Sodium hydroxide, as solvent

It is reported that the two-phase carbonylation methodology has been used on a pilot plant scale by Montedison [31 ] for the conversion of benzyl chloride to phenylacetic acid for use in perfume constituents and pesticides (eq. (8)). The carbonylation is run in a biphasic medium employing diphenyl ether and aqueous 40 % sodium hydroxide as solvents. The catalyst system consists of a cobalt carbonyl complex and a benzyltrialkylammonium surfactant. The reaction takes place at low temperature and CO pressure, while benzyl chloride is added continuously to the reaction mixture. 

Similar results were also obtained by Ju and Varma in the synthesis of tertiary amines from the corresponding alkyl halides and primary or secondary amines (Scheme 6.115 b) [228]. Here, water was used as a solvent and 1.1 equivalents of sodium hydroxide as a base. 

When TBAB is used as a phase-transfer catalyst, sodium hydroxide as a base, and DCE as a solvent, both the molecular weight and yield of the poly(carbonate) are relatively high. Bisphenol AF-derived poly(carbonate) (2) having reduced viscosity of 0.35 dl/g is obtained in a 84% yield at ambient temperature under the... 

As the supported glycol catalysts worked better in promoting reactions in a single solvent system, we explored the direct carbonylation of benzyl halides using an alcohol solvent, base, and cobalt carbonyl. Our initial experiments concentrated on the reaction of benzyl bromide at room temperature and one atmosphere carbon monoxide. We chose sodium hydroxide as the base, methanol as the solvent, and looked at the product distribution. We were interested in the selectivity to ester and the reactivity of this system. The results are given in Table III. 

The general feature of alkylation reactions at a carbon atom is that they can be achieved under sonication using solid bases even in apolar solvents. The advantage is that side reactions are generally minimised. Deprotonation occurs readily on a benzylic position in the presence of aqueous sodium hydroxide, as shown with indene (Eq. 3.21) [117]. A quantitative yield of the alkylated product can be obtained using sonication in the presence of a PTC. It was suggested that alkylation of cyclopentadiene or indene by secondary or tertiary alkyl halides in the presence of potassium hydroxide and Ali-quat occurred via a SET process [118]. 

BOC-Amino acids. Chemists at Fluka- have prepared many of these useful derivatives of amino acids by reaction with this reagent in aqueous organic solvents with sodium hydroxide as base. In general yields arc 65 -95%. 

The addition of hydroxide ions to substituted benzaldehydes (ArCHO + OH <=> ArCH(0H)0 ) is used to establish J-acidity scales in water-ethanol and water-DMSO mixtures containing sodium hydroxide as a base. The pK-values in such mixtures are linearly correlated with Hammett substituent constants. The independence of reaction constant p of solvent composition confirms that substituted benzaldehydes are suitable J- indicators for hydroxide solutions in water-ethanol and water-DMSO mixtures. Dependence of J- values on sodium hydroxide concentration is only slightly affected by ethanol up to 90 % and at a constant sodium hydroxide concentration shows only small increase between 90 and 98 % ethanol. J- increases more with increasing DMSO concentration, but the effect is much smaller than that of DMSO on H- values based on proton abstraction from aniline. 

The optimal reaction conditions for reactions involving catalyst 33 and substrates 16a-c or 34 were investigated, and it was found that best results were obtained at room temperature [36] with toluene as the solvent [37] and with sodium hydroxide or sodium hydride as the base. In particular, the use of potassium hydroxide always gave lower enantioselectivities than sodium hydroxide, and lithium hydroxide was not effective in these reactions. Attempts to use aqueous sodium hydroxide as the base under liquid-liquid phase-transfer conditions resulted in the formation of a negligible amount of product [33,34]. An important finding of these optimization studies was the presence of a significant background reaction [38], Hence, one role of catalyst 33 must be to enhance the reactivity of an enolate when it is coordinated to the catalyst relative to the uncoordinated enolate. 

The successful extension of this asymmetric reaction to the use of allyl halides (instead of benzyl halides) was also reported by the Metzner group [208]. The desired vinyl oxiranes were formed in a one-pot reaction starting from an allyl halide and an aromatic aldehyde in the presence of a sulfide, e.g. 215, and sodium hydroxide as base. A 9 1 mixture of tert-butanol and water was used as solvent. 

It is difficult to make water-soluble peptides form complexes with titanium alkoxide, because they are not soluble in organic solvents. Therefore, such templates cannot be imprinted by the complexation approach. Instead, they could be imprinted in Ti02-gel films by the alternate adsorption approach with Ti(0 Bu)4. Figure 6.24a shows a plot of alternate layer-by-layer assembly of 100 mM titanium butoxide (3 min adsorption in toluene/ethanol) and 10 mM glycyl-L-tyrosine (Gly-L-Tyr, 10 min adsorption in water). The template molecule was removed by treatment with 10 mM aqueous sodium hydroxide, as... 

The early work from this laboratory has been extended to include a large number of solvents which could be used to decontaminate hair externally contaminated with cocaine (Figures 19b and c). After exposure to cocaine (5 Xg/mL in 10 mM phosphate, pH 5.6), the Caucasian brown hair was washed five times with water and then dried. Quantitation was done using radiotracers, as previously described." Each sample was decontaminated with the experimental solution for a period of 1 h. The remaining cocaine in the hair was determined after digestion with sodium hydroxide. The solvents most efficient in removing cocaine were 0.1 M HCl and dimethylformamide. However, even these solutions left approximately 30% of the externally applied cocaine in the hair. 

