Benzophenone hydrazone, oxidation diphenyldiazomethane

Nickel peroxide oxidizes benzophenone hydrazone to diphenyldiazomethane in quantitative yield.9... 

NCS is also regularly used for the direct oxidation of alcohols to ketones. The presence of Triethylamine serves to activate the reagent for rapid quantitative oxidation of catechols and hy-droquinones to o- and p-quinones, respectively, and for the oxidation of benzophenone hydrazone to diphenyldiazomethane. N-Chlorosuccininude—Dimethyl Sulfide is also used in the mild oxidation of alcohols, as well as in the conversion of allylic alcohols to allylic chlorides. 

C. Diphenyldiazomethane. In a pressure bottle are placed 19.6 g. (0.1 mole) of benzophenone hydrazone, 22 g. (0.1 mole) of yellow oxide of mercury, and 100 ml. of petroleum ether (b.p. 30-60°). The bottle is closed, wrapped in a wet towel, and shaken mechanically at room temperature for 6 hours. The mixture is then filtered to remove mercury and any benzophenone azine (Note 5), and the filtrate is evaporated to dryness under reduced pressure at room temperature. The crystalline residue of diphenyldiazomethane melts when its temperature reaches that of the room (Note 6), but it is difficult to purify and this product is pure enough for all practical purposes. The material weighs 17.3-18.6 g. (89-96%). The product should be used immediately (Note 7). 

Diphenyldiazomethane has been prepared only by oxidation of benzophenone hydrazone.3 The procedure given above is that of Staudinger, Anthes, and Pfenninger, with minor changes. The method of preparation of benzophenone hydrazone given above is a modification of the procedure of Curtius and Rauter-berg.4... 

The second project was to determine whether the anodic oxidation of benzophe-none hydrazone could be manipulated to produce diphenyldiazomethane (DDM) as the end product in high yield. Literature evidence95 indicated that the anodic oxidation of benzophenone hydrazone using either a platinum or graphite anode under various conditions with a variety of electrolytes gave a number of products that were... 

A mixture of 39.2 g. (0.20 mole) of benzophenone hydrazone Org. Syntheses Coll. Vol. 2, 497 (1943)], 44 g. (0.20 mole) of yellow mercuric oxide, and 200 ml. of petroleum ether (b.p. 30-40°) is agitated with moderate external cooling for 9 hours. The deep red petroleum ether solution is filtered, and the solvent is removed from the filtrate under vacuum without heating the mixture. The resulting deep red crystals of diphenyldiazomethane, m.p. 29-30°, weigh between 33 and... 

Diphenyldiazomethane 386 A mixture of benzophenone hydrazone (13 g, 0.066 mole), anhydrous sodium sulfate (15 g)> ether (200 ml), ethanol saturated with potassium hydroxide (5 ml or 10 ml if red mercuric oxide is used), and yellow (or red) mercuric oxide (35 g) is shaken in a pressure flask for 75 min. The solids are then filtered off and the solvents are removed in a vacuum at room temperature. The dark red oily product is dissolved in light petroleum (b.p. 30-60°) and this solution is filtered and the solvent is again removed in a vacuum at room temperature. The oil produced is frozen in Dry Ice and gradually allowed to warm to room temperature, whereupon dark red crystals, of m.p. 29-32°, are obtained in 89% yield [cf. also Organic Syntheses, 24, 53 (1944)]. 

Oxidation. Durst and co-workers find that this combination rapidly oxidizes catechols to ortho-quinones and hydroquinones to para-quinones at -25 to 0°. Based on NMR and IR, yields are quantitative. In addition, anthrone is converted into bianthrone (75% isolated yield) and benzophenone hydrazone is oxidized to diphenyldiazomethane. 

Stoichiometrically, one equivalent of HgO is necessary for the dehydrogenation of a hydrazone. Examples have been published in Organic Syntheses Smith and Howard (1955) described the procedure for diphenyldiazomethane, obtained from benzophenone hydrazone in petroleum ether in 89-96% yield. The necessity for the absence of moisture is emphasized, but no activation of the mercury(n) oxide seems to be required. Andrews et al. (1988) have reported on the dehydrogenation of acetone hydrazone to 2-diazopropane (70-90% yield) in ether in the presence of catalytic amounts of KOH in ethanol. There are also cases where two equivalents are used, e.g., the procedure for (benzoyl)(phenyl) diazomethane (2.62, yield 87-94%) published in Organic Syntheses by Nenitzescu and Solomonica (1943). Neither these nor other authors have explained, however, why two equivalents would be necessary. 

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