Cun WY, Keller PA, Pyne SG. Synthesis of 7α-Methoxy-7-(4-phenyl-1
H-1,2,3-triazol-1-yl)acetamino-3'-arylthio-cephalosporic Acid Derivatives from 7-Aminocephalosporic Acid.
Molecules 2023;
28:7338. [PMID:
37959756 PMCID:
PMC10650751 DOI:
10.3390/molecules28217338]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 10/23/2023] [Accepted: 10/26/2023] [Indexed: 11/15/2023] Open
Abstract
The aim of this project was to develop a synthetic protocol for the preparation of a cephamycin scaffold that would readily allow the synthesis of its analogues with variations at the C-7 amino group and the C-3' position. We also aimed to develop a method that avoided the use of toxic and potentially explosive diphenyldiazomethane. These aims were achieved via the synthesis of the novel α-bromo acetamide 18 which allowed functionalization at the α-bromo acetamide position by azide and then the introduction of a 4-phenyl-1H-1,2,3-triazol-1-yl moiety via a Cu(I)-catalysed azide-alkyne cycloaddition reaction with phenylacetylene. Palladium-catalyzed arylthioallylation reactions then allowed the introduction of 3'-arylthiol substituents. We also report for the first time the synthesis of the 4-methoxybenzyl ester of (6R,7S)-3-[(acetyloxy)methyl]-7-amino-7-methoxy-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid and the use of diphenyl trichloroacetimidate, instead of diphenyldiazomethane, and 4-methoxybenzyl trichloroacetimidate to prepare related 4-methoxybenzyl esters. The chemistry described, and several of the synthetic intermediates reported here, are potentially valuable methods and scaffolds, respectively, for further development of β-lactam antibiotics.
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