- Substituent-Dependent Reactivity in the Photodimerization of N-Substituted Dibenz[b,f]azepines
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The photoprocesses of a series of N-substituted dibenz[b,f]azepines (iminostilbenes) were studied by absorption and emission spectroscopy, by laser flash photolysis, and by preparative irradiation with NMR analysis. In solutions, 2π+2π photodimers of N-cyano and N-acyl dibenzazepines are formed via the triplet state upon acetone- or benzophenone-sensitized energy transfer. T-T absorption spectra were measured and absorption coefficients were determined. The triplet energy transfer is equally efficient for N-alkyl dibenzazepines, which do not dimerize. Excited states of nπ* character in the latter cases are discussed to rationalize the different reactivities. In spite of negligible intersystem crossing of 21 dibenzazepine derivatives, photodimers of N-acyl and N-cyano dibenzazepines are formed upon direct excitation in concentrated solutions (0.01-0.1 moldm-3) as well as in the solid state. A selective anti-configuration of the photodimers was found throughout.
- Querner, Jens,Wolff, Thomas,Goerner, Helmut
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- 5-(Cyano)dibenzothiophenium Triflate: A Sulfur-Based Reagent for Electrophilic Cyanation and Cyanocyclizations
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The synthesis of 5-(cyano)dibenzothiophenium triflate 9, prepared by activation of dibenzo[b,d]thiophene-5-oxide with Tf2O and subsequent reaction with TMSCN is reported, and its reactivity as electrophilic cyanation reagent evaluated. The scalable preparation, easy handling and broad substrate scope of the electrophilic cyanation promoted by 9, which includes amines, thiols, silyl enol ethers, alkenes, electron rich (hetero)arenes and polyaromatic hydrocarbons, illustrate the synthetic potential of this reagent. Importantly, Lewis acid activation of the reagent is not required for the transfer process. We additionally report herein biomimetic cyanocyclization cascade reactions, which are not promoted by typical electrophilic cyanation reagents, demonstrating the superior ability of 9 to trigger challenging transformations.
- Li, Xiangdong,Golz, Christopher,Alcarazo, Manuel
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supporting information
p. 9496 - 9500
(2019/06/27)
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- A METHOD FOR PREPARING 5H-CYANO-IMIDO STILBENE
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A method for preparing 5-cyano-5H-dibenz[b,f]azepine, comprises: reacting carbamazepine of formula (II) used as dehydrating agent with bis(trichloromethyl)carbonate of formula (III) in organic solvent for 1-30 hours at 20-150°C, and obtaining 5-cyano-5H-dibenz[b,f]azepine (I) after the post-treatment of the reaction solution. The scheme is shown as below.
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Page/Page column 3
(2011/05/04)
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- PROCESS FOR PRODUCING 10-OXO-L10, 11-DIHYDR0-5H-DIBENZ [B, F] AZEPINE-5-CARBOXAMIDE STARTING FROM 5-CYANOIMINOSTILBENE
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Disclosed herein is a process for producing 10-oxo-10,11-dihydro-5H-dibenz[bf] azepine-5-carboxamide of formula I via novel intermediates 11-alkoxy-10-halo-10,11-dihydro-5H-dibenzo [b,f ] azepine-5-carbonitrile [XIX] or 10-alkoxy-5H-dibenz [b,f] azepine -5-carbonitrile [XX]. Further the present invention also provides a process for preparation of said intermediates.
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Page/Page column 10; 12-13
(2008/06/13)
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- Activated dimethyl sulfoxide dehydration of amide and its application to one-pot preparation of benzyl-type perfluoroimidates
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Various types of primary amides were treated under an activated dimethyl sulfoxide (DMSO) species, (COCl)2-DMSO and Et3N, as a dehydrating agent to obtain nitriles in excellent yield. This dehydration system was extended to a one-pot preparation of perfluoroimidates via volatile perfluoronitriles from perfluoroamides. Fifteen benzyl-type perfluoroimidates can be prepared in 70-90% yield as more stable imidates than the trichloro analogue. MPM- and DMPM-perfluoroimidates can be used to protect alcohols in place of the trichloroacetimidate with excellent chemical properties and in comparable yields.
- Nakajima, Noriyuki,Saito, Miho,Ubukata, Makoto
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p. 3561 - 3577
(2007/10/03)
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- A Convenient Synthesis of Carbamazepine (Tegretol)
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A two-step efficient procedure for the preparation of carbamazepine (3), involves intermediate preparation of N-cyanodibenzazepines (2).Hydrolysis of 2 affords 3 in 73 percent yield.
- Ahmad, S. Salman,Hafeez, Farrukh,Haider, S. Imtiaz,Mahmood, Tariq
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- Process for the production of 5-cyano-and 5-carboxamido-5H-dibenz[b,f]azepines
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The invention relates to a novel and technically advanced process for producing 5-cyano-5H-dibenz[b,f]azepine by reacting 5H-dibenz[b,f]azepine with a halocyanogen in the presence of strongly polar substances. 5-Cyano-5H-dibenz[b,f]azepine can be used as starting material for producing 5-carbamyl-10(11)-oxo-10,11-dihydro-5H-dibenz[b,f]azepine, which is known to have central-depressant, anticonvulsive and central-muscle-relaxing activity.
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