Phenyl formates

Irradiation of at longer wavelengths (>280 nm) provided phenyl formate (6) as a major volatile product, together with minor amounts of phenol and phenoxyacetone (4), as well as other products. A possible pathway for formation of phenyl formate by oxidation and subsequent cleavage is provided in Scheme III. Phenoxyacetic acid (7) was also identified as a minor product by mass-gc analysis. Photolysis of phenoxyacetone ( ) and phenoxyacetic acid (7)12 yields phenol together with photo-Fries products (also shown in Scheme III). 

Phenyl benzoate Phenylboron dichloride Phenylcyclopropane iV-Phenyldiacetimide Phenyl formate Phenylhydrazine 16.43... 

Phenyl formate, physical properties, 6 292t Phenyl glycidyl ether (PGE), 10 376 AT-Phenylglycine, 1 138 9 279 AT-Phenylglycinonitrile, 3 174 Phenylhydrazine synthesis, 13 573 Phenylhydrazone cleavage, microwaves in, 16 562... 

All the radicals concerned are important in oxidation processes of aromatic molecules, and this paper aims to offer a starting point for the thermochemical dissection of such oxidation processes. It is also hoped that it may stimulate further investigations of radical thermochemistry, especially in the aromatic field. Areas for fruitful work on bond energies include the formate and carbonate esters, including phenyl formate and phenyl carbonate, and the bond strengths in formic acid itself and in benzaldehyde. 

Stereochemical studies were oriented toward finding esters of special structure with reversed conformation and/or with the presence of the second conformer in smaller amounts. As reviewed previously2, these attempts were mostly unsuccessful and claims of the conformation ap were again rebutted. The only exception are certain formates, particularly t-butyl formate, in which more ap form is present in polar solvents6,165. A more recent dipole moment study166 assumed the ap form even in nonpolar solvents in para-substituted phenyl formates in an amount of 10%, but the uncertainty was of the same magnitude. 

The H202-HF-SbF5 system has been applied by Jacquesy and co-workers in the hydroxylation of a variety of functionalized arenes.624 Hydroxylation of phenyl esters has been shown to afford themeta and para isomers as main products625 [Eq. (5.217)]. Substantial amounts of the deacylated derivatives were obtained in the reaction of phenyl formate and diphenyl carbonate. In the hydroxylation of 2-chlorophenyl and 4-chlorophenyl acetate, regioselectivity is controlled by the chlorine substituent with the hydroxyl entering into the meta position to the ester group.626 A similar effect was observed in the hydroxylation of anilines and anilides. 

DFT was employed to study the mechanism of ammonolysis of phenyl formate in the gas phase, and the effect of various solvents on the title reaction was assessed by the polarizable continuum model (PCM). The calculated results show that the neutral concerted pathway is the most favourable one in the gas phase and in solution.24 The structure and stability of putative zwitterionic complexes in the ammonolysis of phenyl acetate were examined using DFT and ab initio methods by applying the explicit, up to 7H20, and implicit PCM solvation models. The stability of the zwitterionic tetrahedral intermediate required an explicit solvation by at least five water molecules with stabilization energy of approximately 35 kcalmol-1 25... 

Phenyl formates (see Figure 11.34 for synthesis) hydrolyze to phenols more easily than the phenyl acetates shown in Figure 11.32. Overall, these species bring short reaction sequences to an end which may start with any aromatic methyl ketone or with an electron-rich aromatic aldehyde and which end with a phenol with widely variable substituent patterns. 

Ans. (a) Butyl acetate or butyl ethanoate (b) Phenyl formate or phenyl methanoate... 

C6F5OCHO, CHCI3, rt, 5-30 min, 85-99% yield. The simpler phenyl formate can also be used efficiently (83% yield). ... 

The photo-Fries rearrangement of polymers containing phenyl formate units (e.g. the polymer derived from para-formyloxystyrene) has been examined. 

Phenol is not formylated with HC02Me / HF / BF3. On the contrary phenyl formate 22 gives by Fries rearrangment /t-hydroxybenzaldehyde 22 (Fig. 9). 

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