2.0 g (6.11 mmol) of the compound of Example 15A were dissolved in 20 ml of dioxane and 2 ml of water, the mixture was degassed with argon, 280 mg (0.31 mmol) of tris(dibenzylideneacetone)dipalladium, 325 mg (0.76 mmol) of 2-di-tert-butylphosphino-2′,4′,6′-triisopropyl-1,1′-biphenyl and 1.37 g (24.5 mmol) of powdered potassium hydroxide were added and the mixture was stirred at 100° C. for 2 h. The reaction was then stirred into 50 ml of 1 M hydrochloric acid and extracted twice with in each case 50 ml of ethyl acetate. The combined organic phases were washed with saturated sodium chloride solution, dried over sodium sulphate and concentrated under reduced pressure. The residue was suspended in dichloromethane/pentane (9:1), the solid was filtered off and the filter cake was dried under high vacuum. This gave 980 mg (59% of theory) of the title compound.
