Theoretical investigation of the coordination of dibenzazepine to transition-metal complexes: A DFT study

DFT calculations with full geometry optimizations have been carried out on a series of hypothetical compounds of the CpM(C₁₄NH₁₁) and (CO)₃M(C₁₄NH₁₁) (M = transition metal and C₁₄NH₁₁ = dibenzazepine ligand) type. A rationalization of the bonding in hypothetical complexes is provided. Depending on the electron count and the nature of the metal, the dibenzazepine ligand can bind to the metal through the η¹, η², η³, η⁴ , η⁵, η⁶ , or η⁷ coordination mode adopting structures of types a or b. In the investigated species, the most favored closed-shell count is 18-MVE except for the Sc and V models which prefer the 16-MVE configuration.     

Spectrophotometric determination of some dibenzazepine drugs by electrophilic coupling

Two sensitive spectrophotometric methods for the determination of imipramine hydrochloride, clomipramine hydrochloride, desipramine hydrochloride, and trimipramine maleate in bulk and in dosage forms are described. The first method is based on the interaction of diazotized p-nitroaniline (DPNA) with the dibenzazepine drug in 5M hydrochloric acid. The second is based on the oxidative coupling of the dibenzazepine drug with 3-methylbenzothiazolin-2-one hydrazone (MBTH) in the presence of ammonium iron(III) sulphate in 0.1M hydrochloric acid. The resulting chromophores are measured at 575 nm (for the DPNA method) or at 620-630 nm (for the MBTH method), and are stable for at least 24 hr. The commonly encountered excipients and additives do not interfere with the determinations. Results from the analysis of pure drugs, commercial tablets and laboratory-prepared tablets by these methods agree well with those of official methods.     

Synthesis of homologous monomers and polymers of carbazole,phenothiazine and dibenzazepine

Monomers and polymers of 3-vinyl-N-ethylcarbazole, 3-vinyl-N-methylphenothiazine, 3,7-divinyl-N-methylphenothiazine, N-acrylylcarbazole, N-acrylylphenothiazine, and N-acrylyl- and N-methacrylyldibenzazepine have been synthesized. The synthetic procedures for preparing the monomers and polymers are described.     

Synthesis of tricylic systems incorporating the azepine ring

Some tricyclic compounds (derivatives of pyrazino[2,1-a]benzazepine, diazepino[7,1-a]isoquinoline, and some pyrimido[6,1-a]isoquinolines) which are analogs of the anthelmintic praziquantel have been synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1665–1669, December, 1990.     

Synthesis of pyrrolo- and pyrido[1,2-a]xanthene [1,9-de]azepines: a study of the azepine ring construction

Pentacyclic pyrrolo- and pyrido[1,2-a]xanthene[1,9-de]azepines were synthesized in various oxidation states by assembling the azepine ring following two strategies: 7-endo-trig cyclization of the aryl radical derived from a gamma-methylene lactam and cyclodehydration of aldehydes. Other strategies examined (Heck reaction and intramolecular acylation) did not afford azepines, but six-membered nitrogenated rings.     

Mechanistic study on rearrangement cascades starting from annulated 2-aza-hepta-2,4-dienyl-6-ynyl anions: formation of aniline and azepine derivatives

Deprotonation of benzothiophene-derived alkynyl imine 11 with lithium diisopropylamide (LDA) and subsequent transmetalation with ZnCl2 etherate furnished azepine 12 upon aqueous workup. Similarly, alkynyl benzaldimine 1a gave a mixture of benzazepine 13 and naphthylamine 14. Allylic benzonitriles 15 a,b reacted to produce naphthylamine 16 upon deprotonation with LDA at room temperature. In an analogous manner, imino benzonitrile 17 may be converted into 4-amino isoquinoline 18 by means of an intramolecular nucleophilic attack on the nitrile function upon treatment with LDA. The allylic benzonitriles 19 a,b were prepared by LDA treatment of alkynyl imine 11. They were further converted to amino dibenzothiophene 20 by LDA deprotonation and aqueous workup. These various transformations represent the key steps of a multistep reaction cascade, which was previously postulated on the basis of quantum chemical calculations. Thus, all features of this complex rearrangement mechanism could now be confirmed experimentally. DFT calculations support the lower reactivity of zinc species in the ring-opening step compared to the lithium intermediates. All new compounds were completely characterized by spectroscopic data, including X-ray diffraction studies for the key compounds 12, 19 a, and 20.     

