反应详情

A mixture of ethyl 6-chloro-3-pyridazine carboxylate (6.5 g) [British patent number 856, 409], potassium isocyanate (3.5 g), tert-butanol (6.0 ml), tetrakis(triphenylphosphine)palladium (400 mg) and diglyme (6 ml) in DMF (50 ml) was heated at reflux for 2 hours, cooled and partitioned between diethyl ether and water. The organic layer was dried (MgSO4), filtered through silica gel and evaporated. The resulting solid was purified by crystallisation from iso-hexane to give ethyl 6-(tert-butoxycarbonylamino)-3-pyridazine carboxylate (2.4 g), mp 87°-88° C.

1. temperaturewas heated
2. temperatureat reflux for 2 hours
3. temperaturecooled
4. custompartitioned between diethyl ether and water
5. dry with materialThe organic layer was dried (MgSO4)
6. filtrationfiltered through silica gel
7. customevaporated
8. customThe resulting solid was purified by crystallisation from iso-hexane