反应详情

To a solution of 2,2-dimethyl propionic acid 4-methoxybenzyl ester (4.7 g, 20 mmole) and N-CBz-D-valine (5.5 g, 22 mmole) in dichloromethane (100 ml) were added 4-dimethyaminopyridine (305 mg, 2.5 mmole) and DCC (5.15 g, 25 mmole). After 18 hr, the solution was washed successively with sodium bicarbonate aqueous solution, citric acid solution and water. The organic phase was dried and the residue was dissolved in dichloromethane (100 ml). To the solution was added trifluoroacetic acid (10 ml). After 3 hr, it was evaporated and the product was isolated with silica gel column chromatography. 4.5 g. The compound may be activated and esterified to a drug or further modified as described below.

1. washthe solution was washed successively with sodium bicarbonate aqueous solution, citric acid solution and water
2. customThe organic phase was dried
3. dissolutionthe residue was dissolved in dichloromethane (100 ml)
4. additionTo the solution was added trifluoroacetic acid (10 ml)
5. waitAfter 3 hr
6. customit was evaporated
7. customthe product was isolated with silica gel column chromatography