反应详情

To 2,2,2-trichloroethyl 4-bromo-1-methyl-1H-pyrazol-3-ylcarbamate (2.402 g, 6.83 mmol), 4-methoxybenzyl 2-hydroxy-4-methylpentanoate (3.45 g, 13.67 mmol) and triphenyl phosphine (3.58 g, 13.67 mmol) in dry DMF (50 mL) under dry nitrogen was added dropwise diisopropyl azodicarboxylate (2.7 mL, 13.67 mmol) over 45 minutes and the reaction mixture stirred for 2 days. Water was added and the product extracted with ether (2×), dried over Na2SO4, concentrated in vacuo and purified by flash chromatography over silica gel (EtOAc/Hex, 2/8) to afford 4-methoxybenzyl N-(4-bromo-1-methyl-1H-pyrazol-3-yl)-N-[(2,2,2-trichloroethoxy)carbonyl]leucinate.

1. extractionthe product extracted with ether (2×)
2. dry with materialdried over Na2SO4
3. concentrationconcentrated in vacuo
4. custompurified by flash chromatography over silica gel (EtOAc/Hex, 2/8)