反应详情

To phosphoric trichloride (136 ml) was added N,N-dimethylformamide (339 ml) under ice-cooling, and the mixture was stirred under ice-cooling for 30 minutes. To the mixture was added a solution of 2,3-dihydro-1H-imidazo[1,2-b]pyrazole-1-carbaldehyde (100 g) in N,N-dimethylformamide (200 ml), and the mixture was stirred at 80° C. for 1.5 hours. The reaction mixture was carefully added to a mixture of ethyl acetate and water under ice-cooling, and the mixture was adjusted to pH 6. The organic layer was dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The residue was triturated with diisopropyl ether and dried in vacuo to give 2,3-dihydro-1H-imidazo[1,2-b]pyrazole-1,7-dicarbaldehyde (102 g).

1. temperaturecooling
2. temperaturecooling for 30 minutes
3. stirringthe mixture was stirred at 80° C. for 1.5 hours
4. temperaturecooling
5. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe residue was triturated with diisopropyl ether
9. customdried in vacuo