Patent GB-493211-A (GB)
Title: Process for the manufacture of leuco sulphuric acid esters of vat dyestuffs
IPC: C09B5/26
Filed: 1937-04-21
Abstract: Phthaloyl-carbazoles containing trifluoromethyl groups which dye cotton and viscose artificial silk are made by heating compounds of the formulae <PICT:0493211/IV/1> wherein A is an anthraquinone radicle (in formula I at least one o-position to the nitrogen linkage of A is unsubstituted), at least one X is CF3 and the other Xs are hydrogen or any substituents, of which two adjacent ones may form a further ring system, or similar compounds containing the azimide radicle twice. The heating may be carried out in a high-boiling solvent such as diphenylamine, and the products may be converted to their acid leuco-sulphuric esters by reduction and esterification. The compounds of formula I may be obtained by (a) reacting an a -halogen anthraquinone which may contain halogen, methoxy, or acylamino substituents, in presence of an acid-binding agent and copper with a trifluoromethyl-substituted azimino compound, or (b) condensing an a -aminoanthraquinone with an o-nitrohalogenbenzene containing one or more trifluormethyl groups, or an a -halogenanthraquinone with an o-aminonitrobenzene containing one or more trifluoromethyl groups, followed by reduction of the nitro group and diazotization.  Compounds of formula II are obtained by reacting an o-amino-a -halogenanthraquinone with an aromatic amine containing one or more trifluoromethyl groups, followed by diazotization.  In examples, (1) 1-chloranthraquinone is reacted with 1-trifluoromethyl-3.4-aziminobenzene, and the product heated with diphenylamine (greenish yellow shades on cotton and viscose artificial silk); (2) 1-amino-anthraquinone is reacted with 1 - trifluoromethyl - 3 - nitro - 4 - chlorbenzene, followed by reduction, diazotization, and heating with diphenylamine to give the same product as in (1); (3) 1-amino-4-methoxy-anthraquinone, and (4) 1-amino-4-benzoylaminoanthraquinone are substituted for 1-aminoanthraquinone in the process of (2) (red-orange and red shades on cotton respectively); (5) 1,5-dichloranthraquinone; (6) 1,4-dichloranthraquinone, and (7) 1-chloro-5-benzoylaminoanthraquinone are each reacted with 1 - trifluoromethyl - 3,4 - aziminobenzene, followed by heating with diphenylamine (orange, red-violet, and golden-yellow tints respectively); (8) 1-chloro-5-benzoylaminoanthraquinone is reacted with 4-amino-3-nitro-1-trifluoromethylbenzene, followed by reduction, diazotization, and heating in molten diphenylamine (golden-yellow shades).  In example (9), 1,2 - phthaloyl - 6 - trifluoromethylcarbazole or a halogenation product is converted to its leuco-sulphuric ester potassium salt, using pyridine and sulphur trioxide (greenish-yellow tints and suitable for printing).  1 - Trifluoromethyl - 3,3 - aziminobenzene is obtained by diazotizing.  1 - Trifluoromethyl - 3,4 - diamino benzene which is obtained from 1-trifluoromethyl-4-chlorbenzene (see Specification 395,227, example 1) by nitration to produce 1-trifluoromethyl-3-nitro-4-chlorbenzene, reaction with ammonia to give 1-trifluoromethyl-3-nitro-4-aminobenzene, and reduction of the latter.