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

HRID 222560Notes

Reaction equation

HRID 222560 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 (Tietze, L. F. et al., Synthesis 1996, 851-857), a stirred suspension of NaH (865 mg, 36.0 mmol) in THF (200 mL) was treated with 17 (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. customa reported procedure (Tietze, L. F. et al., Synthesis 1996, 851-857)
  2. waitAfter 16 h
  3. customThe reaction mixture was quenched
  4. additionby adding aqueous NH4Cl
  5. additionEthyl acetate was added
  6. customthe organic layer was separated
  7. washThe organic layer was washed with water, brine
  8. dry with materialdried (Na2SO4)
  9. concentrationConcentration
  10. customfollowed by crystallization (ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-3542a5de30da4492b31a0204b27af820
Source dataset
uspto-grants-2012_06
Patent number
US08207329B2

Reaction notes

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