Diphenyl-hydrazine

Nitric acid may be precipitated by nitron [2218-94-2] (4,5-dihydro-l,4-diphenyl-3,5-phenylimino-l,2,4-triazole). The yellow precipitate maybe seen at dilutions as low as 1 60,000 at 25°C or 1 80,000 at 0°C. To prevent nitrous acid from interfering with the test results, it may be removed by treating the solution with hydrazine sulfate, sodium azide, or sulfamic acid. 

The use of diphenyl hydrazone 33 has been used in the synthesis of pyrazoles under modified conditions where the hydrazine is released in situ. Some reversal of regiochemistry is seen in the reaction with unsymmetrical dicarbonyls. With aryl hydrazine and diphenyl hydrazone, the ratio of 41 to 42 is 22 1 and 5 1, respectively. 

Chloro-5,6-diphenyl-as-triazine readily undergoes methoxy-de-chlorination at 25° (< 12 hr) with methanolic methoxide and at 65° (4.5 hr) in non-basified methanol. The chloro group is also displaced by hydrazine (80°, 1 hr), ammonia (140°, 6 hr), and phenyl-magnesium bromide (70°, 12 hr), the latter forming the triphenyl compound 315.3-Chloro-6-phenyl-as-triazine is unstable to cold water or alkali and to hot alcohol or aqueous potassium carbonate. ... 

Because of the ease of ring synthesis, symmetrically trisubstituted s-triazines have been more thoroughly studied, but a few nucleophilic substitutions of derivatives bearing a single leaving group are known. 2-Chloro-4,6-diphenyl- and 2-chloro-4,6-dimethyl-s-triazines (318) undergo facile nucleophilic displacements with ammonia, amines, and hydrazine, with alkoxide, or with hydrosulfide... 

Like lV-methyl-2-phenylbenzothiazoliiim iodide (76KGS635), the salt 19 reacts with hydrazine hydrate to give 3,6-diphenyl-l,2-dihydro-l,2,4,5-tetrazine and di(o-lV-methylaminophenyl) ditelluride (92MI1). 

Hydrazobenzene 1 (1,2-diphenyl hydrazine) is converted to benzidine 2 (4,4 -diaminobiphenyl) under acidic conditions.This unusual reaction is called the benzidine rearrangement, and can be observed with substituted diphenyl hydrazines as well. 

Diphenyl-1 -acyl-hydrazine werden durch Lithiumalanat in siedendem Dibutylather bci 142° zu den 2-Alkyl- 1,2-diphenyI-hydrazinen und unter Spaltung der N-N-Bindung (s. S. 484) zu den N-Alkyl-anilinen reduziert4 ... 

Azobenzol kann mit guter Ausbeute im Kohlendioxid-Strom reduktiv unter C02-Addition zum 1,2-Diphenyl-l,2-dicarboxy-hydrazin reduziert werden (geteilte Zellc)3 ... 

The reaction of 5,6-diphenyl-3-cyano-l,2,4-triazine with hydrazine gives the amidrazone which, with 1,2-diketones, yields 3,3 -bistriazinyls 74 <95MI03 96CA(124)86945>. 

See Hydrogen peroxide Diphenyl diselenide Hydrazine derivatives... 

Of the further functional derivatives of cyclopropenones in the diphenyl series, the oxime115,121) and several hydrazones115) (e.g. 158/159), and a2ines (e.g. 760U5)), are easily available from the ethoxy cation 75 and hydroxylamine, hydrazines, and hydrazones, respectively. Sometimes oximation of cyclopropenones produces unexpected results (see later and Ref.42 ). 

Whilst anhydrous hydrazine is reported124) to give products of nucleophilic ring opening and cyclization (7 62/7 63) with diphenyl cyclopropenone, hydrazine hydrochloride yielded the azine 16112s ... 

Analogously, l,2-diphenyl-4,4-diacetyl- and -4,4-dibenzoyl triafiilvene are reported292 to be transformed by hydrazine to pyridazine derivatives 494, involving attack of the nucleophile at C1 2 and cyclization of intermediate 493 ... 

A variety of miscellaneous derivatives of gulonolactone has been reported. Linn treated D-glucofuranurono-6,3-lactone (7) with chlorobenzene and aluminum trichloride in order to obtain115 6-deoxy-6,6-diphenyl-L-gulonic acid (70). Various related compounds were also prepared. When 7 was treated with sulfur dioxide and 2-(isonicotin-oyl)hydrazine in water, 6-deoxy-6-(2-isonicotinoylhydrazino)-6-sulfo-D-gulono-1,4-lactone (71) was formed in 81% yield.116,117 Kawabata... 

The dications, characterized by spectroscopic means, are useful oxidizing agents as shown by the oxidation of thiophenol to diphenyl disnlphide by dications E and F as well as of diphenyl hydrazine to azobenzene by dication F. 

The phenylhydrazone of acetone gave on hydrogenation over colloidal platinum a 90% yield of A(-isopropyl-A(-phenylhydrazine [950], and the semi-carbazone of benzil on electroreduction a 70% yield of A(-aminocarbonyl-N - 1,2-diphenyl-2-ketoethyl)hydrazine [95/]. 

A similar sequence of reactions occurs with diphenyl cyanocarbonimidate (127). Sequential reaction of (127) with aniline and hydrazine gave 3-amino-5-phenylaminotriazole (Scheme 23) <82JHC1205, 87JHC275). With amino acids as the first nucleophile, more complex triazoles can be formed <93T165>. 

The method of choice for the synthesis of triazoles depends largely on the substitution pattern required. Acyclic compounds are usually the preferred substrates and the hydrazines are readily available and cheap. For 3-aminotriazoles, dimethyl A-cyanoisothiourea or diphenyl cyano-carbonimidates, although more expensive, are valuable precursors since the 5-substituent can be varied widely. 1,3-Dipolar addition using nitrilimines has been extensively used and again can be... 

---