Anisole as solvent

LaY zeolites show good activity in the acylation of anisole as solvent reagent with AC and AAN. The activity of LaY zeolite is dependent on the lanthanum(III) content increased yield of para-product is found for high levels of lanthanum(III) exchange [60% yield of para-acetylanisole with 93% lanthanum(III) exchange]. 

The intermediacy of palladacycles in the reaction of bromobenzene with norbornene in the presence of Pd(PPh3)4 as catalyst and KOAc as a base in anisole as solvent was initially suggested by the isolation, among other products, of two compounds (Eq. 9), the former resulting from norbornene insertion into an alkylpalladium bond, the latter clearly deriving from palladium migration from the alkyl to the aryl site and double norbornene insertion. In both cases the termination step involved p,y-C-C bond cleavage followed by P-H elimination. The stereochemistry of the norbornane unit invariably was exo [19]. 

The checkers distilled the anisole from calcium sulfate before use. This reagent functions not only as a reactant, but also as solvent. In some similar preparations the intermediate trichloride is rather insoluble, as in the case of bis(3-methyl-4-methoxyphenyl)tellurium dichloride. The addition of co-solvents such as bis-(2-methoxyethyl) ether is beneficial. ... 

Anisole and mixtures of diethyl ether with aromatic hydrocarbons have both been widely employed as solvents for these reactions. Ethers other than diethyl ether and anisole have also been successfully used (cf. refs. 14-17). Hcxamethylphosphorotriamide has recently been used as a solvent for indole Grignard reactions. Young and Mizianty have recently described the use of an aromatic magnesium halide (phenylmagnesium bromide) for the synthesis of indole magnesium bromide. 

At stage 1 of the synthesis, m-bromoanisole [1] and n-butyUithium are converted via bromo/lithium exchange in order to obtain m-lithium anisole [2] and n-bromobutane. At stage 11, the reaction mixture is treated with dimethylformamide, and then the reaction is quenched using 3 M hydrochloric acid. Tetrahydrofurane is used as solvent at both synthetic stages. 

Thioanisolc. A system utilizing thio-anisole as an organic mediator was developed for the oxidation of secondary alcohols to ketones (Fig. 5 2-octanol to 2-octanone 99%, menthol to menthone 92%, cyclododecanol to cyclododecanone 75%) [43]. The use of 2,2,2-trifluoroethanol as a solvent in the mediatory system improved the yields [44]. 

A solution of 26.6 g 3,4-diethoxyphenol in 50 mL MeOH was mixed with another containing 9.6 g KOH pellets dissolved in 200 mL hot MeOH. There was then added 21.4 g methyl iodide, and the mixture was held at reflux for 2 h on the steam bath. This was then quenched in 3 volumes of water, made strongly basic with 25% NaOH, and extracted with 3x 150 mL CH2C12. Evaporation of the solvent from the pooled extracts gave 19.3 g of 1,2-diethoxy-4-methoxybenzene (3,4-diethoxy-anisole) as a clear, pale amber oil that solidified when cooled. The mp was 20-21 °C. 

To a solution of 9.7 g 3-ethyl-4-(methylthio)phenol in 50 mL MeOH there was added a solution of 4.6 g 85 % KOH in 50 mL hot MeOH. There was then added 5.4 mL methyl iodide and the mixture was held at reflux on the steam bath for 18 h. Removal of the solvent under vacuum gave a residue that was poured into 1 L H20 and made strongly basic by the addition of 5 % NaOH. This was extracted with 3x75 mL 01,0, and the extracts were pooled and the solvent removed under vacuum. There remained 11.0 g of an almost white oil with a startling apple smell. This oil was distilled at 78-88 °C at 0.3 mm/Hg to give 7.9 g 3-ethyl-4-(methylthio)-anisole as a white oil. Anal. (C10H14OS) C,H. 

As would be expected, high rate accelerations can result when reactions proceeding through ionic intermediates, e.g. carbocations, are performed in ionic liquids. For example, Seddon and coworkers [100] studied the Friedel-Crafts acylation of toluene, chlorobenzene (Fig. 7.30) and anisole with acetyl chloride in [emi-m][Al2Cl7], whereby the ionic liquid is acting both as solvent and catalyst. They ob-... 

