Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/124—Duplicating or marking methods; Sheet materials for use therein using pressure to make a masked colour visible, e.g. to make a coloured support visible, to create an opaque or transparent pattern, or to form colour by uniting colour-forming components
  • B41M5/132—Chemical colour-forming components; Additives or binders therefor
  • B41M5/136—Organic colour formers, e.g. leuco dyes

Definitions

• the invention further relates to a process which is characterized in that the solutions of the diaminobenzohydroles of the formula (I) obtained by peduction of the diaminobenzophenone compounds of the formula (II) with alkali borohydride in organic solvents are acidified with aliphatic mono- or dicarboxylic acids and by Reaction with compounds of the formula or their alkali or alkaline earth metal salts in the compounds of the formula wherein A, B, R 1 , R 2 , R 3 and R4 have the same meaning as in formula (I), and the radical D represents an optionally substituted alkyl, aryl, aralkyl, cycloalkyl or hetaryl radical.
• the alkyl radicals mentioned in the formulas (I) and (II) are generally those having 1-6 C atoms.
• the alkyl radicals mentioned under D can have up to 20 carbon atoms.
• Particularly suitable substituents of the alkyl radicals are, for example, halogen, hydroxy, C 1 -C 4 alkoxy or cyano.
• Aryl is preferably understood to mean phenyl or 1- or 2-naphthyl and aralkyl is benzyl and ⁇ -phenyl-C 1 -C 4 -alkyl.
• the phenyl rings can be replaced, for example, by 1-4 radicals such as halogen, C 1 -C 4 alkyl, hydroxy, C 1 -C 4 alkoxy, C 1 -C 4 alkoxycarbonyl, carboxyl, amidocarbonyl, cyano, nitro, amidosulfonyl, C 1 -C 3 alkylcarbonylamino or benzoylamino.
• Cycloalkyl is especially cyclopentyl and cyclohexyl, e.g. can be substituted by 1-4 radicals, in particular methyl.
• heterocyclic rings which are formed by R 1 and R 2 or by R 3 and R 4 with the adjacent nitrogen atom are the piperidine, N-methylpiperazine and the morpholine ring.
• heterocyclic rings which are formed by R, and / or R 2 being attached to the aromatic radical A or by that R 3 and / or R 4 are bound to the aromatic radical B may be mentioned julolidine, lilolidine, N-methyltetrahydroquinoline and 1,2-dimethylindoline.
• a and B are preferably a 1,4-phenylene or 1,4-naphthylene radical. These radicals can be substituted by 1-4 substituents such as C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen.
• Halogen is understood to mean in particular fluorine, chlorine and bromine.
• Suitable hetaryl residues D are e.g. the quinoline (5), quinoline (6) and indazole (7) residues.
• Alkali borohydrides are preferably understood to mean sodium potassium and lithium borohydride.
• the process is particularly suitable for the production of Michler's hydrol (4,4'-tetramethyl-diamino-benzhydrol) from Michler's ketone (4,4'-tetramethyl-diamino-benzophenone).
• the alkali metal hydroxide preferably used in the process according to the invention is potassium hydroxide.
• Suitable solvents are monohydric and polyhydric alcohols and their ethers, for example methanol, ethanol, isopropanol, methyl glycol, ethyl glycol, butyl glycol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether; Dioxane, tetrahydrofuran and acetonitrile are also suitable as solvents.
• Suitable starting materials of the general formula (II) are 4,4'-diaminobenzophenone, 4,4'-Tetramethyldiamino- benzophenone, 4,4'-Tetraäthyldiaminobenzophenon, 4,4'-2,2'-dimethoxybenzophenone T etramethyldiamino, 4.4 '-Tetramethyldiamino-2,2'-dimethylbenzophenone, 4,4'-bisbenzylmethylaminobenzophenone, 4,4'-bis-benzylethylaminobenzophenone, 4,4'-bisdibenzylaminobenzophenone, 4,4'-bisphenylmethylaminobenzophenone, 4,4'-bisphenylethylaminobenzophenone, 4'-bispiperidinobenzophenone, 4,4'-bismorpholinobenzophenone, 4,4'-bis-N-methylpiperazinobenzophenone, bis
• the reaction can be carried out at a temperature of 20-100 ° C.
• the preferred temperature range is 50 - 70 ° C.
• solutions of the diaminobenzhydroles obtained in reduction in organic solvents preferably contain 15-35% of the benzhydrols.
• the solutions of 4,4'-diaminobenzhydrols obtained by the process according to the invention can be further reacted directly with sulfinic acids to the sulfinates of the hydrolyses without isolation of the reaction product.
• a low molecular weight aliphatic mono- or dicarboxylic acid is first added to the reaction solution, the color salt of the benzhydrol being formed. After adding the sulfinic acid as the sodium or potassium salt, the color lightens again and the crystalline sulfinate separates out.
• Suitable low-molecular organic mono- or dicarboxylic acids are formic acid, acetic acid, propionic acid, glycolic acid, methoxyacetic acid, ethoxyacetic acid, oxalic acid, maleic acid and succinic acid. Acetic acid is preferred among these carboxylic acids.
• Suitable sulfinic acids are, for example, methanesulfinic acid, ethanesulfinic acid, propanesulfinic acid, butanesulfinic acid, decanesulfinic acid, dodecanesulfinic acid, octadecansulfinic acid, benzylsulfinic acid, 4-methylbenzylsulfinic acid, 4-chlorobenzylsulfinic acid, cyclohexylsulfinic acid, benzenesulfobenzene acid, Methylbenzenesulfinic acid, 4-methylbenzenesulfinic acid, 4-ethylbenzenesulfinic acid, 4-methoxybenzenesulfinic acid and 4-ethoxybenzenesulfinic acid.
• 4-methylbenzenesulfinic acid is particularly preferred.
• diaminobenzhydrols which can be prepared according to the invention are suitable as intermediates for the preparation of basic and acidic di- and triaminotriphenylmethane dyes. They are also suitable as intermediates for the production of printing copy dyes, such as crystal violet lactone, leukauramines and sulfinates of diaminobenzhydrols.
• the reaction mixture is diluted to a volume of 3,700 ml by adding 2 liters of water, the mixture is stirred for another 4 hours, the separated Michlers hydrol (4,4'-tetramethyldiaminobenzhydrol) is suctioned off and washed neutral. After drying in vacuo, 506.2 g of Michler's hydrol are obtained. Melting point 101-103 0 C. Instead of alcohol, the same volume of isopropanol can also be used.
• 42.4 g of 4,4'-diaminobenzophenone are heated to 70 ° C. with 150 ml of ethylene glycol dimethyl ether and a solution of 12 g of sodium borohydride and 1 g of KOH in 24 ml of water are added dropwise within 6 hours. The reaction mixture is left to stir for a further 18 hours at 70 ° C. Then only traces of the starting material 4,4'-diaminobenzophenone are shown in the thin layer chromatogram. A clear solution is formed when diluted with 200 ml of water. The 4,4'-diaminobenzhydrol is salted out by adding 500 ml of saturated saline.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Citations (4)

• 1978
  • 1978-05-10 DE DE19782820485 patent/DE2820485A1/de not_active Withdrawn
• 1979
  • 1979-04-30 DE DE7979101294T patent/DE2960507D1/de not_active Expired
  • 1979-04-30 EP EP79101294A patent/EP0005475B1/fr not_active Expired
  • 1979-05-08 JP JP5536879A patent/JPS55374A/ja active Pending
  • 1979-05-09 BR BR7902841A patent/BR7902841A/pt unknown

Patent Citations (4)

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