General procedure for the synthesis of N-Boc-(methylamino)acetaldehyde from N-BOC-N-methylaminoethanol: (a) Dess-Martin periodontane (22 g, 52 mmol) was added batchwise to a solution of 2-(N-Boc-methylamino)ethanol (8.8 g, 50 mmol) dissolved in dichloromethane at 0 °C. The reaction mixture was naturally warmed to room temperature and stirred continuously for 3 hours. Upon completion of the reaction, saturated aqueous sodium bicarbonate solution and sodium thiosulfate solution were added and stirring was continued for 0.5 hours. Subsequently, the organic phase was separated, washed with saturated sodium bicarbonate solution, dried over anhydrous magnesium sulfate, and concentrated to give 9 g (quantitative yield) of the title compound N-Boc-(methylamino)acetaldehyde. The product was analyzed by GC-MS and showed m/z 174 (M + 1).
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