تفاعل #910

معادلة التفاعل

HCl

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

n-butyllithium

methyl chloroformate

→

title compound

المردود 55.9%

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

المردود 55.9%

المذيبات

THF

—

hexanes

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   درجة الحرارةto warm to room temperature
3. 3
   workup.STIRRINGstir for ca. 1.5 hours
4. 4
   درجة الحرارةwas cooled to 0° C.
5. 5
   أخرىThe THF phase was separated
6. 6
   غسيلwashed with brine
7. 7
   تجفيفdried (MgSO4)
8. 8
   تركيزconcentrated to an amber oil
9. 9
   أخرىchromatographed on silica (30% ethyl acetate/70% hexanes)

الإجراء التجريبي

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.

المصدر