TEMPERATURE OPTIMIZATION AGAINST P-METHOXYCINAMIC ACID SYNTHESIS THROUGH ULTRASONIC WAVE-ASSISTED KNOEVENAGEL CONDENSATION

Abstract

Cinnamic acid derivative compounds are found in almost all plants but the quantity is very small that
it cannot only rely on the results collected from the extraction method or the isolation of plant parts alone.
Increasing amount of production of cinnamic acid derivatives can be done by chemical synthesis. One of the
cinnamic acid derivatives that can be synthesized is p-methoxycinamic acid. It is a derivative of cinnamic acid
that is substituted by a methoxy group at para position. The synthesis of this cinnamic derivative was obtained
through the knoevenagel condensation reaction with the sonochemical method by reacting 6.61 mmol
anisaldehyde, 16.8 mmol malonic acid, and 1.12 mmol β-alanine dissolved in 37.1 mmol pyridine in an
Erlenmeyer flask, then sonicated for 60 minutes at temperatures (40⁰C, 50^oC, 60^oC). The synthesized compound
was tested organoleptically and its melting point was measured. The result structure was elucidated using FTIR
and GC-MS. The synthesized compound in the form of shiny white fine crystals had a distinctive odor and an
optimum temperature of 60⁰C and produces % yield of 92.71%. The results of the structural elucidation test of
the synthesized compound using FTIR-ATR showed the presence of an OH carboxylate group, C=O
carboxylate, C=C, an aromatic group, C=C conjugated aromatic group, and aromatic substitution in the para
position. Testing by GC-MS found that the compound has a purity of 100% with a retention time of 11.71
minutes, with a base peak of 178 m/z with a relative abundance of 100%.

Keywords: elucidation, knoevenagel, p-methoxycinamic acid, synthesis, sonochemical.