Methanol → HCID 178428360, compound

Participants

Reaction Conditions

Reaction Steps

Raney Nickel (2.5 g) is added to a mixture of commercially available 4-methyl-3-nitro-pyridin-2-ylamine x175 (7.0 g, 45.7 mmol) in methanol (300 ml), and the obtained reaction mixture is hydrogenated in the Parr apparatus at the hydrogen pressure 3 atm until the total conversion of compound x175 is attained for approximately 1.5-2 h. The catalyst is separated by filtration, the filtrate is washed with methanol, and the alcohol solution is evaporated to dryness. CH(OMe)3 (100 ml) and PTSA (0.5 g) are added to the residue, and an air reflux condenser is mounted. The apparatus is argon-blown, and the obtained reaction mixture is heated to 125° C. under vigorous stirring for 10 h. The formed solution is evaporated, and the residue is dissolved in 5% HCl (100 ml). The solution is refluxed for 1 h and evaporated to one-third volume. The solution is neutralized to pH 7 and extracted with 10% tert-butanol in chloroform (4×100 ml). The organic layer is dried over anhydrous Na2SO4, and the solvent is evaporated. The residue is purified by chromatography on silicagel (chloroform/methanol) to afford 7-methyl-3H-imidazo[4,5-b]pyridine x176.

Provenance & Evidence