Zusammenfassung der Ressource
Aspirin
- How its made
- Salicylic acid + ethanoic anhydride --> Aspirin + Ethanoic acid
- Heat under reflux
- Salicylic acid + Ethanoyl Chloride --> Aspirin + Hydrogen Chloride
- Catalyst of Conc. Sulphuric
Acid and heat under reflux
- Not a common reaction as
Acyl Chlorides are nasty
chemicals to work with.
- Both reactions must take
place in a fume cupboard
- Salicylic acid is found in willow bark
- Structure
- Benzene ring with
functional groups on position
1 and 2.
- The angle around the
O-C=OCH3 is 120, as
there are 3 groups of
electrons around the
central carbon.
- 2-ethanoylhydroxylbenzoic
acid
- Formula
- Contains a benzene ring.
- Benzene with a COOH
group on position 1, and
a OC=OCH3
- C9H8O4
- Systematic nomenclature-
2-ethanoylhydroxylbenzoic acid
- Associated Chemicals
- Salicylic Acid
- Found in willow bark
- Consists of a benzene ring with a
carboxylic acid functional group on
position 1, and an alcohol
functional group on position 2
- 2-hydroxybenzoic acid
- Salicylic acid contains a phenol
group, so will not react with
Carboxylic acids to make esters,
hence why we use ethanoic
anhydride orethanoyl chloride to
make Aspirin.
- Phenol groups can be detected by using
Iron (III) Chloride. If it goes dark purple then
there is a phenol group present. If it stays
orange then there is no phenol group.
- Oil of Wintergreen
- If Salicylic acid is reacted with
Methanol instead of an ethanoic
anhydride or ethanoyl chloride then it
forms oil of wintergreen, which also has
painkilling qualities.
- Oil of Wintergreen is also an
ester, like Aspirin, however the
carboxylic acid functional group
has reacted this time, instead of
the alcohol group, so a different
ester is formed.
- Ethanoic Anhydride
- This is the most used
chemical to react with
salicylic acid to make
Aspirin.
- Formed when 2 ethanoic acid
molecules react to form
ethanoic anhydride and water.
- Condensation reaction
- Ethanoyl Chloride
- Formed when
ethanoic acid and
hydrogen chloride
react to form ethanoyl
chloride and water.
- Substitution reaction
- Not commonly used to react with
salicylic acid to make Aspirin as it
is a nasty chemical to handle.