反应详情

To a solution of pyrazine-2-carboxylic acid (2.0 g, 16.1 mmol) in methylene chloride (54 mL) at 0° C. is added oxalyl chloride (7.1 mL, 80.6 mmol) and N,N-dimethylformamide (0.12 mL, 1.6 mmol). The cooling bath is removed after 10 min and the reaction mixture stirred 18 h at room temperature. The reaction mixture is concentrated in vacuo. The residual oil is dissolved in methylene chloride (54 mL) and treated with N,O-dimethylhydroxylamine hydrochloride (2.36 g, 24.15 mmol) and triethylamine (11.2 mL, 80.6 mmol). The reaction mixture is stirred for 3 h at room temperature and diluted with methylene chloride. The resulting mixture is washed with water (50 mL), saturated aqueous bicarbonate (50 mL), and brine (100 mL), and concentrated in vacuo to yield the title compound, 2.35 g (88%), as a brown oil.

1. customThe cooling bath is removed after 10 min
2. concentrationThe reaction mixture is concentrated in vacuo
3. dissolutionThe residual oil is dissolved in methylene chloride (54 mL)
4. stirringThe reaction mixture is stirred for 3 h at room temperature
5. washThe resulting mixture is washed with water (50 mL), saturated aqueous bicarbonate (50 mL), and brine (100 mL)
6. concentrationconcentrated in vacuo