Topic
Benzopyran
About: Benzopyran is a research topic. Over the lifetime, 1889 publications have been published within this topic receiving 15235 citations.
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2 citations
TL;DR: Condensation of ω-substituted-2,4-dihydroxyacetophenones with 3-(2-aryl)-5-methyl-4isoxazolecarbonyl chlorides in acetone-K2CO3 medium afforded 2-aryl-5- methyl-4 isoxazolyl]-7-hydroxy-3-phenyl-4H-1-benzopyran-4-ones in good yields.
Abstract: Condensation of ω-substituted-2,4-dihydroxyacetophenones (1a-c) with 3-(2-aryl)-5-methyl-4isoxazolecarbonyl chlorides (2a-c) in acetone-K2CO3 medium afforded 2-[3-aryl-5-methyl-4isoxazolyl]-7-hydroxy-3-phenyl-4H-1-benzopyran-4-ones (3a-f) in good yields. Insectantifeedant activity of 3a-f against agricultural pest tobacco caterpillar larvae (Spodoptera litura F) showed 3e and 3f to be active.
2 citations
TL;DR: A tetrabutylammonium hydrogen sulfate (TBA-HS) mediated procedure for one pot synthesis of novel benzopyran-annulated pyrano[2,3-c]pyrazoles via domino/Knoevenagel-hetero-Diels-Alder reaction has been demonstrated.
Abstract: A tetrabutylammonium hydrogen sulfate (TBA-HS) mediated procedure for one pot synthesis of novel benzopyran-annulated pyrano[2,3-c]pyrazoles via domino/Knoevenagel-hetero-Diels–Alder reaction has been demonstrated
2 citations
Patent•
27 Jan 1986
TL;DR: In this article, a compound expressed by formula II is reacted with a compound expressing by formula III, and the resultant compound is then reacted with another compound expressed using formula IV to afford the aimed compound expressed with formula I. The above-mentioned reaction proceeds preferably in the absence of a solvent at 130-150 degC in the former, and in ethanol, methyl ethyl ketone or acetone in the presence of piperidine catalyst at 40-120 degC.
Abstract: NEW MATERIAL:A compound expressed by formula I (n is an integer 1-4; R is H, halogen, alkl, etc; R is H, halogen, alkyl or alkoxyl; R is alkyl) USE:A compound, having photochromic property, useful as various recording and memorizing materials, copying materials, printing photosensitive materials, photosensitive materials for laser, photosensitive materials for photocomposition or optical filters and masking materials, etc, and capable of giving compositions repeadting color formation and decolorization in deep color of good stoage stability due to improved compatibility and solubility in high polymers PREPARATION:A compound expressed by formula II is reacted with a compound expressed by formula III, and the resultant compound is then reacted with a compound expressed by formula IV to afford the aimed compound expressed by formula I The above-mentioned reaction proceeds preferably in the absence of a solvent at 130-150 degC in the former, and in ethanol, methyl ethyl ketone or acetone in the presence of piperidine catalyst at 40-120 degC in the latter
2 citations
2 citations