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Michler s ketone

Crystal violet is an example of a triphenylmethane dye. Its preparation in the laboratory may be illustrated by the condensation of 4 4 -tetramethyl-diaminobenzophenone (Michler s ketone) and dimethylaiiiliue in the presence of phosphorus oxychloride ... [Pg.982]

Michler s ketone is prepared industrially by the interaction of phosgene (COCl,) and dimethyl aniline. [Pg.982]

In a 1 htre round-bottomed flask, provided with an air condenser, place a mixture of 25 g. (26 ml.) of pure dimethylanihne, 10 g. of Michler s ketone (4 4 tetramethyldiaminobenzophenone) and 10 g. (6 ml.) of phosphorus oxychloride. Heat on a boding water bath for 5 hours. Add about 150 ml. of water and sufificient sodium hydroxide solution to render the solution alkaline. Calculate the quantity of sodium hydroxide required upon the basis of the hydrolysis product derived from the phosphorus oxychloride ... [Pg.982]

See also Michler s ketone. [miPHENYLTffiTTiANE AND RELATED DYES] (Vol 24) 4,4pBis(N,Npdimethylamino)benzophenone [90-94-8]... [Pg.111]

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. [Pg.271]

The manufacture of crystal violet (1), however, is a special case which does not involve the isolation of the intermediate Michler s ketone (Fig. 3). Thus, phosgene is treated with excess dimethyl aniline in the presence of zinc chloride. Under these conditions, the highly reactive intermediate "ketone dichloride" is formed in good yield this intermediate further condenses with another mole of dimethyl aniline to give the dye. [Pg.271]

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],... [Pg.303]

The amount of sensitizer is not critical since only enough is needed to absorb all the light. One gram of Michler s ketone will not be totally dissolved in 250 ml. of butadiene, but will be totally dissolved after the reaction is finished. Michler s ketone as obtained from Eastman Organic Chemicals was used without purification. [Pg.67]

Photoredox systems involving carbonyl compounds and amines are used in many applications. Carbonyl compounds employed include benzophenone and derivatives, a-diketones [e.g. benzil, cainphoroquinone (85),2W 291 9,10-phenanthrene quinone], and xanthone and coumarin derivatives. The amines are tertiary and must have a-hydrogens [e.g. N,A7-dimethylani 1 ine, Michler s ketone (86)]. The radicals formed are an a-aminoalkyl radical and a ketyl radical. [Pg.102]

The yields of cyclopropanes in this case are low in relation to the amount of acetophenone formed. However, similar cyclopropane product ratios are obtained when photolysis is carried out in the presence of Michler s ketone as sensitizer. Thus the carbene intermediate produced in the direct irradiation is thought to be a triplet, as suggested by the nonstereospecificity of its addition. Whether this intermediate arose from singlet diazoacetophenone (via singlet decomposition and intersystem crossing of the singlet carbene) or by decomposition of the triplet molecule was not determined. [Pg.256]

When both electron donor (D) and acceptor (A) groups are attached to a w-electron system it is not possible to consider the transition in terms of the excitation of one electron since it is a composite of several different one-electron excitation types. An example of a molecule which has electronic transitions of this type is Michler s ketone ... [Pg.315]

Where the + — terms refer to / an type excitations and the to a n - v type transition. These absorptions occur at longer wavelengths than the related model compounds (benzene and dimethylamine for Michler s ketone), have a high intensity, emax 104 liter/mole-cm, a small singlet-triplet splitting, and undergo a red shift of the absorption on going to a more polar solvent. [Pg.315]

In acidic solution the rearrangement of a-santonin to lumisantonin and then ultimately to photosantonic acid is not as efficient as rearrangement to the hydroxy ketone, isophotosantonic lactone (5), shown on page 308. Fisch and Richards(6) found that the photorearrangements of a-santonin could be sensitized with benzophenone or Michler s ketone. Moreover, if the irradiation of a-santonin (3660 A) is carried out in piperylene as solvent, the photoreaction is completely quenched. This suggests that the rearrangements proceed via triplet states. [Pg.460]

Reduction of Michler s ketone gives Michler s hydrol (6.159), which forms Michler s Hydrol Blue in the presence of acid (Scheme 6.27). Michler s hydrol is produced industrially by the oxidation of the diphenylmethane precursor (6.156) further oxidation to give Michler s ketone takes place readily. [Pg.329]


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