Hydrazines alkyl

In a variation of the Raschig process for making hydrazine, amines rather than ammonia ate reacted with chloramine to give the corresponding alkyl hydrazine ... 

Branched-chain alkenes react with hydrazine under acidic conditions to give the corresponding alkyl hydrazine. For example, isobutylene bubbled through an aqueous solution of hydrazine and HCl gives /-butyUiydrazine in reasonably good yields (64). 

The reaction is generally performed between 0 and 100 °C with the majority of the reactions being mn at reflux. Polar protic solvents such as methanol, ethanol, isopropanol, and water are commonly used as solvents. Addition of acid or use of acetic acid as solvent generally helps push sluggish reactions. The use of P-ketoesters as the dicarbonyl partner occasionally requires added base for cyclization to occur to form the pyrazolone. When using alkyl hydrazine salts, base may be required to deprotonate the hydrazine for the reaction to take place. 

More important preparatively is the hydrolysis of 1-alkyl-diaziri-dines to alkyl hydrazines [Eq. (47)]. A number of the alkyl hydrazines thus prepared are shown in Table IX. The synthesis of alkyl... 

The 1-alkyl-diaziridines can easily be hydrolyzed to alkyl hydrazines. Hence alkyl hydrazines are easily available from Grignard reagents and thus from alkyl halides. The three last examples of Table XII show the yield of alkyl hydrazine calculated on the diazirine used. The reaction has preparative interest because the alkylation of hydrazine with alkyl halides only gives monoalkyl hydrazines in exceptional cases. ... 

Yield of 1-alkjd-diaziridine, calculated on the diazirine which was not isolated. A ield of the alkyl hydrazine prepared by hydrolysis of the l-alkyl-diaziridine (calculated on diazirine). 

Diazirines are the cyclic isomers of the alphatic diazo compounds. Both the diaziridines and the diazirines are starting materials for the synthesis of alkyl hydrazines. 3,3-Pentamethyl-enediaziridine can be hydrolyzed quantitatively to hydrazine. Methylamine may be substituted for ammonia in the procedure resulting in l-methyl-3,3-pentamethylenediaziridine (m.p. 35-36°, yield 62% of theoretical) and then methyl hydrazine. Use of ethylenediamine leads to ethylene bis-hydrazine via a bifunctional diaziridine (m.p. 143-144°, yield 48% of theoretical). Ammonia can also be replaced by w-propylamine or cydo-hexylamine cyclohexanone by acetone. 

Pentamethylenediazirine and other diazirines easily add Grignard reagents to the N—N double bond. The reaction leads to N-alkyl diaziridines which can be hydrolyzed to alkyl hydrazines. Cyclohexylhydrazine (85% yield), -propylhydrazine (88%), isopropylhydrazine (95%), and benzylhydrazine were... 

Similar to the aetivity of alkyl hydrazines that liberate alkyl radicals upon metabolic several aryl hydrazines with various para substituents (X = H, CH3,... 

Use of an alkyl hydrazine as the nucleophile followed the expected course of addition. The resulting product (33), however, opened to an N-sulfonylimine (34) which rearranged to a thia-triazoleoxide (35) in 65% yield (Scheme 7) <86H(24)ii93>. 

LaCtman auf l,2-Bis-[l-imino-alkyl]-hydrazine salpctrige Saure einwirken, erfolgt unter Stick-stoff-Eliminierung Cyclisierung zu 2,5-disubstituierten 1,3,4-Oxadiazolen472. Die Reak-tion verlauft iiber 1,2-Diacyl-hydrazine. 

Other alkyl hydrazine s. Picard Boivin (Ref 2) studied the action of 100% HN03, mixed at -30° with acetic anhydride, on various symmetrical disubstituted hydrazines. Westphal Euhen (Ref 1) studied in great detail the properties and thermal disscn of various tetra-alkylhydrazines... 

These radical species may (slowly) combine to form the ju-peroxodico-balt species or, as in the preparation of [CH3Co(NH3)5]2+, react (more rapidly) with the alkyl hydrazine to form the alkylated cobalt(III) species and dinitrogen. Schiff base complexes such as these are discussed in more detail later in this article. 

