반응 #82993

반응 방정식

HCl

3,6-dihydroxyxanthone

diborane

water

→

3,6-Dihydroxyxanthane

수율 93.2%

용매

THF

THF

반응 조건

후처리

1. 1
   기타to give a clear yellow solution
2. 2
   기타to give a clear yellow solution
3. 3
   기타The tetrahydrofuran was removed by rotary evaporation
4. 4
   여과the resulting solid filtered
5. 5
   세척washed with water
6. 6
   workup.DISSOLUTIONredissolved in 10% NaOH
7. 7
   여과This solution was filtered
8. 8
   온도cooled
9. 9
   기타reprecipitated with slow addition of HCl
10. 10
    기타to give a yellow solid which
11. 11
    여과was filtered
12. 12
    세척washed with water
13. 13
    기타dried under vacuum

실험 절차

To a suspension of 3,6-dihydroxyxanthone (46 g, 201 mmol.) obtained as in Example 1 in 1.6 L of THF was added over 1 hr 800 ml of borane-tetrahydrofuran complex (1.0M in THF, caution very vigorous raction at beginning). This mixture was stirred overnight under argon at room temperature to give a clear yellow solution. The excess diborane was decomposed by careful addition of water followed by 1N HCl to give a clear yellow solution. The tetrahydrofuran was removed by rotary evaporation and the resulting solid filtered, washed with water and redissolved in 10% NaOH. This solution was filtered, cooled and reprecipitated with slow addition of HCl to give a yellow solid which was filtered, washed with water and dried under vacuum to give 40.14 g (93%, mp 207-208) of 3,6-Dihydroxyxanthane. H1NMR (DMSO): 9.41 (s, 2H); 6.97 (d, 2H, J=8.4 Hz), 6.4 (dd, 2H, J=8.4, 2.4 Hz), 6.39 (d, 2H, J=2.4 Hz), 3.765 (s, 2H).

출처