反应详情

To a solution of 120 mg of 18 and 500 μl EtOH in a 5 mL round-bottom flask equipped with a magnetic stirrer, a reflux condenser and an inert gas supply was added 120 μl sulphuric acid (96%). The reaction mixture was refluxed for 16 h, cooled to RT and diluted with 1.0 mL of EtOAc then cooled to 0-5° C. The cooled solution was treated with 100 μl of a 28% aqueous NaOH solution and with 257 μl of a 25% aqueous NH4OH. The well stirred mixture was diluted with 1.5 mL of water, extracted and the organic phase was separated, dried (Na2SO4), filtered and evaporated at 20° C./120-10 mbar and dried for 1 h at 20° C./<10 mbar to afford 56 mg of 20 as colorless oil.

1. temperatureThe reaction mixture was refluxed for 16 h
2. temperaturethen cooled to 0-5° C
3. extractionextracted
4. customthe organic phase was separated
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. customevaporated at 20° C./120-10 mbar
8. customdried for 1 h at 20° C./<10 mbar