Iodine → 1-Pyrazolyl iodopropargyl ether

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Reaction Steps

41.6 g of iodine are added, a little at a time, to 20 g of 1-pyrazolyl propargyl ether and 20 g of sodium carbonate in 400 g of acetonitrile at 40° C., while stirring. Stirring is continued for 8 hours at 40° C., after which undissolved material is filtered off under suction, and the filtrate is evaporated down in a rotary evaporator at 30° C. and under 20 mbar. The residue is dissolved in 200 g of dichloromethane, the solution is extracted twice with 200 g of 10% strength aqueous sodium thiosulfate solution, and the organic phase is dried with magnesium sulfate and evaporated down. 40 g (99% of theory) of 1-pyrazolyl iodopropargyl ether are obtained as an oil (H1 --NMR, in ppm: 5.1, s, 2H; 6.2, m, 1H; 7.4, m, 2H).

Provenance & Evidence