Boron tribromide → 3-Isoxazolo[5,4-b]pyridin-3-yl-phenol
Reaction equation
C[O:2][C:3]1[CH:4]=[C:5]([C:9]2[C:17]3[C:12](=[N:13][CH:14]=[CH:15][CH:16]=3)[O:11][N:10]=2)[CH:6]=[CH:7][CH:8]=1.B(Br)(Br)Br>ClCCCl>[O:11]1[C:12]2=[N:13][CH:14]=[CH:15][CH:16]=[C:17]2[C:9]([C:5]2[CH:4]=[C:3]([OH:2])[CH:8]=[CH:7][CH:6]=2)=[N:10]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 50 °C
Procedure
Combine 3-(3-methoxy-phenyl)-isoxazolo[5,4-b]pyridine (4.97 g, 21.97 mmol) and 1,2-dichloroethane (anhydrous, 50 mL), under a nitrogen atmosphere and cool (˜5° C.). Add a solution of boron tribromide (19.26 g, 77.89 mmol) in 1,2-dichloroethane (20 mL), dropwise and stir at 50° C. overnight. Cool (0° C.) the reaction mixture and quench with a solution of sodium hydrogen carbonate, dropwise. Pour the reaction mixture over a solution of dilute sodium hydrogen carbonate (˜300 mL) and stir for 1 hour. Filter and collect the solid. Extract the filtrate with chloroform, dry (Na2SO4), filter, evaporate, and combine with previously collected solid. Triturate with ether, filter and dry under vacuum to give the title compound as a white solid (4.2 g, 90% Yield). Microanalysis (C, H, N) is consistent with the final, desired compound. mp=175-178° C.