Bromine → 3-Bromoisothiazolo(4,5-b)pyrazine

Crude 3-mercaptopyrazine-2-carbonitrile (1.1 g, 8.0 mmol) was dissolved in ethyl acetate (30 mL) and treated with bromine (0.46 mL, 8.8 mmol). The reaction mixture was heated to reflux. As soon as the bromine was added, the mixture became homogeneous but after several minutes a precipitate began to form. After 90 min the reaction mixture was cooled to room temperature and then partitioned between ethyl acetate and saturated aqueous sodium bicarbonate solution. The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to yield 3-bromoisothiazolo[5,4-b]pyrazine as a pale orange solid. MW=215 confirmed by LC-MS, tr=10.34 min (Method Y) MH+=214-216.

1. temperatureThe reaction mixture was heated to reflux
2. waitthe mixture became homogeneous but after several minutes
3. customto form
4. custompartitioned between ethyl acetate and saturated aqueous sodium bicarbonate solution
5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure

ORD record

ord-0c8ed4da1f824a5ba0cc314568edde61

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07776847B2