Synthesis
Step (1) Preparation of tert-butylamidine hydrochloride: To a magnetically stirred mixed solution of 2,2-dimethyl-1-propanenitrile (25.0 g, 0.30 mol) and anhydrous methanol (26.8 mL, 0.79 mol) was added dropwise acetyl chloride (25 mL, 0.36 mol) and ether (30 mL) at 0 °C. After the dropwise addition, stirring was continued at 0 °C for 15 min. Subsequently, the reaction mixture was stirred at room temperature for 3 days. After completion of the reaction, white crystals were obtained by filtration, washed with ether and dried under vacuum. The dried crystals were mixed with an ethanol solution of 10% ammonia (150 mL, 0.90 mol) and stirred at room temperature for 3 days. The reaction mixture was filtered and the filtrate was concentrated to give a white solid. Recrystallization by ethanol gave a white crystalline product (18.9 g, 46% yield) with a melting point of 205°C (literature value 188°-190°C). NMR hydrogen spectrum (DMSO-d6): δ 1.22 (s, 9H), 8.63 (br d, 3H).
