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Fluorine has played an important role in the pharmaceutical
and agrochemical industries already for several decades. It is well
known that the effectiveness of many complex molecules is significantly
enhanced by the presence of even a single fluorine atom.
In the early days, hydrofluoric acid was extensively used to provide
the required fluorine addition. Subsequently potassium fluoride
was used, particularly in halogen exchange reactions where it is
necessary to remove a chlorine atom and replace it with a fluorine
atom. Potassium fluoride is much easier for the user to handle and
demonstrates a much greater degree of selectivity than hydrofluoric
acid. It is still popular today and is used as the preferred fluorine
source in a number of insecticides and herbicides, as well as in
some proprietary analgesic preparations, anti-biotics and anti-depressives.
More recently still, significant progress has been achieved in the
development of a range of organic fluorine compounds based on CF2
and CF3 groups. These included
an anaesthetic preparation and a well-known anti-malaria drug.
In the last couple of years, giant strides in this area of research
have led to the development of a range of increasingly complex organic
intermediates, still based on the old building blocks,
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There is one other extremely important area of medicine where fluorine
chemistry plays a vital part. For many years, chlorofluorocarbons
were used as the propellant in metered dose inhalers. Since the
Montreal protocol and the subsequent agreement to ban CFCs, a new
generation of propellants has been developed. These gases, whose
effect on the ozone layer is zero, are known as hydrofluorocarbons,
usually abbreviated to HFCs. Asthma sufferers around the world who
rely on inhalers for their treatment now benefit from this development.
Work continues also to use these gases to deliver other medicines
to the lungs to treat a broad range of medical conditions.
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