Reaktion #2346359

Reaktionsgleichung

Methyl chloroformate

HCl

n-butyllithium

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

→

title compound

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

Lösungsmittel

—

hexanes

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added dropwise at such a rate as
2. 2
   Sonstigethe temperature below -65° C
3. 3
   Temperaturto warm to room temperature
4. 4
   workup.STIRRINGstirred for ca. 1.5 hours
5. 5
   Temperaturwas cooled to 0° C.
6. 6
   SonstigeThe THF phase was separated
7. 7
   Waschenwashed with brine
8. 8
   Trocknendried (MgSO4)
9. 9
   Einengenconcentrated to an amber oil
10. 10
    SonstigeThe NMR of the crude reaction product

Vorschrift

To a solution of 1 g (4.62 mmol) of N-(1,1-dimethylethyl)-1-methyl-1H-pyrrole-3-sulfonamide in 150 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. 4.1 mL (9.48 mmol) 2.32M n-butyllithium in hexanes. The resulting amber turbid solution was stirred at -78° C. for ca. 30 minutes. Methyl chloroformate (0.37 mL, 4.86 mmol) was added in one portion and the resulting gold reaction mixture was allowed to warm to room temperature and stirred 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 NMR of the crude reaction product was consistent with the title compound, additionally the NMR indicated that a trace of the starting material was also present. The crude material was combined with the product from a similar reaction run on the scale described below and chromatographed to give the title compound.

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