synthesis of new macrocyclic polyamides as antimicrobial agent candidates新型大环的合成聚酰胺作为抗菌剂的候选人.pdf

Molecules 2012, 17, 14510-14521; doi:10.3390/molecules171214510 OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Article Synthesis of New Macrocyclic Polyamides as Antimicrobial Agent Candidates Osama I. Abd El-Salam 1, Mohamed A. Al-Omar 2,3, Ahmed A. Fayed 4, Eman M. Flefel 4 and Abd El-Galil E. Amr 1,2,* 1 Applied Organic Chemistry Department, National Research Center, Dokki 12622, Cairo, Egypt 2 Pharmaceutical Chemistry Department, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia 3 Pharmaceutical Chemistry Department, Drug Exploration Development Chair (DEDC), College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia 4 Photochemistry Department, National Research Center, Dokki 12622, Cairo, Egypt * Author to whom correspondence should be addressed; E-Mail: aamr1963@. Received: 17 September 2012; in revised form: 26 November 2012 / Accepted: 28 November 2012 / Published: 6 December 2012 Abstract: A series of macrocyclic imides and Schiff-bases have been prepared via the cyclocondensation of pyridine-2,6-dicarbonyl dichloride (1) with L-ornithine methyl ester to give the corresponding macrocyclic bisester 2. Treatment of 2 with hydrazine hydrate gave macrocyclic bisacid hydrazide 3, which was used as starting material. Condensation of bishydrazide 3 with diacid anhydrides or aromatic aldehydes in refluxing acetic acid or ethanol gave the corresponding macrocyclic bisimides 4, 5a,b and macrocyclic bis- hydrazones 6a–j, respectively. The structure