Method Outline
Week 1:
- Add reagents and reflux
- Repeat
Week 2:
- Analyze pheacetin through MP, IR, H NMR, and mass
- Once again add reagents and reflux
- Adjust the pH*
- Add reagents and... reflux!
Phenacetin
Summary of Results
Introduction
- Percent yield: 60%
- MP: 123 (lit 134)
- IR: good.
- H NMR: good.
Week 3:
- Analyze dulcin through MP, IR, H NMR, and mass
Dulcin
- Percent yield: 110%...
- MP: 160 (lit 173 dulcin)
- IR: bad.
- H NMR: bad.
Objectives
Week 1:
- Synthesize phenacetin from acetaminophen/Tylenol
Week 2:
- Identify product phenacetin though spectra and MP before continuing the synthesis
- Synthesize dulcin from phenacetin
Week 3:
- Identify dulcin through spectra and MP
Chemical Equations
[Attempted] Synthesis of the Sweetener Dulcin from Acetaminophen
what dulcin H NMR should
have looked like
para substituted
aromatic ring
next to
electronegative
atom (ethyloxy-)
next to unsaturated center
Experimental & Literature Spectra for Products Phenacetin and Dulcin
Dulcin (?)
Phenacetin
Sources
- Goldsmith, R.H. 1987. “A Tale of Two Sweeteners,” J. Chem. Ed., 64(11):954-955.
- Hill, J.W. 1988. “Using Chemical Principles to Encourage Critical Thinking in Consumer Chemistry,” J. Chem. Ed., 65(3):209.
- PubChem Compound. Phenacetin. http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=4754#x94
- SciFinder Scholar:
- Dulcin H NMR
- Phenacetin H NMR
- Sodium Bicarbonate H NMR
- Spectral Database for Organic Compounds:
- Dulcin IR
- Phenacetin IR
- Williams BD, Williams B, Rodino L. 2000. “Synthesis of the Sweetner Dulcin from the Analgesic Acetaminophen,” J. Chem. Ed., 77(3):357-358.
- 3472: alcohol
- 3281: secondary amine
- 3131, 3073: alkene
- 2927: Csp3-H
same peaks as experimental
COOH
broad stretch
2500-3500
Synthesize dulcin from acetaminophen & identify through H NMR, IR, and MP
- But was able to find what the final reaction solid was :)
Synthesize phenacetin from acetaminophen & identified through H NMR, IR, and MP.
Conclusions
Week 3
- Impurities in the phenacetin H NMR tube
Week 2
- pH adjustment
- Use liquid sodium bicarbonate
- Burning the reaction mixture
- Phenacetin was positively identified the first time, but the reaction was not able to continue to dulcin due to this
Week 1
- Not drying the product enough by using an oven/heat source
- Thought drying in drawer would be sufficient
Possible Errors