Hydrochloric Acid → 2-butyl-1H-imidazo[4,5-b]pyridine

Temperature

95 °C

A mixture of 2-amino-3,5-dinitropyridine (5.32 g, 28.9 mmol), THF (100 mL), methanol (250 mL) and Raney-nickel (3 mL of a 1:1 suspension in H2O) was stirred under H2 (1 atm.) was stirred for 5 h. The reaction mixture was quickly filtered into a receiving flask containing 5 mL of conc. HCl and the solvent was removed in vacuo at r.t. To this crude 2,3,5-triaminopyridine.HCl was added valetic acid (9.43 mL, 86.7 mmol) and polyphosphoric acid (100 mL) and this mixture was heated to 95° C. for 6 h. The warmed mixture was poured into stirred ice-H2O (200 mL) and this mixture was cooled and neutralized (to pH 4) by the addition of conc. NH4OH. Extraction with EtOAc (3×75 mL), concentration, and purification (SiO2, 5% MeOH/EtOAc) gave 6-[(1-oxopentyl)amino)]-2-butylimidazo[4,5-b]pyridine as a solid. Step 3: Preparation of 2-butyl-3-[2'-(N-tert-butylaminosulfonyl)[1,1']-biphenyl-4-yl]methyl-6-[(1-oxopentyl)amino)]-3H-imidazo[4,5-b]pyridine

1. stirringwas stirred for 5 h
2. filtrationThe reaction mixture was quickly filtered into a receiving flask
3. additioncontaining 5 mL of conc. HCl
4. customthe solvent was removed in vacuo at r.t
5. additionThe warmed mixture was poured
6. temperaturethis mixture was cooled
7. extractionExtraction
8. concentrationwith EtOAc (3×75 mL), concentration, and purification (SiO2, 5% MeOH/EtOAc)

ORD record

ord-67398f2f435f4164941ffe84f35276f8

Source dataset

uspto-grants-1995_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05412097