Hydrazine, Phenyl

Fructose (V) under similar conditions gives first the phenylhydrazonc (Va) by the direct condensation of the >C 0 group of carbon atom 2 with one molecule of phenylhydrazine. The second molecule of phenylhydrazine then oxidises the primary alcohol group of carbon atom 1 to the -CHO group by removal of two atoms of hydrogen, which as before serve to reduce the phenyl-hydrazine to aniline and ammonia. The compound (Vb) which is thus produced then undergoes direct condensation with the third molecule of phenylhydrazine, giving the osazone of fructose, or fructosazone (Vc). 

Phenyl hydrazine condenses readily with aldehydes and ketones to give phenylhydrazonesy which, being usually crystalline compounds of sharp... 

If ethyl acetoacetate is warmed with an equivalent quantity of phenyl hydrazine, the corresponding phenylhydrazone (A) is readily formed. On... 

For the mechanism of this reaction, see Robinson and Robinson,1918, H3i 639 1924, 145, 827.) The reaction is of wide application for example, the use of methyl-phenyl-hydrazine, CsH5(CHj)> -iN H, in the above reaction gives i-methyl-2-phenylindole, whereas pyruvic acid, CH CO COOH, when converted to its phenylhydrazone and then indolised, gives indole-2-carboxylic... 

Osazone formation. The preparation of glucosazone has already been given (p. 137). It may be carried out on a small scale by either of the following methods, according as (a) the phenyl hydrazine base, or (Z>) one of its salts, is used. 

Prepare a solution of phenylhydrazine by dissolving 1 0 g. of phenyl-hydrazine hydrochloride and 1 5 g. of crystallised sodium acetate in 10 ml. of water if the resulting solution is turbid, filter. Add a solution of 0 5 ml. of cycZohexanone in 8 ml. of water to the reagent... 

Liberate the free base by adding to the phenylhydrazine hydrochloride 125 ml. of 25 per cent, sodium hydroxide solution. Extract the phenyl-hydrazine with two 40 ml. portions of benzene, dry the extracts with 25 g. of sodium hydroxide pellets or with anhydrous potassium carbonate thorough drying is essential if foaming in the subsequent distillation is to be avoided. Most of the benzene may now be distilled under atmospheric pressure, and the residual phenylhydrazine under reduced pressure. For this purpose, fit a small dropping funnel to the main neck of a 100 ml. Claisen flask (which contains a few fragments of porous porcelain) and assemble the rest of the apparatus as in Fig. II, 20, 1, but do not connect the Perkin triangle to the pump. Run in about 40 ml. of the benzene, solution into the flask, heat the latter in an air bath (Fig. II, 5, 3) so that... 

When ethyl acetoacetate is warmed with an equivalent quantity of phenyl-hydrazine, the compound (I), which is not a true hydrazone, is first formed this undergoes ring formation (II) with loss of ethyl alcohol upon further heating. The product (II) is N or l-phenyl-3-methyl-5-pyrazolone. 

Methyl>1,5-dlphsnyl-1,2,4-triazole (3), A mixture of phenyl hydrazine hydrochlonde 1 (14 5 g, 0.11 moQ, N-acetytbenzamide 2 (16.5 g, 0.1 moQ and NaOAc (10 g, 0.12 mol) in AcOH (30 mL) was refluxed for 10 h. The product was made elkaline wNaOH solution and extracted with Et20 Evaporation gave a pale yellow oil which slowly sofidiTied, mp 80-61 0. Recrystallization from 90% EtOH and petroleum ether afforded IS 4 g of 3 (76%). 

Knorr reported the first pyrazole derivative in 1883. The reaction of phenyl hydrazine and ethylacetoacetate resulted in a novel stmcture identified in 1887 as l-phenyl-3-methy 1-5-pyrazolone 9. His interest in antipyretic compounds led him to test these derivatives for antipyretic activity which led to the discovery of antipyrine 10. He introduced the name pyrazole for these compounds to denote that the nucleus was derived from the pyrrole by replacement of a carbon with a nitrogen. He subsequnently prepared many pyrazole analogs, particularly compounds derived from the readily available phenyl hydrazine. The unsubstituted pyrazole wasn t prepared until 1889 by decarboxylation of liT-pyrazole-3,4,5-tricarboxylic acid. ... 

Condensation of ethyl acetoacetate with phenyl hydrazine gives the pyrazolone, 58. Methylation by means of methyl iodide affords the prototype of this series, antipyrine (59). Reaction of that compound with nitrous acid gives the product of substitution at the only available position, the nitroso derivative (60) reduction affords another antiinflammatory agent, aminopyrine (61). Reductive alkylation of 61 with acetone in the presence of hydrogen and platinum gives isopyrine (62). Acylation of 61 with the acid chloride from nicotinic acid affords nifenazone (63). Acylation of 61 with 2-chloropropionyl chloride gives the amide, 64 displacement of the halogen with dimethylamine leads to aminopropylon (65). ... 

