反应详情

To a solution of methyl 3-amino-2-fluoro-5-nitrobenzoate (D138) (12 g, 56 mmol, 1 equiv) in CH2Cl2 (150 ml) at room temperature were added NEt3 (11.7 ml, 84 mmol, 1.5 equiv) and 4-chlorobutanoyl chloride (6.9 ml, 61.6 mmol, 1.1 equiv) and the resulting mixture was stirred for 2 h then washed with a 2N aqueous HCl solution and a saturated aqueous NaHCO3 solution, dried over MgSO4 and concentrated in vacuo. Purification of the residue by flash chromatography on silica gel (iso-hexane/AcOEt: 4/1) gave methyl 3-[(4-chlorobutanoyl)amino]-2-fluoro-5-nitrobenzoate (D139) (16.2 g, 91%) as a yellow solid. [M+H]+=319.1, RT=3.12 min.

1. washthen washed with a 2N aqueous HCl solution
2. dry with materiala saturated aqueous NaHCO3 solution, dried over MgSO4
3. concentrationconcentrated in vacuo
4. customPurification of the residue by flash chromatography on silica gel (iso-hexane/AcOEt: 4/1)