Benzyltrimethylammonium hydroxid reaction with

The increase in alkylation efficiency of HEC with quaternary ammonium hydroxide is not limited to DPGE. Experiments were conducted in which HEC was alkylated with 1-bromohexadecane (cetyl bromide), 3-n-pentadecenyl phenyl glycidyl ether (PDPGE)14, or 1,2-epoxyhexadecane (C]6 a-olefin epoxide) in the presence of either sodium hydroxide or benzyltrimethylammonium hydroxide. As before, the molar A/HEC ratio was 0.50, and the water content of the diluent in the benzyltrimethylammonium hydroxide experiment was decreased to compensate for the higher water content of the base so that the final water content of both reactions was the same (14.4%). The hexadecyl content of the polymers was measured by gas chromatography. The sodium hydroxide mediated reaction of 1-bromohexadecane yielded a hexadecyl alkylation efficiency of 0.5%, while the benzyltrimethylammonium hydroxide reaction yielded a hexadecyl alkylation efficiency of 6.2%. A twelve-fold increase in the hexadecyl alkylation efficiency was observed in the reaction conducted with the quaternary ammonium hydroxide. 

A sample of the monohydroperoxide, previously reported by Bickel and Kooyman (2), was obtained by autoxidation of 9,10-dihydroanthra-cene in benzene under ultraviolet irradiation. When this compound was treated under nitrogen with benzyltrimethylammonium hydroxide, it decomposed to give a mixture of anthracene and anthrone. (Under acidic conditions, it decomposed entirely to anthracene.) A fresh sample of the hydroperoxide was then oxidized. The physical appearance of the reaction mixture was similar to that in the oxidation of anthrone. The product was analyzed, and the conversion to anthraquinone was only 59%. Again, other oxidation products or anthrone may have contributed to the anthraquinone estimate. 

The phase transfer catalyzed alkylation reaction of dodecyl phenyl glycidyl ether (DPGE) with hydroxyethyl cellulose (HEC) was studied as a mechanistic model for the general PTC reaction with cellulose ethers. In this way, the most effective phase transfer catalysts and optimum reaction concentrations could be identified. As a model cellulose ether, CELLOSIZE HEC11 was chosen, and the phase transfer catalysts chosen for evaluation were aqueous solutions of choline hydroxide, tetramethyl-, tetrabutyl-, tetrahexyl-, and benzyltrimethylammonium hydroxides. The molar A/HEC ratio (molar ratio of alkali to HEC) used was 0.50, the diluent to HEC (D/HEC) weight ratio was 7.4, and the reaction diluent was aqueous /-butyl alcohol. Because some of the quaternary ammonium hydroxide charges would be accompanied by large additions of water, the initial water content of the diluent was adjusted so that the final diluent composition would be about 14.4% water in /-butyl alcohol. The results of these experiments are summarized in Table 2. 

Reaction of pirenperone 5 (R = H) with paraformaldehyde and 40% benzyltrimethylammonium hydroxide in methanol at 60-70°C in piperidine... 

Serum and bile thiocyanates are raised. See also HYDROCYANIC ACID. Unstable and easily oxidized. Explosive polymerization may occur on storage with silver nitrate. Potentially explosive reactions with benzyltrimethylammonium hydroxide + pyrrole, tetrahydrocarbazole + benzyltrimethylammonium hydroxide. Violent reactions with strong acids (e.g., nitric or sulfuric), strong bases, azoisobutyronitrile, dibenzoyl peroxide, di-tert-butylperoxide, or bromine. 

Preparation. The reagent is readily prepared by the condensation of benzil with dibenzyl ketone in the presence of a basic catalyst. Dilthey s original procedure, adopted by Organic Syntheses specifies ethanol as solvent and a solution of potassium hydroxide in ethanol as the base. This procedure suffers from the low boiling point of the alcohol and the limited solubility of both potassium hydroxide and the reaction product in ethanol. In an improved procedure - use of the better solvent triethylene glycol permits operation at a higher temperature, and use of the readily soluble benzyltrimethylammonium hydroxide as base eliminates the step of dissolving potassium hydroxide in ethanol, A mixture of 0.2 mole each of benzil and... 

