Acetic Anhydride → 2-(Tert-butoxycarbonylamino)-1,1-dimethylethyl acetate

Temperature

0 °C

2-Hydroxy-2-methylpropylcarbamic acid tert-butylester (510 mg, 2.69 mmol) was dissolved in dichloromethane (7 ml). The solution was cooled to 0° C. Ethyldiisopropylamine (0.70 ml, 4.04 mmol), 4-dimethylaminopyridine (33 mg, 0.27 mmol), and acetic acid anhydride (0.33 ml, 3.50 mmol) were added successively. The reaction mixture was stirred for 16 h, while slowly warming up to room temperature. It was diluted with ethyl acetate (30 ml) and extracted with 1 N hydrochloric acid (30 ml). The aqueous phase was extracted with ethyl acetate (2×20 ml). The combined organic layers were washed with saturated sodium hydrogen carbonate solution (50 ml) and dried over magnesium sulfate. The solvent was removed in vacuo. The crude product was purified by flash chromatography on silica (100 g), using ethyl acetate/heptane (1:2) as eluent, to give 550 mg of 2-(tert-butoxycarbonylamino)-1,1-dimethylethyl acetate.

1. temperaturewhile slowly warming up to room temperature
2. extractionextracted with 1 N hydrochloric acid (30 ml)
3. extractionThe aqueous phase was extracted with ethyl acetate (2×20 ml)
4. washThe combined organic layers were washed with saturated sodium hydrogen carbonate solution (50 ml)
5. dry with materialdried over magnesium sulfate
6. customThe solvent was removed in vacuo
7. customThe crude product was purified by flash chromatography on silica (100 g)

ORD record

ord-b9ff006ec01c45cf91a0c9e9e3f0204f

Source dataset

uspto-grants-1999_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05977178