p-Toluenesulfonic acid → 2-(4'-Methylphenyl)-7-phenyl-benzoxazole

Participants

Reaction Steps

8.55 g of 2-(4'-methylphenyl)-7-phenyl-benzoxazole (produced by condensation of 2-amino-6-phenylphenol with 4-methyl-benzoyl chloride and subsequent cyclisation in o-dichlorobenzene in the presence of p-toluenesulfonic acid, melting point 144° to 145° C.) and 8.93 g of 4-phenylbenzaldehyde-4'-chloranil are dissolved, under nitrogen, in 150 ml of anhydrous dimethylformamide. After the addition of 6.72 g of pulverised potassium hydroxide, stirring is maintained for a further 15 minutes at room temperature. The temperature is then raised within 30 minutes to 40° to 45° C., and stirring is continued for 2 hours at this temperature. The reaction mixture is subsequently stirred into 450 ml of methanol, and the resulting precipitate is filtered off. The residue is washed with methanol, then with water and again with methanol and finally dried. The yield is 8.5 g of the compound of the formula ##STR14##

Provenance & Evidence