The general procedure for the synthesis of L-2-aminobutyric acid hydrochloride from the compound (CAS: 34047-84-2) was as follows: in step 3, 186 mL of freshly prepared aqueous hydrochloric acid solution was added to a 500 mL three-necked flask, followed by the resulting product (0.14 mol, 31.0 g). The mixture was heated to reflux and the solid was observed to gradually dissolve and become clarified. The reaction was monitored by TLC (unfolding solvent ratio chloroform:methanol:triethylamine = 6:4:1) until the raw material point disappeared completely. Upon completion of the reaction, concentration was carried out under reduced pressure, followed by pulping with the addition of ethyl acetate, at which point a large amount of white solid precipitated. The solids were collected by filtration and the filter cake was washed three times with ethyl acetate and then dried under vacuum to give a white solid crude product. The crude product was further purified by recrystallization with 13.4 g of pure ethyl acetate to finally obtain L-2-aminobutyric acid hydrochloride in a yield of 68.6%, a chemical purity of 99.3% and an ee value of 99.4%.
