(3-Ethynyl-quinolin-6-yloxy)-methylsulfanyl-acetic acid (413 mg), 1-hydroxy-7-azabenzotriazole (HOAT) (267 mg), O-(Benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate (TBTU) (630 mg), 2-amino-3-methoxy-2-methyl-propan-1-ol (180 mg) and triethylamine (0.75 ml) in dry CH3CN (20 ml) were stirred at ambient temperature overnight. The reaction mixture was diluted with ethyl acetate and poured on sat. aq. NH4Cl. The water phase was extracted 3 times with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered and evaporated. The residue was purified by column chromatography (cyclohexane/ethyl acetate 1:1) to give as a yellowish oil 2-(3-Ethynyl-quinolin-6-yloxy)-N-(2-hydroxy-1-methoxymethyl-1-methyl-ethyl)-2-methylsulfanyl-acetamide (200 mg) as a mixture of diastereoisomers.
