Formaldehyde → HCID 131725928, compound

Participants

Reaction Steps

A mixture of 8-[3-(2,4-dichlorophenyl)propoxy]-2-methylimidazo[1,2-α]pyridine (703 mg, 2 mmol, see example 1), dimethylamine hydrochloride (700 mg, 8.48 mmol) and paraformaldehyde (256 mg, 8.48 mmol) in methanol (5 mL) was refluxed for 40 h. The reaction mixture was concentrated in vacuo and the residue was partitioned between dichloromethane (15 mL) and saturated aq sodium bicarbonate solution (5 mL) and water (5 mL). The layers were separated and the aqueous layer was extracted with dichloromethane (2×10 mL). The organic extracts were combined, dried over anhydrous sodium sulfate and concentrated in vacuo. Purification by dry column (60 mL funnel, silica gel 10–40μl, Sigma cat. S-6628) eluted with increasingly polar mixtures of ethyl acetate-hexanes (v/v: 1:1.4, 1.2:1, 2:1, 2.9:1, 5:1, containing 0.5% v/v isopropylamine) yielded 406 mg (52% yield) of 8-[3-(2,4-dichlorophenyl)propoxy]-3-[(methylamino)methyl]-2-methylimidazo[1,2-α]pyridine in the first fraction (Rf=0.20 in ethyl acetate-hexanes, 2:1 v/v, containing 0.5% v/v isopropylamine) and 221 mg (27% yield) of 8-[3-(2,4-dichlorophenyl)propoxy]-3-[(dimethylamino)methyl]-2-methylimidazo[1,2-α]pyridine in the second fraction (Rf=0.07 in ethyl acetate-hexanes, 2:1 v/v, containing 0.5% v/v isopropylamine).

Provenance & Evidence