反应详情

温度

0 °C

A solution of methanesulfonyl chloride (0.593 mL, 7.62 mmol) in 1M NaOH (7.60 mL, 15.2 mmol) and THF (10 mL) was added drop wise to a stirred mixture of (L)-tert-leucine (1.0 g, 7.6 mmol), dissolved in THF (7.6 mL) and H2O (12 mL) at 0° C. The reaction mixture was stirred at 0° C. for 3 h and then at room temperature overnight. The mixture was acidified with 4M HCl and extracted with EtOAc. The organic phase was separated, dried (Na2SO4), filtered and concentrated under reduced pressure to give (2S)-2-methanesulphonylamino-3,3-dimethyl-butyric acid (0.486 g, 30%), which was analyzed by NMR and then used without further purification. The general procedure for the preparation of hydrazides described above was then followed using the crude (2S)-2-methanesulfonylamino-3,3-dimethyl-butyric acid (0.476 g, 2.27 mmol), EDAC (0.481 g, 2.51 mmol), HOBT (0.338 g, 2.50 mmol), NMM (0.275 mL, 2.50 mmol), benzylhydrazine×2HCl (0.489 g, 2.51 mmol) and Et3N (0.700 mL, 4.98 mmol) which gave the title compound (0.416 g, 58%) as a white solid.

1. customat 0° C
2. customat room temperature
3. customovernight
4. extractionextracted with EtOAc
5. customThe organic phase was separated
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure