反应详情

5-Tert-butoxy-3,3-dimethyl-5-oxopentanoic acid (6 g, 27.8 mmol) was dissolved in DMF (111 mL) and benzotriazol-1-yloxytris(pyrrolidino)phosphonium hexafluorophosphate (21.68 g, 41.7 mmol), 1-hydroxybenzotriazole (5.6 g, 41.7 mmol), diisopropylethylamine (19.3 mL, 111 mmol) and ammonium chloride (3 g, 55.6 mmol) were added. The mixture was stirred at room temperature for two hours. The DMF was removed under reduced pressure and the residue dissolved in ethyl acetate. The ethyl acetate was washed with 1N KHSO4, saturated sodium bicarbonate, brine, dried (Na2SO4) and concentrated. The residue was again dissolved in ethyl acetate, washed with 0.1N HCl, 0.1N NaOH, H2O, dried (Na2SO4), passed through a pad of silica and concentrated to give 4.9 g (82%) of the desired product. 1H NMR (DMSO-d6) 7.19 (br s, 1H), 6.71 (br s, 1H), 2.23 (s, 2H), 2.08 (s, 2H), 1.4 (s, 9H), 1.02 (s, 6H).

1. customThe DMF was removed under reduced pressure
2. dissolutionthe residue dissolved in ethyl acetate
3. washThe ethyl acetate was washed with 1N KHSO4, saturated sodium bicarbonate, brine
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated
6. dissolutionThe residue was again dissolved in ethyl acetate
7. washwashed with 0.1N HCl, 0.1N NaOH, H2O
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated