Chlorosulfonic acid → HCID 86761396, compound

Participants

Reaction Steps

Chlorosulfonic acid (5.62 mL, 84 mmol) was dissolved in 20 mL CH2Cl2 and added to a solution of 3-Nitro-N-(thien-2-ylmethyl)benzamide (11.0 g, 42 mmol) in 100 mL CH2Cl2 under vigorous stirring. A gummy solid was formed and the reaction mixture was stirred for 3 h. The reaction was quenched with ice, and ice cold NaHCO3 solution was added to reach pH8.5. The aqueous layer was washed twice with CH2Cl2. Tetrabutylammoniumhydroxide (40% in water) (32 mL, 50 mmol) was added to the aqueous layer, while a solid was formed. The precipitate was extracted into CH2Cl2 and the aqueous layer was washed 3× with CH2Cl2. The combined organic layers were dried over MgSO4 and evaporated to dryness to afford a slightly colored foam of Tetrabutylammonium 5-{[(3-Nitrobenzoyl)amino]methyl}thiophene-2-sulfonate (24 g, 97%). NMR spectra indicated pure compound, which was used for the following chlorination step.

Provenance & Evidence