GB476298A - Improvements in the manufacture and production of leuco esters of dyestuffs of the anthraquinonyl-azole series - Google Patents

Abstract

m -Anthraquinonyl anthraquinone - oxazoles and -thiazoles containing in the anthraquinonyl radicle a primary or secondary amino group in o-position to the carbon atom of the azole ring are converted to their leuco sluphuric esters by treatment with sulphur trioxide or agents supplying the same in the presence of a tertiary base and a metal under mild conditions. Up to four sulphuric ester groups may be introduced, and the initial materials should contain no unprotected amino group other than that above referred to. The products give red or blue shades on the usual fibres. In examples: (1) 1-amino-2-anthraquinonyl - a - monochlor - 2<1>.3<1> - anthraquinoneoxazole is treated with sulphur trioxide and chlorsulphonic acid in pyridine in presence of copper powder, and the tetra-sulphuric ester so obtained may be converted to a disulphuric ester having a greater affinity for the fibre by treating with dilute acetic acid and sodium nitrate or during dyeing; anthraquinonyloxazoles containing a chlorine or bromine atom in 1- or 1<1>- or 3- or 3<1>-position, or other, substituents such as alkoxy, cyano, alkylamino or acylamino, may also be used; (2) 1-amino-2-anthraquinonyl-2<1>.3<1>-anthraquinoneoxazole is treated with chlorsulphonic acid in pyridine in presence of copper powder; the chlorsulphonic acid may be replaced by sulphur trioxide or mixtures of sulphur trioxide and sulphuric acid or chlorsulphonic acid, or chlorsulphonic acid esters and iron powder may replace the copper; the tetrasulphuric ester may be converted to a trisulphuric ester by standing with dilute acetic acid, a conversion which may be accelerated by leading in oxygen or adding sodium nitrite or another oxidizing agent and the disulphuric ester may be prepared by intensifying such treatment; the di- and tri-esters may also be prepared by allowing an acidified solution of the tetraester to stand at elevated temperature, or during dyeing; (3) 1-amino-2-anthraquinonyl - 2<1>.3<1> - anthraquinonethiazole is converted to its tetra-sulphuric ester as in (1) and this may be converted to the di-ester; the thiazole used may be replaced by its 4-ethoxy derivative; (4) 1-amino-2-anthraquinonyl - 4<1> - ethoxy - 2<1>.3<1> - anthraquinoneoxazole is treated as in (2). The 1 - amino - 2 - anthraquinonyl - a -monochlor - 2<1>.3<1> - anthraquinoneoxazole is obtained by treating 2-amino-3-hydroxyanthraquinone with sulphuryl chloride in nitrobenzene, and heating the monochlor body so obtained with 1 - aminoanthraquinone - 2 - carboxylic acid chloride in nitrobenzene. 1 - Amino - 2 - anthraquinonyl - 2<1>.3<1>-anthraquinonethiazole is obtained by condensing 1-aminoanthraquinone-2-carboxylic acid chloride with 2-mercapto-3-aminoanthraquinone. Specification 298,545, [Class 2 (iii)], is referred to.