Extracurricular laboratory: Synthetic route of Ethyl 4-chloro-3-hydroxybutanoate

At the same time, in my other blogs, there are other synthetic methods of this type of compound,10488-69-4, Ethyl 4-chloro-3-hydroxybutanoate, and friends who are interested can also refer to it.

Adding a certain compound to certain chemical reactions, such as: 10488-69-4, Ethyl 4-chloro-3-hydroxybutanoate, can increase the reaction rate and produce products with better performance than those obtained under traditional synthetic methods. Here is a downstream synthesis route of the compound, Recommanded Product: 10488-69-4, blongs to alcohols-buliding-blocks compound. Recommanded Product: 10488-69-4

Example 21 : pH profiles of enzymatic and nonenzymatic test reactions of ethyl 4-chloro- 3-hydroxybutyrate with cyanide Aqueous solutions containing 25 MG/ML sodium cyanide were prepared at pH 5.0, 6.0, 7.0, 7.5, 8. 0, 8. 5, and 9.0 by the addition of 85percent phosphoric acid while monitoring with pH meter. 5 mL of each solution was charged to a SEPARATE 20 ML screw cap vial. Halohydrin dehalogenase SEQ ID NO: 38 (20 mg) was added to each vial, followed by ethyl (S)-4-chloro-3-hydroxybutyrate (50 mg, 0.30 mmoles). For nonenzymatic reactions experiments, the procedure was identical with the exception that the enzyme was omitted. The vials were capped and heated in an oil bath at 55 ¡ãC for 3 hrs, then removed and cooled to room temperature. A 0.4 mL sample of each reaction mixture was extracted with 1 mL butyl acetate and the extracts were analyzed by gas chromatography. The analyzed amounts of substrate and products in each vial are given in Table I, and graphed vs. pH in Figure 1. IN BOTH, CHLOROHYDRIN means ethyl (S)-4-chloro-3- hydroxybutyrate, cyanohydrin means ethyl (R)-4-CYANO-3-HYDROXYBUTYRATE, and crotonate means ethyl 4-hydroxycrotonate. In the Table, ND means not detected. Table I : Millimoles CHLOROHYDRIN, cyanohydrin and crotonate by-product analyzed in test reactions with and without HALOHYDHN dehalogenase. See Example 21 without halohydrin dehalogenase with halohydrin dehalogenase mmol mmol mmol mmol mmol mmol PH chlorohydrin cyanohydrin crotonate chlorohydrin cyanohydrin crotonate 5.0 0. 33 ND ND 0. 27 ND ND 6. 0 0. 29 ND ND 0. 07 0. 20 ND 7. 0 0. 30 ND ND 0. 01 0. 28 ND 7.5 0.3 ND ND 0. 004 0. 30 ND 8. 0 0.30 0.01 ND 0.002 0.29 ND 8. 5 0. 21 0. 05 0. 001 0. 001 0. 24 ND 9. 0 0.11 0.10 0.002 0.001 0.21 ND The pHs of the final test reaction mixtures were remeasured. For the mixtures including halohydrin dehalogenase with initial pHs of 7 or above (being the mixtures in which near complete conversion of the CHLOROHYDRIN to the cyanohydrin occurred, the final mixture pHs were 0.4 to 0.6 pH units below the initial pHs. The other mixtures showed much lesser changes in pH from their initial values. These data show that under these reaction conditions and time, no measurable nonenzymatic reaction of the ethyl 4-CHLORO-3-HYDROXYBUTYRATE with cyanide occurred at any tested pH less than 8. At pH 8 and above, increasing nonenzymatic reaction with cyanide to form ethyl 4-cyano-3-hydroxybutyrate occurred with increasing pH and was accompanied by increasing formation of ethyl 4-hydroxycrotonate by-product. In contrast, the enzymatic reaction with halohydrin dehalogenase occurred at all the tested pH’s greater than 5 and with no detectable formation of ethyl 4-hydroxycrotonate at any tested pH. Additionally, for both enzymatic and nonenzymatic test reactions at pH greater than 8, the mole total of the GC- analyzed products decreased from the initial 0.30 MMOLES provided (as ethyl 4-chloro-3- hydroxybutyrate reactant) indicating the increasing formation of non-analyzable by-products with increasing pH greater than 8. It was separately established that the ester group of the reactant and product are increasingly HYDROLYZED to carboxylic acid groups at pHs greater than 8 and that the resulting carboxylic acids are not extracted in to the extracts of reaction mixture samples that are analyzed by GC. See Example 22.

At the same time, in my other blogs, there are other synthetic methods of this type of compound,10488-69-4, Ethyl 4-chloro-3-hydroxybutanoate, and friends who are interested can also refer to it.

Reference:
Patent; CODEXIS, INC.; WO2005/18579; (2005); A2;,
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts