1H-1,2,4-Triazole → 1,1-Dimethylethyl 4-(1H-1,2,4-triazol-1-yl)-1-piperidinecarboxylate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of: tert-butyl 4-[(methylsulfonyl)oxy]piperidine-1-carboxylate (5.9 g, 21 mmol) and 1,2,4-triazole (1.8 g, 25 mmol equiv.) in DMF at ambient temperature was added sodium hydride (60% in mineral oil, 1.0 g, 25 mmol). The mixture was stirred at 60° C. for 5 days, and the TLC showed no starting mesylate left. The mixture was poured into ice water and extracted with ethyl acetate (3×). The organic layer was dried, evaporated and purified by silica flash column eluting with 0-10% methanol in ethyl acetate to give tert-butyl 4-(1H-1,2,4-triazol-1-yl)piperidine-1-carboxylate as a white solid. The solid was then treated with hydrogen chloride in dioxane (4 N, 10 mL) for 2 h. The mixture was then evaporated to remove most of the dioxane to give a white solid, which was washed with ethyl acetate to give the desired 4-(1H-1,2,4-triazol-1-yl)piperidine hydrochloride salt (5.55 g). 1H NMR (300 MHz, CD3OD): δ 10.00 (s, 1H), 8.97 (s, 1H), 5.10-5.00 (m, 1H), 3.63-3.58 (br. d, 2H), 3.33-3.26 (br. d, 2H), 2.50-2.30 (m, 4H).

Provenance & Evidence