- Permanganate Oxidation of Quinoxaline and Its Derivatives
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The oxidation reaction of a series of quinoxaline derivatives, using KMnO4 in the presence or absence of NaOH, are described.Neutral oxidation of 2-chloro- and 2,3-dichlorodioxalines 2-4 afforded the corresponding chloro- and dichloropyrazinedicarboxilic acids 13 and 14 in good yield.On the other hand, oxidation of quinoxalin-2(1H)-one and 1,4-dihydroquinoxaline-2,3-dione derivatives in alkaline medium gave different products, with the quinoxalin-2(1H)-one (5) forming 1,4-dihydroquinoxaline-2,3-dione (9), while various substituted quinoxalin-2,3-dione derivatives (see 9-11) gave a new type of dimeric products.The structural assignments for the new compounds were based on spectroscopic data.
- Obafemi, Craig A.,Pfleiderer, Wolfgang
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- Synthesis of substituted 2-ethoxycarbonyl- and 2-carboxyquinoxalin -3 ones for evaluation of antimicrobial and anticancer activity
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A series of variously substituted quinoxalin-3-ones bearing an ethoxycarbonyl or carboxy group in the C-2 position has been prepared and their structures proved by 1H NMR spectroscopy. The obtained compounds were investigated in vitro for antimicrobial and anticancer activities. Preliminary results showed a moderate activity against a few strains of bacteria but no significant anticancer and anti-HIV activity.
- Sanna, Paolo,Carta, Antonio,Loriga, Mario,Zanetti, Stefania,Sechi, Leonardo
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p. 455 - 461
(2007/10/03)
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- COMPOSITIONS AND METHODS FOR THE TREATMENT OF IMMUNOMEDIATED INFLAMMATORY DISORDERS
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Compositions and methods for the prevention and treatment of immunomediated inflammatory disorders, especially for those disorders associated with the respiratory tract, are provided. More particularly, a tryptase inhibitor, typically a hydroxyaroyl or hydroxyheteroaroyl substituted dipeptide, is administered. Also provided by this invention are pharmaceutical compositions, typically aerosol or topical, as well as aerosol devices for administering these compositions intranasally.
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- A Comparison of Nucleophilic Reactions of 3-Benzenesulfonyloxyalloxazine and its 1-Methyl Analog.
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Reactions of 3-benzenesulfonyloxyalloxazine (1a) and its 1-methyl analog 1b with a number of nucleophilic reagents are reported.Relatively small nucleophiles, such as hydroxide ion, methanol, ethanol, methylamine, hydrazine and hydroxylamine converted 1a to 4-carboxy-s-triazoloquinoxalin-1(2H)-ones and the corresponding esters or amides.As the size of the amine increased from methylamine to ethylamine, dimethylamine, propylamine and isopropylamine, there were obtained 4-(carboxamido)-s-triazoloquinoxalin-1(2H)-ones, (1-carboxamido)imidazoloquinoxalines and 2,3-bis(ureido)quinoxalines.Sodium hydride or potassium cyanide in hot DMF degraded 1a to imidazoloquinoxaline.However, methylmercaptide and benzylmercaptide ions attacked the sulfonate group of 1a to form 3-hydroxyalloxazine. 1-Methyl-3-benzenesulfonyloxyalloxazine (1b) reacted with methanol, ethanol, 1-propanol, and to some degree 2-propanol, in the presence of triethylamine to furnish anhydro-1-hydroxy-3-methyl-4-(alkoxycarbonyl)-s-triazoloquinoxalinium hydroxides.However, sodium methoxide in methanol converted this starting material to a mixture of anhydro-1-hydroxy-3-methyl-s-triazoloquinoxalinium hydroxide and 1-methyl-3-hydroxyflavazole.A saturated aqueous solution of triethylamine transformed 1b to anhydro-1-hydroxy-3-methyl-s-triazoloquinoxalinium hydroxide, apparently via the corresponding unstable 4-carboxylic acid.The reactions of 1b with a number of aliphatic amines yielded either amides based on the above mesionic system or on the 3-carboxamido-2-quinoxalyl semicarbazide structure.The reaction of 1b with potassium cyanide furnished 1-methylimidazoloquinoxaline.Mechanisms to explain all of the degradations are advanced.
- Hamby, James M.,Bauer, Ludwig
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p. 1013 - 1024
(2007/10/02)
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- DEGRADATIONS OF 1-METHYL-3-BENZENESULFONYLOXYALLOXAZINE BY NUCLEOPHILIC REAGENTS
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Degradation of 1-methyl-3-benzenesulfonyloxyalloxazine by nucleophilic reagents produced derivatives of 2-hydrazino-3-quinoxalinecarboxylic acid and anhydro-1-hydroxy-3-methyl-s-triazolo-quinoxalinium hydroxide.
- Hamby, James M.,Bauer, Ludwig
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- Mechanistic Investigations with the Aid of Isotopic Labeling, VI. Mechanism of the Ring Contraction of 1,5-Dihydro-2H-1,5-benzodiazepine-2,3,4-triones
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Synthesis and ring contraction reactions of 1,5-dihydro-2H-1,5-benzodiazepine-2,3,4-trione hydrate (3) are described.With the aid of 14C-labeling it is shown, that there are different pathways leading to the ring contracted compounds 6 and 7.
- Dolenz, Gerhard,Kollenz, Gert
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p. 593 - 600
(2007/10/02)
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