Hydrazine → 5-Bromo-4-(4-chlorophenyl)-2-hydrazinylpyridine

Temperature

20 °C

To a solution of 5-bromo-2-chloro-4-(4-chlorophenyl)pyridine (1.3 g, 4.3 mmol) in THF (10 mL) was added hydrazine (1.4 g, 43 mmol). The reaction mixture was refluxed under argon for 4 days, then allowed to cool to 20° C. and concentrated in vacuo. The residue was purified by using reverse phase preparative HPLC (Conditions: Phenomenex Luna 5μC 18 30×100 mm; Eluted with 0% to 100% B, 10 min gradient, 100% B hold for 5 min, (A=90% H2O, 10% CH3CN, 0.1% trifluoroacetic acid and B=10% H2O, 90% CH3CN, 0.1% trifluoroacetic acid); Flow rate at 40 mL/min, UV detection at 220 nm), followed by basification with 1N aqueous NaOH to pH 12 and extraction with CHCl3 to afford 0.82 g (63%) of the title compound as an off-white solid. LC/MS (method B): retention time=1.47 min, [M+H]+=298.0.

1. temperatureThe reaction mixture was refluxed under argon for 4 days
2. concentrationconcentrated in vacuo
3. customThe residue was purified
4. washEluted with 0% to 100% B, 10 min gradient, 100% B hold for 5 min
5. extractionFlow rate at 40 mL/min, UV detection at 220 nm), followed by basification with 1N aqueous NaOH to pH 12 and extraction with CHCl3

ORD record

ord-ed8f6cb464514eb384409fa2f56f2d55

Source dataset

uspto-grants-2009_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07632837B2