Preparation from Hydrazine Hydrate

Preparation from Hydrazine Hydrate. Hydrazine hydrate may be substituted for hydrazine sulfate in the preparation of biurea. In this case it is necessary to supply enough additional acetic acid to compensate for the absence of sulfuric acid. Thus, 29 g. of 85% hydrazine hydrate (0.5 mol) and 90 g. of glacial acetic acid (1.5 mol) are dissolved in 500 ml. of water. Eighty-nine grams of potas- 

Biurea is a dense, white crystalline compound which melts with decomposition at 245 to 246°. It is soluble in water to the extent of less than 0.10 g./lOO g. of water at 0° and is insoluble in alcohol and ether. It dissolves without decomposition in warm concentrated potassium hydroxide. It is nonhygroscopic and undergoes no decomposition when heated at 110° for 48 hours. 

Submitted by L. F. Audrieth and Elizabeth B. Mohr Checked by Emanuel DAVisf and W. R. Tomlinson, Jr. t 

Many of the iV-alkyl and iV-aryl derivatives of urazine have been synthesized and characterized, but the parent substance is not well known. In the past, urazine has been prepared by thermal deammonation of carbohydrazide-iV-carboxamide [eq. (I)],1 fusion of hydrazidicarbamide with hydrazinium hydrogen sulfate [eq. (2)],2 fusion of earbohy-drazide with urea [eq. (3)],3 action of sodium hypobromite on semicarbazide [eq. (4)],4 reaction of dichlorourea with concentrated ammonia [eq. (5)],5 and the reaction between 1,2 hydrazine carboxylic ester and hydrazine hydrate 

C2H4N402 4 2NaBr + 2NH3 + 02 (4) 2C0(NHC1)2 + 4NH3 4 2H20 —  

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Dinitrophenylhydrazine has been prepared from hydrazine hydrate and 2,4-dinitrochlorobenzene or 2,4-dinitrobro-mobenzene, and from the same halogen compounds and hydrazine acetate. ... 

Hydrazine hydrate of 60 per cent, and 100 per cent, are available commercially. The preparation from hydrazine sulphate is hardly worth while. 

Trifluoroacetaldehyde azine, prepared from trifluoroacetaldehyde hydrate and hydrazine monohydrate, reacts with triethylamine in methanol to give the 1,4-dihydro-1,2,4,5-tetrazine derivatives 28, whose structure is confirmed by X-ray analysis (95BCJ2085) (Scheme 28). 

Almost all azolo[x,y-d]pyridazines have been prepared from the corresponding azole with two adjacent acyl, aroyl or carboxy derivatives. Thus, pyrrolo[3,4-d]pyridazines 50 are produced from hydrazine hydrate with 49 in ethanol at room temperature (2004BML203ll... 

The independent preparation of potassium phthabmide (from a solution of phthalimide in absolute ethanol and potassium hydroxide in 75 per cent, ethanol) may be avoided in many cases by boiling phthalimide with the halide in the presence of anhydrous potassium carbonate. The N-substituted phthalimide (I) is frequently cleav with difficulty this is often facilitated by reaction with hydrazine hydrate to give an intermediate product, which is easily decomposed by hydrochloric acid to 3deld the insoluble hydrazide of phthaUc acid (II) and the primary amine (III) ... 

Girard s reagent T is carbohydrazidomethyltrimethylammonium chloride (I) and is prepared by the reaction of the quaternary ammonium salt formed from ethyl chloroacetate and trimethylamine with hydrazine hydrate in alco-hoUc solution ... 

Phthalic anhydride and diethyl phthalate are easily converted with hydrazine into 4-hydroxyphthalazin-l(2/f)-one. Its substituted derivatives have been prepared using substituted hydrazines, substituted phthalic anhydrides, or diesters or disodium salts of substituted phthalic acids (Scheme 81). However, condensation of phenylhydrazine with phthalic anhydride gives only a small amount of the corresponding phthalazine, the main product being 2-anilinophthalimide. This can be rearranged in the presence of base into the phthalazine derivative. For the preparation of 2,3-disubstituted derivatives, 1,2-disub-stituted hydrazines are reacted with the appropriate phthalic anhydrides or phthaloyl chlorides. Derivatives of 4-amino- or 4-hydrazino-phthalazin-l(2iT)-one have been prepared either from the corresponding monothiophthalimide and 3-aminoisoindolin-3-one (1S4) or from ethyl 2-cyanobenzoate (155) and hydrazine hydrate (Scheme 82). Similarly,... 

