85267-33-0Relevant articles and documents
Preparation method of cyclic di-p-xylyene
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Paragraph 0038; 0039, (2016/10/07)
The invention discloses a preparation method of cyclic di-p-xylyen. The method mainly includes the steps of: taking p-xylene as the starting raw material, performing bromination to obtain p-methylbenzyl bromide, and then carrying out reaction with triethylamine to obtain a corresponding quaternary ammonium salt, and finally adding the quaternary ammonium salt into a system containing a mixed solvent, alkali liquor and a mixed catalyst dropwise, and carrying out reaction for certain period of time to obtain cyclic di-p-xylyene, and finally performing aftertreatment to obtain a cyclic di-p-xylyene pure product. The method provided by the invention has the advantages of cheap and easily available raw materials, short reaction time, strong continuity, high yield, high purity and small solvent consumption, etc., and can be used for large-scale production.
Gas-phase chemistry of benzyl cations in dissociation of N-Benzylammonium and N-benzyliminium ions studied by mass spectrometry
Chai, Yunfeng,Wang, Lin,Sun, Hezhi,Guo, Cheng,Pan, Yuanjiang
experimental part, p. 823 - 833 (2012/09/07)
In this study, the fragmentation reactions of various N-benzylammonium and N-benzyliminium ions were investigated by electrospray ionization mass spectrometry. In general, the dissociation of N-benzylated cations generates benzyl cations easily. Formation of ion/neutral complex intermediates consisting of the benzyl cations and the neutral fragments was observed. The intra-complex reactions included electrophilic aromatic substitution, hydride transfer, electron transfer, proton transfer, and nucleophilic aromatic substitution. These five types of reactions almost covered all the potential reactivities of benzyl cations in chemical reactions. Benzyl cations are well-known as Lewis acid and electrophile in reactions, but the present study showed that the gas-phase reactivities of some suitably ring-substituted benzyl cations were far richer. The 4-methylbenzyl cation was found to react as a Bronsted acid, benzyl cations bearing a strong electron-withdrawing group were found to react as electron acceptors, and parahalogen- substituted benzyl cations could react as substrates for nucleophilic attack at the phenyl ring. The reactions of benzyl cations were also related to the neutral counterparts. For example, in electron transfer reaction, the neutral counterpart should have low ionization energy and in nucleophilic aromatic substitution reaction, the neutral counterpart should be piperazine or analogues. This study provided a panoramic view of the reactions of benzyl cations with neutral N-containing species in the gas phase. American Society for Mass Spectrometry, 2012.
EFFECTS OF SUBSTITUENTS IN THE BENZYL BROMIDE ON THE KINETICS OF THE BENZYLATION OF AMINES
Shpan'ko, I. V.,Korostylev, A. P.,Rusu, L. N.
, p. 1715 - 1723 (2007/10/02)
The kinetics of the reactions of 3- and 4-substituted benzyl bromides with amines having various structures in nitrobenzene at 40 deg C were investigated.The 4-substituted benzyl bromides have higher reactivity compared with that calculated on the basis of the linear correlations according to the Hammett-Taft equation for unsubstituted and 3-substituted benzyl bromides containing electron-withdrawning substituents.The reactivity of benzyl bromides containing electron-donating substituents obeys a linear correlation with the ?+ constants.The effects of structural changes in the substrate and the nucleophile on the character of the transition states of the investigated reactions is discussed.
