In the reaction shown below, 2-methyl-2-butanol is reacted with a solution of ex
ID: 492805 • Letter: I
Question
In the reaction shown below, 2-methyl-2-butanol is reacted with a solution of excess, equimolar ammonium chloride and ammonium bromide in sulfuric acid and water. The reaction forms 2-bromo-2-methylbutane and 2-chloro-2-methylbutane. The products shown are liquid at room temperature. Devise a separation scheme to isolate the products together from the reaction mixture. Assume that 2-methyl-2-butanol is the limiting reagent and has a lower boiling point than the two products. Below is a list of reagents available in lab. You may use any of these given reagents (e.g., acids, bases) as needed in your separation scheme and you also have access to a solvent evaporator if a solvent must be evaporated, and a filtration apparatus to filter. Be specific in each reagent name and technique used in your separation scheme. The most efficient separation scheme will receive the most credit.Explanation / Answer
Boiling point of 2-methyl-2-butanol is 101 to 103 °C
Boiling point of 2-Bromo-2-methylbutane is 73.3 °C
Boiling point of 2-chloro-2-methylbutane is 85 to 86 °C
The products has to be extracted with diethylether using a seperating funnel, the extraction has to be done 3 times. Remember the top layer is diethyl ether, and it contains our product.
After extracting in diethyl ether, wash the organic layer with 10 % NaOH to remove excess acid. It will also remove unreacted starting material, 2-methyl-2-butanol by forning water soluble alkoxide ion.
wash the organic layer with distilled water.
Collect organic layer, dry over anhydrous Na2SO4, filter into Round bottom flask, evaporate solvent at low temp.