Hydrochloric Acid → 4-Iodo-3,5-dimethyl-phenol

Participants

Reaction Steps

3,5-dimethyl-4-iodophenol was prepared as follows: To a solution of 59.1 g (484 mmol) of 3,5-dimethylphenol in 1 l of methanol was added 395 ml of 36% hydrochloric acid, with occasional cooling to maintain the temperature at 20°-30° C. To the resulting solution was then added a solution of 54.3 g (327 mmol) potassium iodide and 33.5 g (157 mmol) potassium iodate in 500 ml water over a 5 minute period. The solution became red and cloudy and a tan precipitate formed. After stirring at room temperature for 20 hours, the reaction mixture was cooled in ice and the precipitate collected and washed with ice cold 2/1 (v:v) water/methanol. The resulting tan solid was recrystallized several times from hot methanol and water to yield 36.4 g (15% yield) of white needles, mp 131°-132° C., which were identified as 3,5-dimethyl-4-iodophenol. 1H NMR analysis indicated the following: (δ, CDCls) 8.03 (br s, lH), 6.52 (s, 2H) and 2.35 (s, 6H). Mass spectrum analysis indicated the following: (m/e) 248 (m+, 100%), 121, 91 and 77.

Provenance & Evidence