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

Participants

Reaction Steps

A solution of 2.1 g (20 mmol) of n-butyl nitrite (97%) and 4 g (15 mmol) of 2,3-dimethyl-4-methylsulfonylbromobenzene in 50 ml of dimethylformamide is cooled to from −55 to −60° C., and a solution of 2.8 g (25 mmol) of potassium tert-butoxide in 35 ml of dimethylformamide is added dropwise at this temperature, over a period of 20 minutes. The reaction is monitored by HPLC. For work-up, initially 10 ml of water are added, and the mixture is then adjusted to pH 5-6 using about 9 ml of glacial acetic acid. The mixture is then poured onto 100 ml 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 3.6 g of an oily crude product (90% by HPLC) which can be purified by recrystallization from toluene.

Provenance & Evidence