Process for producing a carbonic acid diester

Organic compounds -- part of the class 532-570 series – Organic compounds – Carbonate esters

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C07C 6800

Patent

active

054262097

DESCRIPTION:

BRIEF SUMMARY
This application is a continuation pursuant to 35 U.S.C. .sctn.371 of International Application No. PCT/JP93/01610, filed Nov. 5, 1993.


TECHNICAL FIELD

The present invention relates to a process for producing a carbonic acid diester, for example, a carbonic acid dialkylester, from carbon monoxide and a nitrous acid ester. Particularly, the present invention relates to a process for selectively producing a carbonic acid diester at a high stability over a long time at a high reaction rate by mixing a chloroformic acid ester into a starting material gas containing carbon monoxide and nitrous acid ester, and subjecting the mixed material gas to a catalytic reaction in the presence of a solid catalyst.
The carbonic acid diesters are industrially very useful as intermediates of polymers such as polycarbonates and polyurethane, as synthesis materials of various chemical reagents, and as solvents.


BACKGROUND ART

A conventional method of producing a carbonic acid diester by a reaction of phosgene with an alcohol is a well known and very old method that has been practiced for some time. Nevertheless, this conventional method is disadvantageous in that phosgene has an extremely strong toxicity, and thus is not preferable as a starting material in view of environmental and health considerations. Also, since the reaction of the conventional method produces hydrochloric acid as a by-product, which corrodes the reaction device, an expensive material must be selected and employed for the reaction apparatus.
Therefore, there is a strong demand for a new method of producing a carbonic acid diester without using phosgene, in consideration of the environmental and health and industrial difficulty.
In response to this demand, various attempts have been made to produce a carbonic acid diester from an alcohol and carbon monoxide, as disclosed in, for example, Japanese Unexamined Patent Publication (Kokai) No. 60-75,447, and 63-72,650, and Japanese Examined Patent Publication (Kokoku) 63-38,018.
In those methods, the carbonic acid diester is produced by a catalytic oxygen-oxidizing reaction of carbon monoxide with an alcohol in a liquid phase, in the presence of a catalyst consisting of a copper halide or palladium halide. These methods are disadvantageous in that, in the catalytic oxygen-oxidizing reaction, carbon dioxide is produced as a by-product, and thus the production of the carbonic acid diester is effected with a low selectivity based on the amount of carbon monoxide supplied to the reaction system, and the catalytic oxygen-oxidizing reaction produces water as another by-product, and thus the isolation of the resultant carbonic acid diester is difficult. Further, the methods as disclosed in the above-mentioned publications are not always industrially advantageous in that the reactions of the conventional methods are liquid phase reactions and thus a procedure for separating the resultant product from the catalyst is necessary.
There have been attempts made to eliminate the above-mentioned disadvantages, and as one such attempt, Japanese Unexamined Patent Publication (Kokai) No. 60-181,051 discloses a method of producing carbonic acid diester by a catalytic oxidizing reaction of a nitrous acid ester with carbon monoxide, in a gas phase, in the presence of a catalyst composed of a solid platinum group metal or compound thereof carried on a solid carrier and an oxidant in an amount of 10 molar % in terms of O.sub.2, per mole of carbon monoxide present in the reaction mixture.
This method however, is disadvantageous in that the oxidant in the above-mentioned specific amount based on the carbon monoxide effectively inhibits a production of oxalic acid diester as a by-product, but the addition of the oxidant in the above-mentioned specific amount based on the carbon monoxide cannot completely inhibit the production of the oxalic acid diester, and therefore, the target carbonic acid diester is produced with an unsatisfactorily low selectivity, and the reaction rate and the durability of the catalyst are unsatisfactory.
Fu

REFERENCES:
patent: 4318862 (1982-03-01), Romano et al.
patent: 5089650 (1992-02-01), Yokota et al.
patent: 5162563 (1992-11-01), Nishihira et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Process for producing a carbonic acid diester does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for producing a carbonic acid diester, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing a carbonic acid diester will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1845192

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.