AoS 1: How the diversity of carbon compounds can be explained and categorized

Background

Plants have through out human history been used for medicinal purposes. The Chinese used tea from sweet wormwood leaves to cure chills and fevers, Egyptians used a brew from a plant called khella to help pass kidney stones. Bundjalung Aboriginal people from the coast of New South Wales crushed tea-tree (Melaleuca alternifolia) leaves and applied the paste to wounds as well as brewing it to a kind of tea for throat ailments.

Throughout the ages people have relied on medicinal compounds derived from plants. In medieval times people utilised a tea brewed from Willow bark to relive aches and pains. In 1763 the active ingredient of Willow bark was identified as Salicylic Acid. As an analgesic, salicylic acid is highly effective, however its tendency to cause stomach bleeding seriously limited in its usage. Felix Hoffmann [1], a chemist at Bayer [2], has been credited with the synthesis of aspirin in 1897. Aspirin (acetyl salicylic acid) tends to be less harmful than salicylic acid taken directly. Another derivative of Salicylic acid is its methyl ester, which is commonly called Oil of Wintergreen or simply Wintergreen.

Methyl salicylate is used as a liniment and is the active ingredient in products such as Deep Heat. Methyl salicylate and salicylic acid were originally derived from plants however in todays world they are produced through chemical reactions utilizing base chemicals such as phenol, methanol and acetic anhydride.

Please note that from 2019, this program runs from 9.30am – 2.00pm.

Prior Knowledge

This program will best suit students who have an understanding of basic organic chemistry, in particular, functional groups and IUPAC nomenclature.

Learning Intentions

In this program student’s will:

Be able to identify functional groups and their reactions.
Be able to describe formation of esters
Be able to correctly identify key peaks in IR spectra
Analyse data from HPLC to quantify active ingredients in analgesic tablets
Use chemical apparatus correctly to synthesize Methyl salicylate

Activities

Examine esterification reactions and produce Methyl salicylate (Oil of Wintergreen)
Use the Ecolinc Infra-Red Spectrometer to identify functional groups from their IR spectra
Use the Ecolinc HPLC to determine the amounts of Aspirin and paracetamol in a number of commercial analgesics.

VCE links

Students will gain key knowledge and skills consistent with the VCE Chemistry study design: Unit 4 AoS1. This program could be used as a basis for Outcome 3 – Practical Investigation.

Notes

Please note that from 2019, this program runs from 9.30am – 2.00pm.