The assignment of the 1H-NMR and 13C-NMR spectra of 5H-dibenz[b,f]azepine and 10,11-dihydro-5H-dibenz[b,f]azepine

The total assignments of the ¹H-nmr and ¹³C-nmr spectra of 5H-dibenz[b,f]azepine [1] and 10,11-dihydro-5H-dibenz[b,f]azepine ( 2 ) have been made based on comparison with the corresponding 4,6-dideuterated derivatives 3 , and 4 . These compounds were prepared via repeated lithiations and subsequent deuterations of 1 and 2 .     

Phase transfer catalysis in N-alkylations of the pharmaceutical intermediates 5H-dibenz[b,f]azepine and 5H-10,11-dihydrodibenz[b,f]azepine

The two title compounds were alkylated under very mild phase-transfer-catalysis conditions. Differences in reactivities of the two heterocyclic nucleophiles, and in the reactivities of various alkyl halides are discussed.     

Synthesis and reactions of pyrrolo[2,3-c]azepine derivatives

The construction of the pyrrolo[2,3-c]azepine system by the reaction of 2-oxo-3-hydroxy-4-cyano-2H, 1,5,6,7-tetrahydroazepine with glycine ester and subsequent cyclization of the resulting N-substituted amino nitrile in an alcohol solution of sodium ethoxide was studied. The pyrrolo[2,3-c]azepine system was converted to the three-ring pyrimido[4,54,5]pyrrolo[2,3-c]azepine system, the alkylation of which gave N,N-dialkyl and N,N,N-trialkyl derivatives. Cyclization of 3-benzyl-4, 6-dioxo-5-(N,N-dimethyl)aminoethyl-6H,3,4,7,8,9,10-hexahydropyrimido[4,54,5]pyrrolo[2,3-c] azepine hydrochloride under the influence of phosphorus oxychloride gave the four-ring pyrazino[3,2,1-b,c]azepino[3,4-b]pyrrolo[3,2-d]-pyrimidine system. The structures of the compounds obtained were confirmed by their IR, UV, and PMR spectra.Communication 34 from the series Research on Lactams. See [1] for communication 33.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1097–1100, August, 1980.     

Naphthyridine chemistry: Ring enlargement to a pyrido[2,3-b] azepine

The boron trifluoride-catalyzed rearrangement of the epoxide derived from 3-benzylidene- 7-methyl-2,3-dihydro-1,8-naphthyridin-4-(1H)one (II) is described. The structure of the obtained 8-methyl-4-phenyl-1,2,3,4-tetrahydro-5H-pyrido[2,3,-b]-azepin-3, azepin-3,5-dione (X) has been elucidated with aid of chemical and spectral evidence.     

Metallations of 5 H-dibenz [b,f] azepine and 10,11-dihydro-5H-dibenz [b,f] azepine. Synthesis of 4-substituted derivatives

The synthesis of 4-substituted 5 H-dibenz [b, f] azepines and 10, 11-dihydro-5 H-dibenz [b, f] azepine resulting from the reaction of the corresponding 4, 5-dilithio derivatives and different N, N-dimethylamides is reported. The total assignment of the pmr spectra of the prepared formyl derivatives based on decoupling experiments is also described.     

An asymmetric aminohydroxylation approach to the azepine core of (-)-balanol

[reaction: see text]An efficient formal synthesis of the potent protein kinase C inhibitor (-)-balanol that relies on a modified asymmetric aminohydroxylation of the alpha,beta-unsaturated aryl ester (1) is reported. The aryl ester functionality and the dihydroquinyl alkaloid ligand system (DHQ)2-AQN are used to control the regio- and enantioselectivity of the process.     

Three closely related dibenzazepine carboxylic acids: hydrogen‐bonded aggregation in one,two and three dimensions

In the structure of (6R*,11R*)‐5‐acetyl‐11‐ethyl‐6,11‐dihydro‐5H‐dibenzo[b,e]azepine‐6‐carboxylic acid, C₁₉H₁₉NO₃, (I), the molecules are linked into sheets by a combination of O—H...O and C—H...O hydrogen bonds; in the structure of the monomethyl analogue (6RS,11SR)‐5‐acetyl‐11‐ethyl‐2‐methyl‐6,11‐dihydro‐5H‐dibenzo[b,e]azepine‐6‐carboxylic acid, C₂₀H₂₁NO₃, (II), the molecules are linked into simple C(7) chains by O—H...O hydrogen bonds; and in the structure of the dimethyl analogue (6RS,11SR)‐5‐acetyl‐11‐ethyl‐1,3‐dimethyl‐6,11‐dihydro‐5H‐dibenzo[b,e]azepine‐6‐carboxylic acid, C₂₁H₂₃NO₃, (III), a combination of O—H...O, C—H...O and C—H...π(arene) hydrogen bonds links the molecules into a three‐dimensional framework structure. None of these structures exhibits the R₂²(8) dimer motif characteristic of simple carboxylic acids.