2-Aminopyridine → 6-Aminopyridine-3-sulfonic acid

Participants

Reaction Conditions

Reaction Steps

2-Aminopyridine (80 g, 0.85 mol) was added portionwise over 30 minutes to stirred oleum (320 g) and the resulting solution heated at 140° C. for 4 hours, then allowed to cool. The reaction mixture was poured onto stirred ice (200 g) and this mixture stirred at ice-salt bath temperature for a further 2 hours. The resulting suspension was filtered, then the collected solid washed successively with ice-water (200 ml) and cold industrial methylated spirit (IMS) (200 ml) and, finally, dried under suction to provide the title compound (111.3 g, 75%) as a solid. LRMS: m/z 175 (M+1)+.

Provenance & Evidence