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

Participants

Reaction Steps

A mixture of toluene-4-sulfonic acid 1,4-dioxaspiro[4.5]dec-8-yl ester (2.0 g, 6.4 mmol; prepared according to U.S. Pat. No. 4,360,531 example I.B), 4-iodopyrazole (1.36 g, 7.01 mmol), K2CO3 (1.06 g, 7.7 mmol), 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, and the reaction mixture was extracted with EtOAc (3×40 mL). The EtOAc extracts were washed with water (30 mL), dried over Na2SO4, filtered, and concentrated at reduced pressure. The crude material was purified by column chromatography on silica gel using EtOAc/CH2Cl2 (1:9) to give the title compound. 1H NMR (CDCl3, 300 MHz): δ=1.66-2.17 (m, 8H), 3.97 (s, 4H), 4.17-4.23 (m, 1H), 7.27 (d, J=3.3 Hz, 1H), 7.48 (d, J=3.3 Hz, 1H).

Provenance & Evidence