Nitric Acid → 2-Chloro-7-nitro-6-trifluoromethoxybenzothiazole

Participants

Reaction Conditions

Reaction Steps

10 g of 2-chloro-6-trifluoromethoxybenzothiazole are added dropwise over one hour to a mixture, cooled to 10° C., of concentrated sulphuric acid (50 cm3) and concentrated nitric acid (25 cm3). The mixture is then heated for one hour at 60° C. After cooling, the mixture is poured into an ice/water mixture (1/1 by weight) and extracted with 3 times 100 cm3 of chloroform. The organic phases are dried over magnesium sulphate and concentrated under vacuum (2.7 kPa). The residue is purified by flash chromatography with a chloroform/cyclohexane mixture (4/6 by volume) as eluent. 6.4 g of 2-chloro-7-nitro-6-trifluoromethoxybenzothiazole are thus obtained, melting at 64° C.

Provenance & Evidence