161 mg (1.17 mmol) of 3-cyclopropyl-5-hydroxy-1-methylpyrazole and a few drops of N,N-dimethylaminopyridine were added to 272 mg (1.06 mmol) of 4-chloro-3-cyclopropylmethylthio-2-methylbenzoic acid. 244 mg (1.27 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added, and the mixture was stirred at RT for 16 h. For work-up, 3 ml of 1M HCl were added, and the organic phase was freed from the solvent. 214 mg (2.12 mmol) of triethylamine, 10 drops of acetone cyanohydrin and a spatula tip of KCN were added to the residue in 15 ml of acetonitrile. This reaction mixture was stirred at RT for 16 h and then freed from the solvent. 2 ml of 1M HCl were added to the residue in 15 ml of CH2Cl2. The organic phase was freed from the solvent, and the residue was then purified chromatographically. This gave 154 mg of pure product.
