4-Toluenesulfonyl chloride → 4-Bromo-2-formyl-n-p-tosylpyrrole

HRID 874146Notes

Reaction equation

HRID 874146 reaction equation
[H-].[Na+].[Br:3][C:4]1[CH:5]=[C:6]([CH:9]=[O:10])[NH:7][CH:8]=1.[C:11]1([CH3:21])[CH:16]=[CH:15][C:14]([S:17](Cl)(=[O:19])=[O:18])=[CH:13][CH:12]=1>C1COCC1>[CH3:21][C:11]1[CH:16]=[CH:15][C:14]([S:17]([N:7]2[C:6]([CH:9]=[O:10])=[CH:5][C:4]([Br:3])=[CH:8]2)(=[O:19])=[O:18])=[CH:13][CH:12]=1

Participants

5

Reactant 3

HCID 73974-Toluenesulfonyl chlorideHCID 24758Sodium hydrideHCID 5996274-Bromo-1H-pyrrole-2-carbaldehyde

Product 1

HCID 116884614-Bromo-2-formyl-n-p-tosylpyrroleYield 68.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Following a reported procedure,18 a stirred suspension of NaH (865 mg, 36.0 mmol) in THF (200 mL) was treated with 6 (5.22 g, 30.0 mmol) at room temperature. When the evolution of gas had ceased, the mixture was stirred for 1 h before treating with p-toluenesulfonyl chloride (6.30 g, 33.0 mmol). After 16 h, the conversion was complete as monitored by TLC. The reaction mixture was quenched by adding aqueous NH4Cl. Ethyl acetate was added and the organic layer was separated. The organic layer was washed with water, brine and dried (Na2SO4). Concentration followed by crystallization (ethyl acetate/hexanes) afforded pale yellow crystals (6.75 g, 68%): mp 83-85° C.; 1H NMR δ 2.43 (s, 3H), 7.09 (d, J=2.0 Hz, 1H), 7.35 (d, J=8.3 Hz, 2H), 7.57 (d, J=2.0 Hz, 1H), 7.81 (d, J=8.3 Hz, 2H), 9.94 (s, 1H); 13C NMR δ 22.0, 101.8, 125.4, 127.8, 127.9, 130.6, 133.5, 134.7, 146.7, 178.5. Anal. Calcd or C12H10BrNO3S: C, 43.92; H, 3.07; N, 4.27; S, 9.77. Found. C, 43.92; H, 3.02; N, 4.26; S, 9.84.

Workup

  1. waitAfter 16 h
  2. customThe reaction mixture was quenched
  3. additionby adding aqueous NH4Cl
  4. additionEthyl acetate was added
  5. customthe organic layer was separated
  6. washThe organic layer was washed with water, brine
  7. dry with materialdried (Na2SO4)
  8. concentrationConcentration
  9. customfollowed by crystallization (ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-5d905a1bdaa8454d853f8964c8d14df0
Source dataset
uspto-grants-2015_03
Patent number
US08980565B2

Reaction notes

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