反应详情

1.000 g (6.31 mmol) of 6-chloro-pyrazine-2-carboxylic acid were dissolved in 75 mL of 50% v/v acetonitrile in dichloromethane containing. 2.810 g (7.48 mmol) of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)uronium hexafluorophosphate were added, then 8.0 mL (16 mmol) of 2 M dimethylamine in anhydrous THF was added and stirring was continued for 18 h. The resulting solution was distributed between ethyl acetate and a 2 M aqueous solution of sodium carbonate. The organic phase was washed with brine, dried over sodium sulfate and evaporated. The resulting crude was purified by flash chromatography on silica gel using a gradient of ethyl acetate and hexanes to afford 695 mg (3.74 mmol, 59%) of 6-chloro-pyrazine-2-carboxylic acid dimethylamide as a pale yellow oil. 1H-NMR [500 MHz, d6-DMSO] δ: 8.91 (s, 1H), 8.84 (s, 1H), 3.04 (s, 3H), 2.98 (s, 3H); MS [MH+] m/z: 186.

1. washThe organic phase was washed with brine
2. dry with materialdried over sodium sulfate
3. customevaporated
4. customThe resulting crude was purified by flash chromatography on silica gel using a gradient of ethyl acetate and hexanes