Butyric Acid → 7-methyl-2-propyl-6-[(1-oxobutyl)amino]3H-imidazo[4,5-b]pyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 2-amino-3,5-dinitro-4-methylpyridine (3.1 g, 15.6 mmol), THF (100 mL), methanol (100 mL) and Raney-nickel (6 mL of a 1:1 suspension in H2O) was stirred under H2 (1 atm.) for 6 h. The mixture was quickly filtered into a receiving flask containing 3 mL of conc. aqueous HCl, and the solvent was removed in vacuo at r.t. To the resulting crude 2,3,5-triamino-3-methylpyridine.HCl complex was added butyric acid (4.3 mL, 46.9 mmol) and polyphosphoric acid (100 mL) and this mixture was heated to 85° C. for 10 h. The warmed mixture was poured into stirred ice-H2O (200 mL) and this mixture was cooled and neutralized (to pH 3) by the addition of conc. NH4OH. Extraction with CH2Cl2 (3×50 mL), drying (Na2SO4), and concentration gave the title compound as a solid.

Herkunft & Nachweise