Réaction #1121762

Équation de réaction

NaH

6

4-Bromopyrrole-2-carboxaldehyde

p-toluenesulfonyl chloride

→

crystals

Rendement 68.6%

4-Bromo-2-formyl-N-p-tosylpyrrole

Rendement 68.6%

Solvants

THF

Conditions de réaction

Traitement

1. 1
   workup.WAITAfter 16 h
2. 2
   AutreThe reaction mixture was quenched
3. 3
   workup.ADDITIONby adding aqueous NH4Cl
4. 4
   workup.ADDITIONEthyl acetate was added
5. 5
   Autrethe organic layer was separated
6. 6
   LavageThe organic layer was washed with water, brine
7. 7
   Séchagedried (Na2SO4)
8. 8
   ConcentrationConcentration
9. 9
   Autrefollowed by crystallization (ethyl acetate/hexanes)

Mode opératoire

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.

Source