A mixture of 2,3-dichloro-1,4-naphthoquinone (57.0 gm), 4-(4-chlorophenyl)-cyclohexane-1-carboxylic acid (60.0 gm) and silver nitrate (42.7 gm) is taken in acetonitrile (600 ml) and then a solution of ammonium persulphate (180.12 gm) in water (780 ml) is added. The mixture is heated to reflux, maintaining good stirring. The mixture was refluxed for 4 hrs. Then cooled in ice for about 1 hr after which it is filtered. The filtrate is kept aside for acetonitrile recovery. The solid is extracted with hot methylene chloride (100 ml×3). The inorganic salt is collected separately for recovery of silver. The organic layer is dried over anhydrous sodium sulphate and concentrated to get light brownish yellow solid (38.5 gm).
