- Method for synthesizing musk xylene from gamma-lactone byproduct azeotrope
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The invention discloses a method for synthesizing musk xylene from a gamma-lactone byproduct azeotrope. The method comprises the following steps: 1, carrying out chlorination reaction on tert-butyl alcohol namely a byproduct in the production process of gamma-lactone and hydrochloric acid to obtain chloro-tert-butane; 2, carrying out a condensation reaction on chloro-tert-butane and m-xylene, neutralizing, washing with water, and distilling to recover m-xylene so as to obtain 1,3-dimethyl-5-tert-butyl benzene; and 3, carrying outnitration reaction on 1,3-dimethyl-5-tert-butyl benzene to obtain a musk xylene crude product, carrying out neutralization washing, crystallization, centrifugation and a series of separation and purification to obtain a 99% musk xylene product. An initiator di-tert-butyl peroxide used in the production process of gamma-lactone is hydrolyzed, the high-content musk xylene is prepared from the generated byproduct 80% tert-butyl alcohol and a water azeotrope starting raw material through chlorination, condensation and nitration reactions, the synthesis steps are relatively simple, and the byproduct resources are comprehensively utilized.
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Paragraph 0044; 0050-0053; 0059; 0065-0068
(2021/04/17)
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- Examination of the Dynamic Covalent Chemistry of [2 + 3]-Imine Cages
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The synthesis of shape-persistent organic cage compounds by the formation of imine bonds opens the possibility to realize cages of different sizes, geometries, topologies, and functions. It is generally assumed that the imine bond is rather chemically labile allowing a self-correction mechanism until thermodynamic equilibrium is reached, which is often the case if a cage is formed. However, there are some contradictory experimental data to this assumption. To get a deeper insight into the imine bond dynamics of covalent organic cages, we studied the formation and exchange of both dialdehydes and triamines of two different [2 + 3] imine cages with the aid of a deuterated dialdehyde molecular building block.
- Schick, Tobias H. G.,Rominger, Frank,Mastalerz, Michael
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p. 13757 - 13771
(2020/12/15)
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- A tubular reactor for the preparation of 5 - tert-butyl m-xylene method (by machine translation)
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The invention discloses a tubular reactor for the preparation of 5 - tert-butyl m-xylene method, comprises the following steps: S1, preparation auxiliary catalyst; S2, the auxiliary catalyst and aluminum trichloride is blended into the composite catalyst, the composite catalyst and meta-xylene mixed to obtain the raw material A, B [...] butyl chlorine as the raw material, the raw material A and B respectively adopt two feeding manner to feed reaction; S3, to the reaction solution after the reaction post processing to obtain 5 - tert butyl m-xylene product. The invention greatly shortens the reaction time, significantly increases the conversion rate, reduce the formation of by-products, with simple and clear operation, safety and reliability, the prepared 5 - tert-butyl-xylene yield of 95% or more, more traditional technique improves the 20% or more, has solved the traditional kettle type reactor in the process of the impact of the back, and the problem of charge and the ex-denning is difficult. (by machine translation)
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Paragraph 0017-0031
(2019/03/23)
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- Access to "friedel-Crafts-Restricted" tert -alkyl aromatics by activation/methylation of tertiary benzylic alcohols
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Herein we describe a two-step protocol to prepare m-tert-alkylbenzenes. The appropriate tertiary benzylic alcohols are activated with SOCl2 or concentrated HCl and then treated with trimethylaluminum, affording the desired products in 68-97% yields (22 examples). This reaction sequence is successful in the presence of a variety of functional groups, including acid-sensitive and Lewis-basic groups. In addition to t-Bu groups, 1,1-dimethylpropyl and 1-ethyl-1-methylpropyl groups can also be installed using this method.
- Hartsel, Joshua A.,Craft, Derek T.,Chen, Qiao-Hong,Ma, Ming,Carlier, Paul R.
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p. 3127 - 3133
(2012/05/20)
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- Nickel-catalyzed Kumada cross-coupling reactions of tertiary alkylmagnesium halides and aryl bromides/triflates
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We report a Ni-catalyzed process for the cross-coupling of tertiary alkyl nucleophiles and aryl bromides. This process is extremely general for a wide range of electrophiles and generally occurs with a ratio of retention to isomerization >30:1. The same procedure also accommodates the use of aryl triflates, vinyl chlorides, and vinyl bromides as the electrophilic component.
- Joshi-Pangu, Amruta,Wang, Chao-Yuan,Biscoe, Mark R.
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supporting information; experimental part
p. 8478 - 8481
(2011/06/25)
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- Preparation of 5-tert-butyl-metaxylene using a solid active clay catalyst
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Alkylation of metaxylene with isobutylene using a solid active clay catalyst produces 5-tert-butyl-metaxylene with high isomer selectivity with respect to 4-tert-butyl-metaxylene. The process is controlled to extend catalyst life and significantly reduce environmentally unfriendly waste.
