反应详情

A solution of diisopropylamine (13.2 ml; 0.094 mol) in 130 ml tetrahydrofurane (THF) was cooled down to about −40° C. n-Butyllithium (37 ml of a 2.5 M solution in hexane; 0.094 mol) was added dropwise. The temperature was left to return to about 0° C. At this temperature, Boc-glycine (5 g; 0.028 mol) in solution in 30 ml THF was introduced into the mixture. After ten minutes at this temperature, 1-bromo-4-methylpentane (7.9 ml; 0.056 mol) in solution in 20 ml THF was quickly added. The temperature was then left to return to about 23° C. and the mixture agitated for about one hour at this temperature. After hydrolysis with 100 ml water and acidification with 150 ml of a saturated potassium hydrogenosulfate solution, the obtained mixture was extracted with 2 times 50 ml ethyl acetate. The organic phase was washed with 100 ml water followed by 100 ml of a saturated sodium chloride solution. After drying on magnesium sulfate and evaporation of the solvent, the residue obtained was purified on a silica column (eluent: ethyl acetate-heptane/6-4) to produce a white-colored powder with a yield of 50%. MH+=260.3.

1. addition0.094 mol) was added dropwise
2. waitThe temperature was left
3. customto return to about 0° C
4. waitThe temperature was then left
5. customto return to about 23° C.
6. extractionthe obtained mixture was extracted with 2 times 50 ml ethyl acetate
7. washThe organic phase was washed with 100 ml water
8. customAfter drying on magnesium sulfate and evaporation of the solvent
9. customthe residue obtained
10. customwas purified on a silica column (eluent: ethyl acetate-heptane/6-4)
11. customto produce a white-colored powder with a yield of 50%