Question

Prepare a flow chart outlining the reactive acid-base extraction for this experiment. It should indicate which compounds end up in each layer of your separatory funnel in each step of your extraction, showing all compounds in the correct protonation state. Please keep in mind that acid chlorides are rapidly hydrolyzed in acidic or basic aqueous solution.

Answer 1

Acid-base extraction procedure for the given reaction of acid chloride with amine to form an amide.

1. Add water to the reaction mixture.

2. Transfer the contents into an separatory funnel and shake it while putting a stopper on it. The Organic components would go in the lower CH2Cl2 layer. Et3NHCl will go in water (upper) layer. Separate the organic layer from aqueous layer. Repeat this step atleast 3 times.

3. Tranfer the organic CH2Cl2 layer back to the separatory funnel and add 10% NaHCO3 (aq) to it. shake well and let the layers separate. The acid chloride remained after the reaction gets hydrolyzed and goes in water layer. Organic product amide stays in lower CH2Cl2 layer. Separate the two layers. Repeat this step atleast 3 times.

4. Transfer the CH2Cl2 back to the separatory funnel and add water to it. Shake well, let it settle and separate the two CH2Cl2 layer with product amide in it (lower layer) from aqueous layer in an erlenmeyer flask.

5. Dry the orgaic layer by adding anhydrous MgSO4. Evaporate solvent (CH2Cl2) to obtain the amide product.