Iodine → 2,5-Dichloro-3-iodobenzoic acid

Participants

Reaction Conditions

Reaction Steps

In a flask 48.35 grams (0.191 mole) of iodine was dissolved in 90 mL of dimethyl sulfoxide. To this solution was added 29.47 grams (0.286 mole) of tertiary butyl nitrite. A solution of 39.25 grams (0.191 mole) of 3-amino-2,5-dichlorobenzoic acid in 130 mL of dimethyl sulfoxide was added dropwise to the solution of iodine and butyl nitrite. During this addition the temperature rose from 20° C. to 50° C., at which temperature the addition was stopped until the reaction mixture had cooled to 35° C. The addition was then completed. When the addition was complete, the reaction mixture was stirred for approximately 16 hours, then poured into water, and this mixture was extracted with ethyl acetate. The extracts were combined and washed with an aqueous solution of sodium hydrogen sulfite and finally with water. The combined extracts were dried over anhydrous sodium sulfate and filtered. The solvent was evaporated from the filtrate under reduced pressure, yielding 51.34 grams of 2,5-dichloro-3-iodobenzoic acid as a solid.

Provenance & Evidence