Electron impact mass spectral fragmentation of 2a,4-disubstituted 2-chloro/2,2-dichloro-2,2a,3,4-tetrahydro-1H-azeto[2,1-d][1,5]benzothia zepin-1-ones

The mass spectrometric behaviour of nine 2a,4-disubstituted 2-chloro/2,2-dichloro-2,2a,3,4-tetrahydro-1H-azeto[2,1-d][1,5]b enzothiazepin-1-ones has been studied with the aid of mass-analysed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization. All compounds show a tendency to eliminate a neutral chlorine atom, or a chloroketene, or neutral propene, or styrene or substituted styrene molecule, plus Cl and/or H (or Cl) atom(s), to yield [M-Cl]+ ions, 2,3-dihydro-1,5-benzothiazepine derivative ions, 4,5-dihydro-5H-1,5-benzothiazepin-4-one ions which can further lose CO to give 1,4-benzothiazine ions. Both molecular ions and [M-Cl]+ ions show a tendency to eliminate an ethyl or benzyl/substituted benzyl radical to produce 2,2a-dihydro-1H-azeto[2,1-c][1,4]benzothiazin-1-one ions. The [M-Cl]+ ions could undergo rearrangement to yield 2,2a-dihydro-1H-azeto[2,1-d][1,5]benzothiazepin-1-one ions, 2,2a,3,4-tetrahydro-1H-azeto[1,2-a]quinoline ions or 1,1a,2,3-tetrahydro-azirino[2,1-d][1,5]benzothiazepine ions by loss of an ethane or a benzene/substituted benzene, a SH radical or a CO molecule. The molecular ions could also undergo rearrangement reactions to form other small fragment ions.     

The mass spectral fragmentation of 1a,3-disubstituted 4-benzoyl-1a,2,3,4- tetrahydrooxazirino

The mass spectrometric behaviour of four 1a,3-disubstituted 4-benzoyl-1a,2,3,4-tetrahydrooxazirino[2,3-a][1,5]benzodiazepines has been studied with the aid of mass-analyzed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization. All compounds show a tendency to eliminate a neutral oxygen atom, or oxygen atom plus benzoyl or aryl radicals, or oxygen atom plus CO molecule to yield 2,3-dihydro-1H-1,5-benzodiazepine derivative ions, or 1-benzoyl-2,3-dihydro-1H-1,5-benzodiazepine ions, which could further lose benzoyl to give 2,3-dihydro-1H-1,5-benzodiazepine ions. All compounds also show a tendency to eliminate a benzoyl radical to produce 1a,2,3,4-tetrahydrooxazirino[2,3-a][1,5]benzodiazepine ions. Both oxazirino[2,3-a][1,5]benzodiazepine ions and 2,3-dihydro-1H-1,5-benzodiazepine ions can undergo diazepine ring contraction rearrangement to yield benzimidazole ions by loss of propene or styrenes and other small fragments. The oxazirino[2,3-a][1,5]benzodiazepine ions [M(+)-PhCO] also undergo rearrangement reactions to form benzoxazole ions and benzimidazole ions. Copyright 1999 John Wiley & Sons, Ltd.     

Electron impact mass spectral fragmentation of 3a,5-disubstituted 1, 3-diphenyl-3a,4,5,6-tetra-hydro-3H-1,2,4-triazolo[4,3-a][1, 5]benzo-diazepines

The mass spectrometric behaviour of six 3a,5-disubstituted 1, 3-diphenyl-3a,4,5,6-tetrahydro-3H-1,2,4-triazolo[4,3-a][1, 5]benzodiazepines has been studied with the aid of mass-analyzed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization. All compounds show a tendency to eliminate (substituted) styrene molecules, aryl radicals, arylmethyl radicals or phenylnitrene (PhN:). All of the resulting fragment ions, except [M - PhN:](+.), could further undergo a reverse [2 + 3] cycloaddition. The [M - PhN:](+.) ions could further lose styrene derivatives and undergo a ring enlargement rearrangement. The molecular ions also show a tendency to eliminate a phenyl radical, and the [M - Ph](+) ions could eliminate styrene derivatives. The [M - R(1)CH = CH(2)](+.) ions could further lose NH(2) to yield stable tetracyclic 1,3-diphenyl-1,2,4-triazolo[4,3-d]phenanthridine ions, which could further lose benzonitrile, or undergo a reverse [2 + 3] cycloaddition. The molecular ions could also undergo a reverse [2 + 3] cycloaddition to produce N-phenylbenzonitrile imine ions and 2, 4-disubstituted 2,3-dihydro-1H-1,5-benzodiazepine ions, whose further fragmentations were also investigated.     

