反应详情

A mixture of 5.0 g (31.2 mmol) 3-methyl-1H-indazole-5-carbaldehyde (Example 1A), 3.61 g (34.3 mmol) sodium (1Z)-1-cyanoprop-1-en-2-olate, 2.23 ml (39 mmol) acetic acid and 0.31 ml (3.12 mmol) piperidine in dry dichloromethane (250 ml) containing 4 Å molecular sieve was stirred under reflux for 12 h. Upon cooling, a precipitate was formed which was collected by filtration and washed with saturated aqueous sodium bicarbonate solution and water. The solid was dissolved in ethanol, and the molecular sieve was filtered off. The filtrate was concentrated under reduced pressure, and the residue was treated with ethyl acetate and saturated aqueous sodium carbonate solution. The organic layer was washed with water, dried, and concentrated under reduced pressure to afford the title compound (3.5 g, 50% of th.) as a pale yellow solid which was used in the next step without further purification.

1. additioncontaining 4 Å molecular sieve
2. temperatureunder reflux for 12 h
3. temperatureUpon cooling
4. customa precipitate was formed which
5. filtrationwas collected by filtration
6. washwashed with saturated aqueous sodium bicarbonate solution and water
7. dissolutionThe solid was dissolved in ethanol
8. filtrationthe molecular sieve was filtered off
9. concentrationThe filtrate was concentrated under reduced pressure
10. additionthe residue was treated with ethyl acetate and saturated aqueous sodium carbonate solution
11. washThe organic layer was washed with water
12. customdried
13. concentrationconcentrated under reduced pressure