33 mg of 1,3,5-trimethyl-1H-pyrazole-4-sulfonic acid chloride (0.16 mmol, 1.2 eq) were weighted into a reaction tube and dissolved in dry tetrahydrofuran (1 ml). 44 mg of [2-(2-phenyl-chroman-6-yloxy)-thiazol-5-ylmethyl]amine (0.13 mmol) in dry tetrahydrofuran (3 ml) and 30 mg triethylamine (0.3 mmol, 2.3 eq) were added, the tube was flushed with argon, closed with a screw cap, and shaken over night at 40° C. 0.008 ml of tris-(2-aminoethyl)amine in 0.5 ml tetrahydrofuran were added, the mixture was shaken for 2 h at room temperature and then evaporated. The residue was dissolved in 2 ml of a mixture of dimethylformamide/trifluoroacetic acid (19:1), filtered, and submitted to preparative reversed phase HPLC purification (water/acetonitrile gradient (+0.1% trifluoroacetic acid)). 1,3,5-Trimethyl-1H-pyrazole-4-sulfonic acid [2-(2-phenyl-chroman-6-yloxy)-thiazol-5-ylmethyl]-amide was obtained as a white solid (42 mg, 63%).
