6-fluoro-1H-indazole-5-carbaldehyde → HCID 68364207, compound

Participants

Reaction Steps

A solution of 150 mg (0.55 mmol) 6-fluoro-1H-indazole-5-carbaldehyde (Example 5A) and 142 mg (1.21 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 acetic acid (0.5 ml) containing powdered 4 Å molecular sieve was heated to reflux temperature for 5 h. After cooling, the reaction mixture was diluted with THF and filtered. The filtrate was directly purified by preparative RP-HPLC (acetonitrile/water+0.1% TFA gradient) yielding 147 mg (72% of th.) of the title compound.

Provenance & Evidence