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Synthesis of Oil of Wintergreen. Chemistry 1060 Laboratory. Analysis. Purity determination Thin Layer Chromatography (TLC) Separation and identification stationary phase – silica gel mobile phase – organic solvent Relative attraction to the two phases Polarity. Solvent front.
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Synthesis of Oil of Wintergreen Chemistry 1060 Laboratory
Analysis • Purity determination • Thin Layer Chromatography (TLC) • Separation and identification • stationary phase – silica gel • mobile phase – organic solvent • Relative attraction to the two phases • Polarity
Solvent front Rf = 3/5 = 0.60 5 cm 3 cm Origin Analysis • Thin Layer Chromatography (TLC) • Retention factor (Rf) values
Analysis • Thin Layer Chromatography (TLC) • Salicylic acid (starting material) • Pure oil of wintergreen (from stockroom) • Isolated product • UV detection • Results • Isolated product • Rf pure oil of wintergreen • Salicylic acid removed?
Analysis • Structure confirmation • 1H nuclear magnetic resonance (1H NMR) - or proton magnetic resonance (PMR)
Analysis • 1H NMR
Analysis • 1H NMR radio-frequency region of the spectrum
Analysis • 1H NMR – Shielding
Analysis • 1H NMR – Chemical Shifts, Chemical Equivalency tetramethylsilane (TMS)
Analysis • 1H NMR – Chemical Shifts, Integration 3 1
Analysis • 1H NMR – Chemical Shifts, Complex Patterns
Analysis • 1H NMR – Characterizing starting material and product salicylic acid methyl salicylate
Summary • GoalsWeek 1: • To synthesize methyl salicylate, or oil of wintergreen, from salicylic acid and methanol • To isolate the product using liquid-liquid extraction Week 2: • To verify the purity and identity of the product using thin layer chromatography (TLC) • To further confirm the identity of the product by nuclear magnetic resonance (NMR) spectroscopy