(8-Carbamoylmethyl-7-chloro-naphthalen-2-ylmethyl)-(2-fluoro-ethyl)-carbamic acid tert-butyl ester (80 mg, 0.20 mmol) and (1-methyl-1H-indol-3-yl)-oxo-acetic acid methyl ester (57 mg, 0.26 mmol) are dissolved under an atmosphere of argon in dry THF (4 ml). Activated molecular sieves 3 Å (100 mg) is added. After 10 minutes at RT, a solution of 1.0 M KOtBu in THF (0.61 ml, 0.61 mmol) is added in one portion. The reaction mixture is diluted with EtOAc and poured into a saturated aqueous NH4Cl solution. The organic layer is separated, washed with brine, dried over Na2SO4 and concentrated. The residue is directly used in the next reaction. ES+-MS: 579.2, 580.5 [M+H+H2O]+. ES−-MS: 560.2, 561.5 [M−H]−.
