How is 4-Amino-3-phenylbutanoic acid hydrochloride (CAS: 3060-41-1) typically synthesized?

4-Amino-3-phenylbutanoic acid hydrochloride is usually synthesized via a multi-step process starting with 3-phenylbutyric acid and amino group introduction. Common methods include Grignard reagent addition followed by hydrolysis and acidification. The final step involves neutralization with hydrochloric acid to form the hydrochloride salt. This process is carried out under anhydrous conditions to ensure product purity and yield, typically around 90-95%.