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

HRID 2259178Notes

Reaction equation

[CH3:1][C:2]([NH:5][S:6]([C:9]1[CH:13]=[CH:12][N:11]([CH3:14])[CH:10]=1)(=[O:8])=[O:7])([CH3:4])[CH3:3].C([Li])CCC.Cl[C:21]([O:23][CH3:24])=[O:22].Cl>C1COCC1.[Au]>[CH3:4][C:2]([NH:5][S:6]([C:9]1[CH:13]=[CH:12][N:11]([CH3:14])[C:10]=1[C:21]([O:23][CH3:24])=[O:22])(=[O:8])=[O:7])([CH3:1])[CH3:3]

Participants

Conditions

Temperature: -78 °C

Procedure

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. 1H NMR (CDCl3, 200 MHz.) δ: 6.71(dd,2H), 5.72(bs,1H), 3.95(s,3H), 3.91(s,3H), 1.24(s,9H).

Workup

additionwas added dropwise
temperatureto warm to room temperature
stirringstir for ca. 1.5 hours
temperaturewas cooled to 0° C.
customThe THF phase was separated
washwashed with brine
dry with materialdried (MgSO4)
concentrationconcentrated to an amber oil
customchromatographed on silica (30% ethyl acetate/70% hexanes)

Sources & evidence

ORD record: ord-98b389ccaa2e4b71a5fc5de5f8fd9eda
Source dataset: uspto-grants-1995_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05472933

Reaction notes

Loading…