This is a lab question. In the lab this is what we performed: Measure 0.6 mL of

Question

This is a lab question. In the lab this is what we performed:

Measure 0.6 mL of a 4.4 M solution of sodium methoxide in methanol and 1 mL of ethanol into a 5 mL reaction vial. Add 2.5 mmol of acetaminophen and a stirring vane . Set up for reflux (see picture below) and carefully add 0.3 mL ofethyliodide through the condenser. Reflux for 1 hour. After 1 hour at reflux temperature, slowly add 2 mL of water down the condenser while the reaction mixture is still hot. If a precipitate forms, heat until it dissolves. Pour the reaction mixture into a small beaker and add an additional 2 mL of water. Cool the beaker in an ice bath until recrystallization is complete. Collect the crystals by vacuum filtration. We collected the cystals and repreformed recrystallization.

Question 5: In the end of the synthesis you recrystallize your product. What was the contamination that you were trying to

Explanation / Answer

The conversion of acetaminophen to phenacetin by the method described in the question, involves strong base NaOCH3, which may cause hydrolysis of the amide bond in acetaminophen to yield p-aminophenol and acetic acid as byproducts or impurities along with unreacted acetaminophen. These are the compounds that are considered impurties and phenacetin is purified from it.

All these products are sparingly soluble in water and the major product phenacetin is insoluble in water. Therefore it is recrystallised from the reaction bath by heating to higher temperature and slowly cooling the mixture in an ice bath.

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