4-Amino-1-naphthalenesulfonic acid → 4-Methanesulfonamido-1-naphthalene sulfonic acid pyridinium salt

Participants

Reaction Steps

A suspension of 4-amino-1-naphthalene sulfonic acid (200 g, 0.897 mole) in 800 ml of pyridine was stirred mechanically while methanesulfonyl chloride (70 ml, 0.9 mole) was added slowly over about 10 min. The reaction warmed to about 60° as the solid dissolved and then slowly cooled to room temperature. The mixture was stirred overnight while a solid precipitated. After filtering and washing with 500 ml of ether, the solid was dried under a nitrogen stream to afford 211 g (62%) of 4-methanesulfonamido-1-naphthalene sulfonic acid pyridinium salt.

Provenance & Evidence