Phenanthridine → Phenanthridinesulfonic acid

Participants

Reaction Conditions

Reaction Steps

Add phenanthridine (5 g, 28 mmol) in portions to chlorosulfonic acid (5.6 mL, 84 mmol) cooled to 10° C. over 20 minutes Heat the reaction mixture to reflux for 20 hours. Cool the now black reaction mixture to 0° C. and add cautiously to crushed ice (500 mL). Filter the solid and dry in vacuo to give the sulfonic acid (3.61 g) as an ivory colored solid consisting of a partially resolved 7:3 mixture of regioisomers. Rf=0.35 (major), 0.19 (minor (15:85 methanol:methylene chloride, 0.2% acetic acid buffer).

Provenance & Evidence