Phosphorus sulfide (P2S5) → 2,6-Diphenylthiopyrylium perchlorate

The 1,5-diphenyl-1,5-pentanedione prepared in step 1 (10 mmol, 2.52 g) is mixed with phosphorus pentasulfide (15 mmol, 3.34 g), acetic acid (60 mL) and lithium perchlorate (60 mmol, 6.40 g) in a 100 mL two-necked round-bottomed flask, and then refluxed for 3 hours. The solution then becomes orange and a white precipitate forms. The precipitate is removed by filtration on a sinter funnel and then washed with hot acetic acid. The solution is concentrated on a rotary evaporator and recrystallized by addition of ether (500 mL). The precipitate obtained is filtered off on a sinter funnel and then dried on a rotary evaporator. The product obtained is a yellow solid in a mass of 850 mg. The reaction yield is 24%.