Into a
1-l. round-bottomed flask equipped with a reflux condenser are introduced
100 g. (0.385 mole) of technical grade triphenylcarbinol (Note
1),
105 g. (0.81 mole) of dry aniline hydrochloride (Note
2), and
250 ml. of glacial acetic acid. The mixture is heated at the reflux temperature for 3 hours. During the period of reflux a clear brown homogeneous solution is formed. The solution while still hot is poured with stirring into a
4-l. beaker containing 2 l. of water.
p-Aminotetraphenylmethane hydrochloride, which is not very soluble in water, separates as a light-brown solid. It is collected on a
Büchner funnel and washed with 1 l. of water. The solid is then put back into the beaker, and a solution of
40 g. of sodium hydroxide in 2 l. of water is added. The mixture is heated to boiling for 1 hour to convert the hydrochloride to the free base (Note
3), which likewise is not very soluble in water. The mixture is allowed to cool to room temperature and is filtered with suction through a Büchner funnel. The solid material is washed with 500 ml. of water and is dried in an oven at 110–120°. The crude substance melts at
243–247°. It is purified by crystallization from
1.7 l. of toluene. The purified product (
90–95 g.,
70–74%) melts at
249–250° (Note
4).