Reacción #1121762

Ecuación de reacción

NaH

6

4-Bromopyrrole-2-carboxaldehyde

p-toluenesulfonyl chloride

→

crystals

Rendimiento 68.6%

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

Rendimiento 68.6%

Disolventes

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITAfter 16 h
2. 2
   OtroThe reaction mixture was quenched
3. 3
   workup.ADDITIONby adding aqueous NH4Cl
4. 4
   workup.ADDITIONEthyl acetate was added
5. 5
   Otrothe organic layer was separated
6. 6
   LavadoThe organic layer was washed with water, brine
7. 7
   Secadodried (Na2SO4)
8. 8
   ConcentraciónConcentration
9. 9
   Otrofollowed by crystallization (ethyl acetate/hexanes)

Procedimiento

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.

Fuente