Pyridine → 8-Bromo-1,6-naphthyridine

To a stirred solution of [1,6]-naphthyridine (4.73 g, 36.4 mmol) in CCl4 (200 mL) was added Br2 (2.25 mL, 43.7 mmol) in CCl4 (35 mL) dropwise via an addition funnel. The resulting solution was heated at reflux for 1 hour. Pyridine (2.94 mL, 36.4 mmol) in CCl4 (30 mL) was added dropwise to the refluxing solution, and the mixture was refluxed overnight. The cooled reaction mixture was filtered, and the solids were digested with 1 M NaOH (200 mL) for 1 hour. The basic solution was extracted into CH2Cl2 (2×200 mL), and the organic fractions were combined, dried over Na2SO4 and concentrated. The resulting oil was purified by column chromatography (10% EtOAc/CH2Cl2) affording 2.03 g (27%) of the title compound as yellow crystals: mp 79-81° C.

1. temperatureThe resulting solution was heated
2. temperatureat reflux for 1 hour
3. temperaturethe mixture was refluxed overnight
4. customThe cooled reaction mixture
5. filtrationwas filtered
6. extractionThe basic solution was extracted into CH2Cl2 (2×200 mL)
7. dry with materialdried over Na2SO4
8. concentrationconcentrated
9. customThe resulting oil was purified by column chromatography (10% EtOAc/CH2Cl2)

ORD record

ord-3a5cd81e10d0428da65b9dc6ea8bfa91

Source dataset

uspto-grants-2002_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06465482B2