Ethanolamine → tert-butyl N-(2-hydroxyethyl)carbamate

Participants

Reaction Steps

Sodium hydroxide (800 mL of 2M in water) was added to a solution of ethanol amine (100 6, 1.64 mole) in tetrahydrofuran (850 mL). The reaction mixture was placed in a 25° C. water bath and stirred rapidly. A solution of tert-butyl dicarbonate (358 g, 1.64 mole) in tetrahydrofuran (800 mL) was added dropwise over a period of 1 hour. The reaction mixture was stirred for a total of 4 hours at which time analysis by TLC indicated that all of the starting material had been consumed. The tetrahydrofuran was removed under reduced pressure to provide an aqueous slurry. The slurry was cooled in an ice bath. The pH was adjusted to pH 2 by the addition of sulfuric acid (1 L of 1M in water). The resulting solution was extracted with ethyl acetate (4×500 mL). The combined extracts were washed sequentially with water (3×500 mL) and brine (2×500 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to give a first lot of crude product. Analysis of the aqueous and brine washes indicated that they contained product so they were extracted with ethyl acetate. The combined extracts were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to provide a second lot of crude product. The two lots were combined to provide 263.8 g of tert-butyl (2-hydroxyethyl)carbamate as a colorless oil.

Provenance & Evidence