反应详情

Crude 3-(5-iodo-1H-indazol-1-yl)benzoic acid (144c, 3.5 g, 9.6 mmol) was dissolved in THF (70 mL, dried over 4 Å MS) under argon atmosphere and cooled in an ice bath. Borane-THF complex (1M, 12 mL, 12 mmol) was added during 2 min. The cooling bath was removed and the mixture was stirred at r.t. for 15 min, then heated at reflux for 35 min. Additional borane reagent was added and the heating was continued for 20 min, at which time all starting material had been consumed. Sat. aqueous NR4Cl (25 mL) was added followed by ethyl acetate. The phases were separated and the organic phase was washed trice with water and finally with brine. Evaporation left a residue that was subjected to chromatography (SiO2, 10-80% EtOAc in Heptane) to afford a material that was crystallized from ethyl acetate-Heptane to give (3-(5-iodo-1H-indazol-1-yl)phenyl)methanol (1.69 g) as off white crystals. From the mother liquor was obtained in the same way additional 223 mg of the title compound. Total yield 60% over two steps.

1. temperaturecooled in an ice bath
2. additionBorane-THF complex (1M, 12 mL, 12 mmol) was added during 2 min
3. customThe cooling bath was removed
4. temperatureheated
5. temperatureat reflux for 35 min
6. additionAdditional borane reagent was added
7. waitthe heating was continued for 20 min, at which time
8. customall starting material had been consumed
9. additionSat. aqueous NR4Cl (25 mL) was added
10. customThe phases were separated
11. washthe organic phase was washed trice with water
12. customEvaporation
13. waitleft a residue that
14. customto afford a material that
15. customwas crystallized from ethyl acetate-Heptane