Claims
- 1. A process for producing a diaryl oxalate, characterized in that an alkylaryl oxalate is subjected to a disproportionation reaction in the presence of a disproportionation catalyst, thereby to produce a diaryl oxalate, while removing a by-product comprising a dialkyl oxalate.
- 2. The process for producing a diaryl oxalate as claimed in claim 1, wherein a dialkyl oxalate and a phenol compound are subjected to an ester interchange reaction in the presence of an ester interchange catalyst, thereby to produce an alkylaryl oxalate, while removing a by-product comprising an aliphatic alcohol, and the resultant reaction mixture containing the alkylaryl oxalate is subjected to a disproportionation reaction for which the ester interchange catalyst contained in the reaction mixture is used as a disproportionation catalyst, thereby to produce a diaryl oxalate, while removing a by-product comprising dialkyl oxalate.
- 3. The process for producing a diaryl oxalate as claimed in claim 1 or 2, wherein the removal of the by-product dialkyl oxalate and the disproportionation reaction of the alkylaryl oxalate are carried out in a reaction apparatus comprising a reactive distillation column.
- 4. The process for producing a diaryl oxalate as claimed in claim 2, wherein in a first reactive distillation column, the ester interchange reaction of the dialkyl oxalate with the phenol compound is carried out and the by-product aliphalic alcohol is removed by evaporation, and then in a second reactive distillation column, the alkylaryl oxalate is subjected to the disproportionation reaction and the dialkyl oxalate and the phenol compound contained in the reaction mixture are removed by evaporation.
- 5. The process for producing a diaryl oxalate as claimed in claim 4, wherein a vapor containing the dialkyl oxalate and the phenol compound removed by evaporation from the second reactive distillation column is liquefied by cooling, the resultant liquid mixture is returned to the first reactive distillation column and subjected to the ester interchange reaction.
- 6. The process for producing a diaryl oxalate as claimed in claim 4, wherein at least one of the first reactive distillation column and the second reactive distillation column has a distillation column provided with a plurality of trays.
- 7. The process for producing a diaryl oxalate as claimed in claim 1 or 2, wherein the disproportionation catalyst to be used for the disproportionation reaction contains at least one compound selected from compounds and complexes of alkali metals, cadmium and zirconium, lead-containing compounds, iron-containing compounds, copper-group metal-containing compounds, zinc-containing compounds, organic tin compounds, aluminum-containing Lewis acid compounds, titanium-containing Lewis acid compounds, arid vanadium-containing Lewis acid compounds and is soluble in the disproportionation reaction system.
- 8. The process for producing a diaryl oxalate as claimed in claim 1 or 2, wherein the disproportionation reaction is carried out in the reactive distillation column, the concentration (C) of the disproportion action catalyst contained in the reaction mixture in the reactive distillation column is controlled to a range of from 0.001 to 45% by weight, and the temperature (T) of the disproportionation reaction is controlled to a range of from 100 to 280.degree. C.
- 9. The process for producing a diaryl oxalate as claimed in claim 8, wherein in the disproportionation reaction of the alkylaryl oxalate in the disproportionation reactive distillation column, (a) when the disproportionation reaction temperature (T) is 100.degree. C. or more but less than 220.degree. C., the residence time (H) of the reaction mixture in the disproportionation reactive distillation column is controlled to 0.01 to 10 hours, (b) when the disproportionation reaction temperature (T) is 220.degree. C. or more but less than 250.degree. C., the residence time (H) of the reaction mixture in the disproportionation reactive distillation column is controlled to 0.01 to 2 hours, and (c) when the disproportionation reaction temperature (T) is 250.degree. C. more but not exceeding 280.degree. C., the residence time (H) of the reaction mixture in the disproportionation reactive distillation column is controlled to 0.01 to 0.5 hours.
- 10. The process for producing a diaryl oxalate as claimed in claim 8, wherein in the disproportionation reaction of the alkylaryl oxalate in the disproportionation reactive distillation column, the disproportionation reaction temperature (T) is controlled to 125.degree. C. to 215.degree. C., the concentration of the disproportionation catalyst in the reaction mixture is controlled to 0.005 to 25% by weight, and the residence time of the reaction mixture in the disproportionation reactive distillation column is controlled to 0.01 to 10 hours.
Priority Claims (1)
Number |
Date |
Country |
Kind |
7-323181 |
Dec 1995 |
JPX |
|
Parent Case Info
This is a 371 of application PCT/JP96/03636 filed Dec. 12, 1996.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/JP96/03636 |
12/12/1996 |
|
|
8/7/1997 |
8/7/1997 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO97/21660 |
6/19/1997 |
|
|
US Referenced Citations (4)
Foreign Referenced Citations (3)
Number |
Date |
Country |
56-2541 |
Jan 1981 |
JPX |
56-8019 |
Feb 1981 |
JPX |
57-47658 |
Oct 1982 |
JPX |