Formic Acid → HCID 14836073, compound

A stirred mixture of 3,4-diaminopyridine (10.0 g, 0.092 mol) and formic acid (20 ml) was neated under reflux for 2.5 hours. The resulting mixture was cooled and the formic acid was evaporated off under reduced pressure to yield a residue. The residue was dissolved in ethanol (300 ml) at 80° C. and the resulting solution was treated with calcium carbonate (lOg) 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. temperatureunder reflux for 2.5 hours
2. temperatureThe resulting mixture was cooled
3. customthe formic acid was evaporated off under reduced pressure
4. customto yield a residue
5. temperatureunder reflux for 1 hour
6. filtrationThe hot mixture was filtered
7. washthe residue was washed with hot ethanol (3×300 ml)
8. customthe ethanol was evaporated off under reduced pressure

ORD record

ord-ef3673a0a1ef4cb79085ad756bbef93d

Source dataset

uspto-grants-1990_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04962106