Chlorosulfonic acid → 2-Thiophenesulfonyl chloride

Participants

Reaction Steps

2-H-thiophene-urea (85 mg, 0.27 mmol), available from Step C of Preparative Example 16.3, was partially dissolved in methylene chloride (4 mL and added dropwise to a stirred solution of chlorosulfonic acid (0.09 mL, 1.35 mmol) in 4 mL of methylene chloride at room temperature. After 10 min, the mixture was poured into crushed ice and extracted with ethyl acetate several times. The extracts were washed with water and brine, dried with sodium sulfate, and concentrated to give the corresponding thiophene sulfonyl chloride as a greenish oil (45 mg) used in next step directly.

Provenance & Evidence