4.7 g (20 mmol) of (5-Hydroxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl)-acetonitrile, prepared as described in example 7.1, are dissolved in 50 ml of THF and cooled in an ice bath. After adding 5.1 g (21 mmol) of diphenylphosphinic chloride to the solution, 3.0 g (29 mmol) of triethylamine are added dropwise, keeping the temperature below 5° C. The reaction mixture is stirred at 5° C. for 30 min. The reaction mixture is poured into 50 ml of water, and filtered off. The yellow solid is washed with 50 ml of water and 50 ml of a mixture of water and CH3OH (10:1). The product is purified by the recrystallization from 2-PrOH to afford a yellow solid, mp 165-167° C.(Dec). The structure is confirmed by the 1H-NMR spectrum (CDCl3). δ [ppm]: 2.31 (s, 3H), 6.09 (d, 1H), 6.82 (d, 1H), 7.12-7.35 (m, 4H), 7.48-7.65 (m, 6H), 7.95-8.04 (m, 4H).
