反应详情

To 4-methoxybenzyl N-(4-bromo-1-methyl-1H-pyrazol-3-yl)leucinate (1.19 g, 2.89 mmol) in MeOH (60 mL) was added dropwise an aqueous LiOH solution (1.0 M, 14.5 mL, 14.5 mmol) and the reaction was stirred for ½ hour. The reaction was acidified (pH=4–5) with aqueous 10% HCl and the product extracted with EtOAc (3×), dried over Na2SO4, concentrated in vacuo and purified by flash chromatography over silica gel (Hex/EtOAc/AcOH, 70/29/1, then 50/49/1) to afford N-(4-bromo-1-methyl-1H-pyrazol-3-yl)leucine.

1. extractionthe product extracted with EtOAc (3×)
2. dry with materialdried over Na2SO4
3. concentrationconcentrated in vacuo
4. custompurified by flash chromatography over silica gel (Hex/EtOAc/AcOH, 70/29/1