Acetic Acid → 6-Methoxy-5,6,7,8-tetrahydroimidazo[1,2-a]pyridine

Participants

Reaction Steps

Add acetic acid (40 mL) to a heterogeneous solution of 6-methoxyimidazopyridine (1.0 g; 1.0 equiv; 6.75 mmoles) and 10% palladium on carbon (1.0 g; 1.4 equiv; 9.40 mmoles). Evacuate and backfill the reaction vessel with nitrogen (3×) then hydrogen (3×). Vigorously stir the reaction under hydrogen at ambient temperature for 3 hours. Filter the reaction mixture through celite, and wash the filter cake with a 1:1 mixture of dichloromethane and methanol. Concentrate the filtrate and dissolve the crude product mixture in 20 mL methanol, then load onto a scx ion-exchange column. Elute with methanol followed by 2M ammonia in methanol to give 6-methoxy-5,6,7,8-tetrahydroimidazo[1,2-a]pyridine (1.00 g; 97%) as a colorless oil. 1H NMR (DMSO): δ 1.84-1.94 (m, 1H), 2.00-2.09 (m, 1H), 2.63-2.68 (m, 2H), 3.27 (s, 3H), 3.77-3.82 (m, 1H), 3.92-4.03 (m, 2 H), 6.74 (d, 1H), 6.91 (d, 1H).

Provenance & Evidence