Pyridine → N-(2-hydroxy-2-(4-(5-(2-(1-phenylcyclohexyl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)-beta-alanine

Participants

Reaction Conditions

Reaction Steps

Cyanuric fluoride (0.018 mL, 0.215 mmol) was added to a mixture of 3-(1-phenylcyclohexyl)propanoic acid (50 mg, 0.215 mmol) and pyridine (0.017 mL, 0.215 mmol) in dichloromethane (5 mL). After 1 h, the reaction mixture was diluted with dichloromethane and washed with 1M aq. HCl solution. The organic layer was dried (MgSO4), filtered and concentrated. The residue was diluted with ethyl acetate and washed with saturated aqueous NaCl solution. The organic layer was dried (MgSO4), filtered and concentrated. This crude residue was dissolved in acetonitrile (5 mL). (Z)-tert-butyl 3-(2-hydroxy-2-(4-(N′-hydroxycarbamimidoyl)phenyl)ethylamino)propanoate (69.6 mg, 0.215 mmol) and diisopropylethyl amine (0.038 mL, 0.215 mmol) were added and the mixture was heated to 75° C. After 2 h, a 1M solution of tetra-n-butylammonium fluoride in THF (0.215 mL, 0.215 mmol) was added and the mixture was heated at 75° C. overnight. The reaction mixture was diluted with ethyl acetate and washed with saturated aqueous NaCl solution. The organic layer was dried (MgSO4), filtered and concentrated. The crude residue was treated with 1:1 mixture of dichloromethane and trifluoroacetic acid for 1 h. The mixture was concentrated, diluted with AcCN, filtered, and purified by HPLC (HPLC conditions: Phenomenex Luna C18 5 micron column (250×30 mm); 25-100% AcCN/water (0.1% TFA); 25 minute gradient; 20 mL/min) to obtain N-(2-hydroxy-2-(4-(5-(2-(1-phenylcyclohexyl)ethyl)-1,2,4-oxadiazol-3-yl)phenyl)ethyl)-beta-alanine (35 mg, 24% yield) as a colorless oil. 1H NMR (400 MHz, DMSO-d6): δ ppm 8.63 (1H, d), 7.95 (2H, d, J=8.57 Hz), 7.56 (2H, d, J=8.35 Hz), 7.30-7.45 (4H, m), 6.33 (1H, br, s), 4.95 (1H, dd, J=10.11, 2.2 Hz), 3.13-3.32 (3H, m), 2.99-3.09 (1H, m), 2.69 (2H, td, J=7.25, 2.64 Hz), 2.52-2.59 (2H, m), 2.15 (2H, d, J=14.5 Hz), 1.16-1.72 (11H, m).

Provenance & Evidence