- Ultrasound assisted arylation of benzyl alcohol with 4-nitrochlorobenzene under a new multi-site phase-transfer catalyst in solid-liquid condition
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The ultrasound assisted preparation of 1-(benzyloxy)-4-nitrobenzene from the reaction of 4-chloronitrobenzene (CNB) and benzyl alcohol was carried out successfully using potassium hydroxide and catalyzed by a new multi-site phase-transfer catalyst (MPTC) viz., 1,3,5-triethyl-1,3,5-trihexyl-1,3,5- triazinane-1,3,5-triium trichloride in a solid-liquid reaction condition (SL-MPTC). The advantage of using SL-MPTC is to avoid a serious hydration of potassium salt of benzyl alcohol in the reaction between 4-chloronitrobenzene (CNB) and benzyl alcohol. The reaction is greatly enhanced in the solid-liquid system, catalyzed by multi-site quaternary ammonium salt (MPTC) and ultrasound irradiation (40 kHz, 300 W) in a batch reactor, it shows that the overall reaction greatly enhanced with ultrasound irradiation than without ultrasound. The reaction mechanism is proposed and verified by examining the experimental evidence. A kinetic model is proposed in which a pseudo first-order rate law is sufficient to describe the results, such as the effects of agitation speed, ultrasound, different phase transfer catalysts and the effect of organic solvents, the amount of newly prepared MPTC, the effect of temperature, the amount of water, the concentration of 4-chloronitrobenzene (CNB) and potassium hydroxide concentrations. The apparent rate constant (kapp) were investigated in detail. Rational explanations to account for the phenomena on the results were made.
- Selvaraj, Varathan,Abimannan, Pachaiyappan,Rajendran, Venugopal
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p. 1805 - 1814
(2014/06/09)
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- Synthesis of N-substituted 1,3,5-triazacyclohexanes catalyzed by starch sulfuric acid
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N-substituted 1,3,5-triazacyclohexanes were simply synthesized from the reaction of aromatic or fatty amines and formaldehyde catalyzed by recyclable starch sulfuric acid with good yields at room temperature.
- Wu, Hui,Yuan, Rui,Wan, Yu,Yin, Wei,Pang, Li-Ling
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experimental part
p. 1097 - 1102
(2012/03/11)
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- Oligomerization catalyst
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An oligomerization catalyst for olefins is obtainable from a) a chromium compound CrX3 and the at least equimolar amount, based on the chromium compound CrX3, of a ligand L or from an existing chromium complex CrX3L, in which the groups X are, independently of one another, abstractable counterions and L is a 1,3,5-triazacyclohexane of the formula I ?where the groups R1 to R9 are, independently of one another: hydrogen or organosilicon or substituted or unsubstituted carboorganic groups having from 1 to 30 carbon atoms, where two geminal or vicinal radicals R1 to R9 may also be joined to form a five—or six-membered ring, andb) at least one activating additive and also a process for preparing oligomers of olefins using these catalysts, the oligomers thus obtainable, and the oxo alcohols obtainable from these oligomers.
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- OLIGOMERISATION CATALYST
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An oligomerization catalyst for olefins is obtainable froma) a chromium compound CrX3 and the at least equimolar amount, based on the chromium compound CrX3, of a ligand L or from an existing chromium complex CrX3L, in which the groups X are, independently of one another, abstractable counterions and L is a 1,3,5-triazacyclohexane of the formula Iwhere the groups Rto Rare, independently of one another: hydrogen or organosilicon or substituted or unsubstituted carboorganic groups having from 1 to 30 carbon atoms, where two geminal or vicinal radicals Rto Rmay also be joined to form a five-or six-membered ring, andb) at least one activating additiveand also a process for preparing oligomers of olefins using these catalysts, the oligomers thus obtainable, and the oxo alcohols obtainable from these oligomers.
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Page/Page column 9
(2008/06/13)
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- REACTIONS OF DICHLOROMETHANE WITH THIOANIONS. 2. FORMATION OF 5-ALKYL-1,3,5-DITHIAZINANES, 3,5-DIALKYL-1,3,5-THIADIAZINANES, AND 1,3,5-TRIALKYL-1,3,5-TRIAZINANES BY REACTION OF DICHLOROMETHANE WITH SODIUM SULFIDE AND MONOALKYLAMINES
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The reaction of dichloromethane with sodium sulfide and monoalkylamines, catalyzed by polyethyleneglycol 1,500, is studied.A mixture of 5-alkyl-1,3,5-dithiazinane, 3,5-dialkyl-1,3,5-thiadiazinane, and 1,3,5-trialkyl-1,3,5-triazinane is obtained.The proportion of these heterocycles depends on the amine structure and the presence of sodium hydroxide. - Key words: 5-Alkyl-1,3,5-dithiazinanes; 3,5-dialkyl-1,3,5-thiadiazinanes; dichloromethane double substitution; polyethyleneglycol as catalyst
- Torres, Martin,Vega, Juan C.
