反应详情

To a suspension of 7.5 g of lithium aluminum hydride in 360 mL of dry ether was added dropwise a solution of 30 g of xanthene-9-carboxylic acid in 90 mL of freshly distilled THF at 0° C. over a period of 30 minutes. The mixture was stirred at room temperature until the color had changed from grey to brownish red (ca. 1.5 hours) The excess LiAlH4 was decomposed by the slow addition, while stirring, of a mixture of 60 mL of methanol and 25 mL of water at room temperature. The milky white suspension was filtered (sintered glass funnel) and rinsed with ether (3×50 mL). The filtrate was washed with water (2×200 mL), dried over anhydrous MgSO4 and the solvent was evaporated under reduced pressure to give 27.5 g (100%) of the crude alcohol as an off-white solid. Recrystallization from Skelly F--ether (2:1) afforded 23.59 g (86.4%) of the pure 9-xanthenemethanol as white crystals, m.p. 66°-68° C.; IR (KBr): 3290 cm-1 (OH); 1H NMR (CDCl3): δ b 1.70 (t, 1H, OH), 3.71 (dt, 2H, CH2), 4.09 (t, 1H, CH), 6.95-7.40 (m, 8H, aryl).

1. customgrey to brownish red (ca. 1.5 hours)
2. additionwas decomposed by the slow addition
3. filtrationThe milky white suspension was filtered (sintered glass funnel)
4. washrinsed with ether (3×50 mL)
5. washThe filtrate was washed with water (2×200 mL)
6. dry with materialdried over anhydrous MgSO4
7. customthe solvent was evaporated under reduced pressure