Chlorosulfonic acid → 6-[2-(4-Chlorosulfonyl-phenoxy)-acetylamino]-n-hexanoic acid 2-(3-nitro-benzenesulfonyl)ethyl ester

Participants

Reaction Steps

To a cooled solution of 6-(2-phenoxy-acetylamino)-n-hexanoic acid 2-(3-nitro-benzenesulfonyl)ethyl ester (4.5 g, 9.4 mmol) in 10 mL of CH2Cl2 was added drop-wise ClSO3H (3.3 mL, 5.5 g, 5 eq., 47.0 mmol)) at 0° C. The chlorosulfonylation reaction was complete in 30 min. The thick reaction mixture was poured onto the crushed ice with vigorous stirring, resulting in a yellow gummy material mostly in the bottom of the flask. The mixture was extracted with CH2Cl2, the organic layers were dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give a syrupy material, which was purified by column chromatography (CH2Cl2 to 1% MeOH in CH2Cl2) to give 6-[2-(4-chlorosulfonyl-phenoxy)-acetylamino]-n-hexanoic acid 2-(3-nitro-benzenesulfonyl)ethyl ester (Intermediate 19, 3.3 g, 60%) as a white foam.

Provenance & Evidence