Dihydropyridazine Derivatives with Cyclopenta-, Benzo-, Furo-, Thiopyrano- and Pyrido-Annulation
作者:Miriam Penning、Jens Christoffers
DOI:10.1002/ejoc.201201158
日期:2013.1
Regioisomeric [c]annulated pyridazines were prepared from arylhydrazines and carbocyclic or heterocyclic β-oxo esters with an α-phenacetyl moiety. With AcOH/EtOH, the hydrazones were preferentially formed at the endocyclic ketone, which are further cyclized with trifluoroacetic acid (TFA)/CH2Cl2 to give 2,4a-dihydropyridazines. Use of TFA/CH2Cl2 led hydrazones at the exocyclic benzoyl group, which