Ethyl 3-(triphenyl-lambda~5~-phosphanylidene)propanoate → 2-(4-Chloro-2-fluoro-5-hydroxyphenyl)-4-methyl-5-(trifluoromethyl)-3(2H)-pyridazinone

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Reaction Steps

Then, 12.9 g of 3,3,3-trifluoro-2-oxopropanal (4-chloro-2-fluoro-5-hydroxyphenylhydrazone) and 22.3 g of carbethoxyethylidenetriphenylphosphorane were dissolved in 110 ml of tetrahydrofuran, and the solution was heated under reflux for 3 hours. The solvent was distilled out under reduced pressure, and the residue was subjected to silica gel chromatography, which afforded 8.8 g of 2-(2-fluoro-4-chloro-5-hydroxyphenyl)-4-methyl-5-trifluoromethylpyridazin-3 One (compound 1-391).

Provenance & Evidence