تفاعل #909

معادلة التفاعل

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

Methyl chloroformate

HCl

n-butyllithium

→

title compound

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

المذيبات

THF

—

hexanes

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONwas added dropwise at such a rate as
2. 2
   أخرىthe temperature below -65° C
3. 3
   درجة الحرارةto warm to room temperature
4. 4
   workup.STIRRINGstirred for ca. 1.5 hours
5. 5
   درجة الحرارةwas cooled to 0° C.
6. 6
   أخرىThe THF phase was separated
7. 7
   غسيلwashed with brine
8. 8
   تجفيفdried (MgSO4)
9. 9
   تركيزconcentrated to an ember oil
10. 10
    أخرىThe NMR of the crude reaction product

الإجراء التجريبي

To a solution of I g (4.62 mol) 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 ember 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.

المصدر