General procedure for the synthesis of methyl 2-amino-2-cyclopropylacetate hydrochloride from DL-cyclopropylglycine: Thionyl chloride (1.3 g, 0.8 mL, 11 mmol) was added slowly and dropwise to a methanol (4.3 mL) solution of DL-cyclopropylglycine (0.50 g, 4.3 mmol) that was cooled to 0°C. The reaction mixture was stirred for 10 minutes and then gradually warmed to room temperature. The reaction mixture was stirred at 0°C for 10 min and then gradually warmed to room temperature. Stirring was continued at room temperature overnight. Upon completion of the reaction, the mixture was concentrated and dried under pressure of 0.5 mmHg at room temperature to afford methyl 2-amino-2-cyclopropylacetate hydrochloride (0.60 g, 85% yield) as a white solid. The product was characterized by 1H NMR (DMSO-d6): δ 0.51-0.69, 1.05-1.17, 3.36-3.39, 3.75, 8.69.
