反应详情

温度

65 °C

To a solution of tert-butyl 5-chloro-6-hydrazinonicotinate hydrochloride salt (5.5 g, 17.4 mmol) in methanol (80 mL) was added methylpyridine-2-carboximidoate (4.73 g, 34.7 mmol). The mixture was heated to 65° C. After 2.5 h, the mixture was cooled to ambient temperature. The solid crashed out was filtered off and the filtrate was concentrated. Purification by silica gel chromatography (100% hexanes→60% hexanes/ethyl acetate) gave 0.44 g of the title compound and 1.3 g of a side product. The side product (1.3 g) was dissolved in methanol (28 mL) and acetic acid (0.53 mL) was added. The mixture was heated to 65° C. After 7 h, the reaction was cooled to ambient temperature and saturated aqueous sodium bicarbonate was added. The mixture was extracted with ethyl acetate (3×). The combined organic layer was washed with brine, dried over sodium sulfate, filtered and concentrated to give another 1.0 g of the title compound: LC-MS [M+1]=331.1.

1. temperaturethe mixture was cooled to ambient temperature
2. filtrationThe solid crashed out was filtered off
3. concentrationthe filtrate was concentrated
4. customPurification by silica gel chromatography (100% hexanes→60% hexanes/ethyl acetate)