p-Toluenesulfonic acid → 3-piperidin-4-yl-3H-imidazo[4,5-c]pyridine

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Reaction Conditions

Reaction Steps

To tert-butyl 4-[(4-nitro-1-oxidopyridin-3-yl)amino]piperidine-1-carboxylate (1.6 g) in toluene (3 ml) was added trimethyl orthoformate (3.6 ml) followed by p-toluenesulfonic acid (105 mg) and the resulting mixture was heated to 105° C. for 4 hours. The mixture was cooled and partitioned between ethyl acetate (75 ml) and water (75 ml). The organic layer was washed with brine, dried and evaporated to dryness to give the title compound as a solid. Yield 1.18 g. NMR (CDCl3) 1.5 (s, 9H), 2.1 (m, 2H), 2.25 (m, 2H), 3.0 (m, 2H), 4.4 (m, 3H), 7.7 (dd, 1H), 8.1 (s, 1H), 8.5 (d, 1H), 8.9 (s, 1H).

Provenance & Evidence