4-ethoxy-2-hydroxybenzaldehyde

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 5 parts of 2-hydroxy-4-ethoxy benzaldehyde and 7 parts of the ethyl ester of 3-phenyl-1,2,4-oxadiazole-5-acetic acid are dissolved in 80 parts of ethanol, then 0.3 part of piperidine is added. The mixture is heated under reflux for one hour, then the precipitate obtained after cooling is filtered. 8 parts of 7-ethoxy-3-(3-phenyl 1,2,4-oxadiazol-5-yl) coumarin are obtained which melts at 229° C. after crystallization in dioxane. The mixture is heated under reflux for one hour the precipitate obtained after cooling is filtered