反应详情

20 g (178.3 mmol) of rac-2-amino-2-methylpentanonitrile (described in: Deng, S L. et al., Synthesis 2001, 2445-2449; Freifelder, M. et al., J. Am. Chem. Soc. 1960, 696-698) were initially charged in 2.63 l of THF/water (8/1), and 76.4 g (552.7 mmol) of potassium carbonate were added. Then 27.6 ml (196.1 mmol) of benzyl chloroformate were slowly added dropwise at 0° C. and the mixture was stirred at RT overnight. The reaction mixture was concentrated, and the residue was admixed with water and extracted twice with ethyl acetate. The combined organic phases were dried over sodium sulphate, filtered and concentrated. The residue was purified by means of silica gel chromatography (eluent:cyclohexane/ethyl acetate=4/1). 43.84 g of the target compound were obtained (76% of theory, 76% purity).

1. concentrationThe reaction mixture was concentrated
2. extractionextracted twice with ethyl acetate
3. dry with materialThe combined organic phases were dried over sodium sulphate
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue was purified by means of silica gel chromatography (eluent:cyclohexane/ethyl acetate=4/1)