1.1: sodium hydroxide / methanol / 0.5 h / 0 - 5 °C / pH 10 1.2: 2 h / 0 - 20 °C / pH 9 2.1: water; sodium hydroxide / methanol / 1 h / pH 11 - 13 / Reflux View Scheme

1: acetoacetic acid methyl ester With sodium hydroxide in methanol T=0 - 5°C; pH=10; 0.5 h; 2: 2-chloro-6-fluoro-N-hydroxybenzimidoyl chloride in methanol T=0 - 20°C; pH=9; 2 h;

in diethyl ether; ethanol T=0 - 20°C;