Potassium Carbonate → 1-(1,4-Dioxaspiro[4.5]dec-8-yl)-4-iodo-1H-pyrazole

Beteiligte Stoffe

Reaktionsschritte

A mixture of 1,4-dioxaspiro[4.5]dec-8-yl 4-methylbenzenesulfonate (prepared according to U.S. Pat. No. 4,360,531) (2.0 g, 6.4 mmol), 4-iodopyrazole (1.36 g, 7.0 mmol), K2CO3 (1.06 g, 7.7 mmol), and 18-crown-6 (0.2 g, 0.7 mmol) in DMF (5 mL) was heated under nitrogen at 50° C. for 16 h. Water (50 mL) was added to the reaction mixture, which was then extracted with EtOAc (3×40 mL). The combined EtOAc extracts were washed with water (30 mL), dried over Na2SO4, filtered, and concentrated in vacuo. The residue was purified by column chromatography on silica gel using EtOAc/CH2Cl2 (1:9) to give the title compound. 1H NMR (CDCl3, 400 MHz): δ=1.67-1.76 (m, 2 H), 1.84-1.91 (m, 2 H), 1.99-2.17 (m, 4 H), 3.95-3.99 (m, 4 H), 4.18-4.27 (m, 1 H). MS (ES+): m/z=334.96 (100) [MH+]; HPLC: tR=3.26 min (polar—5 min, ZQ3).

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