Chemical Storylines
WM1- development of modern ideas about medicine
The active ingredient of medicine is drugs
Medicine prevents bodily harm and intends to cure an illness
Effectiveness of a drug measured by trial and error
WM2/WM3– Medicines from nature
Medicines from willow bark – willow bark contain an active ingredient know as salicylic acid which used to make aspirin (pain reliever)
Identifying salicylic acid
Three chemical tests which are used to predict the structure of salicylic acid
1. Salicylic acid in aqueous solution is weakly acidic ( presence of COOH group)
2. Salicylic acid reacts with alcohols to form esters which give of strong odours.
3. When salicylic acid is added to a neutral solution such as iron chloride it turns intense pink colour. ( presence of a phenol- OH attached to a benzene ring )
WM4-Instrumental analysis
Instrumental analysis includes – mass spectrometry / infrared spectroscopy / nuclear magnetic resonance
N.M.R.S
Investigates the different chemical environment in which the nuclei of one particular element is situated
N.m.r spectrum-it shows the salicylic acid contains – one proton in a COOH environment / one proton in a phenolic environment / 4 protons attached to a benzene ring –
Limitation of this technique is that it can only consider one environment however. in this case there is 6
Mass spectroscopy
From the other tech used is suggests that salicylic acid is hydroxybenzoic acid – as it consists of a COOH and OH group attracted to a benzene ring.
3 possible isomeric hydroxybenzoicacid hence ,mass spectroscopy determines which one 1 of the 3 salicylic acid is
WM5- The synthesis of salicylic acid (2-hydroxybenzoic acid) and aspirin
Medicines are attained from plants. Although its supply is limited due to weather changes, seasons and other aspects such as contamination hence, chemists were producing ways to the synthesis of this active ingredient by