反应详情

温度

80 °C

A stirred mixture of 5-bromobenzofurazan (11.94 g, 60 mmol), 2-hydroxyphenylboronic acid (9.10 g. 66 mmol), tri-o-tolylphosphine (1.82 g, 6 mmol), palladium (II) acetate (0.672 g, 3 mmol), potassium carbonate (12.4 g 90 mmol), and water (90 mL) in dimethylformamide (180 mL) is heated at 80° C. under an argon atmosphere for 30 minutes. The mixture is then treated with water (300 mL) and extracted with ethyl acetate (3×100 mL). The combined extracts are washed (saturated NaCl), dried (Na2SO4), filtered and the solvent is evaporated off under reduced pressure to yield the crude product which is purified by chromatography (silica gel. 20%-100%, ethyl acetate in cyclohexane) and recrystallised from ethyl acetate-hexane to give 5-(2-hydroxyphenyl)benzofurazan as a pale-yellow crystalline solid, m.p. 166-169° C.

1. extractionextracted with ethyl acetate (3×100 mL)
2. washThe combined extracts are washed (saturated NaCl)
3. dry with materialdried (Na2SO4)
4. filtrationfiltered
5. customthe solvent is evaporated off under reduced pressure
6. customto yield the crude product which
7. customis purified by chromatography (silica gel. 20%-100%, ethyl acetate in cyclohexane)
8. customrecrystallised from ethyl acetate-hexane