Dimethylformamide → Chlorfenapyr

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A stirred mixture of 4-bromo-2-(p-chlorophenyl)-5-(trifluoromethyl)pyrrole-3-carbonitrile (17.4 g, 0.05 mole), diethoxymethane (10.4 g, 0.10 mole) and dimethylformamide (DMF) (4.6 g, 0.0625 mole) in toluene, under N2, is treated portion-wise with phosphorous oxychloride (9.6 g, 0.0625 mole) at 35°-45° C. over a 10 minute period, heated at 45°-53° C. for about 0.5 hour, cooled to 35° C. and treated dropwise with triethylamine (7.25 g, 0.0715 mole) over a 2 hour period at 35°-45° C. The reaction mixture is treated with water and the toluene is removed via azeotropic distillation. The remaining residue is treated with water, filtered and the filtercake is dried in vacuo at 60° C. to give the title product, 20.8 g, 92.7% pure, 94.6% yield, identified by HPLC analysis.

Herkunft & Nachweise