It was named after the German chemist August Wilhelm von
Hoffman(1818-92).
A reaction for making primary amines
from amides using bromine or chlorine and sodium hydroxide
RCONH2 _> RNH2.
The halogen replaces a hydrogen atom
from the amido group to form a halo-amide. This then
reacts with the alkali to produce an isocyanate, which
decomposes into the amine and carbon dioxide. The
amine has one carbon atom fewer than the amide from
which it is produced.
This technique is used to reduce
the length of carbon chains in molecules.