5-(3,3-Dimethyl-but-1-ynyl)-3-[(4-hydroxy-cyclohexyl)-(4-methyl-cyclohexanecarbonyl)-amino]-thiophene-2-carboxylic acid methyl ester (92 mg, 0.2 mmol, 1.0 eq.), 4-methyl-4H-[1,2,4]triazole-3-thiol (46 mg, 0.4 mmol, 2.0 eq.), triphenylphosphine (105 mg, 0.4 mmol, 2.0 eq.), DIAD (77 μL, 0.4 mmol, 2.0 eq.) and triethyl amine (42 μL, 0.3 mmol, 1.5 eq.) were weighed into a round-bottomed flask containing THF (2.0 mL). The solution was purged with N2 and stirred at room temperature for 12 h. The solution was concentrated to an oil and then purified by silica gel chromatography (0-100% EtOAc in hexanes) to afford 5-(3,3-dimethyl-but-1-ynyl)-3-{(4-methyl-cyclohexanecarbonyl)-[4-(4-methyl-4H-[1,2,4]triazol-3-ylsulfanyl)-cyclohexyl]-amino}-thiophene-2-carboxylic acid methyl ester (63 mg, 57%).
