2-(4-Chloropropoxybenzoyl)-8-methylimidazo[1,2-a]pyridine → 2-(4-Dibutylaminopropoxybenzoyl)-8-methylimidazo[1,2-a]pyridine

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Reaction Steps

A mixture of 2-(4-chloropropoxybenzoyl)-8-methylimidazo-[1,2-a]pyridine (2.4 g, 6.0 mmol) in dibutylamine (30 ml) was stirred at reflux for 8 hours. The excess dibutylamine was removed by distillation and the resulting oil was flash chromatographed (silica gel, acetone) to give the free base of the title compound (2.5 g, 100% yield) as a thick oil. The HCl salt was prepared by dropwise addition of concentrated hydrochloric acid to a solution of the title compound in methanol, concentrated and recrystallized from methanol-acetone, mp 159 to 161° C. IR(KBr): 3420, 1650 cm−1. MS: 421 (M+). 1HNMR (CD3OD): δ8.89 (s, 1 H), 8.72 (d, J=6.6 Hz, 1H), 8.15 (d, J=8.9 Hz, 2H), 7.89 (d, J=7.3 Hz, 1H ), 7.48 (t, J=6.9 Hz, 1H ), 7.21 (d, J=8.9 Hz, 2H), 4.29 (t, J=7 Hz, 2H), 3.26 (m, 6H), 2.73 (s, 3H), 2.33 (m, 2H), 1.79-1.35 (m, 8H), 1.02 (m 6H).

Provenance & Evidence