Hydrazines from diaziridines

Structural data of a diaziridine come from gas phase electron diffraction measurements (74CC397). The N—N bond of 3-methyldiaziridine (24) is longer than in hydrazine (1.449 A) the C—N bond distances in (24) and in diazirine are nearly equal (1.479 versus 1.482 A),... 

It was reported only recently that A-methyl transfer from an oxaziridine to an amine occurs with formation of an N—N bond (79JA6671). N—N bond forming reactions with A-unsubstituted oxaziridines had been found immediately after discovery of this class of compound (64CB2521) and have led to simple hydrazine syntheses (79AHC(24)63). Secondary amines like diethylamine or morpholine are A-aminated by (52) in the course of some minutes at room temperature with yields exceeding 90% (77JPR195). Further examples are the amination of aniline to phenylhydrazine, and of the Schiff base (96) to the diaziridine (97). 

Maleic hydrazide (149), produced on a large scale as a herbicide, can be obtained, according to a patent, from a simple diaziridine, which on an industrial scale could be less expensive than hydrazine hydrate. In the proposed manufacture of diamide (150) from a diaziridine and urea it must be taken into account that the reaction of urea is preceded by solvolytic hydrazine formation, which probably proceeds under the reported conditions (several hours, 70-80 °C, acidic media) (79AHC(24)63). 

Practically all diaziridines (151) can be hydrolyzed by acids to a carbonyl compound and a hydrazine derivative. The only exceptions are diaziridines derived from formaldehyde, in which acid catalyzed N—N cleavage successfully competes with slow hydrolysis. Monoalkylhydrazines are formed in 80-95% yield, A/,A/ -dialkylhydrazines in 65-85% yield (B-67MI50800). 

In a recent review of heterocyclic compounds no further mention is made of the three-membered ring structures for the condensation products from hydrazine and carbonyl compounds. However, the products obtained from azodicarbonyl derivatives with aliphatic diazo compounds were formulated as diaziridines [Eq. (1)]. Recent investi-... 

The hydrolysis of 1,2-dialkyl-diaziridines to A,A -dialkyl hydrazines is equally possible. Di-n-butylhydrazine is produced from 1,2-di-n-butyl-3-n-propyldiaziridine (60) (Eq, (48)]. ... 

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. ... 

Diaziridines differ from simple amines and hydrazines radically in many properties. First of all, the nitrogen atoms of diaziridines feature high pyramidal stability. The inversion of nitrogen atoms in diaziridine rings has been studied actively since 1967 <67CB1778>. Optically active diaziridines with an asymmetric nitrogen atom have been studied since 1974 <74izvi67i>. In the molecules of... 

Cleavage of diaziridines to a carbonyl compound and hydrazine or a substituted hydrazine can be carried out with almost any diaziridine. In order not to obtain the hydrazine as a solution of its salt, techniques were elaborated to transform dialkyldiaziridines from either acetone or butanone into hydrazones under the influence of catalysts and to trap them as azines... 

With regard to the simple diaziridine synthesis under large-scale conditions from ketone, ammonia, and chlorine, - some patents claim a direct preparation of hydrazine products by reaction of diaziridines with suitable reagents. For example, hydrazine dicarboxylic acid diamide is obtained directly from 3-ethyl-3-methyldiaziridine and urea in acidic so-lution. The reaction conditions, however (some hours at 70°-80°C), point to acid hydrolysis prior to reaction with urea. 

The end-product from synthesis of a diaziridine and its fission to alkylhydrazine is the same as is obtained by direct treatment of an amine with chloramine or hydroxylamine-O-sulfonic acid, as the carbonyl component of the Schiff base is recovered however, the detour through the diaziridine is worthwhile because in the direct reaction a considerable excess of the amine must be used to suppress further reaction of the alkylhydrazine product with the animating agent, whereas the diaziridines are unaffected thereby moreover, the diaziridine route is more widely applicable. Even further, the diaziridine route avoids both the requirement for an excess of alkali and the production of the hydrazine as a very dilute aqueous solution, both of which characterize the direct reaction. Indeed it provides an effective and generally applicable synthesis of mono-284,285 and 1,1-dialkyl-hydrazines.286... 

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