General procedure for the synthesis of tert-butyl 2-(methylamino)ethyl carbamate from (2-(benzyl(methyl)amino)ethyl)carbamate:
1. To a reaction flask were added 20% Pd(OH)2/carbon catalyst (3.1 g), tert-butyl (2-(benzyl(methyl)amino)ethyl)carbamate (3.3 g, 12.5 mmol), methanol (200 mL) and water (2 mL).
2. The reaction system was placed under a hydrogen atmosphere (40 psi) for 2.5 hours.
3. Upon completion of the reaction, the reaction mixture was filtered through diatomaceous earth and concentrated under vacuum to remove the solvent.
4. Water (50 mL) was added to the concentrate and the pH was adjusted to 12 with alkali.
5. The aqueous phase was extracted with dichloromethane (3 x 50 mL) and the organic layers were combined.
6. The organic layer was dried with anhydrous magnesium sulfate, filtered and concentrated in vacuum to give tert-butyl 2-(methylamino)ethylcarbamate (2.0 g, 11.7 mmol, 94% yield) as a colorless oil.
LC-MS [M + H] 686.5 (C35H51N5O7S + H, calculated value: 685.9).
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