Clafanone ,Roche ,US ,1956
38 g benzal-acetophenone and 25 g p-aminobenzene-sulfinic acid are refluxed for 5 hours in 700 cc of 85% ethyl alcohol. Fine crystals soon begin to appear
and fill the reaction vessel. While still hot, the mixture is suction-filtered. The
reaction product is washed first with 750 cc warm absolute alcohol, then with
500 cc water, and finally again with 300 cc alcohol, and then dried in vacuum.
Yield 32 g. MP 210-212°C with decomposition.
