ALDOL CONDENSATION REACTION BASED ON GREEN CHEMISTRY CONCEPT FOR THE DEVELOPMENT OF ORGANIC CHEMISTRY LABORATORY WORKS MODULE

• Main Author: Amri, Yulida
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/37733
• Institution: Institut Teknologi Bandung

Chemistry as one of the fields of science contains many of abstract concepts. Therefore laboratory works play an important role in explaining the chemistry concepts to students. On the other hand, the laboratory skills of students can be developed through laboratory experiments. One aspect that must be considered in the preparation of laboratory works module is the use of chemicals. The educators should be able to apply the concept of green chemistry through the use of chemicals that are easily available, low cost, safe and harmless so as to reduce the risk of danger in the experiment. The concept of green chemistry can be applied to perform the aldol condensation reaction experiment. In this study, polyethylene glycol (PEG-400) was used as solvent in the aldol condensation reaction between benzaldehyde with acetone and benzaldehyde with acetophenone. The reaction of benzaldehyde and acetoneproduced the product with a chemical yields of 97.4%. Recrystallization of product from ethanol was recovered by 15% with a melting point of 192-194 oC. The characterization by FTIR spectroscopy showed characteristric peaks of functional groups of =C-H alkenes (697 cm-1), C=C alkene (1649 cm-1), and C=O carbonyl (1694 cm-1). The 1H-NMR spectroscopy characterizations showed proton signals at the chemical shifts of 7-8 ppm indicating the presence of aromatic groups. In addition, the proton signals was also appeared at the chemical shifts of 6.61 ppm (J = 16.2 Hz) and 6.34 ppm (J = 15.9 Hz) which indicated the existence of protons bound to the trans alkenes. In the reaction of benzaldehyde and acetophenone produced benzalacetophenone (chalcone) with a chemical yields of 74.0%. Recrystallization of product from ethanol-water was recovered by 47.0% with a melting point of 55-57 oC. The 1H- NMR spectroscopy characterizations showed proton signals at the chemical shifts of 7-8 ppm indicating the presence of aromatic groups. The proton signals was also appeared at the chemical shifts of 7.8 ppm (J = 15.7 Hz) and 7.5 ppm (J = 16.25 Hz) which indicated the existence of two protons bound to the trans alkenes. The measurement of MS spectrum showed a signal [M+H]+ at m/z 209.0958 corresponded to m/z value of the chalcone (208.0880). The laboratory works module was subsequently compiled and being tested to the Chemistry undergraduate students of Institut Teknologi Bandung. The positive responses of students to the developed laboratory works module was 85.58%. The green chemistry concepts has been integrated within the developed laboratory works module, and the analysis of the research results showed that the developed laboratory works module has applied at least 9 principles of 12 green chemistry principles.