Isonicotinic Acid → Pyridine-4-carbonyl chloride

Participants

Reaction Steps

Isonicotinic acid was refluxed with an excess of thionyl chloride to produce isonicotinic acid chloride. After the excess thionyl chloride was removed, the crude isonicotinic acid (4-pyridinecarboxylic acid) chloride was dissolved in pyridine and an equal number of moles of commercially available (from Aldrich Chemical Co., Inc.) of α-aminoacetophenone hydrochloride was added slowly with mixing. The mixture was then heated on a boiling water bath for 2 hours and then drowned in water to precipitate the product α-isonicotinamidoacetophenone, which was then recrystallized from hexane. Finally, the α-isonicotinamidoacetophenone was refluxed in a mixture of acetic anhydride (40 parts) and 90% phosphoric acid (3 parts) to form 2-(4-pyridyl)-5-phenyloxazole (4PyPO). By starting with 2-pyridinecarboxylic acid or 3-pyridinecarboxylic acid, the above method may be used to produce 2-(2-pyridyl)-5-phenyloxazole (2PyPO) or 2-(3-pyridyl)-5-phenyloxazole (3PyPO), respectively.

Provenance & Evidence