Réaction #916

Équation de réaction

N-(1,1-dimethylethyl)-1-methyl-1H-pyrrole-3-sulfonamide

N,N-dimethylformamide

HCl

→

title compound

Rendement 39.0%

N-(1,1-Dimethylethyl)-2-formyl-1-methyl-1H-pyrrole-3-sulfonamide

Rendement 39.0%

Solvants

THF

—

hexanes

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   Températureto warm to room temperature
3. 3
   workup.STIRRINGstir for ca. 2 hours
4. 4
   TempératureThe reaction mixture was cooled to 0° C.
5. 5
   AutreThe THF phase was separated
6. 6
   Lavagewashed with brine
7. 7
   Séchagedried (MgSO4)
8. 8
   Concentrationconcentrated in vacuo
9. 9
   AutreThe crude residue was chromatographed on silica (25% ethyl acetate/80% hexanes)

Mode opératoire

To a solution of 12.96 g (60 mmol) of N-(1,1-dimethylethyl)-1-methyl-1H-pyrrole-3-sulfonamide in 300 mL THF under a nitrogen atmosphere cooled to -78° C. was added dropwise, at such a rate as to keep the temperature below -65° C., 52.35 mL (123 mmol) 2.35M n-butylithium in hexanes. The reaction was stirred at -78° C. for ca. 30 minutes. To the reaction mixture was added 4.64 mL (60 mmol) of N,N-dimethylformamide dropwise. The reaction mixture was allowed to warm to room temperature and stir for ca. 2 hours. The reaction mixture was cooled to 0° C. and acidified with 1N HCl. The THF phase was separated, washed with brine, dried (MgSO4) and concentrated in vacuo. The crude residue was chromatographed on silica (25% ethyl acetate/80% hexanes) affording 5.72 g of the title compound as a white solid, m.p. 101.5°-103° C.

Source