Introduction Unsubstituted amides are readily prepared by the ammonolysis of carboxylic acid derivat — Organic Chemistry Chemistry Question

Introduction
Unsubstituted amides are readily prepared by the ammonolysis of carboxylic acid derivatives, e.g. esters, as they are more reactive than the corresponding free acid. Thus, the reaction using carboxylic acid derivatives can be carried out under milder conditions. Esters are amongst the most reactive , particularly when the carbonyl group is further activated by electron-attracting groups. The latter are termed activated carboxylic acid esters. Cyanoacetic ethyl ester is an example of an activated carboxylic acid ester that readily reacts with ammonia easily to give the corresponding amide.

[VISUAL]

Equipment
magnetic stirrer with heating plate
magnetic stirrer bar
Erlenmeyer flask (250 cm 3 )
beaker (250 cm 3 )
2 pipettes (10 cm 3 ) with pipette control
Thermometer
vacuum filter (Ø 5 cm) or Hirsch funnel
dropping funnel
vacuum filtration apparatus
crystallizing dish or beaker
graduated measuring cylinder
balance (precision 0.01 g)
spatula
stand

List of Chemicals
cyanoacetic ethyl ester
aqueous ammonia (25 %)
ethanol
distilled water
ice

Procedure
Place 32.0 cm 3 (0.3 mol) of cyanoacetic ethyl ester into a 200 cm 3 Erlenmeyer flask equipped with a magnetic stirrer bar and an internal thermometer. Support a dropping funnel, containing 37.4 cm 3 (0.5 mol) of aqueous ammonia above the neck of the flask. Add the ammonia solution dropwise, being careful to ensure that the temperature remains between 30 and 35 °C. If necessary, cool the flask with cold water or an ice water bath. When the addition is complete, the reaction mixture is stirred for 30 minutes at room temperature.
Cool the reaction mixture to 0°C to induce crystallization. Collect the colourless crystals on a Hirsch funnel by vacuum filtration. Transfer the remaining crystals from the flask by adding small amounts of cold alcohol. Wash the crude product with several small aliquots of chilled ethanol. Reserve a small sample of the crude product for the determination of its melting point.
Transfer the crude product into a 250 cm 3 beaker and recrystallize it from 70 cm 3 of hot ethanol. Upon complete dissolution of the crude product the reaction mixture should be allowed to cool to room temperature and finally cooled in an ice bath. Collect the product by vacuum filtration and weigh the dried product.