反应详情

A solution of 3.2 ml of methylhydrazine in 30 ml of methanol was added dropwise to an ice-cold solution of 10.5 g of 1,5,6,7-tetrahydro-5-hydroxymethylene-1-methyl-4H-indazol-4-one in 200 ml of methanol. The reaction was heated at reflux for 3.5 hours and the solvent was then removed under reduced pressure. The residue was triturated with a mixture of ether and ethanol to give a crude tan solid. This solid was dissolved in a mixture of ether and ethanol and acidified with ethereal hydrogen chloride. The yellow precipitate which formed was separated by filtration and recrystallized from a mixture of ethanol and propanol to give 1,4,5,6-tetrahydro-1,6-dimethylbenzo[1,2-c:3,4-c']dipyrazole monohydrochloride as a yellow crystalline solid melting at about 222°-226° C. with decomposition (51% yield). This compound has the following structural formula: ##STR6##

1. temperatureThe reaction was heated
2. temperatureat reflux for 3.5 hours
3. customthe solvent was then removed under reduced pressure
4. customThe residue was triturated with a mixture of ether and ethanol
5. customto give a crude tan solid
6. customThe yellow precipitate which formed
7. customwas separated by filtration
8. customrecrystallized from a mixture of ethanol and propanol