Benzoyl chloride → (R)-1-Benzoyl-3-methylpiperazine

Participants

Reaction Steps

(R)-2-methylpiperazine (13.85 g, 138 mmol), and sodium bicarbonate (52.3 g, 622 mmol) were dissolved/suspended in water (182 mL) and acetone (112 mL). The flask was cooled in an ice bath and a solution of benzoyl chloride (17.7 mL, 152 mmol) in acetone (56 mL) was added drop-wise over 1 hour. After 16 hours the acetone was removed on the rotovap. Water (400 mL) was added and the resulting mixture acidified using 6 M HCl to pH <2. The aqueous layer was washed with 200 mL CH2Cl2 three times. Aqueous sodium hydroxide (5M) was added to pH >12, and this solution was extracted three times with 200 mL of CH2Cl2. The combined organics were dried (MgSO4) and evaporated to give a thick yellow oil. MS (M+H)+=205.1

Provenance & Evidence