Effect oF β-Alanine on The Preparation of 4-Ethoxy-Cinnamic Acid

Abstract

Objective: Cinnamic acid and its derivatives have a numerous potential applications in many different fields such as pharmacy, organic “building blocks”, and corrosion inhibitors. Method: It is well-known that Verley-Doebner modification is a high efficient method for the preparation of cinnamic acid derivaties, especially with the compounds containing electron-donating subtituents at para position in aromatic ring. In this paper, 4-ethoxy-cinnamic acid was synthesized according to Verley-Doebner reaction with the use of pyrine acting as catalyst and solvent. The effect of the β-alanine concentration on the conversion of the starting material of 4-ethoxy-benzaldehyde was thoroughly investigated using high performance liquid chromatography. The results showed that consuming of 8% of β-alanine would convert 100% of 4-ethoxy-benzaldehyde to 4-ethoxy-cinnamic acid. Result: The structure of the obtained 4-ethoxy-cinnamic acid was also confirmed using Fourier transform infrared spectroscopy, Raman spectroscopy, and Gas chromatography-Mass spectroscopy. Cinnamic acid and its derivatives have numerous potential applications in many different fields such as pharmacy, organic “building blocks”, and corrosion inhibitors. It is well-known that Verley-Doebner modification is a high efficient method for the preparation of cinnamic acid derivaties, especially with the compounds containing electron-donating subtituents at para position in aromatic ring. In this paper, 4-ethoxy-cinnamic acid was synthesized according to Verley-Doebner reaction with the use of pyrine acting as catalyst and solvent. The effect of the β-alanine concentration on the conversion of the starting material of 4-ethoxy-benzaldehyde was thoroughly investigated using high performance liquid chromatography. The results showed that consuming 8% of β-alanine would convert 100% of 4-ethoxy-benzaldehyde to 4-ethoxy-cinnamic acid. The structure of the obtained 4-ethoxy-cinnamic acid was also confirmed using Fourier transform infrared spectroscopy, Raman spectroscopy, and Gas chromatography-Mass spectroscopy.

Antibacterial Activity Testing on APMS (p-Methoxy Cinnamic Acid) Against Escherichia coli Bacteria

“…The preparation of the compound pmethoxy cinnamic acid refers to Verley-Doebner with a slight modification by going through a knoevenagel condensation reaction between anisaldehyde, malonic acid, andalanine using a pyridine catalyst (Hoai et al, 2018). Through the ultrasonic wave-assisted sonochemical method (Ghomi & Akbarzadeh, 2018).…”

“…Through the ultrasonic wave-assisted sonochemical method (Ghomi & Akbarzadeh, 2018). Knoevenagel condensation uses malonic ester, malonic acid, or acetic acid as a substitute for malonic anhydride to produce good results from cinnamic acid derivatives with electron donor substituents at the para position in the aromatic ring (Hoai et al, 2018). The use of malonic acid and -alanine and the presence of pyridine as a catalyst show great potential in the manufacture of cinnamic acid derivatives (Hoai et al, 2018).…”

“…Knoevenagel condensation uses malonic ester, malonic acid, or acetic acid as a substitute for malonic anhydride to produce good results from cinnamic acid derivatives with electron donor substituents at the para position in the aromatic ring (Hoai et al, 2018). The use of malonic acid and -alanine and the presence of pyridine as a catalyst show great potential in the manufacture of cinnamic acid derivatives (Hoai et al, 2018). The use of pyridine as an organic base catalyst is a tertiary aromatic amine with sp2 hybridization, the lone pair of pyridine nitrogen electrons are more attracted to the aromatic ring so that its basicity and nucleophilicity are rather low (Ekowati et al, 2010).…”

“…This APMS synthesis used a procedure based on Verley-Dobner (Hoai et al, 2018) with slight modifications. A total of 6.61 mmol anisaldehyde, 16.8 mmol malonic acids, and 1.12 mmol -alanine were dissolved in 37.1 mmol pyridines in an Erlenmeyer flask.…”