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

HRID 2376999Notes

Reaction equation

HRID 2376999 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([C:11]2[CH:20]=[CH:19][CH:18]=[CH:17][C:12]=2[C:13]([O:15][CH3:16])=O)(=[O:10])=[O:9])=[CH:4][CH:3]=1.O.[NH2:22][NH2:23]>>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([C:11]2[CH:20]=[CH:19][CH:18]=[CH:17][C:12]=2[C:13]2[O:15][CH:16]=[N:22][N:23]=2)(=[O:10])=[O:9])=[CH:4][CH:3]=1

Participants

3

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 21099525Methyl 2-[(4-bromophenyl)sulfonyl]benzoate

Product 1

HCID 210994102-{2-[(4-Bromophenyl)sulfonyl]phenyl}-1,3,4-oxadiazoleYield 35.7%

Conditions

Temperature
90 °C

Procedure

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).

Workup

  1. customThe excess hydrazine was removed in vacuo
  2. dissolutionthe residue was dissolved in triethylorthoformate (4.6 mL) with catalytic camphorsulfonic acid
  3. customThe cooled reaction mixture
  4. customwas partitioned between EtOAc and water
  5. washthe organic layer was washed with brine
  6. customevaporated in vacuo
  7. customThe residue was purified by flash column chromatography on silica (eluant 50% EtOAc/isohexane)

Sources & evidence

ORD record
ord-61a59ad759c54e2cbaa1ca8890e43f97
Source dataset
uspto-grants-2008_12
Patent number
US07468393B2

Reaction notes

Loading…