Oxidation of 4-aryl-substituted isoxazolin-5-ones. A new synthesis of 2,5-diaryl-1,3-oxazin-6-ones

Beccalli, Egle M.; Rosa, Concetta La; Marchesini, A.

doi:10.1021/jo00196a034

Cited by 37 publications

(26 citation statements)

References 7 publications

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“…We first prepared the α-formylacetic esters 2a and 2b as described by Marchesini [22] and the α-formylacetic esters 2cϪ2e by the method of Spengler. [23] After hydrolysis and an acid/base separation the crude products could be used without further purification.…”

Section: Resultsmentioning

confidence: 99%

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A Short Synthetic Route to 4,7‐Dihalogenated 1,10‐Phenanthrolines with Additional Groups in 3,8‐Position: Soluble Precursors for Macrocyclic Oligophenanthrolines

Schmittel

Ammon

1998

European J Organic Chem

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A short and efficient preparation of 3,8‐dialkylated or 3,8‐diarylated 1,10‐phenanthrolines‐4,7‐diones is described. Their chlorination or bromination furnishes the corresponding, highly soluble 4,7‐dichloro‐ or 4,7‐dibromo phenanthrolines that constitute versatile precursors to macrocyclic oligophenanthrolines with exo‐coordination sites. They can be further reacted by nucleophilic aromatic substitution or Heck‐coupling reactions.

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Section: Resultsmentioning

confidence: 99%

“…[25] . The α-formylacetic esters 2a؊e were prepared according to literature procedures [22] [23] and used as crude products.…”

Section: Methodsmentioning

confidence: 99%

A Short Synthetic Route to 4,7‐Dihalogenated 1,10‐Phenanthrolines with Additional Groups in 3,8‐Position: Soluble Precursors for Macrocyclic Oligophenanthrolines

Schmittel

Ammon

1998

European J Organic Chem

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“…3-Hydroxy-2-phenylacrylic acid ethyl ester (4a) 15 ). In addition, 20% of 3-(4-methoxyphenyl)-3-oxopropionic acid ethyl ester (5c) 16 was isolated.…”

Section: Methodsmentioning

confidence: 99%

Iron Lewis Acid Catalyzed Reactions of Aromatic Aldehydes with Ethyl Diazoacetate: Unprecedented Formation of 3-Hydroxy-2-arylacrylic Acid Ethyl Esters by a Unique 1,2-Aryl Shift

Mahmood

Hossain

1998

J. Org. Chem.

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The iron Lewis acid [η 5 -(C 5 H 5 )Fe(CO) 2 (THF)]BF 4 (1) was found to catalyze reactions of ethyl diazoacetate (EDA) and aromatic aldehydes, yielding 3-hydroxy-2-arylacrylic acid ethyl esters and the corresponding -keto esters. According to the literature, this is the first report of the formation of enol esters from EDA and aromatic aldehydes. The yield of the enol esters increased with electronrich aldehydes. With 2,4-dimethoxybenzaldehyde the only product isolated was the corresponding enol ester in 80% yield. However, in the presence of electron-deficient aldehydes such as p-nitrobenzaldehyde, formation of enol ester decreased to 32%. The most unique feature of these reactions is that enol esters are formed by an unusual 1,2-aryl shift, from a possible intermediate 8, which in turn is formed from the reaction of the iron aldehyde complex 7 and EDA.

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“…Absorption spectra and spectrophotometric reaction rates were measured with a Hewlett-Packard 8452A spectrophotometer. The concentrations of stock enzyme solutions were determined spectrophotometrically (16).…”

Section: Methodsmentioning

confidence: 99%

Inhibition of β-Lactamases by Monocyclic Acyl Phosph(on)ates

et al. 2003

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The cyclic acyl phosph(on)ates, 1-hydroxy-5-phenyl-2,6-dioxaphosphorinone(3)-1-oxide, its 4-phenyl isomer, and the phosphonate (2-oxo) analogue of the latter inhibited typical class A (TEM-2) and class C (Enterobacter cloacae P99) beta-lactamases in a time-dependent fashion. No enzyme-catalyzed turnover was detected in any case. The interactions occurring were interpreted in terms of the reaction scheme E + I left arrow over right arrow EI left arrow over right arrow EI', where EI is a reversibly formed noncovalent complex, and EI' is a covalent complex. Reactions of the cyclic phosphates with the P99 beta-lactamase were effectively irreversible, while that of the 4-phenyl cyclic phosphate with the TEM beta-lactamase was slowly reversible. The 4-phenyl cyclic phosphate was generally the most effective inhibitor, both kinetically and thermodynamically, with second-order rate constants of inactivation of both enzymes around 10(4) s(-1) M(-1). This compound also bound noncovalently to both enzymes, with dissociation constants of 25 microM from the P99 enzyme and 100 microM from the TEM. It is unusual to find an inhibitor equally effective against the TEM and P99 enzymes; the beta-lactamase inhibitors currently employed in medical practice (e.g., clavulanic acid) are significantly more effective against class A enzymes. The results of lysinoalanine analysis after hydroxide treatment of the inhibited enzymes and of a (31)P nuclear magnetic resonance spectrum of one such complex were interpreted as favoring a mechanism of inactivation by enzyme acylation rather than phosphylation. Molecular modeling of the enzyme complexes of the 4-phenyl phosphate revealed bound conformations where recyclization and thus reactivation of the enzyme would be difficult. The compounds studied were turned over slowly or not at all by acetylcholinesterase and phosphodiesterase I.

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Oxidation of 4-aryl-substituted isoxazolin-5-ones. A new synthesis of 2,5-diaryl-1,3-oxazin-6-ones

Cited by 37 publications

References 7 publications

A Short Synthetic Route to 4,7‐Dihalogenated 1,10‐Phenanthrolines with Additional Groups in 3,8‐Position: Soluble Precursors for Macrocyclic Oligophenanthrolines

A Short Synthetic Route to 4,7‐Dihalogenated 1,10‐Phenanthrolines with Additional Groups in 3,8‐Position: Soluble Precursors for Macrocyclic Oligophenanthrolines

Iron Lewis Acid Catalyzed Reactions of Aromatic Aldehydes with Ethyl Diazoacetate: Unprecedented Formation of 3-Hydroxy-2-arylacrylic Acid Ethyl Esters by a Unique 1,2-Aryl Shift

Inhibition of β-Lactamases by Monocyclic Acyl Phosph(on)ates

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