Method of preparing tartaric acid

Details Method of preparing tartaric acid Method of preparing tartaric acid

1997-05-08

1998-06-09

Geist, Gary

Organic compounds -- part of the class 532-570 series

Organic compounds

Carboxylic acids and salts thereof

562585, C07C 5116, C07C 51245, C07C 59255

Patent

active

057636567

DESCRIPTION:

BRIEF SUMMARY
This application is a 371 of PCT/DE95/01568, filed Nov. 8, 1995.
The invention relates to a method of producing tartaric acid.
Tartaric acid is used above all in many applications in the food and textile industries. For example, tartaric acid is used as a food additive, especially as an antioxidant and acidification agent. In addition, tartaric acid is used as a building material additive for modification of the setting characteristics of cement and serves as a starting substance for numerous chemical reactions, especially for chiral synthesis. One way of producing tartaric acid is to recover it from tartar, a substance which is produced during the production of wine. However, the crude tartar which results from the production of wine is as a rule contaminated by organic materials so that expensive preparation is necessary to obtain the tartaric acid from the tartar.
Because of this drawback, alternatives for the production of tartaric acid have been developed. For example, in U.S. Pat. No. 1,425,605 the production of tartaric acid by oxidation of carbohydrates in the presence of nitrate is described. This procedural method gives rise to various stereoisomers of the tartaric acid and is thus relatively unselective. The yield of the tartaric acid achieved chemically based upon the starting substances used is relatively low. For example, the yield, upon the conversion of 5-ketogluconate or other carbohydrates to tartaric acid using nitric acid as the oxidation agent is about 10% (U.S. Pat. No. 2,380,196) to a maximum of about 40% (W. E. Barch, J. Am. Chem. Soc. 55, 3653, 1933). The conversion of 5-ketogluconic acid to tartaric acid in an alkaline milieu with 1M calcium hydroxide solution or sodium hydroxide gives rise to tartaric acid yields up to about 10% (H. Isbell and N. Hold, The Journal of Research of the Bureau of Standards 35, 433, 1945).
A further process for producing tartaric acid resides in the conversion of glucose to tartaric acid through microorganisms like acetobacter or gluconobacter in the presence of vanadate as trace element (compare U.S. Pat. No. 3,585,109). It can be demonstrated that in these processes the tartaric acid production is carried out in two steps. In the first step 5-ketogluconate is excreted into the medium of microorganisms cultured in a glucose-containing medium, while in a second step the conversion of 5-ketogluconate to tartaric acid is carried out purely chemically with the vanadium salt as trace element, i.e. independently of the presence of microorganisms (R. Klasen, S. Bringer-Meyer and H. Sahm, Biotechnology and Bioengineering 40, 183, 1992). This production process has especially the advantage that only one isomer of the tartaric acid, namely, the desired L-(+)-tartaric acid arises. However, the conversions hitherto achieved with this conversion of 5-ketogluconate to tartaric acid remains unsatisfactory.
It is the object of the invention to provide a simple process for the production of tartaric acid in which a higher conversion of 5-ketogluconate to tartaric acid can be obtained.
This object is achieved, in accordance with the invention, in that 5-ketogluconate is converted to tartaric acid in a carbonate buffer oxidatively at an alkaline pH.
It has been found surprisingly that under these reaction conditions, i.e. also without the addition of vanadate or another catalyst, a conversion of 5-ketogluconate to tartaric acid results whereby a conversion of 5-ketogluconic acid to tartaric acid of up to 55% is achieved.
If vanadate is additionally supplied to the reaction mixture, conversions up to 75% of the 5-ketogluconate used to tartaric acid are obtained. In the presence of another buffer, like for example an alkali borate buffer, the tartaric acid formation by contrast is completely blocked.
The pH range in which the conversion is preferably carried out encompasses the range from pH 8 to pH 10.


EXAMPLE

2.0 ml of an 0.50M solution of the potassium salt of 5-ketogluconic acid is prepared in a 20 ml measuring flask. 0.40 ml of a 50 mM ammonium vanadate solution

REFERENCES:
patent: 1425605 (1922-08-01), Odell
patent: 2197021 (1940-04-01), Pasternack et al.
patent: 2380196 (1945-07-01), Soltzberg
patent: 2419019 (1947-10-01), Hales
patent: 2419038 (1947-04-01), Sanders
patent: 3585109 (1971-06-01), Yamada et al.
patent: 4092220 (1978-05-01), Tsurumi et al.

Affiliated with

Also associated with

Rating

Method of preparing tartaric acid does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of preparing tartaric acid, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of preparing tartaric acid will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2201225