Sofan M.A., El-Taweel F.M.and Elagamey A.G.A. (1990) Studies on 1,3-indandione: Synthesis of Fluorenones and Indeno(2,1-c)pyridazine. Journal für Praktische Chemie, 332, 640-644.

has been cited by the following article:

• TITLE: Synthesis of some new Indeno[1,2-e]pyrazolo[5,1-c]-1,2,4-triazin-6-one and Indeno[2,1-c]pyridazine-4-carbonitrile Derivatives

  AUTHORS: Hamdi M. Hassaneen, Nada M. Abunada, Huwaida M. Hassaneen

  KEYWORDS: Diazonium Chlorides;Indenopyrazolotriazine; Indenopyridazine

  JOURNAL NAME: Natural Science, Vol.2 No.12, December 28, 2010

  ABSTRACT: Diazonium chlorides of 5-amino-3-methypyrazole 1a and 5-amino-4-phenylpyrazole 1b coupled with 1,3-indanedione 2 and led to the formation of acyclic hydrazone 3a and a cyclic product indenopyrazolotriazine 4b respectively. Cyclization of the hydrazone 3a by boiling in acetic acid afforded the corresponding 4a. The hydrazone 3a reacted with malononitrile in boiling ethanol in the presence of piperidine and gave indeno[2,1-c]pyridazine-4-carbonitrile derivatives 5a,b. Also, coupling of 6 with aryl diazonium chlorides gave the corresponding indenopyridazine derivatives 8a-e. Acetylation, benzoylation and hydrolysis of compound 8a afforded the corresponding substitution products 10-12, respectively. The structures of the newly synthesized compounds were established on the basis of chemical and spectral evidences.