Hydrogen Bromide → 4-(3-Bromofuran-2-yl)-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazole

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Reaction Steps

To a stirred solution of 3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-(4,4-diethoxy-1-hydroxybut-2-ynyl)pyrazole (0.04 g) in dioxane (1 ml) was added dropwise at room temperature hydrobromic acid (0.04 g). After 30 minutes the reaction mixture was poured into water (10 ml) and ether (10 ml). The organic layer was separated, dried (MgSO4) and evaporated. Recrystallisation from ether/hexane gave the title compound as a pale brown solid, m.p. 99-101° C.

Provenance & Evidence