Ethyl phenyl carbonate, hydrolysis

Kinetic studies of the reaction of Z-phenyl cyclopropanecarboxylates (1) with X-benzylamines (2) in acetonitrile at 55 °C have been carried out. The reaction proceeds by a stepwise mechanism in which the rate-determining step is the breakdown of the zwitterionic tetrahedral intermediate, T, with a hydrogen-bonded four-centre type transition state (3). The results of studies of the aminolysis reactions of ethyl Z-phenyl carbonates (4) with benzylamines (2) in acetonitrile at 25 °C were consistent with a four- (5) and a six-centred transition state (6) for the uncatalysed and catalysed path, respectively. The neutral hydrolysis of p-nitrophenyl trifluoroacetate in acetonitrile solvent has been studied by varying the molarities of water from 1.0 to 5.0 at 25 °C. The reaction was found to be third order in water. The kinetic solvent isotope effect was (A h2o/ D2o) = 2.90 0.12. Proton inventories at each molarity of water studied were consistent with an eight-membered cyclic transition state (7) model. 

Under alkaline conditions isolating lignin degradation products which are essentially of a phenyl.ethyl rather than a phenylpropyl nature is structurally important and requires a lignin structure by which the 7-carbon may be removed as a result of a 0-7 carbon-carbon cleavage reaction, either by direct alkaline hydrolysis or alkali-catalyzed hydrogenolysis. 

Smutny. The t-butyl ester was used in order to achieve hydrolysis of (30), which required reaction with trifluoroacetic acid at 0 °C for 4—5 h. Treatment of (30) with warm trifluoroacetic acid for 10 min yielded (31). The reaction of (29) with ethyl a-chloroacetate gave (32). A-Phenyl phenylpropynthioamide (33) reacts in a similar manner with active bromomethylene derivatives, such as bromo-acetonitrile, bromonitromethane, and /j-nitrobenzyl bromide, in the presence of triethylamine to give the thiophen (33a). Instead of enamine thioesters such as (29), 2-aminovinyl thioketones (34) react with a-bromo-ketones in the presence of triethylamine to give 2-acyl-thiophens (35). By the ion-pair extraction method, tetrabutylammonium salts of acetylacetone were allowed to react with carbon disulphide to give (36), which upon reaction with chloroacetone gave a 45% yield of the thiol (37), in addition to a thieno[2,3-A]thiophen derivative. ... 

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