Ube Industries, Inc.

Koichi Kashiwagi

Katsumasa Harada

Ryoji Sugise

Keigo Nishihira

Shuji Tanaka

Takashi Doi

Satoru Fujitsu

Yoichi Imbe

Hirofumi Ii

Sadao Niida

Yuki Nishida

Toshihiko Sumida

Masayuki Nishio

Toshio Kurafuji

Ii Hirofumi

An improved process for preparing an organic phosphonium chloride is performed by bringing an organic phosphonium bromide into contact with a chloride ion in a heterogeneous mixture solution of water and an organic solvent.

Preparation of organic phosphonium chloride

A catalyst composed of an organic phosphorus compound having a trivalent or pentavalent phosphorus atom and at least one carbon-phosphorus bonding or a combination of the organic phosphorus compound and a halogen atom-containing compound is effective for decarbonylation, that is, for releasing carbon monoxide from a compound containing a moiety of --CO--CO--O-- in its molecular structure.

Catalyst for decarbonylation reaction

A process for preparing a diaryl carbonate from a diaryl oxalate in a liquid phase by decarbonylation is conducted by the steps of:

Process for preparing diaryl carbonate

A diaryl carbonate with a high degree of purity is produced at a high yield by (A) subjecting (a) a diaryl oxalate and a phenol compound or (b) an alkylaryl oxalate to transesterification reaction in one or two stages in the presence of a catalyst to prepare a diaryl oxalate, while removing a by-product from the reaction system; (B) collecting the diaryl oxalate from the resultant reaction product mixture of the step (A); (C) subjecting the diaryl oxalate to a decarbonylation reaction, preferably in the presence of a phosphorous compound-containing catalyst, to convert the diaryl oxalate to a corresponding diaryl carbonate, while removing a reaction by-product comprising carbon monoxide from the reaction system; and (D) collecting the diaryl carbonate from the reaction product mixture of the step (C).

Process for producing a diaryl carnonate

An improved process for preparing a diaryl carbonate from a diaryl oxalate in a liquid phase by decarbonylation utilizes a reaction vessel composed of two or more reaction chambers which are connected in series. The process is composed of the steps of continuously introducing the diaryl oxalate and an organic phosphorus compound having a trivalent or pentavalent phosphorus atom and at least one carbon-phosphorus bonding into the first chamber and continuously recovering a reaction mixture mainly containing the diaryl carbonate from the last chamber under the condition that a mixture of the diaryl oxalate and the organic phosphorus compound is heated in the reaction chambers, while discharging carbon monoxide released from the mixture.

Preparation of diaryl carbonate

Process for producing a diaryl carbonate

A diaryl carbonate is prepared at a high yield and a high selectivity by heating a diaryl oxalate in the presence of an organic phosphorous compound to release carbon monoxide therefrom. A halogen atom-containing compound can be employed in combination with the organic phosphorous compound.

Growing community of inventors

Yamaguchi, Japan

Koichi Kashiwagi