Benzaldehyde → 2-Oxo-4-phenyl-but-3-enoic acid

Participants

Reaction Conditions

Reaction Steps

In a 2 L 3-necked flask equipped with a mechanical stirrer, dropping funnel and thermometer was placed benzaldehyde (119.8 g, 1.13 mol) and pyruvic acid (99.44 g, 1.13 mol) in methanol (100 mL) under argon. The reaction mixture was cooled to 10° C. A freshly prepared solution of potassium hydroxide (95.2 g, 1.7 mol) in methanol (350 mL) was added over 30 min. During the addition, the solution turned yellow and eventually a precipitate was formed. The reaction was allowed to warm to room temperature and was placed in a refrigerator overnight. The granular solid in the flask was collected, and was suspended over a cold mixture of methanol (500 mL) and ether (500 mL). After stirring for 1 hr, the solid was collected and dried in a dessicator under high vacuum to give 185 g of a solid. This solid was dissolved in water (1500 mL) and extracted with ethyl acetate (2×200 mL). The aqueous layer was acidified with 3M HCl to pH 2 and extracted with dichloromethane (5×250 mL). The combined organic layers were washed with brine (2×250 mL), dried over magnesium sulfate (30 g) and concentrated under reduced pressure to give 84 g of intermediate 1 as an oil which solidified (32%).

Provenance & Evidence