To a solution of silver nitrate (14.17 g, 0.0838 moles) dissolved in 200 ml water, 100 gm (0.419 moles) trans-4-(4-chlorophenyl)cyclohexane carboxylic acid and acetonitrile (500 ml) was added. The solution was heated to reflux followed by addition of 1,4-naphthoquinone (80 gm, 0.506 moles). A solution of ammonium persulfate (239 g; 1.048 moles) in water (600 ml) was added dropwise to the above solution and continued reflux for half an hour. The reaction mass was then cooled to 30-32° C. and extracted with methylene chloride. The organic layer was first washed with water, followed with 10% sodium carbonate aqueous solution, and further with water until neutral pH. The organic layer was concentrated to afford the compound of Formula II (2-[4-(4-chlorophenyl)cyclohexyl]-1,4-naphthoquinone, 149 gm).
