1,1'-Carbonyldiimidazole → 5-AMINO-6-CHLORO-N-[1-(3-METHOXYPROPYL)-4-PIPERIDINYL]IMIDAZO[1,2-a]PYRIDINE-8-CARBOXAMIDE

Participants

Reaction Steps

To a suspension of the 5-amino-6-chloroimidazo[1,2-a]pyridine-8-carboxylic acid (EXAMPLE 1, METHOD A, Step 4, 210 mg, 0.99 mmol) in N,N-dimethylformamide (5 mL) was added 1,1′-carbonyldiimidazole (177 mg, 1.09 mmol) and stirred at room temperature for 20 min. To this resulting solution was added 1-(3-methoxypropyl)-4-piperidinamine (A. Karasawa et al., WO 9950264, 188 mg, 1.09 mmol) and the mixture was stirred overnight under nitrogen at room temperature. The mixture was concentrated in vacuo, chromatographed on a column of silica gel eluting with dichloromethane/methanol/25% aqueous ammonia (95:5:0.5) to afford a yellow oil, which was dissolved in dichloromethane (300 mL), washed with water (75 mL×3), brine (75 mL) and dried over magnesium sulfate. After treatment with charcoal, removal of solvent gave a cream solid, which was recrystallized from diethyl ether to afford 175 mg (48%) of the title compound as a solid.

Provenance & Evidence