Nitrogen → 7-Bromo-isoquinoline-5-Sulfonic Acid

Participants

Reaction Steps

Add fuming H2SO4 (2,000 mL, 21.33 mol; 26-29.5% free SO3) to a 5-L round bottom flask, equipped with a mechanical stirrer, reflux condenser, N2 line, and thermometer. Cool the fuming H2SO4 to ˜10° C. with an ice/acetone bath, then add 7-bromoisoquinoline HCl (500.00 g, 2.04 mol) portion-wise, keeping the temperature of the reaction mixture below ˜15-20° C. Upon complete addition of 7-bromoisoquinoline HCl, heat the resulting reaction mixture at ˜100° C. overnight. Cool the reaction mixture to room temperature, then slowly pour into a stirring solution of ice H2O. Recover the resulting precipitate by vacuum filtration, washing with H2O, then Et2O, and dry under vacuum filtration, followed by drying in a drying oven under reduced pressure at ˜35° C. to afford the title compound (501.42 g, 85% yield) as an off-white solid: TOF-MS [ES+; m/z] 287.9331/287.9330.

Provenance & Evidence