Mass Spectrometry of 2a, 4-Disubstituted 5-Benzoyl-2a, 3,4,5-tetrahydro-2-phenoxy-azeto [ 1,2-a ] [1,5 ] benzodiazepin - 1 （2H）-ones Under Electron Impact Ionization Conditions

The mass spectrometric fragmentation of 2a, 4-disubstituted 5-benzoyl-2a, 3,4, 5-tetrahydro-2-phenoxy-azeto[1,2-α] [ 1,5 ] benzodiazepin-I (2H)-ones has been investigated by means of mass-analyzed ion kinetic energy spectrometry under electron impact ionization conditions. All compounds tend to lose different moieties, such as phenoxy, phenoxy and H, and phenoxyketene. Both [ M^ - PhO ] and [ M^ - PhOH ] ions could further lose CO, and the [ M^ - PhOCH = C = O] ions could lose propene or styrene, PhCON, PhCOHN, and other fragments.     

Reaction of 2,3-Dihydro-1,5-benzothiazepines and Phenylacetyl Chloride in the Presence of Triethylamine： A New Aspect on the Formation Mechanism of Dihydro-1,3-oxazin-4-one Derivatives

2a,4-Disubstituted 2,2a,3,4-tetrahydro-2-phenyl-1H-azeto[2,1-d][ 1,5]benzothiazepin-1-ones, as well as 2-substi-tuted 2,3-dihydro-3-phenylacetyl-2-styryl-benzothiazoles and 4a,6-disubstituted 3- .benzyl-4a,5-d/hydro-2-phenyl-1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, were obtained from the reaction of 2,4-disubstituted 2,3-dihydro-1,5-benzothiazepines with phenylacetyl chloride in the presence of triethylamine. The mechanism for the formation of 4a,5-dihydro-1H,6H-[1,3]oxazino[2,3-d][1,5]benzothiazepin-1-ones, 2,3-dihydro-1,3-oxazin-4-one derivatives, was suggested.     

Cyclocondensation of 5-benzoyl-3-ethoxycarbonyl-6-methylthio-1-R-1,2-dihydropyrid-2-ones with heterocyclic N,N-and N,C-1,3-dinucleophiles

[3+3] Cyclocondensation of 5-benzoyl-3-ethoxycarbonyl-6-methylthio-1-R-1,2-dihydropyrid-2-ones with heterocyclic N,N-and N,C-1,3-dinucleophiles proceeds regioselectively to give a series of new tri-and tetracyclic heterosystems, viz. derivatives of 5,6-dihydropyrazolo[1,5-a]pyrido[2,3-d]pyrimidin-6-one, 1,2-dihydropyrido[2,3-d]pyrido[2′,3′: 3,4]pyrazolo[1,5-a]pyrimidin-2-one, 8,9-dihydro-5H-pyrido-[2,3-d]thiazolo[3,2-a]pyrimidin-8-one, 1,2-dihydrobenzo[4,5]imidazo[1,2-a]pyrido[2,3-d]pyrimidin-2-one, and 1,2-dihydrobenzo[4,5]imidazo[1,2-g][1,6]naphthyridin-2-one.     

Schmidt Reaction on 2-Aryl-1,2,3,4-tetrahydro-4-quinolone

Synthesis and stereochemistry of 2-aryl-1,2,3,4-tetrahydro-5H-1,4-benzodiazepin-5-one and 2-aryl-2,3-dihydro-4H-tetrazolo [1,5-d]-1H-1,4-benzodiazepine is reported by the Schmidt reaction on 2-aryl-1,2,3,4-tetrahydro-4-quinolone.     

Mass spectrometric studies of cis- and trans-1a,3-disubstituted-1, 1-dichloro-4-formyl-1a ,2,3,4-tetrahydro-1H-azirino [ 1,2-a] [1,5] benzodiazepines

The mass spectrometric behaviour of four cis- and trans-la, 3-disubstituted -1,1 -dichloro-4-formyl-1a,2,3,4-tetrahydro-1H-azirino[1, 2-a] [1,5] benzodiazepines has been studied with the aid of mass-analysed ion kinetic energy spectrometry and exact mass measurements under electron impact ioniza-tion. All compounds show a tendency to eliminate a chlorine atom from the aziridine ring, and then eliminate a neutral propene or styrene from the diazepine ring to yield azirino[ 1, 2-6][1,3]benzimidazole ions. These azmno[1,2-a] [1,5]-benzodiazepines can also eliminate HCl, or Cl plus HG simultaneously to undergo a ring enlargement rearrangement to yield 1,6-benzodiazocine ions, which further lose small molecular fragments, propyne or phenylacetylene, with rearrangement to give quinoxaline ions.     

