Hydrochloric Acid → 2-Iodo-5-(trifluoromethyl)benzoic acid

Participants

Reaction Conditions

Reaction Steps

5-Trifluoromethylanthranilic acid (43 g, 0.21 mol) is suspended in a mixture of concentrated HCl (40 mL) and water (240 mL), cooled to 0° C. and stirred. Sodium nitrite (18 g, 0.26 mol) is dissolved in water (50 mL) and slowly added taking care to maintain the temperature of the reaction mixture below 5° C. Stirring is continued at 0° C. for 30 minutes. Potassium iodide (65 g, 0.39 mol) is dissolved in a mixture of concentrated H2SO4 (15 mL) and water (100 mL) and the solution is added dropwise to the reaction mixture while keeping the temperature below 10° C. The mixture is then heated to 100° C. and stirred for 2 hours. After cooling to room temperature, the mixture is partitioned between EtOAc (750 mL) and saturated sodium bisulfite solution (500 mL). The organic layer is washed again with saturated sodium bisulfite solution (500 mL) and then brine (500 mL), dried (MgSO4) and concentrated by rotary evaporator to give 5-trifluoromethyl-2-iodobenzoic acid (m.p. 171–172° C.).

Provenance & Evidence