Hydrochloric Acid → 4-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)piperidine hydrochloride

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-[4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazol-1-yl]-piperidine-1-carboxylic acid tert-butyl ester (3.02 g, 8.00 mmol) in 1,4-dioxane (30 mL, 400 mmol), 4.0 M of HCl in 1,4-Dioxane (30 mL) was added and the reaction was stirred at 35° C. for 3 h. The reaction mixture was concentrated in vacuo to a white solid. The material was slightly hygroscopic. All free-flowing material was transferred to a vial and dried under vacuum for several hours. The material thus obtained was used in further reactions without purification. 1H NMR (400 MHz, CDCl3): δ=1.33 (s, 12H), 2.49 (br s, 4H), 3.18 (br s, 2H), 3.59-3.70 (m, 2H), 4.71 (br s, 1H), 7.87 (s, 2H), 9.84 (br s, 2H). MS (ES+): m/z 278.11 (100) [MH+]. HPLC: tR=1.99 min (ZQ3, polar—5 min).

Provenance & Evidence