2-[4-(3-Chloro-propoxy)-phenyl]-imidazo[1,2-a]pyridine → Dibutyl-[3-(4-imidazo[1,2-a]pyridin-2-yl-phenoxy)-propyl]-amine

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Reaction Steps

A suspension of 2-(4-chloropropoxyphenyl)imidazo[1,2-a]-pyridine (5.2 g, 14 mmol) in dibutylamine (30 ml) was stirred at reflux for 5 hours. The excess dibutylamine was removed by distillation and the resulting oil was flash chromatographed (silica gel, 9:1 CH2Cl2 : acetone) to give the free base of the title compound (5.1 g, 93% yield) as an oil. The HCl salt was prepared by dropwise addition of concentrated hydrochloric acid to a solution of the free base in methanol, concentrated and recrystallized from methanol acetone to yield 2-(4-dibutylaminopropoxyphenyl)imidazo- [1,2-a]pyridine as a white crystalline solid, mp 179° C. to 183° C. IR(KBr): 3400, 2620, 1650, 1620 cm-1. MS: 380 (MH+). 1H NMR (CD3OD): δ8.80 (d, J=8 Hz, 1H), 8.52 (s, 1H), 7.92-7.49 (m, 5H), 7.18 (d, J=8 Hz, 2H), 4.23 (t, J=4.6 Hz, 2H), 3.50-3.13 (m, 6H), 2.25 (m, 2H), 1.82-1.34 (m, 8H), 1.01 (m, 6H).

Provenance & Evidence