Results 171 to 180 of about 16,938 (213)

Sulfamic Acid: An Efficient Catalyst for the Diastereoselective, One-Pot Synthesis of Pyrano Benzopyrans, Furano Benzopyrans and Ethoxy Benzopyrans

Letters in Organic Chemistry, 2005
Sulfamic acid catalyses the one-pot three components coupling of aldehydes, anilines and electron rich dienophiles such as dihydropyran, dihydrofuran and ethyl vinylether resulting in the formation of pyrano, furano and ethoxy benzopyrans.
R. Kumar, R. Nagarajan, K. Vijay, P. Perumal   +3 more
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2-Benzopyran-3-one

Journal of the Chemical Society, Chemical Communications, 1983
Trapping and low temperature matrix isolation experiments show that 2-benzopyran-3-one (1) is efficiently generated by thermolysis or photolysis of the bis-lactone (2); flash vacuum thermolysis of (2) yields isocoumarin (5) and photolysis of (2) in an argon matrix gives (1) and the ketene (6).
David A. Bleasdale, David W. Jones, G�nther Maier, Hans Peter Reisenauer   +3 more
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Benzopyrans. Part 44. Synthesis of 3‐(4‐Oxo‐4H‐1‐benzopyran‐2‐yl)indolizines.

ChemInform, 2003
AbstractFor Abstract see ChemInform Abstract in Full Text.
Chandra Kanta Ghosh, Sumit Kumar Karak, Amarendra Patra   +2 more
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Benzopyrans. Part 23. Nitrogen heterocycles fused with or linked to 1-benzopyran from 3-acyl-2-methyl-1-benzopyran-4-one

Journal of the Chemical Society, Perkin Transactions 1, 1988
The enamine (2), prepared from the title benzopyranone (1; R2= H, Me, and Ph) and dimethylformamide dimethyl acetal, on treatment with ammonia and hydroxylamine gives the fused pyridine (5) and pyridine 2-oxide (10), respectively. Hydrazine, phenylhydrazine, and guanidine undergo initial 1,6-addition to the enamine (2) ultimately giving the pyrazoles ...
Chandra Kanta Ghosh, Chandana Pal, Jharna Maiti, Manjusha Sarkar   +3 more
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Benzopyrans from Melicope ptelefolia leaves

Phytochemistry, 1997
Abstract Investigation of leaves of Melicope ptelefolia afforded 18 2,2-dimethyl-2H-1-benzopyrans, consisting of 14 new members, including one benzodipyran and four known compounds. Their structures were established by mass and NMR spectroscopy, especially NOE and HMBC experiments. © 1997 Elsevier Science Ltd.
Christine Kamperdick, Nguyen Hong Van, Tran Van Sung, Günter Adam   +3 more
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Benzopyran sulfonamides as KV1.5 potassium channel blockers

Bioorganic & Medicinal Chemistry Letters, 2007
K(V)1.5 blockers have the potential to be atrium-selective agents for treatment of atrial fibrillation. The benzopyrans provide a template for the synthesis of potent and selective K(V)1.5 blockers.
John, Lloyd, Karnail S, Atwal, Heather J, Finlay, Michael, Nyman, Tram, Huynh, Rao, Bhandaru, Alexander, Kover, Joan, Schmidt, Wayne, Vaccaro, Mary Lee, Conder, Tonya, Jenkins-West, Paul, Levesque   +11 more
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Benzopyran dimers from melicope ptelefolia

Phytochemistry, 1998
Abstract The leaves of Melicopte ptelefolia afforded two new 2,2–dimethyl–2H–1–benzopyran dimers named 5,5’–dimethoxy–alloagerasanin and melifolin. Their structures were established by NMR spectroscopy, especially NOE and HMBC. © 1998 Published by Elsevier Science Ltd. All rights reserved.
Nguyen Hong Van, Christine Kamperdick, Tran Van Sung, Günter Adam   +3 more
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Benzopyran derivatives from Werneria nubigena

Phytochemistry, 1997
Abstract The investigation of Werneria nubigena afforded the rare 2,2-dimethyl-6-acetyl-8-(3′-hydroxy-3′-methyl- trans -but- 1′-enyl)-chrom-3-ene and new 2,2-dimethyl-6-acetyl-8-(3′-hydroxy- 3′-methyl- trans -but-1′-enyl)-chroman-4-one ( 1 ). Thechemotaxonomic relevance is discussed briefly.
PIACENTE, Sonia, Nora Herrera Hernandez, DE SIMONE, Francesco, Olga Lock de Ugaz, PIZZA, Cosimo   +4 more
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A benzopyran derivative substituted at position 3

Acta Crystallographica Section C Crystal Structure Communications, 2002
In (E)-3-[[(diphenoxyphosphoryl)methylhydrazono]methyl]-4H-1-benzopyran-4-one, C(23)H(19)N(2)O(5)P, the benzopyran-methylhydrazone moiety is planar and the two phenoxy phenyl rings are inclined at angles of 21.29 (6) and 89.33 (5) degrees. Weak C[bond]H...O and C[bond]H...N intramolecular interactions exert some influence on the planarity and ...
Agnieszka J, Rybarczyk-Pirek, Magdalena, Małecka, Sławomir J, Grabowski S, Jolanta, Nawrot-Modranka   +3 more
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A New Efficient Synthesis of Spirocyclic Benzopyrans

Synthesis, 2003
AbstractFor Abstract see ChemInform Abstract in Full Text.
Gregoire Pave, Pierre Chalard, Marie‐Claude Viaud‐Massuard, Yves Troin, Gerald Guillaumet   +4 more
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