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p. 125 - 130
(2007/10/03)
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- Dichloromethane as a Reactant in the Synthesis of 1,2,3,4-Tetrahydropyrimidine Derivatives
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5-p-methoxyphenyl-1,2-dithiole-3-thione (Sulfarlem) reacts with primary amines in dichloromethane to give in good yield 1,3-dialkyl-6-methoxyphenyl-1,2,3,4-tetrahydropyrimidine-5-carbothioamides.In this reaction dichloromethane serves as a C-1 unit donor yielding, in the presence of elemental sulphur, 1,3,5-trisubstituted 1,3,5-triazanes and 3,5-disubstituted 1,3,5-thiadiazanes.These Mannich-type compounds react with enamine intermediates to give the title products.
- Martens, Thierry,Souquet, Florence
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p. 1671 - 1683
(2007/10/02)
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- Alkylation of 6-mercaptopurine (6-MP) with N-alkyl-N-alkoxycarbonylaminomethyl chlorides: S6-(N-alkyl-N-alkoxycarbonyl)aminomethyl-6-MP prodrug structure effect on the dermal delivery of 6-MP
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The S6-(N-alkyl-N-alkoxycarbonyl)aminomethyl-6-MP (6-CARB-6-MP) prodrugs 5-20 were synthesized from the reaction of 6-MP weith N-alkyl-N-alkyoxycarbonylaminomethyl chlorides (4) in dimethyl sulfoxide in overall yields of 5-62%, depending on the N-alkyl and the alkoxy groups involved. The derivatives were fully characterized by spectral and micranalyses. The assignment of the substitution pattern as S6-alkyl was based on comparisons of the UV, 1H NMR and 13C NMR spectra with model compounds. A S6,9-bis-alkyl derivative was obtained from the reaction of 2 equivalents of 4 with 6-MP but the product was unstable and decomposed on standing to a 9-alkyl derivative. The 6-CARB-6-MP prodrugs reverted to 6-MP in water by an S(N)1-type mechanism involving unimolecular charge separation in the transition state of the rate determining step. There was no effect of dermal enzymes on the rate of hydrolysis. The solubilities in isopropyl myristate (IPM) for all of the 6-CARB-6-MP prodrugs were significantly greater than the solubility of 6-MP in IPM but only one prodrug (5) was apparently even as soluble as 6-MP in water. Selected 6-CARB-6-MP prodrugs were examined in diffusion cell experiments. Only the N-methyl-N-methoxycarbonyl derivative 5 gave a steady-state rate of delivery of 6-MP from IPM that was significantly greater than the steady-state rate of delivery of 6-MP from 6-MP in IPM. All the other derivatives gave steady-state rates of delivery of 6-MP from IPM that were either not significantly different, or were significantly lower than the rate obtained from 6-MP in IPM. In all cases, the effect of the 6-CARB-6-MP:IPM suspensions on the permeability of the skin, as determined by the second application flux of theophylline:propylene glycol, was of the same magnitude as the effect of IPM alone.
- Siver,Sloan
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- SYNTHESE D'IMINES LINEAIRES NON-STABILISEES PAR REACTIONS GAZ-SOLIDE SOUS VIDE(1).
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Unstabilized imines are synthetized in gram-scale by vacuum dehydrochlorination of N-chloroalkylamines and by vacuum dehydrocyanation of α-aminonitriles on solid base.All the new compounds are characterized at low temperature by 1H, 13C NMR and IR spectroscopy.
- Guillemin, Jean-Claude,Denis, Jean-Marc
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p. 4431 - 4446
(2007/10/02)
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- Reaction of Rifamycins with Hexahydro-1,3,5-triazines Prepared from Formaldehyde and Primary Aliphatic Amines
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Rifamicin S (1) and 25-O-deacetylrifamycin S reacted with 1,3,5-tributylhexahydro-1,3,5-triazine to give deep-blue compounds.The structures of the deep-blue compounds are discussed based on 13C NMR data, and it is concluded that the earlier structures should be partly re-revised.The mechanism of formation of the deep-blue compounds and the reaction of 1 with several hexahydro-1,3,5-triazines, which were prepared from formaldehyde and primary aliphatic amines, are also described.
- Taguchi, Masahiro,Aikawa, Norio,Tsukamoto, Goro
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p. 2431 - 2436
(2007/10/02)
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- Flash Vacuum Thermolysis of α-Aminonitriles and Subsequent HCN Removal on Solid Base, a 'One Line' Multistep Sequence to Reactive N-Methyleneamines
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Reactive methyleneamines bearing alkyl or functional groups are isolated at low temperature in the condensate state by flash vacuum thermolysis of α-aminonitriles and subsequent vapour phase HCN removal on solid base.
- Guillemin, J. C.,Denis, J. M.
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p. 951 - 952
(2007/10/02)
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