Spiro[9H-fluorene-9,9'-[9H]xanthene]-3',6'-diol synthesis

Yield:4081-00-9 83%

Reaction Conditions:

with SO₄^2-/TiO_{2 super acid} in toluene; for 0.416667 h;Microwave irradiation;Green chemistry;Reagent/catalyst;

Steps:

1-6 Example 2

20 mL of toluene and 9-fluorenone 3.6 g (0.02 mol) and resorcinol 11 g (0.1 mol) were successively put into a reaction flask, and SO₄^2-/TiO₂ 0.2 g was added under stirring; In the microwave reactor with air condensing tube and reflux condensing device, the microwave power is adjusted to 600W, microwave reaction for 25 min; the solid acid SO₄^2-/TiO₂ is filtered out (the solid acid can be recycled and reused), and cooled to room temperature. , adding an appropriate amount of water, stirred for 30 minutes, the solid precipitate was filtered; the reaction resultant was filtered cake was dissolved in a solvent with ethanol, the insolubles were filtered off to give a clear and transparent filtrate, solvent evaporation under reduced pressure, the crude product is recrystallized to give spiro [fluorene -9,9'-xanthene-3',6'-diol 6.0 g, yield 83%; melting point and nuclear magnetic resonance spectrum were the same as in Example 1.

References:

CN109456299,2019,A Location in patent:Paragraph 0005; 0025-0036