INTRODUCTION In experimental chemistry, especially synthetic, a lot of harmful solvents are used to improve reaction conditions and toxic by-products are often generated .
These chemicals are a source of pollution and are hazardous to the ecosystem.
It is faster than the more traditional method of filtering under gravity.
Recrystalisation involves dissolving a product in the minimum amount of hot solvent and then quickly cooling down this solvent.
With the conventional heating method, a 52.4% yield was obtained, while an 83.5% yield was obtained by microwave heating.
The high-yielding microwave irradiation method also displayed higher purity with a melting temperature range of 128-132�C (lit.
The hot solution will be saturated, meaning that crystals will form out if the solution as it cools down and can therefore hold less solute.
It is common practice to scratch the inside of the vessel with a glass rod, below the level of solvent to encourage crystals to grow.
Furthermore, by Lewis theory, the lone pairs on the oxygen atoms also make sodium carbonate a base. 5 - base-catalyzed reaction with salicylic acid The ionic character of the sodium salicylate makes attack on the carbonyl of acetic anhydride favourable.
In figure 5, the carbonate abstracts a proton from the carboxylic group to form bicarbonate because this functional group is the stronger acid. This forms an intermediate that requires a proton to hydrolyze and form acetic acid. 6 - Attack on acetic anhydride The molecule produced in figure 6 is clearly very unstable. In the microwave synthesis spectrum, the resolution was quite good and this phenomenon can be observed.