Sulfuric Acid → HCID 178468354, compound

To 3-aminopyridine (564 mg, 6.00 mmol) were added 4 mL of concentrated sulfuric acid and 1.2 mL of water at 0° C., and the mixture was stirred at room temperature until it was clear. To the reaction mixture was added a solution of sodium nitrite (414 mg, 6.00 mmol) in water (1.2 mL) at 0° C. The mixture was stirred for several min (>15 min). The solution of diazonium salt was poured into the solution of 2,4-pentanedione (600 mg, 6.00 mmol) and potassium acetate (18.0 g, 180 mmol) in ethanol (120 mL) at 0° C. The mixture was stirred at 0° C. for 30 min and at room temperature for 30 min. The reaction mixture was added to 120 mL of saturated Na2CO3 aqueous solution. The mixture was extracted with dichloromethane, washed with water and brine, dried over Na2SO4, and concentrated under reduced pressure to give 3-(pyridin-3-ylhydrazono)pentane-2,4-dione (242 mg, yield 20%).

1. stirringThe mixture was stirred for several min (>15 min)
2. stirringThe mixture was stirred at 0° C. for 30 min and at room temperature for 30 min
3. extractionThe mixture was extracted with dichloromethane
4. washwashed with water and brine
5. dry with materialdried over Na2SO4
6. concentrationconcentrated under reduced pressure

ORD record

ord-f7636db26e164e9792420873acbee607

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08778944B2