144726-74-9

Upstream product

• 25225-62-1 p-tolyl-2 <4H> benzoxazine-1,3 one-4 
• 69-72-7 salicylic acid 
• 104-85-8 para-methylbenzonitrile 
• 19227-13-5 (Z)-N'-hydroxy-4-methylbenzimidamide 
• 347370-91-6 (1H-benzo[d][1,2,3]triazol-1-yl)(2-hydroxyphenyl)methanone 
• 65-45-2 salicylamide 
• 874-60-2 4-methyl-benzoyl chloride 
• 57135-18-9 2-hydroxy-N-(4-methylbenzoyl)benzamide 
• 57135-21-4 2-p-tolyl-benzo[e][1,3]oxazin-4-one; perchlorate 

Downstream Products

• 1374754-47-8 2-(5-butyl-3-(p-tolyl)-4,5-dihydro-1,2,4-oxadiazol-5-yl)phenol 
• 263153-63-5 3-[4-(bromomethyl)phenyl]-5-[2-[(methoxymethyl)oxy]phenyl]-1,2,4-oxadiazole 
• 263154-20-7 5-(2-methoxymethoxy-phenyl)-3-p-tolyl-[1,2,4]oxadiazole 

Relevant academic research and scientific papers

Synthesis of benzoxazines, quinazolines and 4H-benzo[e][1,3]thiazine by ANRORC rearrangements of 1,2,4-oxadiazoles

1,2,4-Oxadiazoles undergo ANRORC (addition of nucleophile, ring-opening and ring-closure) rearrangements upon reaction with excess of n-butyllithium to give benzoxazines, benzothiazines, and quinazolines in good yields under mild conditions. Georg Thieme Verlag Stuttgart · New York.

Antimicrobial effects of novel siderophores linked to β-lactam antibiotics

As a strategy to increase the penetration of antibiotic drugs through the outer membrane of Gram-negative pathogens, facilitated transport through siderophore receptors has been frequently exploited. Hydroxamic acids, catechols, or very close isosteres of catechols, which are mimics of naturally occurring siderophores, have been used successfully as covalently linked escorting moieties, but a much wider diversity of iron binding motifs exists. This observation, coupled to the relative lack of specificity of siderophore receptors, prompted us to initiate a program to identify novel, noncatechol siderophoric structures. We screened over 300 compounds for their ability to (1) support growth in low iron medium of a Pseudomonas aeruginosa siderophore biosynthesis deletion mutant, or (2) compete with a bactericidal siderophore-antibiotic conjugate for siderophore receptor access. From these assays we identified a set of small molecules that fulfilled one or both of these criteria. We then synthesized these compounds with functional groups suitable for attachment to both monobactam and cephalosporin core structures. Siderophore-β-lactam conjugates then were tested against a panel of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus strains. Although several of the resultant chimeric compounds had antimicrobial activity approaching that of ceftazidime, and most compounds demonstrated very potent activity against their cellular targets, only a single compound was obtained that had enhanced, siderophore-mediated antibacterial activity. Results with tonB mutants frequently showed increased rather than decreased susceptibilities, suggesting that multiple factors influenced the intracellular concentration of the drugs. (C) 2000 Elsevier Science Ltd.

SYNTHESIS AND STUDY OF THE STRUCTURE OF o-HYDROXYARYL-1,2,4-OXADIAZOLES

The reaction of 4-oxo-1,3-benz- and naphthoxazinium perchlorates with hydroxylamine leads to 5-(-o-hydroxyaryl)-1,2,4-oxadiazoles rather than to 3-(o-hydroxyaryl)-1,2,4-oxadiazoles, as was previously assumed.The structure of the compounds obtained was pro