Acetic Acid → 5-chloro-3-(3-methoxypropyl)-2-(piperidin-3-yl)-3H-imidazo[4,5-b]pyridine

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Reaction Steps

Compound 35B (crude material, 2.84 mmol max) prepared in Step 13 was added to a 50 trLL round-bottomed flask equipped for stirring under nitrogen. Glacial acetic acid (10 mL) was then added and the resultant solution was stirred at reflux under nitrogen for 16 hr. The reaction solution was concentrated in-vacuo to give a brownish oil. Toluene (30 mL) was added and the subsequent solution was concentrated in vacuo; this was repeated three times to remove any trace quantities of acetic acid affording the title compound as a brown oil. This oil was then purified by preparative LC/MS (5-50% CH3CN in H2O) to afford 5-chloro-3-(3-methoxypropyl)-2-(piperidin-3-yl)-3H-imidazo[4,5-b]pyridine (35C) as a tan oil. (088 mmol, 0.122 g, 10% yield over 3-steps). Subsequent analysis of a later derivative of this compound revealed that the chiral center had been epimerized during this reaction sequence. ESI-MS: m/z 309.4 (M+H)+.

Provenance & Evidence