Synthesis of ethyl 2-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)-4H/2H-chromene-3-carboxylates by cycloaddition of ethyl 2-(azidomethyl)-4H-chromene-3-carboxylates with alkynes

The cycloaddition reaction has been carried out between ethyl 2-(azidomethyl)-4H-chromene-3-carboxylates and phenylacetylenes/ activated alkynes. Phenylacetylene, 4-fluorophenylacetylene were provided mixture of 2H- and 4H-triazolylchromene-3-carboxylates, whereas methyl, methoxyphenylacetylene and acetylenedicarboxylates were provided exclusively 2H-triazolylchromene-3-carboxylates. Interestingly, prop-2-yn-1-ol and ethyl propiolate were provided exclusively 4H-triazolylchromene-3-carboxylates

Synthesis of Novel Valine-based Dipeptide Carboxamide Bearing Benzene Sulfonamide Moiety as Antimalarial Agent

Communication in Physical Sciences 2020, 5(2): 176-197 Authors: James A. Ezugwu, *Ucheckukwu. C. Okoro, Mercy A. Ezeokonkwo, and China R. Bhimapaka Received 15 April 2020/Accepted 14 May 2020   Syntheses of eleven novel Valine-based dipeptide carboxamide derivatives bearing benzensulphonamide are reported. These were achieved by facile amidation reaction of p- substituted benzenesulphonamoyl alkanamides with 2-amino-4-methyl-N-substituted phenyl butanamide using classical peptide coupling reagents. The chemical structures of the synthesized compounds were established by 1H-NMR, 13C-NMR, ESI- HRMS, and FT-IR spectroscopic techniques. The synthesized compounds were evaluated for in vivo antimalarial against P. berghei. Haematological analysis was also evaluated on the synthesized compounds. At 50mg/kg body weight, the compounds 8e, 8g, 8i, 8k, 8d and 8h inhibited the multiplication of the parasite by 46-71% on day seven of post-treatment exposure comparable to the 67% reduction with artemisinin

Free-radical scavenging and α-glucosidase inhibitory activities of pyrazoline and pyrazole heterocyclic compounds

399-404A total of fifty pyrazolines 3a-y and pyrazoles 4a-y have been evaluated for their free-radical scavenging and α-glucosidase inhibitory activities. The pyrazolines 3e, 3h, 3p, 3s and pyrazole 4e have been identified as potent ABTS.+ free-radical scavengers. The thiophene substituted pyrazoline 3s has shown potent ABTS.+ free radical scavenging activity compared to thiophene substituted pyrazole 4s. Furanyl (4r), pyrazolyl (4t), 2-chloropyridinyl (4u-w), 2-chloroquinolinyl (4x) and 4-chlorocoumarin (4y) pyrazoles have displayed moderate ABTS.+ free-radical scavenging activity. Pyrazoline 3i and pyrazole 4b have shown moderate DPPH free-radical scavenging activity

Free radical scavenging and α-glucosidase inhibitory activity of (E)-methyl/ethyl-3-(2-hydroxyphenyl)acrylates

111-116(E)-Methyl/ethyl-3-(2-hydroxyphenyl)acrylates 3a-x have been prepared by the reaction of salicylaldehydes 1a-l with Wittig reagents such as methyl (triphenylphosphoranylidene)acetate 2a and ethyl (triphenylphosphoranylidene)acetate 2b in dry DCM at room temperature. All the synthesized compounds have been evaluated for free-radical scavenging and α-glucosidase inhibitory activities. Compounds 3c and 3d display DPPH free radical scavenging activity. All the compounds have shown ABTS free radical scavenging activity except four compounds 3s-t and 3w-x. Compounds 3g, 3p and 3r display α-glucosidase inhibitory activity

Free radical scavenging and α-glucosidase inhibitory activity of (E)-methyl/ethyl-3-(2-hydroxyphenyl)acrylates

(E)-Methyl/ethyl-3-(2-hydroxyphenyl)acrylates 3a-x have been prepared by the reaction of salicylaldehydes 1a-l with Wittig reagents such as methyl (triphenylphosphoranylidene)acetate 2a and ethyl (triphenylphosphoranylidene)acetate 2b in dry DCM at room temperature. All the synthesized compounds have been evaluated for free-radical scavenging and α-glucosidase inhibitory activities. Compounds 3c and 3d display DPPH free radical scavenging activity. All the compounds have shown ABTS free radical scavenging activity except four compounds 3s-t and 3w-x. Compounds 3g, 3p and 3r display α-glucosidase inhibitory activity.

