3-Chloro-2-fluorobenzaldehyde

261723-30-2

85070-48-0

36.3 g of sodium bicarbonate and 500 g of dichloromethane were added to a 1 L four-necked flask, followed by 0.5 g of TOMO as a catalyst. The reaction mixture was cooled to 0 to 5°C with stirring. To this cooled mixture was slowly added a mixed solution of 50 g of (3-chloro-2-fluorophenyl)methanol and 100 g of dichloromethane. Next, 230 g of sodium hypochlorite solution was added slowly and dropwise. The reaction mixture was held at 0 to 5°C for 1 hour. The progress of the reaction was monitored by sampling and the reaction was stopped when the content of raw (3-chloro-2-fluorophenyl)methanol was ≤ 1%. After completion of the reaction, the mixture was left to stratify. The organic layer (dichloromethane layer) was separated and the dichloromethane was recovered by simple distillation. Finally, vacuum distillation of the remaining oil layer gave 46.1 g of 3-chloro-2-fluorobenzaldehyde with 97.5% product purity and 91% yield.