Citric Acid → 5-Methanesulfonamidoisoquinoline

Participants

Reaction Steps

Methanesulfonyl chloride (3.2 ml, 0.042 mol) was added to a solution of 5-aminoisoquinoline (5.0 g, 0.035 mol) in pyridine (40 ml) and the mixture was allowed to stand for 72 hours. The reaction mixture was then poured into aqueous citric acid (10%, 400 ml) and extracted with ethyl acetate (2×230 ml). The organic layer was evaporated to give a residue which was purified on silica gel, eluting with dichloromethane:methanol (95:5, v/v), to afford the subtitle compound as a solid (3.55 g, 46%). Rf 0.03 (CH2Cl2:diethyl ether 4:1, v/v). 1H NMR (D6-DMSO) Γ: 3.07 (3H, s), 7.68 (1H, t), 7.75 (1H, d), 8.03 (1H, d), 8.10 (1H, d), 8.54 (1H, d), 9.32 (1H, s), 9.79 (1H, bs).

Provenance & Evidence