Pyrimidine derivatives and related compounds. A novel synthesis of pyrimidines,pyrazolo[4,3-d]pyrimidines and isoxazolo[4,3-d] pyrimidine

Benzoylacetonitrile (II) reacted with trichloroacetonitrile (III) to yield the β-amino-β-trichloromethylacrylonitrile IV. Compound IV reacted with hydrazine hydrate to yield 5-amino-4-cyano-3-phenylpyrazole (V) and with 2-aminopyridine to yield the aminopyridine derivative VIII (cf., Chart I). Compound IV reacted with III to yield 2,4-bis(trichloromethyl)-5-cyano-6-phenylpyrimidine (I) which could be converted into a variety of pyrazolo[4,3-d]pyrimidine derivatives by treatment with hydrazine hydrate under a variety of different experimental conditions (cf., Chart II).     

Osmium(VIII)-Catalyzed Oxidation of Some Cyclic Amines by Potassium Hexacyanoferrate(III) in Alkaline Media: a Kinetics and Mechanistic Study

Reactions of morpholine, piperidine, and piperazine with Os(VIII)-catalyzed hexacyanoferrate(III) in alkaline media to produce the corresponding lactam have been studied at constant temperature and ionic strength. The reactions followed first-order kinetics with respect to [amine] and [Os(VIII)] but were independent of [Fe(CN)₆ ^3-] and [OH^-]. The effects of introduced electrolytes, potassium hexacyanoferrate(II), relative permitivity, and temperature have also been studied. A mechanism accounting for these results has been proposed.     

Hemoglobin-superoxide dismutase-chemical linkages that create a dual-function protein

Chemical reagents were designed to cross-link and connect hemoglobin and superoxide dismutase, combining the oxygen transport and superoxide-removal capabilities of the red cell in a dual-function protein. Reaction of 1 with thiol-protected hemoglobin followed by reduction produces cross-linked hemoglobin with a free thiol on the cross-link. Reaction of SOD with 5 produces a cross-linked protein with a maleimide on the cross-link. Addition of the hemoglobin-thiol to the SOD-maleimide produces a protein with the desired dual properties. Hemoglobin's oxygenation cooperativity is lowered as a result of being in the conjugate, while SOD's activity is equal to that of the native protein.     

Substituted γ-Lactones. 35 . Reduction of 4-aroyl-3-hydroxy-2(5H)-furanones

The reduction of 4-aroyl-3-hydroxy-2(5H)-furanons 1a-c was investigated using different reducing agents. Sodium borohydride reacts with type 1 compounds by loss of water to yield 4-(arylmethylene)-2,3(4H,5H)-furandiones 2a-c . Platinum or charcoal supported by pallodium chloride transforms 1a to 4-benzyl-3-hydroxy-2(5H)-furanone ( 3). Compounds 2a and 2b react with o-phenylenediamine to give 3-(E-(1′-hydroxymethyl-2′-aryl)ethenyl]-2-quinoxalinones 4a and 4b . The lactone 3 under the same conditions splits out formaldehyde and forms 3-(2′-phenylethyl)-2-quinoxalinone ( 6 ). The structure assignments of the novel compounds are based on elemental analysis and nmr as well as ir spectroscopic data.     

Reaction of difluorocarbene with 2H-azirines: generation and transformations of strained azomethine ylides -- aziriniodifluoromethanides

The reaction of difluorocarbene with azirines affords a new type of azomethine ylides, viz., strained aziriniodifluoromethanides. 1,3-Dipolar cycloadditions of ylides derived from 2-unsubstituted 3-arylazirines to dimethyl acetylenedicarboxylate and aldehydes give derivatives of 2,2-difluoro-1-azabicyclo[3.1.0]hex-3-ene-3,4-dicarboxylic acids and 1,4-oxazin-3(4H)-ones, respectively. Ylides derived from 2-mono- and 2,2-disubstituted azirines undergo isomerization to 2-aza-1,3-diene derivatives. 2,2-Difluoro-1-azabicyclo[3.1.0]hex-3-enes are transformed into 2-fluoropyridine derivatives in high yields and react with amines to give 2,4-diamino-1-azabicyclo[3.1.0]hex-2-ene derivatives.     

