Cesium carbonate → Methyl 5-cyano-4-[2-(diphenylmethylene)hydrazino]-2-furoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Palladium acetate (2.098 g; 9.347 mmol), DPPF (10.36 g; 18.69 mmol) and cesium carbonate (85.27 g; 0.262 mmol) were charged in a dry reaction flask under argon. A preformed dry solution of methyl 4-bromo-5-cyano-2-furoate (43.00 g, 0.187 mol) and benzophenone hydrazone (44.02 g, 0.224 mol) in 1.2 L of toluene was transferred via cannula into the reaction flask. The resulting suspension was vigorously stirred at 100-104° C. for 45 hours under argon. The reaction mixture was cooled to about 70° C., added with 65 g of Dicalite® and filtered; the panel was washed twice with hot toluene (400 mL). The filtrate was concentrated under vacuum to a small volume and kept at +4° C. for 18 hours. The solid was collected by filtration and washed with 60 mL of toluene to yield 53.52 g of yellowish product.

Herkunft & Nachweise