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Full-Text Articles in Physical Sciences and Mathematics
Routes To Acylated Sydnone Esters, Amanda Marie Balaguer
Routes To Acylated Sydnone Esters, Amanda Marie Balaguer
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Various 4-acyl-3-[2'-(carboalkoxy)phenyl]sydnones were synthesized by reaction of the parent sydnone with the corresponding anhydrides and Montmorillonite K-10. In the Q-tube, the acylation using acetic anhydride, which normally took 1.5 days for complete conversion thermally, was complete in 8.5 hours. Use of bismuth triflate as catalyst reduced the reaction time to 5 hours and, in the microwave, reactions were complete in 30 minutes and provided comparable yields. New sydnones were synthesized with acetic, propionic, butyric, and isobutyric anhydrides. Extension to various homogeneous metal triflates (lanthanum, yttrium, scandium, hafnium, gadolinium, and indium) was explored. Reactions were performed with 3-phenylsydnone as reactant, initially …
Synthetic Routes To A Fused-Ring Sydnoquinazoline, Gregory Edmond Storer
Synthetic Routes To A Fused-Ring Sydnoquinazoline, Gregory Edmond Storer
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In this research, 5-methylsydno-[3,4-a]quinazoline was synthesized via multiple methodologies, the best of which yielded the target compound in 50 % overall yield for the six steps. Synthesis of this compound in reasonable yields and exploration of its chemical behavior is of particular interest as a putative NO-prodrug. As an initial approach to the synthesis and accumulation of the compound of interest, attempts were made to optimize the existing synthetic pathway to its precursors. The starting material, 3-(2-acetylphenyl)sydnone, was prepared in 3 steps from commercially available starting material in good yields. This sydnone compound was then converted to the versatile intermediate, …
Preparation And Derivatization Of Novel Sydnonimines And Their Esters, Timothy Luke Teschler
Preparation And Derivatization Of Novel Sydnonimines And Their Esters, Timothy Luke Teschler
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Some years ago, we reported that 3-phenylsydnone underwent dilithiation to yield the dilithio species, upon treatment with n-butyllithium. Subsequent reactions with electrophiles led to variously substituted aryl sydnones, dependent on the nature of the electrophile employed. Sydnonimines, exocyclic nitrogen analogs of sydnones, exhibit interesting biological properties and, accordingly, it was of value to explore whether or not the dilithiation approach could be extended to such species. In the present work a series of N-6-ethoxycarbonyl-3-arylsydnonimines were synthesized from the corresponding sydnonimine hydrochlorides in moderate yields (22-77%). Attempted dilithiations of N-6-ethoxycarbonyl-3-arylsydnonimines and trapping with iodine proved to be problematic, yielding only the …
Formation Of A Sydno[3,4- A]Indolone And Reactions Thereof, Ryan Christopher Vikan
Formation Of A Sydno[3,4- A]Indolone And Reactions Thereof, Ryan Christopher Vikan
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In the present work, a synthetic route to the formation of a sydno[3,4- a]indolone was explored in the hope of attaining the first example of a fused-ring sydnone with an sp2-hybridized bridge. Formation of this product and exploration of its chemical behavior was anticipated to be of particular interest to the formation of NO-releasing prodrugs. A direct synthetic pathway to yield the target sydnoindolone starting from 3-(2-methoxycarbonylphenyl)sydnone and reaction with a base was proposed and explored. Attempted formation and isolation of the target sydnoindolone proved impossible under a variety of different conditions, undoubtedly due to the instability of this …
Sonogashira Coupling Routes To Ortho-Alkynl-And- Fused-Ring Sydnones, Andrew John Weisner
Sonogashira Coupling Routes To Ortho-Alkynl-And- Fused-Ring Sydnones, Andrew John Weisner
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In the present work, suitably functionalized arylsydnones were used to synthesize a variety of ortho-alkynyl sydnones both as potential precursors to novel sydnoquinolines and to provide non-linear optical (NLO) species of interest to Wright-Patterson Air Force Base (WPAFB). The versatile intermediate, 3-(2-(trimethylsilylethynyl)phenyl)sydnone, was prepared in good yield by the coupling of 3-(2-iodophenyl)sydnone with trimethylsilyl acetylene under Sonogashira conditions. From this intermediate, several ortho-alkynyl sydnones were prepared via a one-pot desilylation with tetrabutylammonium fluoride and Sonogashira coupling with para-substituted aryl iodides. In addition, a three-reaction-in-one-pot procedure was developed to access some of these species directly from 3-(2- iodophenyl)-sydnone. Subsequent reaction of …