.png){kind=icon}
.png){kind=icon}
Return
Laboratory Synthesis of Octyl Methoxycinnamate Using Knoevenagel–Doebner Condensation Followed by Transesterification
.png){kind=icon}
OA
AI
R
S
M
DOI：10.1021/acs.jchemed.5c01740.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
This three-week undergraduate organic chemistry laboratory module details the synthesis of the sunscreen agent 2-ethylhexyl trans-4-methoxycinnamate, commonly known as octyl methoxycinnamate (OMC). In the first week, students perform a modified Knoevenagel–Doebner condensation between 4-methoxybenzaldehyde and monoethyl malonate utilizing a pyridine/morpholine cocatalyst system to yield ethyl trans-4-methoxycinnamate. The second week involves an acid-catalyzed transesterification with 2-ethylhexanol to produce OMC. To address the inherent limitations of this equilibrium-controlled transesterification reaction, students employ preparative thin-layer chromatography in the final week to isolate the pure product. This module integrates multistep synthesis with advanced instrumental analysis, including 1H, 13C, and DEPT-135 NMR spectroscopy. The experiment reinforces critical pedagogical concepts, such as the mechanism of carbonyl condensation and thermal decarboxylation, the application of Le Chatelier’s principle, and the relationship between molecular structure and chromatographic mobility.
Keywords:
Second-Year Undergraduate
Upper-Division Undergraduate
Laboratory Instruction
Knoevenagel−Doebner
Carbonyl Condensation
Decarboxylation
Transesterification
Equilibrium
TLC
Journal
IF:
2.9
Papers:
1.2K
Citations:
2.3W
Organization
Cited Papers