Water → 3-Chloro-2-methyl-6-methylsulfonylbenzaldoxime

Participants

Reaction Steps

A solution of 12.7 g (119 mmol) of n-butyl nitrite (97% pure) and 20 g (92 mmol) of 2,3-dimethyl-4-methylsulfonylchlorobenzene in 100 ml of dimethylformamide is cooled to from −55 to −60° C., and a solution of 16.8 g (147 mmol) of potassium tert-butoxide in 70 ml of dimethylformamide is added dropwise at this temperature, over a period of 30 minutes. The reaction is monitored by HPLC. For work-up, initially 50 ml of water are added, and the pH is subsequently adjusted to 5-6 using approximately 30 ml of glacial acetic acid. The reaction mixture is subsequently poured into 0.7 kg of ice-water, and the aqueous phase is extracted with methylene chloride. The organic phase is washed with sodium bicarbonate solution, dried over magnesium sulfate and concentrated. This gives 18.4 g of a light-beige crude product which is purified by recrystallization from approximately 30 ml of toluene.

Provenance & Evidence