What is a schiff base??

What is a schiff base???
A Schiff's Base is made by reacting an
aldehyde (like Lilial or Lyral) with a
compound containing an amino
group (NH2). In Perfumery the most
commonly used Schiff's Base is
Aurantiol (made from reacting
Methyl Anthranilate with
Hydroxycitronellal). Schiff's Bases
tend to be highly coloured, usually
bright yellow to orange and have a
fixative effect. They are definitely
base notes. Rather difficult to make
yourself as a by product of the
reaction is water, which is very
difficult to remove, although it is
easy to see the reaction working. If
you mix the two materials together
in the right proportions and warm
gently, you will see a change in
colour and viscosity. However the
product will be cloudy, due to the
water. Aurantiol, and the Schiff's
Bases using Lilial and Lyral, do
indeed smell like Orange blossom,
or Tuberose.