Acetic Acid → Methyl 4-(1-methylpiperidin-4-YL)benzoate

Participants

Reaction Conditions

Reaction Steps

Water (0.2 mL), paraformaldehyde (0.470 g, 15.64 mmol) and acetic acid (0.895 mL, 15.64 mmol) were added to a stirred suspension of 4-(4-(methoxycarbonyl)phenyl)piperidinium chloride (1 g, 3.91 mmol) in THF (20 mL) under nitrogen. Sodium cyanoborohydride (0.369 g, 5.87 mmol) was added portionwise over a period of 10 mins. The resulting mixture was stirred at 60° C. for 19 h. The reaction mixture was evaporated to dryness and mixed with water (20 mL) and 1M HCl (5 mL). The solution was washed with EtOAc (2×15 mL), basified with K2CO3 and extracted with EtOAc (2×15 mL). The organic layer was washed with saturated brine and dried over MgSO4, filtered and evaporated to afford pure methyl 4-(1-methylpiperidin-4-yl)benzoate (0.459 g, 50.4%) as a colourless oil which crystallised on standing.

Provenance & Evidence