反应详情

Add oxalychloride (5.3 mL, 60.24 mmol, 1.6 eq.) slowly to the solution of 4-methyl-2-oxovaleric acid (4.90 g, 37.65 mmol, 1.0 eq.) in dichloromethane (50 mL) at 0° C. under nitrogen. Add Dimethylforamide (2 drops) last. Stir the reaction mixture overnight. Concentrate in vacuo. Add dichloromethane (100 mL). Add this solution to the solution of pyrrolidine (6.90 g, 97.02 mmol, 2.6 eq.) in dichloromethane (50 mL) at 0° C. slowly under nitrogen. Stir the reaction mixture for 1 hour at room temperature after addition. Wash with HCl (1 N) until the aqueous layer is acidic, then with aqueous saturated sodium chloride (2×20 mL) and water (2×30 mL). Dry the organic phase over MgSO4 and filter the drying reagent off. Concentrate in vacuo. Purify by column chromatography (0%→5% ethyl acetae in dichloromethane) to afford product (4.60 g, 66%).

1. concentrationConcentrate in vacuo
2. stirringStir the reaction mixture for 1 hour at room temperature
3. additionafter addition
4. washWash with HCl (1 N) until the aqueous layer
5. dry with materialDry the organic phase over MgSO4
6. filtrationfilter the drying reagent off
7. concentrationConcentrate in vacuo
8. customPurify by column chromatography (0%→5% ethyl acetae in dichloromethane)