Trifluoroacetic acid → 4-[(1S)-1-({[5-Chloro-2-(4-fluorophenoxy)pyridin-3-YL]carbonyl}amino)ethyl]benzoic acid

Beteiligte Stoffe

Reaktionsschritte

Trifluoroacetic acid (10 mL) was added to a solution of tert-butyl 4-[(1S)-1-({[5-Chloro-2-(4-fluorophenoxy)pyridin-3-yl]carbonyl}amino)ethyl]benzoate (step 4, 2.1 g; 4.3 mmol) in dichloromethane (30 mL). The reaction mixture was stirred at room temperature until the starting material was fully consumed (4 h). The solvent and most of the trifluoroacetic acid were removed under reduced pressure. The residue was purified by flush silica gel column chromatography on silica gel (50 g) eluting with dichloromethane/methanol (20/1) and recrystallization (ethyl acetate-diisopropyl ether) to give 1.24 g, (86%) of the title compounds as white crystals: mp 198.2° C.;

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