Trifluoroacetic anhydride → 2-Propoxy-5-iodonicotinic acid

Participants

Reaction Steps

N-Iodosuccinamide (18.22 g, 0.08 mol), trifluoroacetic acid (100 ml) and trifluoroacetic anhydride (25 ml) were added to 2-propoxynicotinic acid (0.054 mol). The mixture was refluxed for 2.5h, cooled and the solvents evaporated. The residue was extracted from water with ethyl acetate and the organics washed with water (twice) and brine (twice), dried (MgSO4) and concentrated. The red residue was redissolved in ethyl acetate washed with sodium thiosulfate solution (twice), water (twice), brine (twice), redried (MgSO4) and concentrated to give the desired product as a solid; 1H NMR (300 MHz, CDCl3): δ=1.05 (t, 3H), 1.85-2.0 (m, 2H), 4.5 (t, 2H), 8.5 (s, 1H), 8.6 (s, 1H), Analysis: found C, 35.16; H, 3.19; N, 4.46. Calcd for C9H10INO3: C, 35.19; H, 3.28; N, 4.56%; LRMS (TSP): 529.5 (MH+).

Provenance & Evidence