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ChemicalBook CAS DataBase List L-VALINEETHYLESTER
17431-03-7

L-VALINEETHYLESTER synthesis

11synthesis methods
-

Yield:17431-03-7 100%

Reaction Conditions:

with thionyl chloride at -10;Heating / reflux;

Steps:



Synthesis of N-(2-hydroxypropyl)-L-valine ethyl ester (67) To a suspension of L-valine (2 g) in ethanol (50 mL) cooled to -10° C., was slowly added thionyl chloride (2 equivalents). The reaction mixture was then refluxed for 4 hours, and then left to stir overnight. After removal of solvents under reduced pressure, ethanol was added and the resultant suspension was concentrated again. The desired final product (66) (quantitative yield) was further dried in a dessicator over NaOH. 66: MS: M+H+=146. Above ethyl ester (2 g) was then dissolved in water (10 mL) in a sealed Pyrex tube, and to this was added propylene oxide (2 g). The reaction mixture was stirred at 50° C. for 4 h, then cooled, concentrated under reduced pressure and lyophilized. The crude product was purified by reverse-phase column chromatography to afford N-(2-hydroxypropyl)-L-valine ethyl ester (67) (1.5 g). 67: MS: M+H+=204. The Ddisubstituted compound (68) was also isolated from the reaction mixture.

References:

US2006/199853,2006,A1 Location in patent:Page/Page column 46-47