The mass spectra of some 4-arylhydrazono-3-methyl-2-pyrazolin-5-ones

The mass spectra of the title compounds, having various substituents on the aryl group are presented and discussed. High resolution mass measurements and metastable ions allow the fragmentation to be rationalized. The system is typified by the occurrence of intense molecular ions and of ions due to consecutive decomposition of the nitrogen-containing part of the molecule. Ions attributable to substituted, aniline-like fragments, and their decomposition products, are also abundant and may be used to identify the aryl group present.     

QuEChERS method for the simultaneous quantification of phorate and its metabolites in porcine and chicken muscle and table eggs using ultra‐high performance liquid chromatography with tandem mass spectrometry

An analytical method to detect phorate and its metabolites, including phorate sulfone, phorate sulfoxide, phoratoxon, phoratoxon sulfone, and phoratoxon sulfoxide, in porcine and chicken muscles and table eggs was developed and validated. Extraction was performed using a quick, easy, cheap, effective, rugged, and safe method and analysis was conducted using ultra‐high performance liquid chromatography‐tandem mass spectrometry. Matrix‐matched calibrations were linear over the tested concentrations, with determination coefficient ≥ 0.995 for all tested analytes in the different matrices. The limits of detection and quantification were 0.001 and 0.004 mg/kg, respectively. The calculated recovery rates at three fortification levels were satisfactory, with values between 74.22 and 119.89% and relative standard deviations < 10%. The method was applied successfully to commercial samples collected from locations throughout the Korean Peninsula, and none of them showed any traces of the tested analytes. Overall, the developed method is simple and versatile, and can be used for monitoring phorate and its metabolites in animal products rich in protein and fat.     

On the structure of the bioactive constituent from ayurvedic medicine Salacia reticulata: revision of the literature

The reported structure of a potent α-glucosidase inhibitor 7 isolated recently from ayurvedic medicine Salacia reticulata was found incorrect, and the compound was proved to be de-O-sulfated kotalanol 4. Discussion and detailed analysis of the spectral data leading to the revised structure are presented.     

Synthesis of some 4-arylazo-3-hydroxythiophene disperse dyes for dyeing polyester fabrics

A series of novel 4-arylazo-3-hydroxythiophene disperse dyes was synthesized by heterocyclization of ethyl 2-arylhydrazono-2-phenylthiocarbamoyl acetates with a variety of α-halogenated reagents. The structures of the synthesized dyes were confirmed by UV-Vis, IR, ¹H NMR, and MS spectroscopic techniques and elemental analysis. The dyes were applied to conventional polyester fabric by high temperature exhaust dyeing. These dyes were found to give orange to reddish-violet shades with very good depth, levelness, and brightness on polyester fabric. The dyed fabric showed moderate to good light fastness and very good fastness to washing and perspiration. Also the position of color in CIELAB coordinates (L^*, a^*, b^*, H^*, and C^*) was assessed.     

Synthesis of some 4-arylazo-3-hydroxythiophene disperse dyes for dyeing polyester fabrics

A series of novel 4-arylazo-3-hydroxythiophene disperse dyes was synthesized by heterocyclization of ethyl 2-arylhydrazono-2-phenylthiocarbamoyl acetates with a variety of α-halogenated reagents. The structures of the synthesized dyes were confirmed by UV-Vis, IR, ¹H NMR, and MS spectroscopic techniques and elemental analysis. The dyes were applied to conventional polyester fabric by high temperature exhaust dyeing. These dyes were found to give orange to reddish-violet shades with very good depth, levelness, and brightness on polyester fabric. The dyed fabric showed moderate to good light fastness and very good fastness to washing and perspiration. Also the position of color in CIELAB coordinates (L^*, a^*, b^*, H^*, and C^*) was assessed. Correspondence: Ehab Abdel-Latif, Department of Chemistry, Faculty of Science, Mansoura University, 35516 Mansoura, Egypt