Two closely related indoles fused to an additional saturated ring have been described as CNS agents. The first of these is obtained in straightforward manner by Fischer indole condensation of functionalized cyclohexanone 0 with phenyl hydrazine (19). The product, cyclindole (21) shows antidepressant activity. The fluorinated analogue flucindole (26) can be prepared by the same scheme. An alternate route starting from a somewhat more readily available intermediate involves as the first step Fischer condensation of substituted phenyl hydrazine with 4-hydroxycyclohexanone (23). The resulting alcohol (24) is then converted to its tosylate (25). Displacement by means of dimethyl amine leads to the antipsychotic agent flucindole (26). ... 

The 17tt,20,20,21-bis(methylenedioxy )-11 (3-hydroxy-2-hydroxy methylene-6,16a-dimethyl-4,6-pregnadiene-3-one (1.19 g) is dissolved In 25 cc of ethanol. 300 mg of phenyl hydrazine is added and the mixture is refluxed under nitrogen for one hour. About 25 cc of water is added. The product is then extracted into 150 cc of ether. The extracts are washed with 2N HCI, with saturated sodium bicarbonate, water and saturated sodium chloride solution, and then dried over sodium sulfate and evaporated to dryness to give about 1.2 g... 

Acylation of 965 gave 966, whose cyclization with hydrazine or phenyl hydrazine afforded [89IJC(B)829] triazolotriazines 967 or 968, respectively (Scheme 177). 

P-coupling occurs in the formation of azophosphonic esters [ArN2PO(OCH3)2] from diazonium salts and dimethyl phosphite [HPO(OCH3)2] (Suckfull and Hau-brich, 1958). P-coupled intermediates are formed in the reaction between diazonium salts and tertiary phosphines, studied by Horner and Stohr (1953), and by Horner and Hoffmann (1956). The P-azo compound is hydrolyzed to triphenylphosphine oxide, but if a second equivalent of the tertiary phosphine is available, phenyl-hydrazine is finally obtained along with the phosphine oxide (Scheme 6-26 Horner and Hoffmann, 1958). It is likely that an aryldiazene (ArN = NH) is an intermediate in the hydrolysis step of the P-azo compounds. 

In Dimethoxymethan wird z. B. 2-[l-Dimethylamino-propyl-(2)]-l-acetyl-hydrazin zu 2-Athyl-l-[/-dimethylamino-propyl-(2)]-hydrazin (17% d.Th.) reduziert1 2 und 2-Phenyl- 1-acetyl-hydrazin zu 2-Athyl-l-phenyl-hydrazin (89% d.Th.)3 ... 

V. Mit Organo-stickstoff-Verbindungen (Hydroxylaminen, Diazomethan, Phenyl-hydrazin bzw. Hydrazobenzol)... 

Aeridin laBt sich dureh Phenyl-hydrazin in DMF (5 Stdn. 130°) in 72%iger Ausbeute zu 9,9 -Bi-acridanyl reduzieren. N-Methyl-acridiniumjodid liefert entspreehend (30 Min. Koehen in Athanol od. Erhitzen auf 110° in DMF) JO, 10 -Dimethyl-9,9 -bi-acridanyl (73 bzw. 88% d.Th.)11. 

Auch Nitroso-Verbindungen werden gelegentlich durch Phenyl-hydrazin zu Aminen reduziert (s. ds. Handb., Bd. XI/1, Tab. S. 494). 

Isatogensaure-methylester werden in der Kalte durch stark verdiinntes Phenyl-hydrazin deoxygeniert, wahrend bei leichtem Erwarmen auch die Oxo-Gruppe angegriffen wird1 ... 

O7) see Prenalterol [4-(phenyImethoxy)phenyl]hydrazine (C13H14N2O 5-/-/45-5S-5) see Oxitriptan... 

Maikov et al. [37] prepared a series of C2-symmetric bipyridine-type ligands, the chiral moieties arising from the isoprenoid chiral pool (/3-pinene, 3-carene, 2-carene, or a-pinene, for example). Some representative examples are drawn in Scheme 16 (see 25, 26, 27) and were used as copper ligands of a copper(I) species obtained by an in-situ reduction of Cu(OTf )2 with phenyl-hydrazine. The use of the resulting catalysts in enantioselective cyclopropana-tion proceeded with up to 76% ee (for ligand 27) and high diastereoselectivity (up to 99 1). 

Diimidazolides of dicarboxylic acids react with hydrazines in a 1 1 molar ratio to form cyclic hydrazides e.g., the diimidazolide of 2,2-dimethylmalonic acid and phenyl-hydrazine affords 1-phenyl-4,4-dimethyl-3,5-dioxopyrazolidine in 67% yield ... 

It was observed in those cases in which the oxidation was arrested too soon that an appreciable amount of silver chloride was deposited when the solution was concentrated. Furthermore, the mother liquor, when treated with phenyl-hydrazine in acetic acid, deposited some yellow crystalline D,L-mannose phenylhydrazone, m. p. 195-200° (Maquenne block). It is apparent that too vigorous oxidation results in the formation of hexoses. 

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