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

Temperature

-78 °C

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.

1. additionwas added dropwise at such a rate as
2. customthe temperature below -65° C
3. temperatureto warm to room temperature
4. stirringstirred for ca. 1.5 hours
5. temperaturewas cooled to 0° C.
6. customThe THF phase was separated
7. washwashed with brine
8. dry with materialdried (MgSO4)
9. concentrationconcentrated to an ember oil
10. customThe NMR of the crude reaction product

ORD record

ord-a32d55e896f94ee09bb5a13e0797fb99

Source dataset

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05723410