In a 500 mL four-necked flask, sodium hydrogen carbonate 126.0 g (1.50 mol) and 146.8 g of toluene were added, and the mixture was stirred while cooling. The internal temperature was maintained below 5 ° C, 112.9 g (1.00 mol) of chloroacetyl chloride was added dropwise over 4 hours, and 49.6 g (1.10 mol) of dimethylamine gas was blown over 4 hours. After stirring at -2 to 1 ° C. for 1 hour, the reaction solution was filtrated under reduced pressure to remove inorganic salt crystals by filtration. The crystals were washed with 100 g of toluene, and the filtrate and washings were combined. After separating and removing the aqueous layer in the filtrate washings, the toluene layer was concentrated under reduced pressure to obtain 113.2 g (0.93 mol) of oily 2-chloro-N, N-dimethylacetamide. The yield was 93.1%.
