Question

Question 1 20 pts of an amine with an aldehyde or ketone produces a imine. These mines are also known as Oximes O Amines Schiff bases Amides Question 2 20 pts When ortho-vanillin and p-toluidine combine to for a imine the byproduct of this reaction is __.- Liquid Water Nitrogen Gas OLiquid Methanol Hydrogen Gas O Methane Gas

Answer 1

Question 1 20 pts The condensation of an amine with an aldehyde or ketone produces a imine These mines are also known as Oximes Amines Schiff bases Amides Question 2 20 pts When ortho-vanillin and p-toluidine combine to for a imine the byproduct of this reaction is __.- O Liquid Water Nitrogen Gas Liquid Methanol OHydrogen Gas Methane Gas

Question 3 20 pts When the imine is formed during this reaction a bright yellow color appears but when the imine is reduced with sodium borohydride the color disappears How can you explain the appearance and disappearance of this color? O The bright yellow color is the result of the extended conjugation that extends throughout the entire molecule. When the imine is reduced the molecules is no longer completely conjugated and the color is lost. O The bright yellow color is due to the byproducts of the imine formation, when the compound is dissolved ethanol before the sodium borohydride is added the byproducts are diluted and the color is lost. No bright color is observed in the formation of imine Question 4 20 pts During the reduction of the imine using sodium borohydride how do you know the reduction has been complete and you can proceed to the amide synthesis with the addition of acetic acid and heat? O The reduction takes ten minutes, after 10 minutes proceed to the amide formation step O The reduction is complete when the solution is colorless When the release of hydrogen has stopped and the solution is no longer bubbling it can be assumed that the imine is reduced and the reaction can proceed to the amide synthesis

Question 5 20 pts To form the amide acetic acid is added. Mechanistically, the lone pair on the amine acts as a nucleophile and attacks the electrophilic carbon of acetic acid. The leaving group in this reaction is the OH of acetic acid. OH is typically a poor leaving group, why would it not be a good idea to use acetic anhydride, which produces a good leaving group in the form of acetic acid, as an electrophile to produce the desired amide? OAcetic anhydride is to reactive and there is a possibility that acetic anhydride would react with the phenol and form an ester O Acetic anhydride is necessary to quench the excess sodium borohydride. Acetic anhydride cannot quench the excess sodium borohydride. Acetic acid is more reactive than acetic anhydride, thus speaks the reaction up OAcetic acid has a greater solubility in ethanol than acetic anhydride therefore it is advantageous to use acetic acid instead of acetic anhydride.