Pyridine → N-benzooxazol-2-yl-3-cyclopentyl-2-(3,4-dichloro-phenyl)-propionamide

Temperature

0 °C

A solution of triphenylphosphine (274 mg, 1.04 mmol) in methylene chloride (6 mL) was cooled to 0° C. and then treated with N-bromosuccinimide (211 mg, 1.18 mmol). The resulting brownish-purple mixture was stirred at 0° C. for 5 min until the reaction mixture became homogeneous. The reaction mixture was then treated with 3-cyclopentyl-2-(3,4-dichloro-phenyl)-propionic acid (prepared as in Example 1, 200 mg, 0.70 mmol). The reaction mixture was stirred at 0° C. for 20 min and then allowed to warm to 25° C. where it was stirred for 30 min. The reaction mixture was then treated with 2-aminobenzoxazole (140 mg, 1.04 mmol) and pyridine (0.17 mL, 2.09 mmol), and the reaction mixture was allowed to stir at 25° C. for 20 h. The resulting reaction mixture was diluted with water (15 mL) and then extracted with methylene chloride (3×15 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 40S, Silica, 80/20 hexanes/ethyl acetate) afforded N-benzooxazol-2-yl-3-cyclopentyl-2-(3,4-dichloro-phenyl)-propionamide (214 mg, 76%) as a light yellow foam: EI-HRMS m/e calcd for C21H20Cl2N2O2 (M+) 402.0902, found 402.0908.

1. stirringThe reaction mixture was stirred at 0° C. for 20 min
2. temperatureto warm to 25° C. where it
3. stirringwas stirred for 30 min
4. stirringto stir at 25° C. for 20 h
5. customThe resulting reaction mixture
6. extractionextracted with methylene chloride (3×15 mL)
7. dry with materialThe combined organic layers were dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo

ORD record

ord-39dff54c647945debacecb69c20e5e7c

Source dataset

uspto-grants-2003_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06545155B2