反应详情

Hydrogen chloride in dioxane (4 M; 6.5 mL; 26 mmol) was added to a solution of free base 8.5 (3.38 g; 6.46 mmol) in methanol (34 mL). The slightly turbid solution was filtered through a plug of glass wool and the glassware rinsed with methanol (2×5 mL). Anhydrous ether was carefully added until a persistent precipitate just formed (56 mL). After 1 h at room temperature the flask was put into a refrigerator overnight. The white precipitate was collected on a Buchner funnel and rinsed with 4:1 ether:methanol (30 mL), 9:1 ether:methanol (30 mL) and ether (50 mL). Product was obtained as a white solid (2.88 g; 75%), mp. 195° C. (decomp.). ESIMS 522.9/524.9 (80/28) [MH+], 262.0 (50), 198.0 (100). 1H NMR (D2O) δ 8.14 (m, 2H), 7.83-7.62 (m, 4H), 7.40 (m, 1H), 7.22-7.01 (m, 3H), 4.87 (m, 1H), 4.43 (s, 2H), 3.82-3.46 (m, 8H), 2.31 (m, 4H), 1.94 (s, 3H). UV (MeOH): λmax/nm (log ε)=237 (4.72), 205 (4.78).

1. filtrationThe slightly turbid solution was filtered through a plug of glass wool
2. washthe glassware rinsed with methanol (2×5 mL)
3. additionAnhydrous ether was carefully added until a persistent precipitate
4. customjust formed (56 mL)
5. customThe white precipitate was collected on a Buchner funnel
6. washrinsed with 4:1 ether
7. customProduct was obtained as a white solid (2.88 g; 75%), mp. 195° C. (decomp.)