Butyryl chloride → (1R,2S)-1-(3-chloro-4-cyano-2-methylphenylamino)-1-(5-phenyl-1,3,4-oxadiazol-2-yl)propan-2-yl butyrate

Participants

Reaction Steps

To a solution of 2-chloro-4-((1R,2S)-2-hydroxy-1-(5-phenyl-1,3,4-oxadiazol-2-yl)propylamino)-3-methylbenzonitrile (200 mg, 0.54 mmol) in pyridine (1.0 mL) and CH2Cl2 (7.0 mL) was added n-butyryl chloride (84 μL, 0.81 mmol). Upon complete addition the reaction mixture was stirred for 60 h, then quenched with 10% aqueous HCl (10 mL). The mixture was partitioned between H2O (25 mL) and CH2Cl2 (30 mL). The aqueous layer was extracted with CH2Cl2 (25 mL). The combined organic extracts were washed with NaHCO3 (30 mL), dried (Na2SO4), filtered and concentrated under reduced pressure to provide an orange viscous oil, which was purified by flash chromatography over silica gel (15-30% EtOAc in hexanes) to provide the title compound as a colourless solid (231 mg, 97%): 1H NMR (400 MHz, CDCl3, δ in ppm) 7.99 (td, J=1.4, 8.8 Hz, 2H), 7.57-7.47 (m, 3H), 7.38 (d, J=8.6 Hz, 2H), 6.73 (d, J=8.6 Hz, 1H), 5.59 (pentet, J=6.5 Hz, 1H), 5.19 (d, J=8.0 Hz, 1H), 5.03 (dd, J=5.9, 7.8 Hz, 1H), 2.34 (dt, J=2.3, 7.6 Hz, 2H), 2.31 (s, 3H), 1.64 (sextet, J=7.4 Hz, 2H), 1.37 (d, J=6.5 Hz, 3H), 0.92 (t, J=7.4 Hz, 3H).

Provenance & Evidence