反应详情

9.61 g (0.04 mol) of methyl 9-xanthenecarboxylate (obtainable according to step 1.1.a) are dissolved in 150 mL of tetrahydrofuran, combined with a solution of 5.0 g (0.042 mol) potassium lert-butoxide in THF, and stirred for 10 minutes. 5 mL (0.08 mol) of methyl iodide are then added dropwise with gentle cooling; after all has been added, the mixture is stirred for 1 hour at ambient temperature. The reaction mixture is diluted with water to a total volume of 800 mL, extracted with diethyl ether, and the organic phase is extracted with saturated, aqueous Na2CO3 solution, washed with water, dried over magnesium sulfate, and the solvent is distilled off. The product is purified by recrystallization from methanol. Yield: 6.05 g of white crystals (70% of theoretical yield); melting point: 91° C.-92° C.

1. additionafter all has been added
2. stirringthe mixture is stirred for 1 hour at ambient temperature
3. extractionextracted with diethyl ether
4. extractionthe organic phase is extracted with saturated, aqueous Na2CO3 solution
5. washwashed with water
6. dry with materialdried over magnesium sulfate
7. distillationthe solvent is distilled off
8. customThe product is purified by recrystallization from methanol