反应详情

To 4-methoxybenzyl N-(4-bromo-1-methyl-1H-pyrazol-3-yl)-N-[(2,2,2-trichloroethoxy)carbonyl]leucinate (1.72 g, 2.89 mmol) in dry THF (50 mL) was added activated zinc powder (1.89 g, 28.9 mmol) followed by an aqueous solution of KH2PO4 (1.0 M, 5.8 mL, 11.6 mmol) and the reaction mixture was stirred for ½ hour. Additional aliquots of activated zinc powder (950 mg, 14.45 mmol) and aqueous solution of KH2PO4 (1.0 M, 2.9 mL, 2.9 mmol) were added and the reaction mixture stirred for 1½ hour. The zinc powder was filtered off, rinsed with Et2O and water and the product extracted with ether (2×), dried over Na2SO4, concentrated in vacuo and purified by flash chromatography over silica gel (EtOAc/Hex, 25/75, then 3/7) to afford 4-methoxybenzyl N-(4-bromo-1-methyl-1H-pyrazol-3-yl)leucinate.

1. stirringthe reaction mixture stirred for 1½ hour
2. filtrationThe zinc powder was filtered off
3. washrinsed with Et2O and water
4. extractionthe product extracted with ether (2×)
5. dry with materialdried over Na2SO4
6. concentrationconcentrated in vacuo
7. custompurified by flash chromatography over silica gel (EtOAc/Hex, 25/75