反应详情

β-Phenyl-α,α-dimethyl-β-alanine hydrochloride (1.88 g, 8.19 mmol) was dissolved in DMF (100 ml). To the resulting solution, triethylamine (Et3N) (3.5 ml, 25.11 mmol) and 4-cyanobenzoyl-N-hydroxysuccinimide ester (4-cyanobenzoyl-OSu) (2.2 g, 9.01 mmol) were added under cooling with ice and the mixture was stirred at room temperature overnight. The solvent was distilled off and the residue was dissolved in a 5% aqueous ammonia and washed with ether. The aqueous layer was adjusted to pH 3 with citric acid under cooling with ice and extracted with ethyl acetate. The collected ethyl acetate layer was washed with a saturated aqueous solution of NaCl and dried over anhydrous sodium sulfate. The solvent was distilled off and a crystal of N-4-cyanobenzoyl-β-phenyl-α,α-dimethyl-β-alanine was obtained upon recrystallization from an ether-hexane mixed solution (2.54 g, 96.2%).

1. temperatureunder cooling with ice
2. distillationThe solvent was distilled off
3. dissolutionthe residue was dissolved in a 5% aqueous ammonia
4. washwashed with ether
5. temperatureunder cooling with ice
6. extractionextracted with ethyl acetate
7. washThe collected ethyl acetate layer was washed with a saturated aqueous solution of NaCl
8. dry with materialdried over anhydrous sodium sulfate
9. distillationThe solvent was distilled off