94562-25-1Relevant articles and documents
Pyridazine-4,5-dicarboxylic Anhydride: Versatile Synthon for the Preparation of 1,3,7,8-Tetra-azaspirodecane Derivatives with Nitrogen 1,3-Binucleophiles
Chimichi, Stefano,Nesi, Rodolfo,Neri, Martino
, p. 2491 - 2495 (2007/10/02)
The title compound (1) reacted smoothly with 1,2,3-triphenyl- and 1,3-diphenyl-guanidine, with N,N'-diphenyl- and N-phenyl-thiourea, and with benzamidine to give in very good yields the 1,3,7,8-tetra-azaspirodecane derivatives (2), (4), (6), (9), and (11), respectively, through a Smiles-type rearrangement.The reaction of compound (1) with 1,3-diphenylguanidine showed a different regiospecificity from that observed for the spiro-cyclization of dimethyl pyridazine-4,5-dicarboxylate (15) into methyl 4-oxo-1-phenyl-2-phenylimino-1,3,7,8-tetra-azaspirodeca-6,9-diene- 10-carboxylate (19), carried out with the same reagent in the presence of sodium hydride.The structures of the new heterospiro compounds were determined on the basis of chemical and specteroscopic evidence.