Methanol → 6-[(1-Oxopentyl)amino]-2-butyl-5-methylimidazo[4,5-b]pyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 2-amino-3,5-dinitro-4-methylpyridine (5.2 g, 26 mmol), THF (100 mL), methanol (1300 mL) and Raney-nickel (3 mL of a 1:1 suspension in H2O) was stirred under H2 (1 atm.) for 5 h. The mixture was quickly filtered into a flask containing 3 ml of conc. HCl and the solvent was removed in vacuo at r.t. To the resulting crude 2,3,5-triamino-6-methylpyridine HCl complex was added valeric acid (8.68 mL, 80 mmol) and polyphosphoric acid (100 mL) and this mixture was heated to 80° C. for 7 h. The warmed mixture was poured into stirred ice-H2O (500 mL) and this mixture was cooled and neutralized (to pH 3) by the addition of conc. NH4OH. Extraction with CH2Cl2 (5×50 mL), drying (Na2SO4), concentration and purification (SiO2, 5% MeOH/EtOAc) gave the title compound as a solid.

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