A mixture of 2-amino-2- methylpropanoic acid (3 g, 29.1 mmol), benzyl alcohol (12 mL, 115 mmol), and p- toluenesulfonic acid monohydrate (5.53 g, 29.1 mmol) in toluene (40 mL) was heated under reflux overnight. Additional benzyl alcohol (12 mL, 115 mmol) was added and the reaction mixture was heated with a Dean Starck overnight. The reaction mixture was concentrated under reduced pressure and washed with diethyl ether. Diethyl ether was removed, and then the residue was dissolved in ethyl acetate and washed with a saturated aqueous NaHC03 solution. The organic layer was dried over Na2S04 and concentrated under reduced pressure. The resulting product was triturated with diethyl ether and HCI in dioxane. The solid was filtered, washed with diethyl ether and dried under reduced pressure to afford benzyl 2-amino-2-methylpropanoate hydrochloride (H-Aib-OBzl).
