DE2456631A1 - Undecenoic acid esters with hydroxy acids - prepd by reacting undeceonoyl halides with hydroxy carboxylic acid esters in the presence of a base - Google Patents

Abstract

Esters of formula CH2=CH-(CH2)8-CO-O-A, (I), (where A is the residue of a mono- or dihydroxy mono-, di-or tricarboxylic acid ester, the no. of C-atoms in the hydroxy carboxylic acid being 3-6, and one or both OH groups being esterified in the case of a dihydroxy acid), e.g. undecenoyl-lactic acid ethyl ester, have microbistatic or microbicidal properties, and inhibit the growth of pathogenic germs on the skin surface. They also inhibit undesirable development of the normal skin bacterial flora, thus preventing the decomposition of perspiration by bacterial action and consequently having strong deodorant properties due to inhibition of the formation of unpleasant-smelling perspiration decomposition products. The toxicity of (I) is low, and the cpds. are well tolerated by the skin.

Description

Novel esters of undecenoic acid with hydroxycarboxylic acid esters and process for their preparation The present invention encompasses esters of undecenoic acid with hydroxycarboxylic acids of the general formula wherein A is the radical of a mono- or dihydroxy-mono-, -di or -tricarboxylic acid ester, the number of carbon atoms of the hydroxycarboxylic acid being between 3 and 6 and wherein, if it is a dihydroxy-mono-, -di or -tricarboxylic acid ester acts, one or both hydroxyl groups can be esterified.

The previously known undecenoic acid esters were after the general applied method of ester formation, by the action of the acid on an alcohol, manufactured.

However, it has been shown that the esters of undecenoic acid with the The above-mentioned hydroxy acid esters cannot be obtained by the usual methods can.

Only the implementation of an undecenoyl halide with one of the mentioned Hydroxycarboxylic acid ester under the anhydrous conditions of the unicorn variant the Schotten-Baumann reaction led to the desired success.

In this case, the hydroxycarboxylic acid ester is dissolved with the addition of a suitable one Base in an organic, water-immiscible solvent, for example a chlorinated hydrocarbon, or it can be dissolved directly in an organic base such as pyridine, quinoline, triethylamine etc. and adds an undecenoic acid halide, preferably Undecenoic acid chloride, too. The reaction is exothermic, possibly with cooling, so that the temperature does not rise above approx. + 500 C. At higher temperatures it comes oxidation reactions lead to reduced yields. Preferred reaction temperatures lie between -10 and + 300 C. The amount of undecenoic acid halide depends on the reactivity of the hydroxycarboxylic acid ester used; in the case of a reactive ester the equivalent amount of the acid halide is sufficient, while in the case of less reactive Esters an excess of acid halide is indicated.

In the case of the esters of mono- or dihydroxy-mono-, di- or tricarboxylic acids it is primarily a matter of lower alkyl esters with 1 to 4 carbon atoms.

The new esters show microbistatic or microbicidal properties. You not only prevent the development of pathogenic germs on the surface of the skin, but also inhibit the undesired development of the bacterial flora of the species.

This prevents the decomposition of the weld due to bacterial activity contained and prevented the occurrence of unpleasant smelling sweat decomposition products, which is why they also have strong deodorant properties. Also draw the new esters of the formula I are characterized by low toxicity and particularly pronounced Skin tolerance.

Example 1 Undecenovol lactic acid ethyl ester 118 g (1 mol) lactic acid ethyl ester are dissolved in 480 ml of pyridine. With ice-cooling and stirring, 320 g (1.58 Mol) undecenoyl chloride was added dropwise, the temperature not exceeding 300.degree should. After standing overnight at room temperature, the reaction solution is poured onto ice water poured and acidified with hydrochloric acid. One separates on the surface organic layer, which is taken up in chloroform. The separated chloroform phase is washed several times with sodium hydrogen carbonate solution and finally with anhydrous Dried sodium sulfate. The dried solution is taken on a rotary evaporator The water jet vacuum is concentrated to such an extent that no more chloroform distills over.

The yield of the crude product obtained in this way is over 90% d.Th. The substance can be purified by vacuum distillation. You get one colorless, water-clear liquid, which at a temperature of 136 - 1370 C and boils at a pressure of 0.5 torr. The following values were determined: Analysis: Calculated C16H2804 (284.40) calcd. C: 67.57% H: 9.93% found. C: 68.05% H: 9.98% n25 1.4409 n d 25 0.93 Example 2 Undencenoyllactic acid butyl ester 73.1g (0.5 mol) Lactic acid butyl ester, dissolved in 44 ml of pyridine, are treated as in Example 1 with 122 g (0.6 mol) of undencenoyl chloride reacted. After the distillation, 143.6 g of des Esters obtained, which corresponds to a yield of 92% of theory. The product has a boiling point of 1350 ° C. at a pressure of 0.2 torr.

Analysis: Calculated for C18H3204 (312.45) calcd. C: 69.20% H: 10.32 % found C: 69.19% H: 10.36 6 n19 1.4449 D d 20 0.93 Example 3 Diundecenoyltartaric acid diethyl ester According to the method described in Example 1, 51.6 g (0.25 mol) of diethyl tartrate are obtained reacted in 44 ml of pyridine with 122 g (0.6 mol) of undecenoyl chloride and the reaction solution worked up. The crude yield of ester is 144.3 g. That Product can be purified by vacuum distillation, with a boiling point of 2320 ° C at 0.2 Torr.

Analysis was calculated for: C30H5008 (538.74) calcd. C: 66.89 6 H: 9.35 6 found. C: 66.79 6 H: 9.14 6 n19 1.4563 D d 20 0.97 example 4 Undecenoyl citric acid triethyl ester According to the method described in Example 1 138.2 g (0.5 mol) of citric acid triethyl ester, dissolved in 76.2 ml of triethylamine, reacted with 122 g (0.6 mol) of undecenoyl chloride. After the usual work-up 237.1 g of a crude product are obtained, which is purified by distillation.

The ester shown boils at 1970C / 0.2 torr.

Analysis calculated for C23H3808 (442.56) calcd .: C: 62.42% H: 8.65 ffi found: C: 62.86% H: 8.56 6 n18 1.4533 D d 20 1.02

Claims (6)

Claims 1. New esters of undecenoic acid with hydroxycarboxylic acid esters of the general formula wherein A is the radical of a mono- or dihydroxy-mono-, di- or tricarboxylic acid ester, 'where the number of carbon atoms of the hydroxycarboxylic acid is between 3 and 6 and where, if it is a dihydroxy-mono-, -di or tricarboxylic acid ester, one or both hydroxyl groups can be esterified. 2. Undecenoyllactic acid ethyl ester. 3. Undecenoyl lactic acid butyl ester. 4. Diundecenoyltartaric acid diethyl ester. 5. Undecenoyl citric acid triethyl ester. 6. Process for the preparation of esters of undecenoic acid with hydroxycarboxylic acid esters of the general formula wherein A is the radical of a mono- or dihydroxy-mono-, -di or -tricarboxylic acid ester, wherein the number of carbon atoms of the hydroxycarboxylic acid is between 3 and b and wherein, if it is a dihydroxy-mono-, -di or -tricarboxylic acid ester acts, one or both hydroxyl groups can be esterified, characterized in that a solution of the hydroxycarboxylic acid ester in a suitable anhydrous basic or a base-containing solvent at room temperature or with cooling with an undecenoic acid halide, preferably undecenoyl chloride, is reacted.