Pyridine → 6-Chloro-2-propoxy-nicotinonitrile

Temperature

55 °C

To a solution of 6-chloro-2-propoxy-nicotinamide (3.80 g, 17.71 mmol) and pyridine (8.50 mL, 106.21 mmol) in acetonitrile (25 mL) was added phosphorus oxychloride (4.81 mL, 53.13 mmol) over a period of 5 min. The reaction was stirred at 55° C. for 1 h. Acetonitrile was evaporated in vacuo and the resulting residue was neutralized with 1N NaOH at 0° C. until pH reached to ˜7. The reaction mixture was extracted with EtOAc (100 mL). The organic layer was collected and the aqueous layer was further extracted with EtOAc (3×50 mL). All organics were combined washed with brine (2×25 mL), dried over anhydrous Na2SO4, filtered, and concentrated to give yellow oil. Purification was accomplished by flash chromatography on silica gel using 5-25% EtOAc/hexanes gradient elution to yield the title compound (3.4 g, 98%) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 8.29 (d, J=7.9 Hz, 1H), 7.29 (d, J=7.9 Hz, 1H), 4.31 (t, J=6.5 Hz, 2H), 1.79-1.66 (m, 2H), 0.96 (t, J=7.5 Hz, 3H).

1. customAcetonitrile was evaporated in vacuo
2. customwas neutralized with 1N NaOH at 0° C. until pH
3. extractionThe reaction mixture was extracted with EtOAc (100 mL)
4. customThe organic layer was collected
5. extractionthe aqueous layer was further extracted with EtOAc (3×50 mL)
6. washAll organics were combined washed with brine (2×25 mL)
7. dry with materialdried over anhydrous Na2SO4
8. filtrationfiltered
9. concentrationconcentrated
10. customto give yellow oil
11. customPurification
12. washwas accomplished by flash chromatography on silica gel using 5-25% EtOAc/hexanes gradient elution

ORD record

ord-c74bc1ae3f6e434da5030344314281a3

Source dataset

uspto-grants-2013_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08461135B2