反应详情

2-methyl-2-(3-pyridin-3-yl-phenoxy)-propionic acid ethyl ester (6.0 g, 21.03 mmol) was dissolved in methanol (70 mL) and followed by the addition of 37% HCl (5.3 mL) and 10% Pt/C (0.60 g). The mixture was shaken with hydrogen under 50 psi at 50° C. in a Parr bottle for 5 h, filtered through a pad of Celite, and rinsed with methanol. GC/MS showed complete hydrogenation and only 50% of methyl ester conversion. Concentrated H2SO4 (2.0 mL) was added to the filtrate and the resulting solution was allowed to reflux under nitrogen overnight. After removal of excess methanol, the residue was treated with saturated Na2CO3 (150 mL) and extracted with ethyl acetate (2×200 mL). The organic extract was washed with water, dried over sodium sulfate, and concentrated to give 4.80 g (82%) of 2-methyl-2-(3-piperidin-3-yl-phenoxy)-propionic acid methyl ester as a yellow oil: 1H NMR (CDCl3) δ 1.59 (s, 6H), 1.78 (br, 1H), 1.97 (br d, 1H), 2.02 (br, 2H), 2.61 (m, 3H), 3.06 –3.13 (m, 2H), 3.76 (s, 3H), 6.61 (dd, 1H), 6.70 (s, 1H), 6.83 (d, 1H), 7.14 (t, 1H); MS m/z (relative intensity) 277 (M+, 2), 218 (6), 176 (100).

1. filtrationfiltered through a pad of Celite
2. washrinsed with methanol
3. additionConcentrated H2SO4 (2.0 mL) was added to the filtrate
4. temperatureto reflux under nitrogen overnight
5. customAfter removal of excess methanol
6. additionthe residue was treated with saturated Na2CO3 (150 mL)
7. extractionextracted with ethyl acetate (2×200 mL)
8. extractionThe organic extract
9. washwas washed with water
10. dry with materialdried over sodium sulfate
11. concentrationconcentrated