Diphenyl carbonate → Oxalic acid, diphenyl ester

Participants

Reaction Steps

400 parts of an aqueous solution of sodium hydrogencarbonate having a pH of 10 were added to 200 parts of diphenyl carbonate, obtained through the decarbonylation reaction of diphenyl oxalate using triphenyl phosphine oxide and oxalyl chloride as catalysts, the mixture was heated to 90° C. and stirred for 1 hour. To the obtained heavy solution (diphenyl carbonate layer) was further added 400 parts of distilled water, and the resulting mixture was heated to 90° C. and stirred for 1 hour to obtain diphenyl carbonate containing 10.3 ppm of hydrolyzable chlorine. An ester interchange reaction between this diphenyl carbonate and bisphenol A was carried out in the same manner as in Example 1 except that a disodium salt of bisphenol A was used in place of sodium hydroxide as an ester interchange catalyst in an amount of 2.0×10−6 mole, in terms of sodium, based on bisphenol A, to synthesize polycarbonate. The conditions and results are shown in Tables III-A and III-B below.

Provenance & Evidence