p-Toluenesulfonic acid → 2-(4-Fluorophenyl)benzoxazole

Participants

Reaction Conditions

Reaction Steps

After the flask containing 4-Fluoro-N-(2-hydroxyphenyl)-benzamide in 250 ml of toluene of step 1 was equipped with a Dean-Stark apparatus, p-toluenesulfonic acid (12.2 g, 64 mmol, 0.2 eq) was added. The mixture was stirred at 110° C. for 8 hours. Then heating was stopped and the solution was subsequently washed with 100 ml of water, 2*100 ml of (0.2M) NaOH solution and 100 ml of water. Toluene was removed via rotary evaporator yielding 64 g (94%) of slightly off white 2-(4-fluorophenyl)-1,3-benzoxazole.

Provenance & Evidence