General procedure for the synthesis of tert-butyl (4-methylpiperidin-4-yl)carbamate from (1-benzoyl-4-methylpiperidin-4-yl)carbamate:
1. tert-Butyl (1-benzoyl-4-methylpiperidin-4-yl)carbamate (318 mg, 1.0 mmol) was dissolved in ethanol (3 mL).
2. 6 N aqueous sodium hydroxide (1.0 mL, 6.0 mmol) was added to the above solution.
3. The reaction mixture was heated at reflux for 8 hours. 4.
4. Upon completion of the reaction, the mixture was concentrated under reduced pressure.
5. Ethyl acetate (30 mL) was added to the concentrated mixture.
6. The organic layer was separated and washed twice with distilled water.
7. Dry the organic layer with anhydrous magnesium sulfate.
8. Concentrate the dried organic layer under reduced pressure and dry under reduced pressure to afford the target product tert-butyl (4-methylpiperidin-4-yl)carbamate (145 mg, 0.67 mmol, 67% yield).
Characterization data:
Mass spectrum (EI, m/z): 214 [M]+.
1H-NMR (CDCl3) δ: 4.37 (1H, br s), 2.84-2.80 (4H, m), 1.91 (2H, dt, J = 13.3, 3.9 Hz), 1.51 (2H, td, J = 12.9, 6.2 Hz), 1.44 (9H, s), 1.34 (3H, s).
