Phenylene carbonate

Checked by Arthur C. Cope, Harris E. Petree, and Elmer R. Trumbull. 

Caution This preparation should be conducted in a hood to 

Concentration of the filtrate yields a second crop of impure product, which is recrystallized from toluene and then melts at 119-120°. The combined yield of pure white o-phenylene carbonate from the first and second crops is 107-116 g. (79-86%). 

Catechol obtained from the Koppers Company, Pittsburgh, Pennsylvania, was recrystallized from toluene. 

Water that was deaerated by boiling was used, and an atmosphere of nitrogen essentially free from oxygen (such as the Seaford grade of the Air Reduction Company) was maintained, in order to prevent discoloration of the alkaline solution of catechol due to oxidation. 

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Pentyn-1-ol, 33, 68 Peracetic acid, 33, 79 -Phenetidine hydrochloride, 31, 11 a-Phenoxyacetoacetic acid, 33, 44 Phenylacetamide, 32, 92 Phenylacetic acid, 32, 93, 94 33, 70 imino ether hydrochloride, 32, 94 N-Phenylacetimidochloride, 31, 51 Phenylacetonitrile, 30, 44 32, 92 Phenylacetylene, 30, 72 7-Phenylallylsuccinic acid, 31, 85 7-Phenylallylsuccinic anhydride, 31, 86 Phenylazide, 31,16 Phenylazoacetoacetic acid, 32, 85 Phenyl benzoate, 32, 103 IttZtti-l-PHENYL-l,3-BUTADIENE, 30, 75 7-Phenylbutyric acid, 33, 91 a-PHENYL-a-CARBETHOXYGLUTARO-NITRILE, 30, 80, 82 tt-Phenylcinnamonitrile, 32, 63 Phenyldichlorophosphine, 31, 88 0-PhENYLENE CARBONATE, 33, 74 o-Phenylenediamine, 30, 56, 86... 

PhENYLENE CARBONATE, 33, 74 o-Phenylenediamine, 30, 56, 86 a-Phenylglutaric acid, 30, 82 a-PlIENYLGLUTARIC ANHYDRIDE, 30, 81 Phenyl glycidyl ether, 31, 3 Phenylhydrazine, 30, 90 2-Phenyl-2-hydroxyethane-l-sulfonate, 34, 89... 

Oxygen. The very weak aromaticity in vinylene carbonate (92) and o-phenylene carbonate is enhanced by protonation to 93 and 97, respectively, as evidenced by electronic spectra of 94135 and lH NMR spectra of 93136 (Scheme 44). 

The protonation of o-phenylene carbonate [195], a further analogue of coumarin in which a C=C group has been replaced by O,... 

RiS theory is applied to investigate chain configuration of POLA. Independent conformations for each repeat monomer unit of the chain are assumed in the calculations of the unperturbed dimensions. Rotations about the oxygen-phenytene-carbon bonds are considered to be free with twofold symmetric potentials. The trans and cis conformations of the carbonyl-phenylene-carbon and the indan-carbonyl residues are assumed to have equal probability. The bond vectors for this model lie in a plane because every torsion angle is 0D or 180°. 

If we reverse the carbonyl and either the ether or amine groups above, we convert the putatively antiaromatic eight-7t phthalic anhydride and phthalimide into the putatively aromatic ten-7t phenylene carbonate (X = Z = O, Y = CO) (XX) and 2-benzimidazolinone (X = Z = NH, Y = CO) (XXI), and interpolating these last species 2-benzoxazolinone (X = O, Y = CO, Z = NH) (XXII). Calorimetric data are absent for phenylene carbonate (benzo-l,3-dioxole-2-one). 

In contrast, radical polymerization of 2,3-benzo-7-methylene-l,4,6,9-tetraoxa-spiro[4.4]nona-2-ene (138) gave only a vinyl polymer (139) with no occurrence of ring-opening isomerization, even in the solution polymerization at 165 °C. [105] It appears that the propagating radical having a spiro orthocarbonate structure is too stable to liberate the corresponding carbonyl compound, phenylene carbonate. 

The phosgenation of catechol is of high interest, because the resulting o-phenylene carbonate is the key starting material for the preparation of the insecticide Propoxur as shown in schenne 168. 

With heterogeneous Pd/C catalyst, CU2O showed superior performance in oxidative carbonylation of phenols [29]. However, copper ICCs promote side reactions such as phenol oxidation by oxygen to form 2,2-biphenol [16] or formation of o-phenylene carbonate [51]. 

Figure 13.18. Phenylene bridged FBCC-ZnBC dimers 1, and 2, and porphyrin analogs 3, and 4. Note that in 1 and 2 the rotation around the meso carbon phenylene carbon bond will lead to situations in which the Qx dipole moments (arrows) will be parallel in 1, and orthogonal in 2.

Variable-temperature CSA lineshapes for a solid polycarbonate (PC) sample, with single-site C enrichment at one of the two phenylene carbons ortho to the carbonate, are shown in Figure 6.5 as a function of temperature... 

Figure 6.5 Variable-temperature 62.9 MHz CSA lineshapes of one of the two phenylene carbons ortho to the carbonate in solid polycarbonate. The solid vertical line indicates the position of the maximum in the rigid lineshape corresponding to The dashed vertical line indicates the position of the maximum in the high-temperature, motionally averaged spectra. At the intermediate temperatures of — 60" and — 80"C, two maxima corresponding to the two lines are observed, which is indicative of an inhomogeneous distribution of dynamic processes.

A final example of aryne formation involves the reaction of o-phenylene carbonate (90) with phosphines. An analogous reaction with thiocarbonates (91) fails as does generation of the anion of 2-phenyl-1,3-benzodioxole (92), which had been expected to lose benzoate ion to give benzyne. ... 

Phosgenation of catechol affords o-phenylene carbonate, which is the key starting... 

The smallest possible five-membered aromatic cyclic carbonate is a derivative of catechol benzo-l,3-dioxolan-2-one (o-phenylene carbonate) (1, Scheme 13). It was synthesized using three different methods the reaction of catechol with phosgene (or its dimer or trimer), ° the reaction of catechol with chloroformate, ° or by transesterification of catechol with diphenyl carbonate. ... 

Figure 21 Heterogeneous phenylene dynamics In polycarbonate (PC), (a) Line shape simulations for motlonally narrowed C NMR spectra for heterogeneous Gaussian distributions of flip angles centered at 180° and 90° with different standard deviations ct as Indicated, (b) Experimental C NMR spectra for the two distinct phenylene carbon positions In PC fitted to a heterogeneous Gaussian distribution with full width at half maximum of 80° of flip angles centered at 180°, dashed line. Reproduced with permission from Graf, R. Ewen, B. Spiess, H. W. J. Chem. Phys. 2007,126,041104. Copyright 2007, American Institute of Physics.

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