The condensation of malonic monoester (I) with 7-methoxy-4H-1-benzopyran-3-carbaldehyde (II) by means of piperidine in refluxing benzene gives the 2-methylene propionaate (III), which by reaction with butylhydrazine (IV) and sodium acetate in refluxing ethanol/water yields the pyrazole (V). The condensation of (V) with methyl 2-(bromomethyl)benzoate (VI) by means of NaH in DMF gives the target compound as the methyl ethyl diester (VII), which is finally hydrolyzed with LiOH in refluxing methanol/water.

Reaction of methyl 2-(2-acetyl-5-methoxyphenoxymethyl)benzoate (I) with methyl formate by means of NaH in toluene gives methyl 2-[2-(3-hydroxy-2-propenoyl)-5-methoxyphenoxymethyl]benzoate (II), which is treated with diethylamine in toluene yielding the corresponding diethylamino derivative (III). The cyclization of (III) with butylhydrazine (IV) by means of sodium acetate in methanol/water affords the pyrazole (V), which by reaction with DMF and POCl3 is converted into the pyrazole-4-carbaldehyde (VI). The hydrolysis of the methyl ester of (VI) with LiOH in hot methanol/water gives the acid (VII), which is condensed with the malonic monoester (VIII) by means of piperidine in refluxing benzene yielding the target compound as the ethyl ester (IX). Finally, this compound is saponified with LiOH in refluxing methanol/water.