A convenient synthesis and biological activities of N-(pyridin-3-ylmethylene) benzohydrazides by the condensation of nicotinaldehydes with benzohydrazides

117-126Series of N'-(pyridine-3-ylmethylene)benzohydrazides 3a-y have been prepared by the condensation of nicotinaldehydes 1a-e with benzohydrazides 2a-e in the presence of glacial AcOH in ethanol at room temperature. Total twenty five compounds have been prepared and confirmed based on spectral data. The compounds have been evaluated for anti-microbial, free radical scavenging (DPPH, ABTS.+) and α-glucosidase inhibitory activities. Compound 3h has shown potent anti-fungal activity. Compounds 3f-g and 3j have shown potent ABTS.+ free radical scavenging activity. Compound 3d has shown potent anti-hyperglycemic activity

A convenient synthesis and biological activities of N-(pyridin-3-ylmethylene) benzohydrazides by the condensation of nicotinaldehydes with benzohydrazides

Series of N'-(pyridine-3-ylmethylene)benzohydrazides 3a-y have been prepared by the condensation of nicotinaldehydes 1a-e with benzohydrazides 2a-e in the presence of glacial AcOH in ethanol at room temperature. Total twenty five compounds have been prepared and confirmed based on spectral data. The compounds have been evaluated for anti-microbial, free radical scavenging (DPPH, ABTS.+) and α-glucosidase inhibitory activities. Compound 3h has shown potent anti-fungal activity. Compounds 3f-g and 3j have shown potent ABTS.+ free radical scavenging activity. Compound 3d has shown potent anti-hyperglycemic activity.

Condensation of nicotinaldehydes with acetophenones and NH4OAc: A convenient synthesis and biological activities of 2',6'-diphenyl-3,4'-bipyridines #

1001-10092',6'-Diphenyl-3,4'-bipyridines 3a-t have been achieved by the three-component, one-pot reaction of nicotinaldehydes 1a-b, acetophenones 2a-j and anhydrous ammonium acetate under solvent free conditions at 120°C. All the prepared compounds 3a-t have been screened for anti-microbial, free-radical scavenging and α-glucosidase inhibitory activities. Compounds 3m-r have shown anti-bacterial activity and compounds 3m-n identified as anti-fungal agents. Compounds 3d, 3h, 3m and 3r-s have shown α-glucosidase inhibitory activity

Condensation of nicotinaldehydes with acetophenones and NH4OAc: A convenient synthesis and biological activities of 2',6'-diphenyl-3,4'-bipyridines

2',6'-Diphenyl-3,4'-bipyridines 3a-t have been achieved by the three-component, one-pot reaction of nicotinaldehydes 1a-b, acetophenones 2a-j and anhydrous ammonium acetate under solvent free conditions at 120°C. All the prepared compounds 3a-t have been screened for anti-microbial, free-radical scavenging and α-glucosidase inhibitory activities. Compounds 3m-r have shown anti-bacterial activity and compounds 3m-n identified as anti-fungal agents. Compounds 3d, 3h, 3m and 3r-s have shown α-glucosidase inhibitory activity

Condensation of nicotinaldehydes with phenylethanones: A convenient synthesis and biological activities of chalcones

Claisen-Schmidt condensation of nicotinaldehydes 1a-e with various phenylethanones 2a-d in the presence of base at room temperature have provided chalcones 3a-t. All the synthesized compounds have been evaluated for their anti-microbial, free-radical scavenging and α-glucosidase inhibitory activities. Compounds 3d and 3h have been identified as potent anti-fungal and moderate anti-bacterial agents. Compounds 3c, 3h, 3k-m and 3q have shown α-glucosidase inhibitory activity