2.3- Dihydro-1//-benzo azepines

In 2002, Guingant and co-workers (168) reported a facile synthesis of 1,5-dihydro-benzo[fi]azepin-2-one from A-benzyl quinolinium bromide. This method... 

Construction of the indole ring via Fischer synthesis. Starting from a variety of 3,4-dihydro-lH-benzo[l ]azepine-2,5-diones 40 and arylhydrazines Fischer syntheses of indolo benzazepinones 41 have been reported (Scheme 8 (1999JMC2909)). Usually, the reaction comprises a two-step one-pot procedure with the formation of intermediate arylhydrazones in warm acetic acid followed... 

Construction of the azepine ring by C-N bond formation. Aranapakam et al. synthesized 5,10-dihydro-4H-benzo[l7]thieno[2,3-e]azepine 111 and 4H-benzo[ 7]thieno[3,2-e]azepin-10(9H)-one 113 (X = CO) starting from the corresponding tributylstannyl derivatives 110 and 112, which react with 2-nitrobenzyl bromide and [(Ph)3P]4Pd. Sequential deprotection and reductive cyclization were carried out in one step with zinc and aqueous acetic acid (Scheme 22 (1999BMCL1733)). 

Medium-sized and large ring systems often show complicated conformational interconversions involving pseudorotations in one or even more conformational families. This makes stereochemical assignments in diastereomers rather difficult. Thus, very few systematic studies have been published. The situation is improved if such rings are embedded in polycyclic systems, or if they contain double bonds, which leads to restricted conformational mobility. An example is the differentiation of diastereomeric 2,3-dihydro-lf/-benzo[6]azepines 1 on the basis of y-gauche effects and on d(13C) and 3/H H values640. 

In Gegenwart von Wasser bzw. Aminen werden die Benzo-[c]-l,2-oxazole in2-Oxo-2,3-dihydro-azepine bzw. 2-Amino-3H-azepine umgewandelt. 

Of particular interest is the thermal decomposition of azepines, diazepines, and triazepines. 3,4-Benzo-l,7-diazabicyclo[3.2.0]hepta-3,6-dienes (236) were found to decompose at 180° with loss of a nitrile or hydrogen cyanide. The other products of the (2 + 2)-cycloreversion were highly unstable isoindoles and could not be isolated.296 A similar type of reaction has been proposed for the decomposition of 4,5-dihydro-3//-azepines27 and jV-methylazepines,301 but the corresponding bicyclic intermediates 240 and 263 have not been detected. The question whether these cycloreversions are thermal or photochemical reactions remains unresolved. 

The reactions of 3-formylchromones, e.g. (186), with various ort/io-substituted anilines (Y = S, O, or NH) provide a high-yielding route to the fused benzo-pyrano-compounds (187)." Various substituted 2,3-dihydro-l,4-benzox-azepin-5(4H )-one-7-acetic acid esters were prepared by the Schmidt reactions of chromanone derivatives." ... 

A gold-catalysed cyclopropyl carbinol rearrangement of 2-tosylaminophenyl cyclo-propylmethanols to 2,3-dihydro-l//-benzo[b]azepines and 2-vinylindolines is reported (Scheme 128) ... 

Cl5H13NO, 6,7-Dihydro-6-methyl-5H-dibenz[c,e]azepin-5-one, 39B, 211 Cl 5H1 i,Ni,02 f 4,5-Benzo-8,11,11 - trimethyl-1, 2,7,1 0-tetraazatricyclo-[7.3,0.0 ]dodeca-2,9-diene-6,12-dione, 46B, 273 Cl5H1sBr2N, 1,1-Bis(bromoethyl)-l,2,3,4-tetrahydroacridine, 46B, 273 Cl5H15N2O5, Methyl 8-methoxycarbonylmethyl-2-oxo-2,3,3a,8-tetrahyd-ro-1H-pyrazolo[5,1-a]isoindol-3-carboxylate, 41B, 346 Cl5H16N2O2, 5,7-Dihydroxy-6,6-dimethyl 6,7-dihydrodibenzo[d,f](1,3)-diazepine, 44B, 256... 

Allyl-3-trifluoromethyl-7,8-dihydro-6R-benzo[f] indolo[l,2-a][l,4]di-azepine (3f)... 

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