反应详情

3-(4-Chloro-butanoylamino)-5-ethoxy-benzoic acid methyl ester (D51) (7 g, 20 mmol, 1 equiv) in THF (50 ml) was treated portionwise with NaH (60% in mineral oil, 0.88 g, 22 mmol, 1.1 equiv) over 15 min at room temperature. The resulting mixture was stirred for 30 min and then diluted with AcOEt (300 ml). The resulting solution was washed with 2N aqueous HCl solution (200 ml), dried over MgSO4 and concentrated in vacuo. Recrystallisation of the residue from Et2O/hexane gave 3-ethoxy-5-(2-oxo-pyrrolidin-1-yl)-benzoic acid methyl ester (B11) (3.5 g, 66%) as white solid.

1. washThe resulting solution was washed with 2N aqueous HCl solution (200 ml)
2. dry with materialdried over MgSO4
3. concentrationconcentrated in vacuo
4. customRecrystallisation of the residue from Et2O/hexane