反应详情

The compound of step 1 (800 mg, 3.58 mmol) was dissolved in DCM (25 ml), and N-chlorosuccinimide (526 mg, 3.94 mmol) was added. The reaction mixture was stir at room temperature overnight. The solvent was removed, the resulting solid was dissolved in concentrated acetic acid (15 ml) and heated to 70° C. After the addition of phosphoric acid (3.04 ml, 44.6 mmol; 85%) the reaction mixture was heated to 130° C. for 2.5 h. The cooled mixture was diluted with water and extracted with EA. The extracts were dried over sodium sulfate, filtered and evaporated. The residue was purified by silica gel chromatography (EA/HEP 1:3). 557 mg of the title compound were obtained.

1. customThe solvent was removed
2. dissolutionthe resulting solid was dissolved in concentrated acetic acid (15 ml)
3. temperatureheated to 70° C
4. temperaturewas heated to 130° C. for 2.5 h
5. extractionextracted with EA
6. dry with materialThe extracts were dried over sodium sulfate
7. filtrationfiltered
8. customevaporated
9. customThe residue was purified by silica gel chromatography (EA/HEP 1:3)