نتایج جستجو برای: 2h pyrans

تعداد نتایج: 11400  

2013
P. Sharmila G. Jagadeesan Rajesh Raju Raghunathan Raghavachary S. Aravindhan

In the title compound, C30H29BrN2O5, the β-lactam ring is essentially planar, with the O atom displaced from this plane by 0.856 (9) Å, and forming dihedral angles of 24.35 (13) and 89.42 (14)° with the planes of the benzene substituent groups on this ring. The tetra-hydro-pyran ring adopts an envelope conformation with the C atom bearing the β-lactam ring as the flap. In the crystal, weak C-H⋯...

2012
O. Kotresh K. Mahesh Kumar N. M. Mahabaleshwaraiah H. K. Arunkashi H. C. Devarajegowda

In the title compound, C(20)H(19)N O(2)S(2),the 3Hbenzo-chromene ring system is nearly planar, with a maximum deviation of 0.036 (2) Å, and the piperidine ring adopts a chair conformation: the bond-angle sum for its N atom is 358.7°. The dihedral angle between the 3H-benzo[f]chromene ring and the piperidine ring is 89.07 (8)°. In the crystal, C-H⋯O hydrogen bonds lead to [010] C(6) chains and w...

2012
Henok H. Kinfe Felix L. Makolo Zanele Phasha Alfred Muller

In the title compound, C(14)H(20)O(9), the six-membered pyran and the five-membered dioxalane rings adopt chair and twisted conformations, respectively. In the crystal, the mol-ecules are linked by C-H⋯O inter-actions.

2017
Tsukasa Furuya Takashi Nomoto Tsuyoshi Fukuhara Shoji Hara

We prepared a novel fluorous deoxy-fluorination reagent N,N-diethyl--difluoro-[3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzyl]amine (1b) from 3,5-diiodobenzoic acid (3b) via N,N-diethyl-3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzamide (2b) in four steps and used it for the fluorination of alcohols and diols. After the fluorination reactions, the isolation of the products and recovery of 2b was perfor...

Dadkhoda Ghazanfari Enayatollah Sheikhhosseini, Vida Nezamabadi

p-Dodecylbenzenesulfonic acid (DBSA) was used as a catalyst for a simple and efficient one-pot synthesis of aryl substititued tetrahydrobenzo[b]pyrans and dihydropyrano[c]chromens via initial Knoevenagel, subsequent Micheal and final heterocyclization reactions of aryl aldehyde, malononitrile and 4-hydroxycoumarin/dimedone in moderate to excellent yields. The present method was operationally si...

Journal: :Journal of Organic Chemistry 2021

Substituted pyrans and furans are core structures found in a wide variety of natural products biologically active compounds. Herein, we report practical mild catalytic method for the synthesis substituted using molecular iodine, simple inexpensive catalyst. The described is performed under solvent-free conditions at an ambient temperature atmosphere, thus offering facile alternative to currentl...

Journal: :Molecules 2006
Milan Cacic Mladen Trkovnik Frane Cacic Elizabeth Has-Schon

(7-Hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid hydrazide (2) was prepared from (7-hydroxy-2-oxo-2H-chromen-4-yl)-acetic acid ethyl ester (1) and 100% hydrazine hydrate. Compound 2, is the key intermediate for the synthesis of several series of new compounds such as Schiff's bases 3a-l, formic acid N'-[2-(7-hydroxy-2-oxo-2H- chromen-4-yl)acetyl] hydrazide (4), acetic acid N'-[2-(7-hydroxy-2-oxo-2...

A facile, convenient, green and environmentally benign one-pot three-component synthesis of poly-functionalized 4H-pyrans and 4H-chromenes is described. A basic ionic liquid 2-(2-hydroxyethoxy)ethaneammonium formate was found to be an efficient catalyst or catalytically active solvent for the synthesis of those important classes of heterocyclic compounds.

Journal: :The Journal of organic chemistry 2002
Teresa M V D Pinho e Melo Cláudia S J Lopes António M d'A Rocha Gonsalves Ana M Beja José A Paixão Manuela R Silva Luiz Alte da Veiga

Nucleophilic substitution reactions of 2-halo-2H-azirines 1a, 1b, 1d, and 1e with potassium phthalimide and aniline allowed the preparation of new substituted 2H-azirines 2-5. The reactions of 2-bromo-2H-azirine 1a with methylamine led to the synthesis of alpha-diimines 7 and 8. 2-Halo-2H-azirines were also established as building blocks for the synthesis of a range of heterocyclic compounds, n...

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