GB231149A - Manufacture of new dyestuffs and intermediate products - Google Patents

Abstract

2 - Amino - 1 - oxynaphthalene - S - sulphonamide-4-sulphonic acid is obtained from 1 : 8-naphthsultone by sulphonating, nitrating or nitrosating, treating with ammonia and then reducing; the treatment with ammonia may take place at any stage. According to examples (1) the sultone is sulphonated with fuming sulphuric acid, nitric acid added and the sodium salt of the 1 : 8-naphthsultone-2-nitro-4-sulphonic acid isolated by salting out; the sodium salt is treated with concentrated ammonia to form the 2-nitro-1-oxynaphthalene -8- sulphonamide - 4 - sulphonic acid which is then reduced with iron and sodium bisulphite; the reduction may precede the treatment with ammonia: (2) 1-oxynaphthalene-8-sulphonamide is sulphonated with concentrated sulphuric acid containing a little fuming acid at 10 DEG C. and the sodium salt of the product salted out; the latter is converted to the 2-nitrosocompound by treating with sodium nitrite in acid solution, and reduced with iron and sulphuric acid at 30-40 DEG C. p Azo dyes and soluble metal compounds thereof.-The diazo compound of the above described 2-amino-1-oxynaphthalene-8-sulphonamide - 4 - sulphonic acid, when coupled with the usual components, yields mordant dyestuffs which may be converted into soluble metal compounds by treating with an agent yielding a metal such as a chromium or copper compound. The products dye wool in orange, brown, red, blue, violet &c. shades and may also be used in printing. In an example the diazo compound is coupled with b -naphthol and the dyestuff converted to the chromium compound by boiling with chromium fluoride. A table is given showing the properties of the dyestuffs, and of their chromium and copper compounds, derived from the diazo compound and the following components:-a -and b -naphthol, 5 : 8-dichlor-1-naphthol, 2 : 3-oxynaphthoic acid, 3-oxy-1 : 8-naphthalene-dicarboxylic acid, 1 : 4- and 2 : 6-naphthol sulphonic acids, b -resorcylic acid, resorcin, and 1-phenyl-3-methyl-5-pyrazolone and the 31-sulphamido-, 31-nitro-, and 41-oxy-31-carboxy-derivatives thereof.