Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1991-01-18
1992-01-28
Ivy, C. Warren
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
549549, C07D30100, C07D30338, C07D30348
Patent
active
050845829
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to the preparation of epoxycarboxylic acids. It is based especially on the oxidation, in a liquid medium, of alcohols carrying an epoxy bridge. The method of this invention is particularly useful for obtaining very water-soluble epoxyacids of relatively low molecular weight, which are generally difficult to recover industrially from the aqueous medium. Especially epoxyacids having a C.sub.3 to C.sub.10 and particularly C.sub.3 to C.sub.5 aliphatic chain are favorably amenable to the method of the invention.
Epoxycarboxylic acids have a variety of industrial applications, especially for the synthesis of different derivatives of acids, esters or corresponding salts. Thus, for example, they are used for the synthesis of compounds of biological interest, such as amino acids, pheromones, antibiotics etc. In these fields, the invention brings a marked advantage in that it enables an epoxyacid to be obtained from an optically active alcohol without loss of the chirality desired for the remainder of the synthesis.
The invention enables the epoxyacids to be recovered easily and economically from the medium in which they were prepared. They are recovered by the evaporation of an organic solvent in which the acid prepared is present at the end of the preparation, said solvent being more volatile than this acid.
In the method according to the invention, which consists in oxidizing epoxyalcohols, in a medium containing an organic solvent and water, by means of an oxidizing compound, in the presence of a catalyst based on a ruthenium salt, the proportion of water relative to that of organic solvent is sufficiently small for at least the major part of the oxidizing agent to be in the solid state in the reaction medium, which is heterogeneous.
Depending on the nature of the alcohol to be oxidized, and especially on its miscibility with solvents, solvents which can be employed are ethers, hydrocarbons, halogenated hydrocarbons, nitriles or other organic liquids which are non-oxidizable under the operating conditions of the invention. Thus, for example, it is possible to operate in dioxane, tetrahydrofuran, toluene, octane, decane, dichloroethane, trichloroethylene, chloroform, carbon tetrachloride etc. Particularly useful solvents are those such as methylene chloride and acetonitrile. It is preferred to choose a solvent which is more volatile than the acid to be prepared.
Suitable oxidizing agents are various salts of the oxygenated anions of halogens, such as hypochlorites, hypobromites, chlorites, bromites, iodites, chlorates, bromates, iodates, perbromates or periodates of alkali metals and alkaline earth metals and, if appropriate, those of Zn, Al, Fe etc. Preferred oxidizing agents are hypochlorites and periodates of Na, K or Ca.
The catalysts employed in the method of the invention are Ru salts, in particular RuCl.sub.3.
An important feature of the invention is that the proportion of water in the reaction medium does not exceed 20 mol of H.sub.2 O per mol of alcohol to be oxidized, the volume of organic solvent being greater than that of water, preferably at least twice as much.
The preferred conditions in this method correspond to a proportion of H.sub.2 O of 0.2 to 20 mol per mol of alcohol, preferably 0.5 to 5 and more particularly 1 to 2 mol. This is assured as long as the volume of solvent is adjusted to a value of about 5 to 250 times that of water, preferably 10 to 100 times.
In contrast to the information given in the prior art for a relatively high-molecular epoxyacid containing an aryl group, the highly water-soluble lower-molecular epoxycarboxylic acids cannot be extracted by the classical means from the reaction medium containing a greater or lesser proportion of water. Thus, in J. Org. Chem. 1981, 46, no. 19, top left of page 3938, under (1).sup.b, Carlsen, Katsuki, Martin and Sharpless report the oxidation of 4-phenyl-2,3-epoxybutan-1-ol in solution in acetonitrile, in the presence of 3 ml of water per mmol of this alcohol (i.e. 166 mol of H.sub.2 O/mol of alcohol), by mean
REFERENCES:
patent: 4007217 (1977-02-01), Kogure et al.
Journal of Organic Chemistry, vol. 46, No. 19, 9/11/81, Carlsen et al., "A Greatly Improved Procedure for Ruthenium Tetraoxide Catalyzed Oxidations of Organic Compounds".
Tetrahedron Letters, vol. 22, No. 18, 1981, Menger et al., "Synthetically Useful Oxidations at Solid Sodium Permanganate Surfaces".
Genet Jean-Pierre
Juge Sylvain
Pons Dominique
Covington Raymond
Ivy C. Warren
Societe Nationale Elf Aquitaine
LandOfFree
Oxidation of epoxy alcohols into carboxilic epoxy acids does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Oxidation of epoxy alcohols into carboxilic epoxy acids, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Oxidation of epoxy alcohols into carboxilic epoxy acids will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1862283