3-[(4-methoxyphenyl)methylidene]pentane-2,4-dione

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

Procedure: 3-(4-methoxybenzylidene)-2,4-pentanedione was prepared by the condensation of 4-methoxy benzaldehyde with acetyl acetone in the presence of piperidine and cyclohexane as the reaction medium at reflux temperature under continuous azeotropic water removal. The reaction takes about eight hours to complete. The reaction product was purified by crystallization with methanol and yields about 70% 3-(4-methoxybenzylidene)-2,4-pentanedione (hereinafter “Compound 3”) with a purity, as determined by GC, of about 99.6%. Compound 3 is an off-white free-flowing powder having a melting point of 82-84° C. with a λmax at 319 nm. at reflux temperature under continuous azeotropic water removal The reaction product was purified by crystallization with methanol