- Lewis acid–catalyzed green synthesis and biological studies of pyrrolo[3,4-c]pyrazoles in aqueous medium
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An environmentally benign approach in aqueous medium by means of Lewis acid catalyst affords a wide spectrum of pyrazoline derivatives in satisfactory yields. [3+2] cycloaddition reactions of substituted azomethine-N-imines to maleimide in aqueous medium at relatively high concentrations of Lewis acid catalyst have emerged as an environment friendly alternative to conventional solvents. Promising catalytic activity has been revealed by Lewis acid like Cu (NO3)2 in aqueous medium. The obvious features of this synthetic protocol were short reaction time, high efficiency, less hazardous synthesis by benign solvent, catalysis, modest workup, and a clean reaction methodology.
- Arjuna, Anania,Kaur, Manpreet,Singh, Baldev
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- Continuous efficient production method for high-purity N-substituted maleamic acid
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The invention belongs to the technical field of fine chemicals and particularly relates to a continuous efficient production method for high-purity N-substituted maleamic acid. The method comprises the following steps: solutions are prepared from primary amine and maleic anhydride respectively by inert solvents in nitrogen protective atmosphere; the two solutions are added to an efficient mixer inproportion for mixing; the mole ratio of primary amine and maleic anhydride is 1:1.0-1.5, a reaction product is treated by a solid-liquid separation unit, and the product amido carboxylic acid is separated; a liquid solution separated out by the solid-liquid separation unit and a liquid solution obtained after separation of the product amido carboxylic acid are used for preparing the primary amine and maleic anhydride solutions circularly. With adoption of the method for continuously and efficiently synthesizing high-purity N-substituted maleamic acid with high yield and high selectivity witha reaction-separation coupling control reaction technology, the adding way of primary amine and maleic anhydride and standing time of a chemical reaction are controlled, and isomerization and Michaeladdition side reactions are avoided effectively through rapid reaction and rapid separation.
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Paragraph 0047-0052
(2018/09/08)
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- Synthesis and Evaluation of Novel 5-cyclohexyl-2-(4″-substitutedphenyl)-3-(2″-substitutedphenyl)4H-2,3,3a,5,6,6a-hexahydropyrrolo[3,4-d]isoxazole-4,6-dione Derivatives for Their In Vitro Antioxidant and Antibacterial Activities
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1,3-Dipolar cycloaddition reactions of N-cyclohexyl maleimide (1) with azomethine N-oxide (2) have afforded novel isoxazolidine (3) in excellent yield. Their structures have been characterized from their IR,1H-NMR,13C-NMR,1H,1H-COSY, MS(ESI), and elemental analysis techniques. In vitro antibacterial activity of the synthesized compounds were investigated against a representative panel of pathogenic strains specifically two Gram-positive bacteria (Staphylococcus aureus and Streptococcus pyogenes) and two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli) using agar-well diffusion assay. Some of the compounds (3a, 3k, 3n, and 3o) exhibited promising antibacterial activities. All the synthesized compounds have also been screened for their antioxidant activities and were found to be significantly active.
- Kaur, Manpreet,Kaur, Anjandeep,Singh, Baldev,Singh, Baljit
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- Triethylamine-catalyzed synthesis of oxazepine from maleamic acids
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2-Thioxo-1,3-oxazepine-4,7-dione compounds were obtained via triethylamine-catalyzed condensation of maleamic acids with thiophosgene under anhydrous conditions. This method features relatively a simple methodology, use of inexpensive reagents, convenient operating conditions and high yields.
- Badru, Rahul,Singh, Baldev
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p. 635 - 640
(2015/05/13)
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- Synthesis and bradykinin inhibitory activity of novel non-peptide compounds, and evaluation of in vivo analgesic activity
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A series of novel non-peptide diamide compounds was synthesized and evaluated as antibradykinin agents by utilizing guinea-pig ileum smooth muscle. Among the final compounds, (Z)-4-(4-(bis(4-fluorophenyl)methyl)piperazin-1-yl)-4-oxo-N-(4-phenylbutan-2-yl)
- Kam, Yoo Lim,Rhee, Hee-Kyung,Kim, Hwa-Jung,Back, Seung Keun,Na, Heung Sik,Choo, Hea-Young Park
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experimental part
p. 2327 - 2336
(2010/05/18)
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- Synthesis and antifungal activity of N-(alkyl/aryl)-2-(3-oxo-1,4- benzothiazin-2-yl)acetamide
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A series of N-(alkyl/aryl)-2-(3-oxo-1,4-benzothiazin-2-yl)acetamide have been synthesized by condensation of substituted amines with maleic anhydride (MA) followed by cyclization with o-aminothiophenol (o-ATP). All the compounds have been screened for their antifungal activity against Tricophyton rubrum, Epidermophyton floccosum and Malassazia furfur. In the primary screening, some of the compounds exhibited appreciable activity. The structures of the synthesized compounds 7a-z have been established on the basis of elemental analysis and spectral data.
- Gupta,Wagh
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p. 697 - 702
(2007/10/03)
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- First triphenylphosphine promoted reduction of maleimides to succinimides
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Triphenylphosphine (TPP) in refluxing methanol effectively reduces maleimides 1a-g to the corresponding succinimides 2a-g in good yields. It was observed that some maleimides obtained from aromatic halogen compounds 1h-j were transformed into the corresponding succinamic acid methyl esters 3a-c by this reaction.
- Pal, Bikash,Pradhan, Prasun K.,Jaisankar, Parasuraman,Giri, Venkatachalam S.
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p. 1549 - 1552
(2007/10/03)
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- Synthesis and antimicrobial activities of N-substituted imides
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In the field of our research programs concerning novel antimicrobial agents, a series of N-substituted imides was synthesized. These compounds were obtained by cyclization of amido-acids in acetic anhydride/sodium acetate or hexamethyldisilazane/zinc bromide for the hydroxy-aromatic derivatives. The hydroxy-alkyl maleimides were directly prepared by condensation of the corresponding amino-alcohol with maleic anhydride in boiling toluene. Most of N-substituted maleimides showed an interesting antimicrobial activity towards bacteria from the ATCC collection (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853) but the MIC values for P. aeruginosa were always high (128 μg/ml). The imides with alkyl substituents showed higher activities than aromatic analogues with MIC values in the range of 8-32 μg/ml. Comparatively, succinimides were practically inactive.
- Zentz, Frederic,Valla, Alain,Le Guillou, Regis,Labia, Roger,Mathot, Anne-Gabrielle,Sirot, Danielle
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p. 421 - 426
(2007/10/03)
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- Syntheses of Some N-Alkylmaleimides
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An improved synthesis of N-substituted secondary and tertiary alkylmaleimides is described.
- Wang, Z. Y.
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p. 1607 - 1610
(2007/10/02)
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