反应详情

温度

0 °C

0.68 g of nitronium tetrafluoroborate are added in small portions to a solution of 0.76 g of 2-amino-4-trimethylsilyl-6-trifluoromethoxybenzothiazole in 20 cm3 of acetonitrile cooled to 0° C. Stirring is continued for 12 hours at a temperature close to 20° C. The solution is then diluted with 50 cm3 of water and extracted with 2 times 50 cm3 of ethyl acetate. The organic phases are combined, dried over sodium sulphate and concentrated in vacuum. The residue is purified by flash chromatography on silica gel with a cyclohexane-ethyl acetate mixture (7-3 by volume) as eluent. After recrystallization from a cyclohexane-ethyl acetate mixture (3-2 by volume), 0.3 g of 2-amino-4-nitro-6-trifluoromethoxybenzothiazole melting at 260° C. is obtained.

1. customclose to 20° C
2. extractionextracted with 2 times 50 cm3 of ethyl acetate
3. dry with materialdried over sodium sulphate
4. concentrationconcentrated in vacuum
5. customThe residue is purified by flash chromatography on silica gel with a cyclohexane-ethyl acetate mixture (7-3 by volume) as eluent
6. customAfter recrystallization from a cyclohexane-ethyl acetate mixture (3-2 by volume)