Alkyl Hydrazines are described under individual compds, if they are expls or used in Ordnance. The major physical and chemical props of a large number of alkyl-substituted hydrazines, currently of interest in the rocket propellant field, were detd by R.CHarshman at the Olin Mathieson Chem Corp, Niagara Falls, NY and discussed in Jet Propulsion 27, 398-9(1957)... 

Analysing the products of reaction between alkyl nitrates and hydrazine they detected nitrate and nitrite ions, a corresponding alcohol, alkyl hydrazine, nitrogen oxides, ammonia and traces of aldehyde. If the reaction is performed without solvents in an excess of hydrazine, reduction occurs. In an aqueous solution of alcohol the process of substitution predominates particularly when the concentrations of reagents are low. 

Use of hydrazine hydrate and alkyl hydrazines results in azapeptides with the corresponding N-terminal unprotected azaamino acid residues. 11 Reaction at the substituted amino group of the hydrazine is favored, affording predominantly the correct (a-sub-stituted) product. 

Reaction of isothiocyanates 2, 30, and 31 with the acyl- or aroyl- and alkyl-hydrazine derivatives82 123a, 123b, 124a and 124b has also been... 

In addition to the procedure given here for the oxidation of tert-octylamine to nitroso-tert-octane,2 the oxidation may be carried out with m-chloroperoxybenzoic acid or with a solution of peroxyacetic acid in ethyl acetate.4 The lead dioxide oxidation of alkyl hydrazines to alkyl radicals appears to have general application. In addition to tert-butylhydrazine, various secondary alkylhydrazines (e.g., bornylhydrazine and menthylhydrazine) have been used to good effect. The reduction of tri-tert-alkylhydroxyl amine to the di-tert-alkylamine has also been achieved with sodium in ammonia but the insolubility of the hydrophobic substrate makes this procedure difficult. The use of sodium naphthalenide gives higher yields and is more reproducible. 

In the majority of cases alkyl hydrazines give single pyrazoles.160, 328, 336,337 In 1958 Bertrand established that allenic ketones give pyrazoles quantitatively with hydrazine.338 The reaction may be formulated as follows, the second stage being stabilization by aromatization. Acetylenic nitriles give aminopyrazoles with hydrazine.339... 

The free radical products generated by peroxidases are highly reactive species that can, in some instances, covalently modify the heme group of the enzyme (Fig. 5.10). In the case of HRP, the substrates for which this type of reaction has been observed include aryl and alkyl hydrazines [55, 56], the azide anion [57], nitromethane [58], cyclopropanone hydrate [59], and alkyl acids [60]. Free radicals... 

Aromatic ring N-oxides Aromatic mono- and d-alkyl amino groups Alkyl hydrazines Alkyl aldehydes N-methylol derivatives Monohal alkanes N and S mustards, P-haloethyl... 

Direct alkylation of hydrazine itself with halides and sulfates usually gives mixtures of mono- and poly-alkylated hydrazines. It is possible to get useful yields of the monoalkylhydrazine by using an excess of hydrazine. Several specific procedures leading to monoalkylhydrazines are based on selective alkylation of hydrazine derivatives with protecting groups attached. So, easily prepared acetone N-(diethoxyphosphoryl)hydrazone (75) can be used. Phase-transfer catalyzed N-alkylation of (75), followed by deprotection with p-toluenesulfonic acid provides monoalkylhydrazine sulfonates (76 Scheme 17). Similarly, N-alkyl-N-arylhydrazines have been prepared by phase-transfer catalyzed N-alkylation of arylhydrazones (Scheme 18). An efficient, one-pot method for the synthesis of a variety of polysilyl-ated hydrazines employs hexamethyldisilane (equation 30). Polysilylated hydrazines were found to react with aldehydes or ketones to give hydrazones under anhydrous conditions. By treatment with triphenylphosphine and diethyl azodicarboxylate primary and secondary alcohols can be converted to hy-dr ine derivatives (equation 31). ... 

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