Tautomerism of the Thioamide Group in 4-Methyl-7-nitro-2,3,4,5-tetrahydro-1,5-benzodiazepine-2-thione

When 4-methyl-7-nitro-2,3,4,5-tetrahydro-1H-1,5-benzodiazepin-2-one were reacted with phosphorus pentasulfide, the corresponding benzodiazepine-2-thione and its thiol tautomer were formed, which via the 2-methylmercapto derivative were converted to 4-(2-acetylhydrazino)-2-methyl-8-nitro-2,3-dihydro-1H-1,5-benzodiazepine.     

Nucleophilic Substitution in 1,5-Benzodiazepin-2-ones

The reaction of 3-bromo-4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one with cyclic amines gives 3-aminoalkyl-4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one. Thiazolo[4,5-b][1,5]benzodiazepine was isolated along with the substitution product when thiourea was used.     

Synthesis and crystalline and molecular structure of hydrochloride of 1-[2(2,3-dihydro-1,3,4-oxadiazolyl-5-one)]methyl-7-bromo-5-prenyl-1,2-dihydro-3H-1,4-benzodiazepin-2-one

By the interaction of 1-hydrazinocarbonylinethyl-7-bromo-5-phenyl-1,2-dihydro-3H-1,4-benzodiazepin-2-one with phosgene, the compound 1-[2(2,3-dihydro-1, 3,4-oxadiazolyl-5-one)jmethyl-7-bromo-5-phenyl-1, 2-dihydro-3H-1, 4-benzodiazepin-2-one has been synthesized. Spectroscopic methods and x-ray structure analysis have been used to establish the crystalline and molecular structure of this new derivative of 1, 4-benzodiazepine.A. V. Bogatskii Physicochemical Institute, National Academy of Sciences of Ukraine, Odessa 270080. Institute of Applied Chemistry, Academy of Sciences of the Republic of Moldova, Kishinev 277028. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 689–693, May, 1995. Original article submitted March 17, 1995.     

Chlorination of 4-methyl-8-methoxy-2,3-dihydro-1H,1,5-benzodiazepin-2-one

The results of the chlorination of 4-methyl-8-methoxy-2,3-dihydro-1H,1,5-benzodiazepin-2-ones are compared with the results of quantum-chemical calculations of 4-methyl-2,3-dihydro-1H-1,5-benzodiazepin-2-ones with various substituents in the benzene ring in the case of homolytic halogenation. The chlorination of 4-methyl-8-methoxy-2,3-dihydro-1H-1,5-benzodiazepin-2-one (I) with N-chlorosuccinimide leads to 3-chloro- and 3,3-dichloro-4-methyl-8-methoxy-2,3-dihydro-1H-1,5-benzodiazepin-2-ones, whereas chlorination with sulfuryl chloride leads to 4-chloromethyl and 3,3-dichloro-4-methyl derivatives. The IR, PMR, and mass spectra of the synthesized compounds are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1272–1274, September, 1981.     

Solution-phase parallel synthesis of 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones

Practical and efficient parallel methods have been developed for the synthesis of 7,8-disubstituted 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones and 3,7,8-trisubstituted 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones. This benzothiazepin-4(5H)-one skeleton possesses three or four diversity points. Furthermore, three novel tricycles integrating a benzothiazepin-4(5H)-one scaffold with other privileged structures, such as benzimidazole, benzimidazolone, and thio-benzimidazole, were also developed. The synthetic strategy provides an efficient way to access the benzothiazepinone core, starting from commercially available 1,5-difluoro-2,4-dinitrobenzene (DFDNB), and also allows further derivation of the strategically anchored functionalities.     

Cycloaddition of benzoheteroazepine II Reactions and conformations of cycloadducts on1,5-benzothiazepines and 1,5-benzodiazepines with nitrile imine and nitrile oxides

Benzodiazepine and benzothiazepine derivatives have been well known as therapeutically important compounds. Four new tricyclic heterocyclic compounds, 3a,4,5,11-tetrahydro-3H-1,2,4-triazolo[4,3-d] [1, 5]benzothiazepines (3), 3a,4,5,11-tetrahydro-3H,6H-1,2,4-triazolo[4,3-d][1,5]benzodiazepine (4), 3a, 4,5,11-tetrahydro-1,2,4-oxadiazolo[4,5-d] [1,5]benzothiazepines (5, 6) and 3a,4,5,11-tetrahydro-6H-1, 2,4-oxadiazolo[4, 5-d] [ 1, 5 ] benzodiazepines (7,8), have been synthesized by 1,3-dipolar cycloaddition reactions of 2, 3-dihydro-1, 5-benzothiazepines and 2, 3-dihydro-1H-1, 5-benzodiazepine with benzonitrile N-phenylimine and benzonitrile oxides, respectively. The conformations of some cycloadducts and cycloaddition mechanism are described.     

