200 mg (0.52 mmol) of 3-{[(6-amino-3,5-dicyano-4-phenylpyridin-2-yl)sulfanyl]methyl}-benzenecarboxylic acid (Example 11) were charged in 5 ml of DMF. The reaction solution was cooled to 0° C. 393.58 mg (1.04 mmol) of HATU were added, and the mixture was then stirred at 0° C. for 20 min. 165.84 mg (1.04 mmol) of tert-butyl (2-aminoethyl)carbamate and 133.78 mg (1.04 mmol) of N,N-diisopropylethylamine were added, and the reaction solution was stirred at RT overnight. Water and tetrahydrofuran were added to the reaction mixture until a clear solution had formed. The solution was purified by preparative HPLC (Chromasil, water/acetonitrile+0.1% trifluoroacetic acid).
