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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TL;DR: In this article, the 2-benzopyran-3-ones 10a, 10b and 10c undergo endo-selective intramolecular Diels-Alder addition of the connecting chain to give cis-BC fused ring systems of type 13.
Abstract: Unlike o-quinodimethanes lacking a bridge between the termini of the diene system e.g. 18a (n= 3 or 4), the 2-benzopyran-3-ones 10a, 10b and 10c undergo endo-selective intramolecular Diels–Alder addition of the connecting chain to give cis-BC fused ring systems of type 13. The adduct 13b is converted into the ester 21 with methanolic HCl and into the ketol 36 by LiAlH4 reduction followed by oxidation (MnO2). The ketone 31 is prepared from 21 by epoxidation followed by BF3·Et2O-catalysed rearrangement; with NaOMe–CD3OD it fails to undergo cis-trans isomerisation and fails to incorporate deuterium at C-8 probably due to the overwhelming acidity of the C-6 protons. The cis-dihydronaphthalene 26 obtained from 21 gives cis-27 with KOBut–(CD3)2SO showing the greater thermodynamic stability of the cis-fused ring system in this case.
TL;DR: In this paper, a metal-free method for direct β-C(sp3)-H functionalization of aliphatic amine was developed. But the method is based on a reaction that yields enamine directly from the corresponding amine, which requires the aid of metallic reagent and/or external oxidant.
Abstract: A metal-free method for direct β-C(sp3)–H functionalization of aliphatic amine was developed. The method is based on a reaction that yields enamine directly from the corresponding aliphatic amine, which otherwise requires the aid of metallic reagent and/or external oxidant. The reaction is operationally simple, general, and highly efficient in functionalizing both cyclic and acyclic amines. Structurally diverse unsaturated imines were obtained from N-heterocycles, while acyclic amines provided 2-alkyl cinnamaldehyde and benzopyran derivatives with excellent E/Z-selectivity.
TL;DR: The title compound, C10H10O2, was isolated from Eniconsanthum membranifolium J. Sinclair as discussed by the authors, and it has six independent molcules in the unit cell, where the hydrogen bonds from the hydr-oxy H atoms to the carbonyl O atoms are observed in the crystal structure.
Abstract: The title compound, C10H10O2, was isolated from Eniconsanthum membranifolium J. Sinclair. There are six independent molecules in the unit cell. Intramolecular hydrogen bonds from the hydroxy H atoms to the carbonyl O atoms are observed in the crystal structure.
Patent•
17 Apr 2013
Patent•
16 Mar 2021
TL;DR: In this paper, a benzopyran urea compound with a novel structure was obtained through multi-step reaction, so that the synthesis method is simple, and the reaction yield is very high.
Abstract: The invention discloses a preparation method and application of a benzopyran urea compound capable of being used for sterilization and disinfection, and belongs to the technical field of synthesis ofantibacterial drugs. According to the technical scheme, the benzopyran urea compound is characterized in that the benzopyran urea compound has a structure, wherein R1 is alkyl or olefin or aryl, benzyl or heterocyclic ring with different substituent groups; R2 is an oxygen or sulfur atom. Benzopyran-4-ketone is used as an initial raw material, and the benzopyran urea compound with a novel structure is obtained through multi-step reaction, so that the synthesis method is simple, and the reaction yield is very high. An antibacterial activity test is carried out through an oxford cup agar diffusion method, and it is found that the target compound has a certain inhibition effect on staphylococcus aureus and has the potential of serving as an antibacterial drug.