Showing papers by "Murlidhar S. Shingare published in 2002"
TL;DR: In this paper, the condensation reaction of 4-oxo-(4H)-1-benzopyran-3-carbaldehydes and of aromatic aldehydes with 3-methyl-1-phenylpyrazolin-5-4H-one were carried out in an ionic liquid, ethylammonium nitrate, at room temperature in shorter times with higher yields of 78−92 and 70−75%, respectively, than found using conventional procedures.
114 citations
TL;DR: In this paper, 4-oxo-(4H)-1-benzopyran-3-carboxaldehydes are condensed with 3-methyl-1-phenyl pyrazolin-5-(4h)-one under microwave activation to afford different 3methyl-4-[(chromon-3yl)- methylene]-1-pphenyl prazolin 5-(4 h)-ones (1−13) with alumina support and in solvent free conditions.
19 citations
TL;DR: In this article, various dialkyl-1-(chromon-3-yl)-1-hydroxymethylphosphonates have been synthesized by microwave activation under solvent free condition using modified Abramov reaction.
16 citations
TL;DR: In this article, a solvent free and expeditious method for tetrahydropyranylation and detetrahydro-phrasing of alcohols, phenols and thiols using hydrated zirconia and 3,4-dihydroid-2H-pyran (DHP) is described.
11 citations
TL;DR: The condensation of 4oxo-4H-1-benzopyran-3-carbaldehydes with 3-methyl 1-phenylpyrazolin-5-(4H)-ones in dioxane to afford 3methyl-4-[(chromon-3yl)methylene]-1-pyrrhodophosphamide]-1phenyl pyrazolin 5-(4HO]-ones was performed using MCM-41-SO3H as a catalyst.
7 citations
Journal Article•
TL;DR: In this article, the reaction of 4oxo-4H-[1]-benzopyran-3 carboxaldehydes with 3-methyl-1-phenylpyrazolin-5(4H)-one in dioxane in the presence of triethyl amine was investigated.
Abstract: Reaction of 4-oxo-4H-[1]-benzopyran-3-carboxaldehydes with 3-methyl-1-phenylpyrazolin-5(4H)-one in dioxane in the presence of triethyl amine affords 3-methyl-4- [(chromon-3-yl)methylene]-l-phenylpyrazolin-5(4H)-ones 3a-k.Condensation of 3 with thiourea in alcoholic KOH under reflux yields 2-thio-5-hydroxy-5H-[1]-benzopyrano[4,3-d]pyrimidines 6a-h.
3 citations
Journal Article•
TL;DR: In this paper, an oxidative deblocking procedure of aldoximes using FeCl 3 and ketoxime using SeO 2 in aprotic solvent is reported, where reaction yields are competitive as compared to previous methods.
Abstract: An oxidative deblocking procedure of aldoximes using FeCl 3 and ketoximes using SeO 2 in aprotic solvent is reported. Reaction yields are competitive as compared to previous methods. Reactions are easy to work and conditions are mild. Some important features of FeCl 3 are mentioned.
1 citations
TL;DR: In this paper, a thin layer chromatographic method with densitometric detection has been developed for determination of nicorandil, in the presence of its degradation products and impurities, in tablet formulations.
Abstract: A thin layer chromatographic method with densitometric detection has been developed for determination of nicorandil, in the presence of its degradation products and impurities, in tablet formulations. Nicorandil tablet solution was subjected to stress tests under thermal, photolytic, hydrolytic, and oxidative conditions, to induce degradation of the drug. Nicorandil was separated from the degradation products on RP18 TLC plates by isocratic elution and was determined densitometrically. To assess the specificity of the method two dimensional chromatography was performed with a second mobile phase of different selectivity. Because no interference from degradation products was observed in the assay of nicorandil by the described method, it can be regarded as a stability-indicating method and can be used for analysis of stability study samples and routine quality-control samples. The method requires no sample pretreatment and is accurate (recovery = 100.20%), reproducible, rugged (intermediate precision, %RSD = 1.73; n = 18), and selective. The calibration plot for nicorandil was linear in the range 35 to 65 μg (70 to 130% of assay concentration).
TL;DR: In this article, various dialkyl-1-(chromon-3-yl)-1-hydroxymethylphosphonates have been synthesized by microwave activation under solvent free condition using modified Abramov reaction.
Abstract: Various dialkyl-1-(chromon-3-yl)-1-hydroxymethylphosphonates have been synthesized by microwave activation under solvent free condition using modified Abramov reaction.
TL;DR: In this article, a solvent free and expeditious method for tetrahydropyranylation and detetrahydro-phrasing of alcohols, phenols and thiols using hydrated zirconia and 3,4-dihydroid-2H-pyran (DHP) is described.
Abstract: A solvent free and expeditious method for tetrahydropyranylation and detetrahydropyranylation of alcohols, phenols and thiols is described using hydrated zirconia and 3,4-dihydro-2H-pyran (DHP). A comparison of this microwave-accelerated reaction with conventional heating condition is also presented.