The Influence of p-hydroxyl group on the Synthesis of 2-Ethylhexyl 4-Hydroxycinnamate

The compound 2-ethylhexylcinnamate and its derivatives are known to have a protective effect on the skin against damage caused by UV radiation. A study was conducted to investigate the impact of hydroxyl groups in the para position on the synthesis of 2-ethylhexyl 4-hydroxycinnamate. In this study, compounds 2- ethylhexylcinnamate and 2-ethylhexyl 4-hydroxycinnamate were synthesized from cinnamic acid through nucleophilic acyl substitution reactions via the formation of acyl chloride compounds. The effect of hydroxyl groups in the para position was determined by comparing the percentage yield of 2-ethylhexyl 4- hydroxycinnamate to 2-ethylhexylcinnamate. The p-hydroxyl group is an electron-donating group that can influence the reactivity of the carbonyl group (C=O) through mesomery effects in the acylation reaction. The synthesis of 2-ethylhexyl 4-hydroxycinnamate (12.5%) resulted in a lower percentage yield compared to 2- ethylhexylcinnamate (55.8%). The result of the reaction was assessed for its purity using thin-layer chromatography. The identification of the synthesized product was performed through UV-Vis spectroscopy, infrared analysis, NMR and GC-MS. Hydroxyl groups in the para (p) position can reduce the reactivity of the carbon atom in the carbonyl group (C=O) in the acylation reaction of 2-ethylhexyl 4-hydroxycinnamate.