Cobalt(II) salts are effective catalysts for the oxidation of 1,2-glycols with molecular oxygen in aprotic polar solvents such as pyridine, 4-cyanopyridine, benzonitrile, DMF, anisole, chlorobenzene and sulfolane. Water, primary alcohols, fatty acids and nitrobenzene are not suitable as solvents. Aldehydic products are further oxidized under the reaction conditions. Thus, the oxidative fission of rram-cyclo-hexane-l,2-diol gives a mixture of aldehydes and acids. However, the method is of value in the preparation of carboxylic acids from vicinal diols on an industrial scale for example, decane-1,2-diol is cleaved by oxygen, catalyzed by cobalt(II) laurate, to produce nonanoic acid in 70% yield. ... 

Electrochemical methods for the reduction of aromatic substrates utilizing ammonia and amines as solvents with lithium salts as electrolytes have been successful. Toluene was reduced to the 2,5-dihydro derivative in 95% yield in methylamine-lithium chloride if an undivided cell was used, while a 53 47 mixture of 3- and 4-methylcyclohexenes was formed in a divided cell.. Of greater interest, however, are attempts to achieve these reductions in aqueous media. In one experiment utilizing a two-phase mixture of substrate in aqueous tetra-n-butylammonium hydroxide and a mercury cathode, anisole was reduced on a preparative scale (15 g) to its 2,5-dihydro derivative in 80% yield. The optimal temperature for most reductions appeared to be 60 °C and under these conditions, even suspensions of high molecular weight substrates could be successfully reduced, e.g. steroid (226) afforded a >90% chemical yield of (227). Much higher coulombic yields were obtained when a small amount of THE was added to the mixture, however. 

Dibutyl ether is the only solvent suitable for this reaction. Dibutyl ether has relatively low volatility and complexes with trimethylaluminum without solvent decomposition. Dibutyl ether complexes with BBr, sulTiciently strongly to slow the rate of reaction ofBBrj with AIMe, to a safe rate. Boron tribromide reacts explosively with trimethylaluminum in diethyl ether or anisole solutions because of the weak complexation between these solvents and BBr,. Tetra-hydrofuran and p-dioxane undergo decom X)sition reactions with trimethylaluminum, and thus are unsuitable as solvents in this synthesis. 

A kinetic study of the acylation of phenol with phenyl acetate was carried out in liquid phase at 160°C over HBEA zeolite samples, sulfolane or dodecane being used as solvents. The initial rates of hydroxyacetophenone (HAP) production were similar in both solvents. However the catalyst deactivation was faster in dodecane, most likely because of the faster formation of heavy reaction products such as bisphenol A derivatives. Moreover, sulfolane had a very positive effect on p-HAP formation and a negative one on o-HAP formation. To explain these observations as well as the influence of phenol and phenyl acetate concentrations on the rates of 0- and p-HAP formation it is proposed that sulfolane plays two independent roles in phenol acylation solvation of acylium ions intermediates and competition with phenyl acetate and phenol for adsorption on the acid sites. Donor substituents of phenyl acetate have a positive effect on the rate of anisole acylation, provided however there are no diffusion limitations in the zeolite pores. 

The only reactions which proceeded with good yields were those of phenanthrenequinone. With the exceptions of the steroid ethers, the ether was used as solvent and 1,4-adducts (87) could be isolated in high yield when irradiations were performed at A >3900 A. At shorter wavelengths the dioxane and anisole adducts rearranged to the corresponding 1,2-adducts (88), rearrangement of the anisole adduct being quite facile. The 1,4-adducts of aliphatic ethers were unstable in air 127>. 

Thus, it appears that a large excess of TFA should lead to the exclusive formation of p-trifluoroacetophenone. Indeed, a 80-fold excess of TFA (as solvent) leads to a 25 % yield of trifluoroacetophenone after one month at room temperature without formation of the dimer (the only other product being anisole). Under the same conditions, at 100°C in 15 days, the yield of p.trifluoroacetophenone is 96 % (eqn. 9). 

This document aims to review of the use of anisole as a solvent. 

Anisole, as a solvent, has been widely used in the Grignard reaction. 

Anisole as a solvent for the carbonylation reaction is described in many publications. 

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