反应详情

A mixture of (E,E)-5-[4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethyl]phenyl]-2,4-pentadien-1-al (2.3 g), 2,4-oxazolidinedione (2.0 g), piperidine (0.596 g) and acetic acid (50 ml) was refluxed under heating conditions for 15 hours. The reaction mixture was concentrated; water was added to the residue, followed by acidification with 2N HCl and subsequent extraction with ethyl acetate. The ethyl acetate layer was washed with water, dried (MgSO4), and then concentrated. The residue was subjected to silica gel chromatography to yield 5-[(E,E)-5-[4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethyl]phenyl]-2,4pentadienylidene]-2,4-oxazolidinedione [mixture of the (E)- and (Z)-configurations](1.0 g, 33%) from the fraction eluted with chloroform-ethyl acetate (9:1, v/v), which was then recrystallized from chloroform-methanol to yield light yellow prisms having a melting point of 208°-210° C.

1. temperaturewas refluxed under heating conditions for 15 hours
2. concentrationThe reaction mixture was concentrated
3. additionwater was added to the residue
4. extractionfollowed by acidification with 2N HCl and subsequent extraction with ethyl acetate
5. washThe ethyl acetate layer was washed with water
6. dry with materialdried (MgSO4)
7. concentrationconcentrated