Patent GB-633493-A (GB)
Title: Manufacture of dyestuffs
IPC: C09B9/00
Filed: 1947-03-28
Abstract: Leuco-sulphuric esters are made by reacting leuco derivatives or stable reduction products of vat dyes (see Group IV (c)) or anthraquinone intermediates in presence of an organic amide derived from a secondary amine and in the presence of a nitrogenous base having a dissociation constant not less than 10-7 at 25 DEG  C., with or without diluents, with a sulphating agent consisting of sulphur trioxide or the addition compound of sulphur trioxide and an organic amide or tertiary base, or any substance actually used in practice for, or known from the literature to be capable of, forming sulphuric esters from vat dyestuffs in the presence of metals, from leuco compounds or metal salts thereof, or complex compounds comprising the metal salts thereof.  Amides specified are dimethylformamide, diethylformamide, dimethylacetamide, formylpiperidide, tetramethylurea and N.N-diethyl-p-toluenesulphonamide. Sulphating agents specified are the addition compounds of sulphur trioxide with dimethylformamide or picoline, and chlorsulphonic acid or its esters. Diluents specified are acetone, benzene, chlorobenzene.  Bases specified are ammonia, hydrazine, methylamine, ispropylamine, di- and tri-ethylamine, benzylamine, cyclohexylamine, dicyclohexylamine, piperidine, morpholine, cinchonine, strychnine, and brucine.  The stable reduction products referred to may be prepared by heating a solution of the leuco body, by acidifying the alkaline solution of the leuco-body, or by reducing the vat dye with hydrosulphite in presence of a tertiary base, e.g. pyridine or a small quantity of caustic soda.  In examples, the following bodies are reacted with dimethylformamide-sulphur trioxide in presence of certain of the bases and diluents listed above: (1) 10-hydroxyanthrone; (2) 9.10-dihydroxyanthracene; (3) 4-chloro-10-hydroxyanthrone. Specification 413,344 is referred to.  4-Chloro-10-hydroxyanthrone is prepared by brominating 4-chloroanthrone and hydrolysing the product with aqueous acetone.ALSO:Leuco-sulphuric esters are made by reacting leuco-derivatives or stable reduction products of vat dyes or anthraquinone intermediates (see Group IV (b)) in presence of an organic amide derived from a secondary amine and in the presence of a nitrogenous base having a dissociation constant not less than 10-7 at 25 DEG  C., with or without diluents, with a sulphating agent consisting of sulphur trioxide or the addition compound of sulphur trioxide and an organic amide or tertiary base, or any substance actually used in practice for, or known from the literature to be capable of, forming sulphuric esters from vat dyestuffs in the presence of metals, from leuco compounds or metal salts thereof, or complex compounds comprising the metal salts thereof.  Amides specified are dimethylformamide, diethylformamide, dimethylacetamide, formylpiperidide, tetramethylurea, and N : N-diethyl-p-toluenesulphonamide. Sulphating agents specified are the addition compounds of sulphur trioxide with dimethylformamide or picoline, and chlorsulphonic acid or its esters.  Diluents specified are acetone, benzene, chlorobenzene.  Bases specified are ammonia, hydrazine, methylamine, isopropylamine, di- and triethylamine, benzylamine, cyclohexylamine, dicyclohexylamine, piperidine, morpholine, cinchonine, strychnine, and brucine.  The stable reduction products referred to may be prepared by heating a solution of the leuco-body, by acidifying the alkaline solution of the leuco-body, or by reducing the vat dye with hydrosulphite in presence of a tertiary base, e.g. pyridine or a small quantity of caustic soda.  In examples, the following bodies are reacted with dimethylformamide-sulphur trioxide in presence of certain of the bases and diluents listed above: (1) stable leuco - 1 : 4 - dibenzoylaminoanthraquinone; (2) stable leuco - 6 : 61-diethoxythioindigo; (3) leuco - indigo; (4) stable leuco-5 : 51-dibenzoylamino-terephthal-1 : 11 - dianthraquinoxylamide; (5) stable leuco - 16 : 17 - dimethoxydibenzanthrone; (6) stable leuco - terephthal - 1 : 11 - dianthraquinoxylamide; (7) stable leuco-1 : 5 - dibenzoylaminoanthraquinone; (8) stable leuco - 1 - amino - 2 - (anthraquinone-211 : 311 : 41 : 51 - oxazole - 21) - anthraquinone. Specification 413,344 is referred to.