Sulfuric Acid → 1-tert-Butyl-5-(2-bromophenyl)-1H-tetrazole

Reaction equation

[Br:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[C:8]1[NH:12][N:11]=[N:10][N:9]=1.[CH3:13][C:14](O)([CH3:16])[CH3:15].OS(O)(=O)=O>FC(F)(F)C(O)=O>[C:14]([N:9]1[C:8]([C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[Br:1])=[N:12][N:11]=[N:10]1)([CH3:16])([CH3:15])[CH3:13]

Participants

Procedure

To a solution of 5-(2-bromophenyl)-1H-tetrazole (7.9 g, 0.035 mol) in trifluoroacetic acid (35 mL) was added tBuOH (5.2 g, 0.070 mol) and H2SO4 (1.0 mL, 0.0175 mol). After 18 h, the solution was concentrated and the residue was taken up in EtOAc. The mixture was washed with water, 2.5 N NaOH, water, dried (MgSO4), and concentrated. Purification by flash chromatography (20% EtOAc/hexane) gave 6.6 g (67%) of product as a pale yellow oil.