Ethanol → Chlorfenapyr

Beteiligte Stoffe

Reaktionsschritte

A stirred mixture of sodium hydride (26.5 g, 1.105 mol) in tetrahydrofuran, under nitrogen, is treated slowly with a solution of 4-bromo-2-(p-chlorophenyl)-5-(trifluoromethyl)pyrrole-3-carbonitrile (1.00 g, 0.273 mol) in tetrahydrofuran at ≤60° C. When the addition is complete, the reaction mixture is treated with bromochloromethane (93.0 g, 0.718 mol), heated to 63°-65° C., treated dropwise with absolute ethanol (39.5 g, 0.859 mol) over a 5.5 hour period, stirred at 63°-65° C. for another 3 hours and concentrated in vacuo. The concentrate is dispersed in a mixture of water and methylene chloride. The aqueous phase is separated and washed with methylene chloride. The organic phases are combined and concentrated. The concentrate is dispersed in hexane, cooled to 5°-10° C. and filtered. The filtercake is washed with heptane and dried to give the title product as a white solid, 111.6 g, (91.3% yield) and 91.2% purity by HPLC analysis.

Herkunft & Nachweise