Reaction #7032

Reaction equation

boron trichloride hexane

3-Benzyloxymethyl-5-biphenyl-4-yl-4-(2-fluorophenyl)-4H-1,2,4-triazole

methanol

sodium hydrogen carbonate

→

compound

Yield 44.0%

[5-Biphenyl-4-yl-4-(2-fluorophenyl)-4H-1,2,4-triazol-3-yl]methanol

Yield 44.0%

Solvents

chloroform

Conditions

Workup

1. 1
   Concentrationfollowed by concentration under reduced pressure
2. 2
   workup.ADDITIONTo the resulting residue were added tetrahydrofuran (100 ml), aqueous 2 mol/liter sodium hydroxide solution (100 ml) and tetrabutylammoniumhydrogensulfate (0.10 g)
3. 3
   workup.STIRRINGstirred at ambient temperature for 12 hours
4. 4
   ExtractionThe reaction solution was extracted with ethyl acetate
5. 5
   Dryingthe organic layer was dried over anhydrous magnesium sulfate
6. 6
   OtherAfter the solvent was evaporated under reduced pressure
7. 7
   Otherthe resulting residue was purified by silica gel chromatography (eluent: chloroform/methanol=96/4)
8. 8
   Otherrecrystallized from a mixture solution of n-hexane-ethyl acetate-ethanol

Procedure

3-Benzyloxymethyl-5-biphenyl-4-yl-4-(2-fluorophenyl)-4H-1,2,4-triazole (6.00 g) was dissolved in chloroform (200 ml), followed by dropwise addition of 1 mol/liter boron trichloride-hexane solution (30 ml) at −44° C. and stirred at the same temperature for 30 minutes and at ambient temperature for one hour. To the reaction solution were added methanol (5 ml) and saturated aqueous sodium hydrogen carbonate solution (50 ml), followed by concentration under reduced pressure. To the resulting residue were added tetrahydrofuran (100 ml), aqueous 2 mol/liter sodium hydroxide solution (100 ml) and tetrabutylammoniumhydrogensulfate (0.10 g), and stirred at ambient temperature for 12 hours. The reaction solution was extracted with ethyl acetate, and the organic layer was dried over anhydrous magnesium sulfate. After the solvent was evaporated under reduced pressure, the resulting residue was purified by silica gel chromatography (eluent: chloroform/methanol=96/4) and recrystallized from a mixture solution of n-hexane-ethyl acetate-ethanol, to afford the entitled compound as white crystal (2.09 g, 44%). The physico-chemical values are as follows.

Source