反应详情

Methanesulfonic acid (33.2 mg, 0.346 mmol) was added to a solution of (2S,3R)—N-(2-((3-pyridinyl)methyl)-1-azabicyclo[2.2.2]oct-3-yl)benzofuran-2-carboxamide (125 mg, 0.346 mmol) in hot ethanol (1 mL). Cooling failed to produce a precipitate. The mixture was refluxed, and the hot mixture was filtered through a cotton plug, which was subsequently rinsed with methanol (1 mL). The volatiles were removed by rotary evaporation, and the residue (light yellow foam) was dissolved in hot isopropanol (1 mL). Again, cooling failed to give a precipitate. The isopropanol was evaporated, and the residue was slurried in acetone (1 mL). Filtration and vacuum oven drying (18 h at 50° C.) gave 146 mg (92.5% yield) of light beige solid, mp 240-243° C. 1H NMR (300 MHz, D2O) δ 8.32 (s, 1H), 7.82 (d, 1H), 7.66 (d, 1H), 7.57 (d, 1H), 7.38 (m, 2H), 7.20 (m, 1H), 7.12 (s, 1H), 7.01 (m, 1H), 4.09 (d, 1H), 3.75 (m, 1H), 3.47 (m, 2H), 3.00-3.40 (m, 4H), 2.67 (s, 3H, methanesulfonic acid), 1.75-2.15 (m, 5H).

1. temperatureCooling
2. customto produce a precipitate
3. temperatureThe mixture was refluxed
4. filtrationthe hot mixture was filtered through a cotton plug, which
5. washwas subsequently rinsed with methanol (1 mL)
6. customThe volatiles were removed by rotary evaporation
7. dissolutionthe residue (light yellow foam) was dissolved in hot isopropanol (1 mL)
8. temperatureAgain, cooling
9. customto give a precipitate
10. customThe isopropanol was evaporated
11. filtrationFiltration and vacuum oven
12. customdrying (18 h at 50° C.)
13. customgave 146 mg (92.5% yield) of light beige solid, mp 240-243° C