Synlett 2000; 2000(1): 67-68
DOI: 10.1055/s-2000-6441
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Double Retro Diels-Alder Reaction Applied for Preparation of a Pyrimido[1,2-b]pyridazine

Ferenc Miklós* , Géza Stájer, Pál Sohár, Zsolt Böcskei
  • *Institute of Pharmaceutical Chemistry, Albert Szent-Györgyi Medical University, Szeged, Hungary, H-6701 Szeged, P.O.B. 121; Fax (62) 4 20 6 04; E-mail: stajer@pharma.szote.u-szeged.hu
Further Information

Publication History

Publication Date:
31 December 2000 (online)

Boiling diendo- or diexo-2-aminobicyclo[2.2.1]hept-5-ene-3-carbohydrazides 1 with 3-aroylnorbornenecarboxylic acid 2 in toluene yielded the pyrimido[1,2-b]pyridazine 4 directly in a double retro Diels-Alder process. Similarly, the reaction of anthranilic hydrazide 5 and 2 furnished the tricyclic benzo-fused analogue 7 via a single cycloreversion. The principle of the new method applied: the reactants were built up on cyclopentadienes and the dienes were cleaved by heating after condensation to furnish hetero bicyclic compound.

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