反应详情

Methyl 2-(4-amino-3-methylphenoxy)benzoate (500 mg, 1.94 mmol) was suspended in water (5.7 ml), followed by adding thereto concentrated hydrochloric acid (1.0 ml) and ammonium tetrafluoroborate (693 mg) at 0° C. An aqueous sodium nitrite solution (134 mg/1 ml) was added dropwise to the suspension. A saturated aqueous sodium chloride solution was added thereto, followed by extraction with chloroform. The organic layer was dried over anhydrous sodium sulfate and concentrated. The resulting dark-blue oil was dissolved in chloroform (15 ml), and potassium acetate (381 mg, 3.88 mmol) and 18-crown-6 (15 mg) were added thereto at room temperature and then stirred for 2 hours. To the resulting suspension was added a saturated aqueous sodium chloride solution, followed by extraction with chloroform. The organic layer was washed with a saturated aqueous sodium chloride solution and dried over anhydrous sodium sulfate. The organic layer dried was concentrated and then purified by a silica gel column chromatography (chloroform/methanol=70/1) to obtain methyl 2-(1H-indazol-5-yloxy)benzoate (157 mg, two steps 30%).

1. additionby adding
2. customat 0° C
3. extractionfollowed by extraction with chloroform
4. dry with materialThe organic layer was dried over anhydrous sodium sulfate
5. concentrationconcentrated
6. dissolutionThe resulting dark-blue oil was dissolved in chloroform (15 ml)
7. extractionfollowed by extraction with chloroform
8. washThe organic layer was washed with a saturated aqueous sodium chloride solution
9. dry with materialdried over anhydrous sodium sulfate
10. customThe organic layer dried
11. concentrationwas concentrated
12. custompurified by a silica gel column chromatography (chloroform/methanol=70/1)