3-Amino-4,4-difluorobut-2-enenitrile → HCID 67084928, compound

Participants

Reaction Steps

A suspension of 200 mg (0.87 mmol) (2E)-2-[(6-fluoro-1H-indazol-5-yl)methylidene]-3-oxobutane-nitrite (Example 6A) and 419 mg (3.49 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 (1 ml) was stirred at reflux temperature overnight. After cooling, the mixture was concentrated under reduced pressure, and the residue was suspended in p-xylene (3 ml). Small amounts of p-toluenesulfonic acid and powdered 4 Å molecular sieve were added, and the mixture was stirred at reflux temperature for 16 h. Upon cooling, the mixture was diluted with aceto-nitrile and filtered. The filtrate was concentrated under reduced pressure, and the crude product was purified by preparative RP-HPLC (acetonitrile/water gradient, final mixture 9:1 v/v) to yield 81 mg (28% of th.) of the racemic title compound as a pale yellow solid.

Provenance & Evidence