Reaction of VI with Benzyltrimethylammonium Hydroxide. The hydroxide, 0.125 mmol, (60 mg of a 35% methanol solution) was placed in a tube and the methanol evaporated by warming at reduced pressure. Subsequent addition of 175 mg (0.5 mmol) of VI immediately resulted in the formation of a green color at the contact surface of VI and the solid hydroxide. Warming of the solid mixture to 100°C over a 10 minute period appeared to give complete reaction and heating was dlscontined. The i r spectrum showed greater than 95% decrease in cyano absorbtion and the visible spectrum showed no absorbance characteristic of phthalo-cyanine chromophore. 

Hauser et were able to isolate the intermediate dimeric halide when 9-chlorofluorene was allowed to react with only one equivalent of sodium amide in liquid ammonia. In t-butyl alcohol containing its potassium salt or a dilute aqueous solution of benzyltrimethylammonium hydroxide, the rate of formation of bifluorenylidene is second-order in 9-bromofluorene and first-order in the basicity of the reaction medium as measured by the ionisation of nitroaniline indicators . Under the same reaction conditions, protium exchange of 9-deutero-9-bromofluorene and elimination from 9-bromo-9,9 -bifluorenyl are much faster reactions than the conversion of 9-bromofluorene into bifluorenylidene. These facts are consistent with the displacement mechanism. 

Chiral, isomeric vinyl sulfoxides (88) and (89) were treated separately with benzyltrimethylammonium hydroxide. On cyclization of the proposed incipient amino-anion, (l s)-( )-(88) gave a 63 37 mixture of the diastereoisomeric isoquinolines (90) and (91). An enhancement and reversal of diastereoselectivity was observed on base hydrolysis of (/ s)-(Z)-(89). This reaction gave a 16 84 ratio of (90) (91) in 96% yield from which diastereoisomerically pure (91) was obtained in 78% yield after column chromatography. 

SM) with resaceto-phenone in the presence of potassium carbonate in refluxing acetone for 48 h (31%). SM was prepared by reaction of epichlorohydrin with 2,6-dihydroxyacetophenone in the presence of benzyltrimethylammonium hydroxide in dioxane at 100° for 72 h (37%, oil) [5875]. 

In 1995, Ando reported that a,p-unsaturated esters could be obtained with high Z selectivity from the HWE reaction of aldehydes with diphenylphosphonoacetates in the presence of benzyltrimethylammonium hydroxide (Triton B) or NaH in tetra-hydrofuran [182], Later, Ando [183-186], Motoyoshiya [187, 188], and Touchard [189, 190] further defined this protocol by modifying diphenylphosphonoacetates and found that the employment of bis(o-alkylphenyl)phosphonoacetates led to higher Z selectivity (Scheme 39). The combination of NaH and Nal has been identified as an effective base/additive system to improve the Z selectivity [191]. Moreover, the Ando modification has recently been applied to the ring closure of various macrolides with high Z selectivity, which is complementary to that of traditional intramolecular HWE reaction (Scheme 40) [192, 193]. 

A 500 mL round-bottom flask containing aqueous sodium hydroxide (25 or 50 wt%) and benzyltrimethylammonium bromide as the phase transfer agent (0.2 g, 0.0008 mole) was placed in a constant-temperature oil bath and heated to the reflux temperature of 165°C. Chopped nylon-4,6 fibers (6 g, 0.030 mol) were placed in the reaction flask. The reaction mixture was constantly stirred with a magnetic stirrer and the reaction was carried out at atmospheric pressure for a period of 24 or 36 h (see Table 10.3 for results). The aqueous sodium hydroxide solution containing products of depolymerization was concentrated by evaporation and 30 mL of 35% aqueous hydrochloric acid was added to the concentrate. The precipitate was filtered and washed with water. The product was dried in a vacuum oven at 120°C for 24 h. 

The title compound, K2 [Rh6(CO)i5C], has been prepared in about 70% yield by the reaction of Rh CO) with sodium hydroxide under carbon monoxide in methanol containing some chloroform.1 The benzyltrimethylammonium and jt-nitrido-bis(triphenylphosphorusX 1 +) [bis(triphenylphosphine)imminium] salts have been prepared by reaction of the corresponding [Rh(CO)4 ] salts with CC14.2... 

Alkylation of 4-tert-butylcalix[b]arene has been carried out in 94% yield with triethyleneglycol monomethyl ether 4-tosylate (TsOR) in the presence of benzyltrimethylammonium chloride and potassium hydroxide in chloroform /dichloromethane/methanol solution after stirring for 24 hours at 40°C (ref.42). The synthesis of a number of naphthyl ethers or their further reaction products has been summarised in Table 4.5 (refs.43-46). 

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