反应详情

A mixture of 80 mg (0.46 mmol) 3-ethyl-1H-indazole-5-carbaldehyde (Example 10A), 119 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)] and a trace amount of powdered 4 Å molecular sieve in acetic acid (0.44 ml) was heated to reflux temperature for 4 h. After cooling, the reaction mixture was diluted with THF/methanol and filtered. The filtrate was purified twice by preparative RP-HPLC (acetonitrile/water+0.1% TFA gradient) yielding 99 mg (57% of th.) of the title compound.

1. temperatureto reflux temperature for 4 h
2. temperatureAfter cooling
3. filtrationfiltered
4. customThe filtrate was purified twice by preparative RP-HPLC (acetonitrile/water+0.1% TFA gradient)