反应详情

A mixture of 4-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzaldehyde (2.9 g), sodium pyruvate (3.3 g), sodium carbonate (3.2 g), water (80 ml) and methanol (80 ml) was stirred for 6 hours under reflux. The reaction mixture was concentrated under reflux to about ⅓ of the initial volume. The concentrate was subjected to extraction with ethyl acetate. The aqueous layer was acidified with conc. HCl. Resulting crystalline precipitate was collected by filtration to obtain (E)-4-(5-methyl-2-phenyl-4-oxazolylmethoxy)benzylidenepyruvic acid (1.6 g, 44%). Recrystallization from chloroform-methanol gave colorless needles, m.p.197-198° C.

1. temperatureunder reflux
2. concentrationThe reaction mixture was concentrated
3. temperatureunder reflux to about ⅓ of the initial volume
4. extractionThe concentrate was subjected to extraction with ethyl acetate
5. filtrationResulting crystalline precipitate was collected by filtration