Reaction #1153158

Reaction equation

1-(4-benzyloxyphenyl)-5-trifluoromethyl-1H-tetrazole

hydrogen

→

4-(5-Trifluoromethyl-tetrazol-1-yl)-phenol

Solvents

THF ethanol

Conditions

Workup

1. 1
   OtherThe catalyst was removed by filtration through Celite®
2. 2
   Washthe cake washed with ethanol
3. 3
   Concentrationthe filtrate concentrated
4. 4
   workup.DISSOLUTIONThe product was dissolved in ether
5. 5
   Filtrationfiltered through magnesium sulfate
6. 6
   Concentrationconcentrated
7. 7
   ConcentrationDuring concentration the product
8. 8
   Otherto crystallize, as the product
9. 9
   Othercrystallized the mixture
10. 10
    Otherwas flushed with hexanes
11. 11
    Otherto remove the ether
12. 12
    Filtrationfiltered
13. 13
    Washthe cake washed with hexanes
14. 14
    OtherThe yield
15. 15
    Otherupon drying

Procedure

A solution of 129 g (0.40 mol) of 1-(4-benzyloxyphenyl)-5-trifluoromethyl-1H-tetrazole in 900 mL 1:2 THF/ethanol was hydrogenated at ambient temperature over 6 g 10% Pd/C at 45 psi hydrogen for 12 h. The catalyst was removed by filtration through Celite®, the cake washed with ethanol, and the filtrate concentrated. The product was dissolved in ether, filtered through magnesium sulfate and concentrated. During concentration the product began to crystallize, as the product crystallized the mixture was flushed with hexanes to remove the ether. The resulting slurry was cooled to 0° C., aged 1 hr, filtered, and the cake washed with hexanes. The yield upon drying was 84.8 g (91.5%) of white crystalline 4-(5-trifluoromethyl-tetrazol-1-yl)-phenol: 1H NMR (CDCl3) δ 5.6 (s, 1H), 7.07 (m, 2H), 7.35 (m, 2H). MS (EI) m/z 230. Anal. Calcd for C8H5F3N4O: C, 41.75; H, 2.19; F, 24.76; N, 24.34. Found: C, 41.76; H, 2.23; F, 24.53; N, 24.42. KF <0.1%.

Source