Hydrazine hydrate (1:1) → 2-{2-[(4-Bromophenyl)sulfonyl]phenyl}-1,3,4-oxadiazole

Participants

Reaction Conditions

Reaction Steps

Methyl 2-[(4-bromophenyl)sulfonyl]benzoate (Example 144 Step 1; 150 mg, 0.46 mmol) and hydrazine hydrate (0.06 mL, 2.32 mmol) were stirred together at room temperature for 1.5 h then at 90° C. for 2 h. The excess hydrazine was removed in vacuo and the residue was dissolved in triethylorthoformate (4.6 mL) with catalytic camphorsulfonic acid and the mixture heated at 90° C. overnight. The cooled reaction mixture was partitioned between EtOAc and water and the organic layer was washed with brine and evaporated in vacuo. The residue was purified by flash column chromatography on silica (eluant 50% EtOAc/isohexane) to yield 2-{2-[(4-bromophenyl)sulfonyl]phenyl}-1,3,4-oxadiazole (60 mg, 35%). δH (400 MHz, d6 DMSO): 9.42 (1H, s), 8.35–8.33 (1H, m), 7.97–7.91 (2H, m), 7.86–7.84 (3H, m), 7.80–7.78 (2H, m).

Provenance & Evidence