Diaziridines hydrolysis

Table 2 Rate Constants and Activation Parameters of Diaziridine Hydrolysis...

The acid hydrolysis of diaziridines has been investigated kinetic-ally. The reaction is first order and shows a relatively high temperature coefficient. Thus one finds a relatively high activation enthalpy (23-28 kcal) and a positive activation entropy (2-6 eu). The influence of substitution on nitrogen is small. The velocity of the diaziridine hydrolysis depends only in the weakly acid region on the acid concentration. Between pH 7 and 3 the fc-values rise by nearly 10 . For the... 

Several reactions lead to opening of the diaziridine ring leaving the N—N bond intact. Besides the generally possible hydrolysis to hydrazines there are some thermal reactions of acylated diaziridines proceeding especially cleanly. 

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). 

To prepare alkylhydrazlnes, cyclohexanone is treated with a primary amine and hydroxyl-amine-O-sulfonic acid in a one-pot procedure hydrolysis to the alkylhydrazine is carried out without isolation of the diaziridine (68JPR(37)257). Yields are between 60 and 70%. 

Diaziridine, 1-cyclohexyl-hydrolysis rate constant, 7, 216 (62CB1759) Diaziridine, 1 -cyclohexyl-3,3-dimethyl-hydrolysis rate constant, 7, 216 (62CB1759) Diaziridine, l-cyclohexyl-3-methyl-hydrolysis rate constant, 7, 216 (62CB1759) Diaziridine, l,2-di-t-butyl-3-t-butylimino-IR, 7, 13 <80AG(E)276)... 

Diaziridine, 3-benzyl-1,3-dimethyl-inversion, 7, 7 Diaziridine, 1,2-dialkyl-reaction with iodides, 7, 217 thermal decomposition, 7, 217 Diaziridine, dibenzoyl-rearrangement, 7, 214 Diaziridine, 3,3-dimethyl-Raman spectra, 7, 202 Diaziridine, fluoro-synthesis, 7, 232 Diaziridines acylation, 7, 213 from azomethines, 7, 231 calculations, 7, 198 from chloramine, 7, 230 cycloaddition reactions, 7, 28 electron diffraction, 7, 19 199 c/s-fused NMR, 7, 201 hydrolysis, 7, 216 inversion stability, 7, 200... 

Here a typical property of three-membered rings wdth two hetero atoms is shown and this property is also found in the diaziridines. Only with the oxaziranes which are substituted by aryl groups in the 3-position does the hydrolysis by acids occur according to Eq. (14) with formation of an aromatic aldehyde and alkyl hydroxylamine. 

Diaziridines are decomposed on acid hydrolysis into 1 mole of carbonyl compound and 1 mole of a hydrazine. This shows the presence... 

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 hydrolysis of the diaziridine 34 to the cyclic hydrazonium salt 61 [Eq, (49)] occurs quantitatively. Hydrolysis of the diaziridino-triazolidine (37) gives 3 moles of aldehyde and 1 mole each of hydrazine and ammonia [Eq. (50)]. ... 

The hydrolysis of l-alkyl-2-acyldiaziridines to A -alkyl-A -acyl-hydrazines possesses preparative interest. For example, A -cyclohexyl-A" -toluenesulfonylhydrazine [Eq. (51), yield 67% ] and 1-cyclohexyl-4-phenylsemicarbazide [Eq, (52) yield 73%] can be prepared by hydrolysis of the substituted diaziridines 46 and 62. ... 

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). 

Photolysis of l,6-dimethylpyridazinium-3-olate (137 R = R = Me, R = R" = H) in water gives 2,6-diniethylpyridazin-3-one (140), whereas irradiation in acetonitrile solution gives the fused diaziridine 141 which is converted into compound 140 by water. This transformation (141 - 140) probably involves initial hydrolysis of the amide bond (see Section III,B,7). ... 

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