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- Rhenium complexes-catalyzed alkylation of arenes with alkyl halides
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Rhenium complexes have been shown to catalyze the alkylation of arenes with alkyl halides. When arenes were reacted with an alkyl chloride in the presence of a catalytic amount of rhenium complexes, such as bromopentacarbonylrhenium(I) [ReBr(CO)5], tricarbonylcyclopentadienylrhenium(I) [Re(C5H5)(CO)3] and decacarbonyldirhenium [Re2(CO)10], alkylation of the arenes proceeded under mild conditions to give a mixture of mono- and dialkyl substituted arenes in moderate-to-good yields.
- Nishiyama,Kakushou,Sonoda
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p. 2779 - 2782
(2007/10/03)
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- Selective alkylation of xylenes by alcohols on zeolite catalysts
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The peculiarities of catalytic performance of crystalline aluminosilicates of different types and compositions (X, Y including dealuminated Y′, mordenite, pentasil ZSM-5), as well as of amorphous aluminosilicate catalyst in conversion of xylene + alcohol mixtures were studied. New data were obtained for alkylation of o-xylene with tert-butyl alcohol, concerning controlling the selectivity and stability of the zeolite catalysts in reactions proceeding with the participation of water, including the water evolved during the reaction, in particular by controlling the acidic properties and hydrophobycity of the zeolites. A catalyst ensuring production of 1,2-dimethyl-4-tert-butylbenzene (DMTBB) with a 94% yield and selectivity of alcohol conversion to the target product of 94-97% was developed. The catalyst can be used as the basis for a high-performance and environmentally safe method for the synthesis of DMTBB. The catalysts developed can be also used for selective alkylation of o-xylene by C3-C5 alcohols and for alkylation of m-xylene by tert-butyl alcohol.
- Isakov,Minachev,Kalinin,Isakova
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p. 2763 - 2768
(2007/10/03)
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- Aromatic alkylation by gaseous Me3C+ ions. Kinetic role of deprotonation of intermediate arenium ions
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The alkylation of m-xylene by Me3C+ ions has been studied in the gas phase with the aim of assessing the kinetic role of proton transfer from intermediate arenium ions. Hydrogen kinetic isotope effects (KIEs) emerging from the reaction of m-xylene-4-d and of m-xylene/m-xylene-d10 mixtures have been exploited as mechanistic probes. The Me3C substitution at the 4-position displays a base-strength-dependent KIE related to rate-determining deprotonation of arenium intermediates. The Me3C+ reaction at the 5-position is instead characterized by a base-independent KIE due to 1,2-hydrogen shift to form a highly stable isomeric arenium ion. When the latter species originates from m-xylene-4-d, its neutralization involves an intramolecular competition of proton vs deuteron abstraction, manifesting a net primary KIE. Factors affecting its magnitude and base-strength dependence are discussed.
- Crestoni, Maria Elisa,Fornarini, Simonetta
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p. 5873 - 5879
(2007/10/02)
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- Metacyclophanes and Related Compounds. Part 16. Preparation of 8-Fluoro-t-butylmetacyclophanes and their Treatment with Aluminium Chloride-Nitromethane in Benzene
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The preparation of 8-fluoro-t-butylmetacyclophanes (5) are described.Dithiametacyclophane (3) and metacyclophane bis(sulphones) (4) were obtained as a mixture of transoid and cisoid conformers, but metacyclophanes (5) were exclusively obtained as the transoid conformer after pyrolysis of the sulphones (4).AlCl3-MeNO2-Catalyzed trans-t-butylation of 8-fluoro-16-methyl-5,13-di-t-butylmetacyclophane (5a) in benzene under a variety of conditions faild to give 8-fluoro-16-methylmetacyclophane (32) but, instead, the tetrahydropyrenes (33) and/or (34) were obtained depending upon the conditions used.Internally substituted metacyclophanes were isomerized to the strainless metacyclophanes and these were then oxidized to the tetrahydropyrene (33).
- Yamato, Takehiko,Arimura, Takashi,Tashiro, Masashi
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- Catalysis of Friedel-Crafts Alkylation by a Montmorillonite Doped with Transition-Metal Cations
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Catalysts are obtained by exchange of the interstitial cations in the K10 montmorillonite.They are applied to Friedel-Crafts alkylations with halides, alcohols, and olefins.They are quite effective even with unactivated hydrocarbons.Isomer distribution depends little on the catalyst used.Thermodynamic equilibration does not take place, the reactions appear to be kinetically controlled.Efficiency of the catalysts bears no apparent relation to that of the corresponding Lewis acids under homogeneous conditions, and it depends on the nature of the alkylating agent.Zr(IV) and Ti(IV), in general, give the best results.
- Laszlo, Pierre,Mathy, Arthur
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p. 577 - 586
(2007/10/02)
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- Process for the preparation of 2,6-dialkylaniline from brominated dialkyl t-butylbenzene
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A process for the preparation of 2,6-dialkylaniline which comprises the reaction of 1,3-dialkyl-5-tertiary-butylbenzene with molecular bromine to form 2-bromo-1,3-dialkyl-5-tertiary-butylbenzene, which is subsequently reacted with 1,3-dialkylbenzene in the presence of hydrogen fluoride to form a mixture of 2-bromo-1,3-dialkylbenzene and 1,3-dialkyl-5-tertiary-butylbenzene, which is then reacted with ammonia in the presence of a catalytic amount of cuprous halide.
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