Potassium phenoxide

Cl Disperse Violet 26 is prepared by the reaction of l,4-diamino-2,3-dichloroanthraquinone (Cl Disperse Violet 28 (35)) with potassium phenoxide in phenol as a solvent at high temperature. Introduction of phenoxy groups into the 2,3-position shifts the shade to bright, reddish violet and improves the lightfastness and sublimation resistance. 

Hydroxybenzoic acid has been prepared by heating potassium phenoxide in a stream of carbon dioxide or with carbon tetrachloride, and by heating jfr-cresol with alkalies and various metallic oxides. The procedure described above is similar to one which appears in the early literature ... 

Nitrodiphenyl ether has been prepared by heating p-nitro-chlorobenzene with potassium phenoxide and phenoD and by the nitration of diphenyl ether. ... 

Condensation of dibromodifluoromethane or bromochlorodifluoromethane with potassium phenoxides usually needs an initiation by a thiol and occurs by an ionic chain mechanism [/5, 16 (equations 14 and 15)... 

The para-substituted product, which is not accessible from complex 3, can however be obtained from reaction of potassium phenoxide with carbon dioxide. 

Potassium phenoxide, which is less likely to form such a complex, " is chiefly attacked in the para position. " Carbon tetrachloride can be used instead of CO2 under Reimer-Tiemann (11-17) conditions. 

Sodium or potassium phenoxide can be carboxylated regioselectively in the para position in high yield by treatment with sodium or potassium carbonate and carbon monoxide. Carbon-14 labeling showed that it is the carbonate carbon that appears in the p-hydroxybenzoic acid product. The CO is converted to sodium or potassium formate. Carbon monoxide has also been used to carboxylate aromatic rings with palladium compoimds as catalysts. In addition, a palladium-catalyzed reaction has been used directly to prepare acyl fluorides ArH —> ArCOF. ... 

The trigonal planar zinc phenoxide complex [K(THF)6][Zn(0-2,6-tBu2C6H3)3] is formed by the reaction of a zinc amide complex, via a bis phenoxide, which is then further reacted with potassium phenoxide. TheoX-ray structure shows a nearly perfect planar arrangement of the three ligands with zinc only 0.04 A out of the least squares plane defined by the three oxygen atoms.15 Unlike the bisphenoxide complexes of zinc with coordinated THF molecules, these complexes are not cataly-tically active in the copolymerization of epoxides with C02. The bisphenoxide complex has also been structurally characterized and shown to be an effective polymerization catalyst. 43... 

The product is almost exclusively sodium o-hydroxybenzoate (salicylate, 71) only traces of the p-isomer being obtained if, however, the reaction is carried out on potassium phenoxide the salt of the p-acid becomes the major product. It has been suggested that the preferential o-attack with sodium phenoxide may result from stabilisation of the T.S. (72) through chelation by NaP in the ion pair ... 

Sodium 4-methylphenoxide solution was dehydrated azeotropically with chlorobenzene, and the filtered solid was dried in an oven, where it soon ignited and glowed locally. This continued for 30 min after it was removed from the oven. A substituted potassium phenoxide, prepared differently, also ignited on heating. Finely divided and moist alkali phenoxides may be prone to vigorous oxidation (or perhaps reaction with carbon dioxide) when heated in air. 

A relatively small amount of the p-compound is formed at the same time. It is remarkable that when potassium phenoxide is used the p-compound is the main product. 

The characteristics of homogeneous crown-ether catalysis were nicely demonstrated by Thomassen et al. (1971) who studied the rate of alkylation of potassium phenoxide with 1-bromobutane in dioxan at 25°C. By measuring the initial consumption of phenoxide (r, in M s-1), any effect of the bromide ion was neglected. The results (Table 21) show hardly any effect of tetraglyme... 

Crown ether-catalysed reaction of 1-bromobutane (0.05 or 0.1 M) with potassium phenoxide (0.02 M) in dioxan at 25°C ... 

Fig 2 Effect of Icrown etherl/lphenoxide) ratio on the alkylation of potassium phenoxide with... 

The arylation of potassium phenoxide has been studied by Litvak and Shein (1976). In the absence of crown ether the rate of reaction with p-nitrobromobenzene in various solvents increases in the order dioxan < methanol < pyridine < DMSO. In the presence of either 18-crown-6 [3] or dibenzo-18-crown-6 [11], the order of the reaction rates in dioxan and methanol is reversed (Table 22). The effect of crown ether addition on the rate... 

Reaction of potassium phenoxide with p-nitro-bromobenzene in the presence of 18-crown-6 [3] anddibenzo-18-crown-6 111] at 100°C ... 

By saturating the co-ordination sites of the cation with a crown ether, the relative contribution of the syn-pathway decreases, as was shown by Zavada et ai (1972) for t-BuOK-promoted eliminations from 5-decyl tosylate. Furthermore, trans/cis ratios in both anti- and syn-eliminations were affected by the presence of dicyclohexyl- 18-crown-6 and the nature of the leaving group (Zavada et ai, 1976). Fiandanese et ai (1973) observed that elimination from fluorosulphonylethanes [177] promoted by potassium phenoxide in dioxan... 

McKenzie and Sherrington 174) found that mixtures of solid sodium or potassium phenoxide, 1-bromobutane, and polyethylene glycol) bound to cross-linked polystyrene (54) in refluxing toluene gave good yields of butyl phenyl ether (Eq. (10)). 

Trace amounts of water in the 1-bromobutane/potassium phenoxide mixture aided the reaction as shown in Table 13 178). Specially dried reactants (by methods... 

A variety of other substituents on the chain ends of polyethylene glycol) grafted onto polystyrene have been investigated for catalysis of the reaction of 1 -bromobutane and solid potassium phenoxide. The apparent activities of 2 % CL, 14% RS catalysts 56 (n = 4) wereZ = 2-(l,4-benzodioxanylmethyl) < tetrahydrofuran-2-yl < 2-pyri-dylmethyl < p-toluenesulfonyl < 8-quinolyl < 2-pyrrolidinon-l-yl < 2-methoxy-phenyl < 2-naphthyl179). 

Substrate selectivity effects were investigated with polystyrene-supported polyethylene glycol) catalysts 51 (n = 3,61% RS) and 56 (Z = phenyl, n = 30, 8 % RS) under solid/solid/liquid conditions 180). The difference in rates of reaction of 1-bromobutane and 1-bromooctane with solid potassium phenoxide was a factor of about 3 (51 was more active). Measurements of the distribution of both bromides between... 

The Kp of cryptated potassium phenoxide is higher (about 4 times) for 2,6 dimethylphenoxide compared to 3,5 dimethylphenoxide. 

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