Phosphoric Acid → 5-(4-Methoxyphenyl)-2-(pyridin-4-yl)oxazole

Participants

Reaction Conditions

Reaction Steps

α-isonicotinamido-p-methoxyacetophenone (11.5 g., 0.043 mole) was added portion-wise to a stirred solution of 200 ml of acetic anhydride and 15 ml of 90% phosphoric acid; during the addition an exotherm raised the reaction temperature to 40° C. After the addition was complete the reaction mixture was stirred and refluxed for 2 hours. After cooling, the supernatant liquid was decanted from the viscous precipitate, which was crystallized by titration with 350 ml of 1% aqueous sodium hydroxide. The yellow solid was filtered, washed with distilled water (200 ml), and dried in vacuo yielding 7.76 g. (yield 72%) of 2-(4-pyridyl)-5-p-methoxyphenyloxazole, m.p. 105°-107° C.

Provenance & Evidence