Phosphorus oxychloride → HCID 71470274, compound

Participants

Reaction Conditions

Reaction Steps

L-Boc-Orn(Boc)-OH (0.25 g, 0.75 mmol) was dissolved in 1.5 mL of pyridine. The solution was cooled to −25° C. and phosphorus oxychloride (0.12 g, 0.75 mmol) was added dropwise with vigorous stirring. After stirring for 15 min. at −25° C., 4-((perfluoropyridin-4-yl)ethynyl)aniline, (13a) (0.10 g, 0.38 mmol) in pyridine (1.5 mL) was added slowly. The reaction mixture was stirred for 0.5 h at −25° C. and then at room temperature for 10 h. The reaction mixture was quenched with ice/water and extracted with EtOAc. The organic layer was washed with sat. NaHSO4 three times, dried with Na2SO4 and was concentrated in vacuo. The crude product was subjected to chromatography with MeOH:CH2Cl2=1:80 and the Boc-protected product was obtained in 23% yield. (S)-Di-tert-butyl (5-oxo-5-((4-((perfluoropyridin-4-yl)ethynyl)phenyl)amino)pentane-1,4-diyl)dicarbamate (100 mg, 0.17 mmol) was dissolved in gaseous HCl saturated MeOH (4 mL) at 0° C. and the solution was stirred for 10 hours at room temperature. The precipitated product (40 mg, 51%) was obtained by filtration: 1H-NMR (300 MHz, CD3OD) δ 7.82 (d, J=9.0 Hz, 2H), 7.65 (d, J=8.7 Hz, 2H), 4.15 (t, J=6.3 Hz, 1H), 3.14 (t, J=8.4 Hz, 2H), 2.02-2.09 (m, 2H), 1.83-1.88 (m, 2H)

Provenance & Evidence