반응 #910

반응 방정식

HCl

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

n-butyllithium

methyl chloroformate

→

title compound

수율 55.9%

Methyl 3-[[(1,1-dimethylethyl)amino]sulfonyl]-1-methyl-1H-pyrrole-2-carboxylate

수율 55.9%

용매

THF

—

hexanes

반응 조건

후처리

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   온도to warm to room temperature
3. 3
   workup.STIRRINGstir for ca. 1.5 hours
4. 4
   온도was cooled to 0° C.
5. 5
   기타The THF phase was separated
6. 6
   세척washed with brine
7. 7
   건조dried (MgSO4)
8. 8
   농축concentrated to an amber oil
9. 9
   기타chromatographed on silica (30% ethyl acetate/70% hexanes)

실험 절차

To a solution of 5 g (23 mmol) of N-(1,1-dimethylethyl)-1-methyl-1H-pyrrole-3-sulfonamide in 150 mL THF under nitrogen atmosphere cooled to -78° C. was added dropwise, at such a rate as to keep the temperature below -65° C., 20 mL (47.4 mmol) 2.32M n-butyllithium in hexanes. The resulting amber turbid solution was stirred at -78° C. for ca. 30 minutes. 1.87 mL (24.3 mmol) of methyl chloroformate was add in one portion and the resulting gold reaction mixture was allowed to warm to room temperature and stir for ca. 1.5 hours. The gold reaction mixture was cooled to 0° C. and acidified with 1N HCl. The THF phase was separated, washed with brine, dried (MgSO4) and concentrated to an amber oil. The oil was combined with the crude product from the previous example and chromatographed on silica (30% ethyl acetate/70% hexanes) affording 3.53 g of the title compound as a solid.

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