5H-1,2-Diazepines

There has been relatively little study of this system and synthetic routes are few. The fully unsaturated structure (482) has not been detected, its valence bond isomer (483) being the more stable form cf. 5H- 1,2-diazepines, p. 595). 

Annular tautomerism between one or more NH-forms and various CH forms of 1,2-diazepines is possible with the favored species dependent upon the nature and position of substituents (69ACS3125, 70T739). Interestingly, unlike monocyclic azepines and tautomeric 1,2-diazepines, 5H- 1,2-diazepines (47) exist preferentially in their bicyclic diazanorcaradiene form (48) (72JA2770). 

Variously substituted tetrazolo[l,5-a]pyridines (19) and 2-azidopyridines (20) are photolysed to 2-alkoxy-lH-l,3-diazepines (21), 2-dialkylaraino-5H-1,3-diazepines (22), 2,3-dihydro-lH-l,3-diazepin-2-ones (23), and 2,4-diazabi-cyclo[3.2.0]-hepten-3-ones (24) the relative stabilities of the 2-alkoxy- and... 

B) Preparation of 7-Chloro-1,2,3,4-Tetrahydro-1-Methyl-6H-1,4-Bemodiazepin-5-one A mixture of 25.25 g (0.1 mol) of 4-acetyl-7-chloro-1,2,3,4-tetrahydro-1-methyl-5H-1,4-benzo-diazepin-5-one, 33.3 ml (0.1 mol) of 3 N sodium hydroxide and 350 ml of ethanol was heated under reflux for 15 minutes and then concentrated to dryness in vacuo. The residue was treated with 500 ml of water, collected and washed with ethanol to give 20.2 g... 

Eine ungewohnliche Dimerisierung ist bei der Reduktion von 2,3-Dihydro-6-phenyl-1,4-diazepin-Hydropcrchlorat zu beobachten. Es entsteht - unter Verlust von 1,2-Diami-no-athan - in hoher Ausbeute 2,9-Diphenyl- (R = H) bzw. 7-Methyl-2,9-diphenyl-6,7-dihydro-5H- (pyrrolo-[l,2-d]-l,4-diazepin) (R = CH3) 2... 

Reaction of 4-benzoyl-3-hydroxy-2(5H)-furanone with 1,2-phenylenediamine results in a low yield of diazepine 251 (Eigure 3 (1991JHC1501)). 

Cyclic secondary amines with pyrrolo[2,l-c][l, 4]-benzodiazepine rings were oxidised with TPAP/NMO/PMS/CH3CN to the corresponding imines. Thns (llaS)-1,2,3,10,ll,lla-hexahydro-5H-pyrrolo[2,l-c][l, 4]-benzodiazepine-5-one gave (llaS)-l,2,3,lla-tetrahydro-5H-pyrrolo[2,l-c][l, 4]benzo-diazepine-5-one [23]. 

Likewise, 1,4-diazepine 5i-m,83 1,4-thiazepine 5h,83 1,4-oxazepine 5a-g,83 and 1,4-oxazepin-5-one92 derivatives were formed in good yield on thermolysis of suitably substituted dihetera-tricyclo[3.2.0.02,4]heptanes in refluxing toluene or xylene. 

Tetrazines (39) react with cyclopropenes (149) via the unisolated tricyclic intermediates (150) to form the diazanorcaradienes (151) by loss of nitrogen. Three reactions of the diazanorcaradienes have been observed (1) opening of the ring to give the 5H-diazepines (152) (2) isomerization by the walk mechanism to the diazanorcaradienes (153), which may be transformed into the 4//-diazepines (154) (3) reaction with another molecule... 

A range of multicomponent processes have been reported including an acid-free Ugi reaction for the synthesis of 5H-benzo[e][l,4]diazepines (14SL1680), an interesting post-Ugi copper-catalyzed intramolecular UUmaim coupling approach for the synthesis of 4H-benzo[/]imidazo[l,4]diazepin-6-ones (14TL2070) and a reaction between aromatic 1,2-diamines, Meldrum s acid, an isocyanide, and an arylidene malononitrile for the preparation of l,2,4,5-tetrahydro-2,4-dioxobenzo[l)][l,4]diazepines (14T9512). 

In another report, 1,5-benzodiazepines have been obtained from reaction of alk-3-yn-l-ones with 1,2-phenylenediamines in ethanol under microwave heating without the need for any catalyst (14GC1120). A palladium-catalyzed domino reaction between 1,2-phenylenediamines and 10,11-dihydro-5H-dibenzo[fc,e][l,4]diazepines starting from 2-bromobenzyl bromides has also been developed (14EJ04773). 

H-benzo[d,f] [l,3]diazepines dibenzo[b,g]-l,8-naphthyridines imidazoles (glyoxalines) imidazo [1,2-a] pyridines indolopyridines 12H-indolo[2,3-a]pyridocoli-nium rings... 

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... 

Cl3H12CIN3O2S, 7-Chloro-l,3,5-trimethyl-5H-pyrimido[5,4-b] 1,4)ben-zothiazine-2,4(1H,3H)-dione, 38B, 398 Cl3H12N2O2S, 5,6-Dihydro-6-(2-oxo-propyl)-4H-pyrrolo[1,2-a]thieno-[3,2-f][1,4-diazepine]-4-one, 45B, 380 Cl3H14N2O2S, 2-Amino-4,5-dihydro-7,8-dimethoxynaphtho[1,2-d]thia-zole, 43B, 483... 

Photolysis of azidopyridines in the presence of nucleophiles (sodium methoxide, diethylamine, etc.) proceeded with ring expansion and produced different derivatives of diazepines, (Scheme 2). 2-Azidopyridines gave derivatives of IH-1,3-diazepines and 5H-l,3-diazepines [14,15], 3-azidopyridine -derivatives of 2H-l,4-diazepines and 5H-l,3-diazepines[16,17], and 4-azidopyridine - derivatives of 6H-l,4-diazepines [17,18]. 

Chemical Name 1 -(3,4-Dimethoxyphenyl)-4-methyl-5-ethyl-7,8-dimethoxy-5H-2,3-benz-diazepine... 

Formylation of 5H-benzo[/]pyrrolo[l,2-d][l,4]diazepin-6(7H)-one 180 pyrrole ring with POCI3/DMF is known (Scheme 36, Section 3.1.1.1 (1992BMCL1639)). Formyation of pyrrolo-benzothiazepine can be accomplished using POCI3/ PhNMeCHO (Scheme 76 (2004JMC143)). The monoaldehyde 375 (R = H) is... 

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