反应详情

A suspension of 3.42 g (15.2 mmol) (2E)-2-[(3-methyl-1H-indazol-5-yl)methylidene]-3-oxobutanenitrile (Example 2A) and 7.27 g (60.7 mmol) 3-amino-4,4-difluorobut-2-enenitrile [obtainable by Thorpe reaction of acetonitrile with 2,2-difluoroacetonitrile, cf. Org. React. 15, 1 (1967), ibid. 31, 1 (1984)] in 2-propanol (20 ml) and triethylamine (0.21 ml) was stirred at reflux temperature overnight. After cooling, the precipitate was collected by filtration and washed twice with cold 2-propanol. The crude product was purified by silica gel chromatography (tert-butyl methyl ether/ethanol gradient, final mixture 94:6 v/v) to yield 0.36 g (7% of th.) of the racemic title compound as a pale yellow solid.

1. temperatureat reflux temperature overnight
2. temperatureAfter cooling
3. filtrationthe precipitate was collected by filtration
4. washwashed twice with cold 2-propanol
5. customThe crude product was purified by silica gel chromatography (tert-butyl methyl ether/ethanol gradient, final mixture 94:6 v/v)