Under argon, a mixture of 2.0 g (10.15 mmol) of 2-amino-4-bromobenzonitrile, 2.165 g (2.5 ml, 15.23 mmol) of tert-butyl 2-methylacrylate, 93 mg (0.10 mmol) of tris(dibenzylideneacetone)-dipalladium, 41 mg (0.20 mmol) of tri-tert-butylphosphine and 2.4 ml (11.17 mmol) of N,N-di-cyclohexylmethylamine in 20 ml of dioxane was heated to 120° C. and stirred at this temperature overnight. The reaction was checked (TLC, mobile phase cyclohexane/ethyl acetate 9:1), and another 10 mg of tris(dibenzylideneacetone)dipalladium, 10 mg of tri-tert-butylphosphine and 500 μl of tert-butyl 2-methylacrylate were then added and the mixture was stirred at 120° C. for a further 4 h. The reaction mixture was then filtered through celite, and the filtrate was concentrated under reduced pressure. The residue was purified by chromatography on silica gel (mobile phase cyclohexane/ethylacetate 9:1→4:1). This gave 1.375 g of the title compound (52% of theory).
