Patent GB-482582-A (GB)
Title: Improvements in the conversion of leuco compounds into their oxidised form
IPC: C09B63/00
Filed: 1936-09-26
Abstract: The conversion to oxidized form of leuco compounds which do not require for such conversion the addition of oxygen is effected, in substance or on textile fibres, by treating the leuco compounds with unsaturated organic compounds (or compounds capable of reacting as unsaturated compounds) which are capable of chemically combining with hydrogen.  The term "unsaturated organic compound" denotes an organic compound which contains atoms linked together by more than one valency bond, and covers the type of unsaturation occurring in aromatic compounds.  The following classes of compounds are specified as dehydrogenating agents; (a) ketones capable of being formulated in the enol form, e.g. acetone and its homologues, acetoacetic esters, b -keto-acids, and pyrazolones, and also substances such as isatin and phthalimide which contain, in the stable or the pseudo form, the group -CO-NH-; (b) alkylene oxides and alkylene imines, e.g. ethylene oxide, propylene oxide and homologues thereof, or ethylene imine; (c) aldehydes, e.g. acetaldehyde, benzaldehyde or the aldehydic sugars; (d) substances containing an ethylene linkage, e.g. cinnamic acid, limonene, pinene or ethylene.  When using alkylene oxides, hydroxyalkylation may be minimized by reducing the reaction time as much as possible, e.g. by raising the leuco compound to the optimum reaction temperature and pressure before introducing the alkylene oxide.  The dehydrogenation process is particularly applicable to the treatment of leuco hydroxy-, amino- and hydroxy-aminoanthraquinones, and may be combined with the production of leuco amino-, amino-hydroxy-, substituted amino- or substituted amino-hydroxyanthraquinones by the action of ammonia or amines on suitable leuco anthraquinone derivatives. For this purpose the amidation process may be carried out in the presence of the dehydrogenating agent at a temperature at which dehydrogenation does not occur, after which the temperature is raised sufficiently for dehydrogenation to take place. Alternatively a dehydrogenation catalyst may be added when the amidation is complete.  Suitable starting materials for this modification of the invention are on the one hand the leuco compounds of quinizarin, 1 : 4 : 5-trihydroxyanthraquinone, 1 : 4 : 5 : 8-rahydroxyanthraquinone, alizarin Bordeaux, 1 - hydroxy - 4 - aminoanthraquinone, 4 : 8-diaminoanthrarufin and 4 : 8-diaminoanthrachrysazin, and on the other hand ammonia, alkylamines, e.g. methylamine or monoethanolamine, or arylamines, e.g. aniline or toluidines.  If desired the initial leuco compound may be produced in the same liquor by treating the corresponding anthraquinone compound with a reducing agent, e.g. sodium hydrosulphite.  In examples: (1) leuco-1 : 4-diaminoanthraquinone (the product of reaction of ammonia on leuco quinizarin) is heated to 150 DEG  C. in an autoclave with ethylene oxide in the presence of methyl alcohol; (2) in the process of (1) the ethylene oxide is passed in after the temperature has been raised to 150 DEG  C.; (3) leuco-1 : 4 - di - (methylamino) - anthraquinone is treated as in (1) but at 110-120 DEG  C.; (4) leuco - 1 : 4 - di - (hydroxyethylamino) - anthraquinone is treated as in (3); (5) leuco-1 : 4-di - (hydroxyethylamino) - 5 - hydroxyanthraquinone is similarly treated; (6) leuco - 1 : 4-di - (hydroxyethylamino) - 5 : 8 - anthraquinone is similarly treated; (7) leuco quinizarin is heated to 150-160 DEG  C. with ethylene oxide in the presence of methyl alcohol and caustic soda; (8) and (9) propylene oxide is used in place of ethylene oxide in (1) and (7) respectively; (10 ) and (11) ethylene imine is employed in the processes of (7) and (1) respectively; (12) glucose is employed in the processes of (1); (13) leuco-1 : 4-di-(methylamino)-anthraquinone is heated with glucose in the presence of industrial alcohol; (14) leuco-1 : 4-diaminoanthraquinone is heated with acetaldehyde in the presence of ethyl alcohol and soda ash; (15) benzaldehyde is employed in the process of (14); (16) leuco-1 : 4-diaminoanthraquinone is heated with acetone in the presence of methyl alcohol and soda ash; (17) leuco Caledon Jade Green is heated with acetone in the presence of water and soda ash; (18) methyl acetoacetate is employed in the process of (16); (19) 1-phenyl-3-methyl-5-pyrazolone is similarly employed; (20) leuco-1 : 4-di-(methylamino)-anthraquinone is heated with isatin in the presence of industrial alcohol; (21) phthalimide is employed in the process of (20); (22) leuco-1 : 4-diaminoanthraquinone is heated with cinnamic acid in the presence of methyl alcohol; (23) leuco-1 : 4-di-(methylamino)-anthraquinone is heated with cinnamic acid in the presence of industrial alcohol; (24) American turpentine oil is employed in the process of (23); (25) leuco Thioindigo Black is heated with American turpentine oil in the presence of industrial alcohol and soda ash; (26) leuco-1 : 4-di-(methylamino)-anthraquinone is heated with industrial alcohol saturated with ethylene; (27) leuco-1 : 4-diaminoanthraquinone is heated to 200 DEG  C. in an autoclave with benzene; (28) leuco-1 : 4 - di - (methylamino) - anthraquinone is similarly treated in the presence of soda ash; (29) leuco-1-methylamino-4-ethanolaminoanthraquinone is treated as in (27); (30) Indigosol Purple AR is similarly treated; (31) naphthalene is employed in the process of (27); (32) pyridine is similarly employed; (33) acetonitrile is similarly employed; (34) a mixture of leuco quinizarin, industrial alcohol, methylamine solution and American turpentine oil is heated in an autoclave first to 80-90 DEG C. and later to 150 DEG  C.; (35) cotton fabric impregnated with the leuco compound of Hydron blue G is subjected to an atmosphere of ethylene oxide at 100 DEG  C.