nitro-2-aminophenol --> the same coupling component (dark red shades becoming bluish-grey); the diazo component may be replaced by 4-methyl-5-nitro-2-aminophenol or 5-nitro-2-aminophenol, and the coupling component by b -chloropropionyl-1 : 5 : 7- or 2 : 5 : 7-acid; (3) 4-chloro-6-nitro-2-aminophenol --> b -chloropropionyl-1 : 3 : 6-acid (grey after-chromed shades); the coupling component may be replaced by b -chloropropionyl-1 : 6 : 3- acid, b -bromopropionyl-1 : 3 : 6-acid or derivatives of 1 : 3 : 6-acid substituted in the amino group by radicles of chlorinated butyric acids; (4) 4-chloro-2-aminophenol-6-sulphonic acid --> b -chloropropionyl-1 : 3 : 6-acid (navy-blue shades); the diazo component may be replaced by 4-chloro-2-aminophenol; (5) 4-chloro-5-nitro-2-aminophenol --> b -chloropropionyl-1 : 6 : 3-acid (bluish-grey shades); (6) 4-methyl-6-nitro-2-aminophenol --> b -chloropropionyl-1 : 7 : 3-acid (red shades becoming neutral grey); the diazo component may be replaced by 4-sulpho-2-aminophenol, 4-chloro-6- or 5-nitro-2-aminophenol, or 4-chloro-2-aminophenol; (7) 5-nitro-2-aminophenol --> b -chloropropionyl-1 : 7 : 4-acid (red shades becoming greenish grey); (8) 4-methyl-6-nitro-2-aminophenol illegible data 1 : 7 : 3-acid, the product being treated with b -chloropropionic acid chloride in the presence of sodium acetate or bicarbonate. Specifica tions 25903/11, 2956/12, 12250/15, [all in Class 2 (iii)], 341,461, and 490,389 are referred to. Acylaminonaphthols of the general formula given above are obtainable by the action of chlorides or anhydrides of halogenated car boxylic acids containing more than two carbon atoms on aminonaphthols or their sulphonic acids in the presence of acid-binding agents such as sodium acetate or bicarbonate, chalk or sodium carbonate.