Bis dimethylamino

In the ketone method, the central carbon atom is derived from phosgene (qv). A diarylketone is prepared from phosgene and a tertiary arylamine and then condenses with another mole of a tertiary arylamine (same or different) in the presence of phosphoms oxychloride or zinc chloride. The dye is produced directly without an oxidation step. Thus, ethyl violet [2390-59-2] Cl Basic Violet 4 (15), is prepared from 4,4 -bis(diethylamino)benzophenone with diethylaruline in the presence of phosphoms oxychloride. This reaction is very useful for the preparation of unsymmetrical dyes. Condensation of 4,4 -bis(dimethylamino)benzophenone [90-94-8] (Michler s ketone) with AJ-phenjl-l-naphthylamine gives the Victoria Blue B [2580-56-5] Cl Basic Blue 26, which is used for coloring paper and producing ballpoint pen pastes and inks. 

Michler s ketone [4,4 -bis(dimethylamino)benzophenone] [90-94-8] M 268.4, m 179", pK 9.84. Dissolved in dilute HCl, filtered and ppted by adding ammonia (to remove water-insoluble impurities such as benzophenone). Then crystd from EtOH or pet ether. [Suppan J Ghent Soc, Faraday TransI 71 539 1975.] It was also purified by dissolving in benzene, then washed with water until the aqueous phase was colourless. The benzene was evaporated off and the residue recrystd three times from benzene and EtOH [Hoshino and Kogure J Phys Ghent 72 417 1988],... 

A reaction vessel as shown in Fig. 1 is made from Pyrex tubing (Note 1). The vessel is evacuated and the stopcock closed. A 500-ml. round-bottomed two-necked flask equipped with a gas inlet and a cold finger condenser containing dry ice is charged with 1 g. of finely powdered 4,4 -bis(dimethylamino)benzophenone... 

Bis(K-butylthio)benzene, 42,24 4,4 -Bis(diethy amino)benzil, 41, 3 4,4 -Bis(dimethylamino)benzil, 41, 1 Bis(dimethylamino)methane, reaction... 

Stock solution Dissolve 1 g 4,4 -bis(dimethylamino)thiobenzophenone (Michler s... 

Bis-3,4-dichlorobenzoyl peroxide, 49, 4S decomposition in benzene, 49, 44 4,4 -Bis(dimethylamino)benzophenone as sensitizer for butadiene photolysis, 47, 65... 

The aromatic nitramine (234) can be prepared by nitratingA, A -diphenylethylenediamine ° or 2,2, 4,4 -tetranitro-A,A -diphenylethylenediamine with mixed acid, the latter synthesized from 2,4-dinitrochlorobenzene. The azoxy-nitramine (235) is prepared by nitrating 4,4 -bis(dimethylamino)azoxybenzene with mixed acid. ... 

The chloroform layer is distilled to dryness and the residue is dissolved in 1.5 1. of acetone under reflux. The hot acetone solution is filtered and then allowed to cool in a refrigerator. Yellow 4,4 -bis(dimethylamino)benzil crystallizes from the acetone solution. It is separated by filtration and washed with 100... 

Bis(dimethylamino)benzil has been made previously by heating a mixture of oxalyl chloride and N,N-dimethylaniline under a pressure of 300 atmospheres of carbon monoxide in a steel pressure vessel at 100°.4 The present method is simpler and gives better yields. As 4-dimethylaminobenzaldehyde cannot be converted to the corresponding benzoin,5 this common route to benzils cannot be used to prepare 4,4 -bis (dimethylamino) benzil. 

Cooling below —10° should be avoided because the reaction stops at that temperature and large amounts of oxalyl chloride accumulate in the flask. If this mixture is then allowed to come to room temperature, a vigorous reaction that may get out of control will take place. It is probable that, at reaction temperatures about 10°, the yield of 4,4,-bis(dimethylamino)benzil is less and some Crystal Violet is formed as an impurity, for it has been reported that aluminum chloride effects the conversion of N,N-dimetbylaniline and oxalyl chloride to Crystal Violet in 92-95% yield when the reaction is allowed to proceed without cooling.2... 

The submitters recommend that the following purification procedure be used from this point for the preparation of 4,4 -bis(diethylamino)benzil (72% yield) and 4,4 -bis(di- -propyl-amino)benzil (58% yield). The procedure has also been used as an alternative to the one given for 4,4 -bis(dimethylamino)benzil. 

The residual crude, yellow, semi-solid product is stirred and brought to a boil with 250 ml. of ethyl acetate and then allowed to cool to room temperature while stirring. Filtration affords 39-41 g. (52-55%) 4,4 -bis(dimethylamino)benzil, m.p. 201-203°. Concentration of the mother liquor to 50 ml. gives, after cooling, an additional 3.5-4.5 g. of product, m.p. 175-180°. Recrystallization of 10 g. of the combined products from 120-150 ml. of benzene gives 9.1-9.3 g. of yellow crystals, m.p. 202-203°. 

Bis-(dimethylamino)benzophenone [90-93-7] M 268.4, m 175 . Crystd from EtOH (25ml/g) and dried under vacuum,... 

Polyimides with better viscosity characteristics have been obtained from 3,3 -diamino-4,4 -bis(dimethylamino)-benzophenone and different aromatic tetracarboxylic acid dianhydrides [21] (Scheme 3.4). 

Reactions of 3,3 -diamino-4,4 -bis(dimethylamino)-benzophenone with the dianhydrides of aromatic tetracarboxylic acids (pyromellitic, benzophenone-3,3, 4,4 -tetracarboxylic and diphenyloxide-3,3, 4,4 -tetracarboxylic acids) were carried out using a two-stage process including room temperature reaction of starting monomers in NMP, formation of PCA and subsequent cyclodehydration of the... 

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