tert-Butanol → Ethyl 6-(tert-butoxycarbonylamino)-3-pyridazine carboxylate

Beteiligte Stoffe

Reaktionsschritte

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.

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