Use of glycerol, waste glycerol from biodiesel production and other protic solvents in bioactive alpha, beta-unsaturated ketones synthesis

Author(s)

Torrezan, Guilherme Silva ^[1] ; Polaquini, Carlos Roberto ^[1] ; Lima, Marcelo Freitas ^[1] ; Regasini, Luis Octavio ^[1]

Affiliation

^[1] Sao Paulo State Univ Unesp, Inst Biosci Humanities & Exact Sci Ibilce, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

• Document type: Journal article
• Source: SUSTAINABLE CHEMISTRY AND PHARMACY; v. 16, JUN 2020.
• Web of Science Citations: 0

Abstract

Glycerol is the main co -product from biodiesel production and has been recognized as a sustainable solvent. Herein, we used glycerol and waste glycerol in synthesis of two bioactive ?, ?-unsaturated ketones ( E,E )-1,5- diphenylpenta-2,4-dien-1-one ( 1 ) and ( E,E )-2,6-dibenzylidenecyclohexanone ( 2 ), using aldol mono- and di - condensation reactions, respectively. Crude yield values were calculated from product mass after precipitation and drying. Purity was measured by High Performance Liquid Chromatography with Photodiode Array (HPLC- PAD) using analytical curves and reference compounds. Glycerol and waste glycerol were able to furnish 1 and 2 in higher crude yields and HPLC-PAD purities values than other protic solvents (ethanol, methanol, PEG -400 and water). In order to investigate reasons of glycerol efficiency when compared to water efficiency, we performed computational calculations using Density Functional Theory (DFT). Theoretical predictions confirmed the E1cB mechanism, as well as favourable energy barrier using glycerol in comparison to water, corroborating their sustainable properties. In addition, waste glycerol from corn and sunflower oil transesterifications were used in the synthesis of 1 and 2 for four recycles, displaying good crude yields and HPLC-purities. (AU)

• FAPESP's process: 18/15083-2 - Synthesis and Biological Evaluation of Isobavachalcone (IBC) and Analogs as Potential Agents against Tuberculosis
• Grantee: Luis Octávio Regasini
• Support type: Regular Research Grants
• FAPESP's process: 09/53989-4 - Acquisition of a nuclear magnetic resonance spectrometer for studies of biomolecules
• Grantee: Raghuvir Krishnaswamy Arni
• Support type: Multi-user Equipment Program
• FAPESP's process: 14/50926-0 - INCT 2014: biodiversity and natural products
• Grantee: Vanderlan da Silva Bolzani
• Support type: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 14/18330-0 - Synthesis and biological evaluation of curcumin-cinnamaldehyde hybrids as bacterial cell division inhibitors
• Grantee: Luis Octávio Regasini
• Support type: Regular Research Grants