摘要:
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.
摘要:
A process for preparing a diaryl carbonate from a diaryl oxalate in a liquid phase by decarbonylation is conducted by the steps of:1) performing a decarbonylation reaction of a diaryl oxalate in the presence of an organic phosphorus compound catalyst to give a reaction mixture of a diaryl carbonate and the organic phosphorus compound catalyst;2) recovering the diaryl carbonate from the reaction mixture; and3) performing a decarbonylation reaction of a diaryl oxalate in the presence of the reaction mixture from which the diaryl carbonate has been recovered and to which a halogen atom-containing compound is added, to give a reaction mixture of a diaryl carbonate and the organic phosphorus compound catalyst.
摘要:
A diaryl carbonate is produced by decarbonylating a diaryl oxalate, which can be prepared by transesterification of a dialkyl oxalate with a hydroxyaryl compound, in the presence of a catalyst, while removing the resultant carbon monoxide as a by-product, and then optionally refined by an evaporation and/or distillation, and then the resultant diaryl carbonate is condensation-polymerized with a polyhydroxyl compound, while recovering a resultant hydroxyaryl compound from the reaction system, to produce a polycarbonate.
摘要:
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).
摘要:
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.
摘要:
A high purity diaryl carbonate is produced with a high efficiency by reacting carbon monoxide with an alkyl nitrite and/or an alkyl alcohol; reacting the resultant dialkyl oxalate with a hydroxyaryl compound, for example, phenol; decarbonylating the resultant diaryl oxalate to produce a diaryl carbonate and carbon monoxide; and collecting the diaryl carbonate from the decarbonylation reaction product mixture, the carbon monoxide produced in the decabonylation step being optionally reused for the production of the dialkyl oxalate.
摘要:
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).
摘要:
A process for producing an aryl carbamate of a high purity at a high yield by reacting a diaryl carbonate with an amine compound having one or more hydrogen atoms bonded to the N position in the presence of carboxylic acid(s) of the following general formulae (I): R.sup.1 --COOH and/or (II): R.sup.2 --COOH (wherein R.sup.1 represents an alkyl or cycloalkyl group having an .alpha.-positioned carbon atom bonded to only one hydrogen atom, an alkyl group having an .alpha.-positioned carbon atom bonded to no hydrogen atom, or an aryl or heterocyclic group, and R.sup.2 represents an alkyl group having an .alpha.-positioned carbon atom bonded to two or more hydrogen atoms).
摘要:
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.
摘要:
A dialkyl carbonate (e.g., dimethyl carbonate) is prepared at a high yield and a high selectivity by decarbonylation of a dialkyl oxalate (e.g., dimethyl oxalate) in a gaseous phase in the presence of an alkali metal compound (e.g., potassium carbonate).