Alkylation of aldehydes and -keto esters, This reaction can be conducted by use of solid-liquid phase-transfer catalysis using powdered sodium hydroxide as base and benzene as the solvent. Under these conditions aldehydes with only one a -hydrogen, such as isobutyraldehyde, are alkylated in reasonable yield even by less reactive halides (equation I). 

The saponification (transesterification) of a copolymer of vinyl acetate and silicone is performed in an alcoholic solvent (like methanol) with, for example, sodium hydroxide as catalyst. This leads to a silicone-modified polyvinyl alcohol. Depending on the saponification conditions, a new copolymer of vinyl alcohol and silicone (z = 0) or a new terpolymer of vinyl alcohol, vinyl acetate, and silicone (z > 0) is obtained. A schematic structural formula is given in Fig. 3. 

CuO nanoparticles with an average size of ca. 4 nm have been successfully prepared by microwave irradiation, using copper(II) acetate and sodium hydroxide as the starting materials and ethanol as the solvent [202]. The as-prepared CuO nanoparticles have regular shape, narrow size distribution and high purity. The band gap is estimated to be 2.43 eV according to the results of the optical measurements of the CuO nanoparticles. 

The chemistry of sulfones is dominated by the reactions of sulfonyl carbanions. The sulfone group has a unique ability to facilitate deprotonation of attached alkyl, alkenyl and aryl groups and will permit multiple deprotonation to yield polyanions. These properties, combined with the relative intertness of the sulfone (S02) group to nucleophilic attack, have made the S02 group the first choice for stabilisation of carbanions and account for the extensive application of sulfones in synthesis. Sulfonyl carbanions can be generated and reacted under a wide variety of conditions extending from aqueous phase transfer reactions using sodium hydroxide as base to the use of alkyllithiums in polar aprotic solvents. The reactivity of sulfonyl carbanions depends on the nature of the metal counterion (Li+, Na+, K+ and Mg2+ are the most important ones) and the presence of additives, e.g. TMEDA, HMPA and Lewis acids. 

Permethylation of polysaccharides. Kuhn and Trischmann found that polysaccharides can be methylated very efficiently in DMSO with dimethyl sulfate and barium oxide and/or barium hydroxide. Srivastava et al. used the same method except for the substitution of sodium hydroxide as base. Sodium hydroxide pellets and dimethyl sulfate were added with stirring under nitrogen over 8 hrs. to a solution of undegraded stareh in dimethyl sulfoxide. After stirring for another 16 hrs. the mixture was heated to decompose the dimethyl sulfate, cooled, diluted, and neutralized, and the product was extracted with chloroform and precipitated from acetone with ether yield 91%, OCHa = 42.3%. Here the high solvent power of DMSO clearly contributes to the solvent effect. 

Dichlorocyclopropanes have been converted to l,l-bis(phenylsulfanyl)cyclopropanes in good yield under phase-transfer conditions using sodium hydroxide as base, benzene as organic solvent, and tetrabutylammonium bromide or benzyltriethylammonium chloride as catalyst. Typically, ler/-butyl 2,2-bis(phenylsulfanyl)cyclopropanecarboxylate (3) was obtained in 71 /o yield from tert-butyl 2,2-dichlorocyclopropanecarboxylate by this method. ... 

Kabalka and coworkers reported only a 50% yield of the ditosylate in pyridine using 2 eq of tosyl chloride, and the recovered material was a mixture of the desired ditosylate and the corresponding chloride (Kabalka et al., 1986). These authors reported that better results were obtained using chloroform as the solvent with some pyridine as the base. Other methods for the preparation of the ditosylate esters, such as using dioxane and water with sodium hydroxide as the base, have been used (Cornforth et al., 1973 Ouchi et al.,... 

Hyperbranched PPEs with phenolic terminal groups can be prepared from 4-bromo-4, 4"-dihydroxytriphenylmethane via a modified Ullmann reaction. The monomer is treated with potassium carbonate or sodium hydroxide as a base. Copper chloride is used as a catalyst in an aprotic solvent, namely, dimethyl sulfoxide or sulfolane. The degrees of branching reach from 48-71%. The phenoUc end groups can be easily modified. 

The self-ionization of water provides the basis for a convenient method for expressing numerically just how acidic or basic any water solution is. You may have seen this quantity in use for a consumer product, for example, on the label of a pH-balanced shampoo. (The term refers to a controlled acidity of the solution, so that it is less likely to damage hair.) To understand what pH is requires understanding how to express the concentration of a solution, which is the quantity of a solute dissolved in a specific quantity of solvent or solution. We might give the concentration of a solution of sodium hydroxide as 4.0 g/L, that is 4.0 g of NaOH per liter of solution. In chemistry, however, because of its relation to quantities of chemicals in reactions (Section 8.2), concentration based on the mole is preferred. 

Polyearbonates were prepared by a two-phase eondensation of TCP with bisphenol S. They preeipitate from chlorinated hydrocarbon solvents such as DCM, TCM and DCE. According to bofli flie yield and the inherent viscosity ofthese polymers, the use of BTEAC as a phase-transfer catalyst, sodium hydroxide as a base and DCE as an organic solvent was suitable to prepare a polycondensate having a large molar mass and a high yield. 

Isophthaloyl dichloride and m-phenylene diamine dihydrochloride with trimethylamine hydrochloride as catalyst, dimethylacetamidc as solvent, and sodium hydroxide as HCl scavenger produce a polyamide by polycondensation that can only be spun from its solution in dimethyl acetamide after addition of 3% CaCl2 because of the high melting temperature of 375° C for the polyamide. The nondyeable yarn and fibers can be used for industrial purposes, for example as filter cloths for hot gases or for paper for electrical insulation. 

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