1,3,3a,5-四苯基-3a,4,5,11-四氢-3H,6H-1,2,4-三唑并[4,3-d][1,5]苯并二氮杂的合成及晶体结构

通过2,4-二苯基-2,3-二氢-1H-1,5-苯并二氮杂与苯甲酰氯苯腙的[2+3]环加成反应制备了标题化合物,用X射线单晶衍射仪测定了其晶体结构。晶体属正交晶系,空间群为Fdd2.晶胞参数:a=1.7628(4)nm,b=5.7512(12)nm,c=1.0227nm,V=10.368(5)nm³,Z=16,D_c=1.262g·cm^-3,μ=0.075mm^-1,F(000)=4160,1139个可观测衍射点,R=0.0461,R_w=0.0560.     

Synthesis and properties of some tetracyclic derivatives of 9H-carbazole, 10,11-dihydro-5H-dibenz[b,f]azepine,and 5,11-dihydrodibenz[b,e] [1,4]oxazepine

The behavior of 5,6-dihydro-4H-pyrido[3,2,1-jk]carbazol-4-one (10) , 1,2,7,8-tetrahydro-3H-quino[1,8-ab][1]benzazepin-3-one (11) , 1,2-dihydro-9H-[1]benzazepino[1,9-ab] [4,1]benzoxazepin-4 (3H)one (13) , and 1,2-dihydro-8H-[1]benzazepino[1,9-cd] [1,5]benzoxazepin-4(3H)one (14) towards the Schmidt reaction has been determined in polyphosphoric acid and in benzeneor chloroform-sulfuric acid. Evidence for the structure of the new heterocyclic systems obtained from these four compounds is presented.     

Some stereochemical aspects of the pellizzari rearrangement

Variable temperature nmr spectroscopy and X-ray crystallography have been employed to study the stereochemistry of 2-cyano-3,3-dimethyl-1-phenylpyrazolidin-5-one which thermally rearranges to 2,3-dihydro-2,2-dimethylpyrimido[1,2-a]benzimidazol-4(1H)-one.     

Vilsmeier reaction with 4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one

4-Phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one reacts with the Vilsmeier reagent to give a 3-dimethylaminomethylidene derivative, the hydrolysis of which leads to 3-formyl-4-phenyl-2,3-dihydro-1H-1,5-benzodiazepinone.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 223–225, February, 1984.     

Oxazepines ano Thiazepines,XVII New Procedures for the Preparation of 2,3-Oihydro-1,5-Benzothiazepin-4(5H)-Ones Substituted in Position 2

Abstract

2,3-Dihydro-2-aryl-1,5-benzothiazepin-4(5)-ones and 2,3-disubstituted 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones have hitherto been synthesized by heating the mixture of 2-aminothiophenol and appropriately sub-stituted acrylic acids without solvent.^2–7 This is a very simple and convenient method, but because of the accompanying decompositions, the yield of the reaction is generally quite poor (20 ? 40%). For this reason, it seemed expedient to work out new procedures for the synthesis of these biologically important benzothiaze-pines. Preparation of 2,3-dihydro-2-phenyl-1,5-benzothia-zepin-4(5H)-one (20) was achieved by the ring enlargement of 1-thioflavanone⁸ but, because of the difficulties in the synthesis of the 1-thiochromanone deriva-tives in some cases, this procedure could hardly be generalized.     

Synthsis and mild conversion of 1,5-benzodiazepine iminothioethers into hydrazides

4-Methylthio-2,3-dihydro-1H-1,5-benzodiazepine derivatives were prepared by alkylation of tetrahydro-1H-1,5-benzodiazepine-2-thiones with iodomethane or dimethyl sufate in the presence of base or using phase-transfer catalysis. The desired 4-acyl-hydrazino-2,3-dihydro-1H-1,5-benzodiazepines resulted from the reaction of iminothioethers with hydrazides.Institute of Biochemistry, Vilnius 2600, Lithuania. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 368–372, March, 1998.