Formic Acid → HCID 14836073, compound

A stirred mixture of 3,4-diaminopyridine (10.0 g, 0.092 mol) and formic acid (20 ml) was heated under reflux for 2.5 hours. The resulting mixture was cooled and the formic acid was evaporated off under reduced pressure to a yield a residue. The residue was dissolved in ethanol (300 ml) at 80° C. and the resulting solution was treated with calcuim carbonate (10 g) and neutralized by stirring under reflux for 1 hour. The hot mixture was filtered and the residue was washed with hot ethanol (3×300 ml). The filtrate and washings were combined and the ethanol was evaporated off under reduced pressure to yield 3,4-diformylaminopyridine as a colorless solid. The 3,4-diformylaminopyridine was heated at 200°-220° C. and 0.5 mm.Hg pressure in a Kugelrohr bulb-to-bulb distillation apparatus to yield a crude product as a distillate which solidified on cooling. The crude product was recrystallized from ethyl acetate to yield imidazo[4,5-c]pyridine as a colorless crystalline solid, having a melting point of 174°- 176° C. and the following physical characteristics:

1. temperaturewas heated
2. temperatureunder reflux for 2.5 hours
3. temperatureThe resulting mixture was cooled
4. customthe formic acid was evaporated off under reduced pressure to
5. customa yield a residue
6. temperatureunder reflux for 1 hour
7. filtrationThe hot mixture was filtered
8. washthe residue was washed with hot ethanol (3×300 ml)
9. customthe ethanol was evaporated off under reduced pressure

ORD record

ord-7f9b3e8c74df4fdd8ec0c61e14dabe89

Source dataset

uspto-grants-1989_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04804658