384 mg (2.12 mmol) of ethyl 2-bromopropionate and 1.38 g (4.24 mmol) of caesium carbonate are added to 500 mg (2.12 mmol) of 5-(4-chlorophenyl)-4-cyclopropyl-2,4-dihydro-3H-1,2,4-triazol-3-one from Example 36A in 5 ml acetonitrile and the reaction mixture is heated at 85° C. overnight. It is then concentrated in vacuo, the residue is partitioned between water and dichloromethane, and the separated organic phase is dried over sodium sulphate and again evaporated. After purification of the residue by flash chromatography over silica gel (eluent: first dichloromethane, then dichloromethane/methanol 200:1), 729 mg (97% of theory) of the target compound are obtained.
