Dabco → Azoxystrobin

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of methyl (E)-2-{2-[6-chloropyrimidin-4-yloxy]phenyl}-3-methoxyacrylate (96.2 g; prepared as described in WO 92/08703) in DMF (approximately 100 g) was added a DMF solution of 2-cyanophenyl (78.5 g at 50% w/w 2-cyanophenyl) followed by potassium carbonate (63.5 g) and DABCO (0.34 g). The mixture was heated to 80° C. and held for 75 minutes. The DMF was removed by vacuum distillation to a final temperature of 100° C. Toluene (165.8 g) was charged to the distillation residues and the temperature brought to 75° C. before adding hot water (318.6 g) and stirring for 30 minutes at 80° C. The aqueous phase was removed and then the toluene layer was sampled and analysed. The solution yield of methyl (E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate (azoxystrobin) was 90.0%. The toluene was distilled off under vacuum. Methanol (88 g) was added to the distillation residues at 70° C. and the mixture cooled to <5° C., filtered and the cake washed with methanol (2×30 ml) to give, after drying, methyl (E)-2-{2-[6-(2-cyano-phenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate (83.2% yield).

Herkunft & Nachweise