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Zeitschrift für Naturforschung B Contents Vol. 68b (2013)

Z. Naturforsch. 2013, 68b, 187 – 194

doi:10.5560/ZNB.2013-2270

Heterocycles [h]-Fused onto 4-Oxoquinoline-3-carboxylic Acid. Part X. Synthesis and X-Ray Structure of a Model 4-Oxo[1,4]benzoxazepino[2,3-h]quinoline-3-carboxylic Ester

Batool A. Farrayeh¹, Mustafa M. El-Abadelah¹, Jalal A. Zahra¹, Salim F. Haddad¹, and Wolfgang Voelter²

¹Chemistry Department, Faculty of Science, The University of Jordan, Amman 11942, Jordan

²Interfakultäres Institut für Biochemie, Universität Tübingen, Hoppe-Seyler-Straße 4, 72076 Tübingen, Germany

Reprint requests to Prof. Dr. W. Voelter. E-mail: wolfgang.voelter@uni-tuebingen.de

Received October 17, 2012 / published online February 20, 2013

Direct interaction of salicylaldehyde oxyanion with ethyl 7-chloro-8-nitro-4-oxoquinoline-3-carboxylate (2) delivered the respective 7-(2-formyl-phenoxy)-8-nitro-4-oxoquinoline-3-carboxylic ester 3. Reductive cyclization of 3 furnished the corresponding 4-oxo-[1,4]benzoxazepino[2,3-h]quinoline-3-carboxylic ester 5. Acid-catalyzed hydrolysis of the esters 3/5 produced the respective acids 4/6. Structural assignments for the new compounds 3–6 are supported by microanalytical and spectral (IR, HRMS, NMR) data and confirmed by X-ray structure determination for compound 5. Interestingly, compound 6 exhibited good antifungal activity against C. albicans.

Key words: Salicylaldehyde Oxyanion in S_N(Ar) Reaction, 7-(2-Formylphenoxy)-8-nitro-4-oxoquinoline-3-carboxylic Ester, Reductive Cyclization, 4-Oxo[1,4]benzoxazepino-[2,3-h]quinoline-3-carboxylic Ester

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