One of the most dramatic developments in the chemistry of N2 during the past 30 years was the discovery by A. D. Allen and C. V. Senoff in 1965 that dinitrogen complexes such as [Ru(NH3)5(N2)1 could readily be prepared from aqueous RUCI3 using hydrazine hydrate in aqueous solution. Since that time virtually all transition metals have been found to give dinitrogen complexes and several hundred such compounds are now characterized.Three general preparative methods are available ... 

The pyrrolotriazines 32 were prepared from 3,4-dihydro-5-ethoxy-2//-pyrrole 31 by sequential reaction with hydrazine hydrate and a-oxoesters (85GEP3340026). They are useful as selective herbicides (Scheme 10). 

Although this material contains a small amount of the symmetrical dihydrazide, which is not easily eliminated on crystallization, it is entirely satisfactory for use as a reagent for the isolation of ketones. A purer product, m. p. 192°, with decomposition, can be obtained by adding the solution prepared from ethyl chloroacetate and trimethylamine to an alcoholic solution containing a considerable excess of the hydrazine hydrate. 

Simple 1,2,4-triazole derivatives played a key role in both the synthesis of functionalized triazoles and in asymmetric synthesis. l-(a-Aminomethyl)-1,2,4-triazoles 4 could be converted into 5 by treatment with enol ethers <96SC357>. The novel C2-symmetric triazole-containing chiral auxiliary (S,S)-4-amino-3,5-bis(l-hydroxyethyl)-l,2,4-triazole, SAT, (6) was prepared firmn (S)-lactic acid and hydrazine hydrate <96TA1621>. This chiral auxiliary was employed to mediate the diastereoselective 1,2-addition of Grignard reagents to the C=N bond of hydrazones. The diastereoselective-alkylation of enolates derived from ethyl ester 7 was mediated by a related auxiliary <96TA1631>. 

Suhtnicion nickel powders luive been synthesized successfully from aqueous NiCh at various tempmatuTKi and times with ethanol-water solvent by using the conventional and ultrasonic chemical reduction method. The reductive condition was prepared by flie dissolution of hydrazine hydrate into basic solution. The samples synthesized in various conditions weae claractsiz by the m ins of an X-ray diffractometry (XRD), a scanning electron microscopy (SEM), a thermo-gravimetry (TG) and an X-ray photoelectron spectroscopy (XPS). It was found that the samples obtained by the ultrasonic method were more smoothly spherical in shape, smaller in size and narrower in particle size distribution, compared to the conventional one. 

In the late stage of work up of a sample prepared from acrylonitrile and hydrazine hydrate and stripped of water by a procedure involving dichloromethane, the distillation flask pressurised and burst, shattering the front of the fume cupboard. Previously, slight pressurisation had once been observed. Involving both a nitrile and a hydrazino moiety, this molecule cannot be thermodynamically stable but it has not given previous problems. 

Diaminobiuret has been prepared only from N-tricarboxylic ester and hydrazine hydrate.1 Ethyl hydrazinecarboxylate has been prepared by reduction of nitrourethan electrolytically2 or with zinc dust and acetic acid,3 and by the action of hydrazine hydrate on diethyl carbonate,4 6 ethyl chlorocarbonate,6 and N-tricarboxylic ester.1... 

The reaction of Curtius, which is especially to be preferred in the case of the higher members on account of the favourable solubilities of the intermediate products, involves as its first stage the preparation of the hydrazide from an ester (or acid chloride). The hydrazide is then converted, usually very readily, by the action of nitrous acid into the azide. In many cases it is more convenient to prepare the azide by treating an acid chloride with sodium azide previously activated with hydrazine hydrate.1 Azides easily undergo thermal decomposition, the two azo nitrogen atoms being eliminated as elementary nitrogen. In this way, however, the same radicle is formed as was invoked above to explain the Hofmann reaction ... 

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