- Kinetics and mechanism of conjugate aminomethylation and aralkylation of N,N-dimethylaniline with N,N,N′,N′-tetraalkyldiaminomethane in acetic acid medium
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The aminomethylation of N,N-dimethylaniline with N,N,N′,N′-tetraalkyldiaminomethanes in the medium of 90.0-99.6% acetic acid is accompanied by formation of the bis(4-dimethylaminophenyl)-methane. The amount of the latter grows with increased proportion of water in the system and also depends on the ratio substrate-reagent. Proceeding from kinetic data a mechanism of the process was suggested and confirmed by mathematical simulation. The essence of the mechanism consists in the concept that aminomethylation and aralkylation proceed via a common intermediate. The second among these reactions is catalysed with water.
- Kachurin,Zaraiskii,Velichko,Zaraiskaya,Matvienko
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p. 1650 - 1655
(2007/10/03)
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- Etudes sur les composes gem-diamines-V-Reactions d'anilines sur des composes gem-dimorpholines.
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A systematic study of gem-dimorpholino compounds, which produce aldehydes by hydrolysis, has shown that such compounds do indeed have aldehydic character and can be used in synthesis in place of the corresponding aldehydes.As part of this study we have examined the behaviour of such gem-dimorpholino compounds towards some nucleophilic reagents such as mercaptans, amides and anilines under acid conditions.We have found experimental conditions under which symmetrical geminal compounds are produced: dithioacetals, gem-bis(acylamino), gem-diamino and gem-diaryl compounds.We have thus developed several new synthetic methods which compare favourably with existing methods.In most cases we have been able to show that the reaction proceeds by an intermediate in which only one of the morpholino groups has been replaced by the nucleophile.In this paper we report on the condensation of some anilines with gem-dimorpholino compounds.N,N-dimethylaniline condenses with gem-dimorpholino compounds as with the corresponding aldehydes to give gem-diaryl compounds.The case of primary arylamines is remarkable for the different results obtained.As could be expected from our most recent results, most of the condensation products are complex mixtures which are either non-distillable and non-crystallisable oils or glassy solids with indistinct melting points.It is often impossible to isolate any pure chemical substance from these mixtures.We shall thus only describe certain cases: the behaviour of 2,6-xylidine is particularly interesting.Under certain conditions this aniline derivative can condense on the aromatic ring similarly to N,N-dimethylaniline.The initial product of the reaction is an aldimine or "anil".Benzaldimines which are stabilised by conjugation do not react further while phenylglyoxaldimines are transformed into gem-diaryl compounds by heating in acetic acid. 2,5-dimethoxyaniline also condenses by way of the aromatic ring to give a gem-diaryl compound but the corresponding aldimine could not be shown to be an intermediate. 2-nitro and 3-nitroaniline, in which the aromatic ring is deactivated, can only condense by the nitrogen atom to give gem-diamino compounds.In summary, we think that primary arylamines in acetic acid condense with gem-dimorpholino compounds preferentially on the nitrogen atom of the amino group.These compounds can subsequently, according to their stability, rearrange provided that the aromatic ring is activated by electron-donating substituents.It still remains to be determined if there is a definite point at which a primary aniline starts to act as an ambifunctional nucleophile.
- Floc'H, Yves Le,Morvan, Jean-Marcel,Brault, Auguste
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p. 157 - 162
(2007/10/02)
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