Synthesis of perhydropyrazino[1,2-d][1,4]diazepine,a new heterocyclic compound

A novel heterocycle, perhydropyrazino[1,2-d][1,4]diazepine, is prepared in good yield by an efficient method starting from facile available compounds.     

Pyirolothieno[1,4]diazepines. Part IV. First synthesis of pyrrolo-[1,2-a]thieno[2,3-f][1,4]diazepine Derivatives

Treatment of 3-(2-formyl-1H-pyrrol-1-yl)-2-thiophenecarboxamide by various nucleophiles like methyl ketones, amines, alcohols, thiols or acetates led to new 5,6-dihydro-4H-pyrrolo[1,2-a]thieno-[2,3-f][1,4]diazepines.     

Cyclisations intramoléculaires: Accés aux 9-oxo-4H,9H-pyrrolo[1,2-a]thieno[2,3-d]pyridine et 4-oxo-4H,9H-pyrrolo[1,2-a]thieno[2,3-d]pyridine. Synthèse des pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine et pyrrolo[1,2-a]thieno[2,3-e][1,4]diazepine

Synthesis of 1-(2- or 3-thienylmethyl)methyl)pyrrole and some derivatives are described from halogenomethylthiophenes. The intramolecular cyclisation of carboxylic acid 19 and 20 leads to pyrrolothienopyridines 22 and 23. On the other hand azide-aldehydes 29 and 30 in aqueous acid mixture gave the pyrrolo[1,2a]thieno[2,3-e][1,4]diazepine.     

Triazolobenzodiazepine Derivative (III): Synthesis of s-Triazolo-[4,3-a]-benzimidazolo-[1,2-d][1,4]-benzodiazepines

A 7H-benzimidazolo-[1,2-d] [1,4]-benzodiazepin-6(5H)-one was isolated in high yield from a condensation reaction of 2-(o-aminophenyl)benzimidazole with bromoacetyl bromide. The reactivity of 7H-benzimidazolo-[1,2-d] [1,4]-benzodiazepin-6(5H)-one have been studied.     

Bis(dibenzo[c.e][1,2]oxaphosphorino)dichloroplatinum Complexes

Reaction of a series of P-amino and P-cycloalkoxy dibenzo[c.e][1,2]oxaphosphorines (1), (3) and (5) with cis-bis(benzonitrile)dichloroplatinum(II) afforded the title bis(dibenzooxaphosphorino) complexes (2), (4) and (6), respectively. In the case of chiral P-substituents, the complexes (4) and (6) were obtained in homo and heterochiral forms. Stereospecific ¹J(¹⁹⁵Pt–P) couplings found in the ³¹P-n.m.r. spectra of the products (2), (4) and (6) suggested the cis orientation of the identical substituents.     

Generation of 4,5-Diazacyclopentane-1,3-diyl Radical Cations by Chemical Electron Transfer (CET) Oxidation of Urazole-Bridged Bicyclic Housanes (Bicyclo[2.1.0]pentanes) and Their Chemical Transformations

4,5-Diazacyclopentane-1,3-diyl radical cations 3(*)(+)() were generated from urazole-bridged bicyclic housanes 3 through chemical oxidation by using tris(4-bromophenyl)aminium hexachloroantimonate as oxidant to afford the two olefinic products 4 and 5. Product studies establish that the bisolefins 5 are the result of double oxidation of the housanes 3, whereas the monoolefins 4 are formed by acid-catalyzed rearrangement, which can be suppressed by excess of base (2,6-di-tert-butylpyridine). In the case of dibenzyl substitution (3c), disproportionation of two monoradical species 5(H)c(*) serves as an alternative pathway to the corresponding olefins 4 and 5 because higher amounts of double oxidation product were isolated in the absence of base than expected if only a stoichiometric reaction were operating. Semiempirical MO calculations suggest that ionization takes place from one of the nitrogen lone pairs rather than from the strained central C-C bond as implied by the significantly lower (by ca. 0.5 eV) ionization potential. Furthermore, in the initially puckered radical cation, the positive charge is mainly located at the two nitrogen atoms, while after relaxation to the planar geometry, the charge shifts essentially entirely to the radical cation carbon atoms. The trapping reaction with methanol leads to the hemiaminal-type products 6 and 7, which establish the involvement of the cationic intermediates 3(H)(+)() and 5(H)(+)(). In addition, (13)C NMR spectroscopy confirmed these cationic intermediates [3(H)(+)() and 5(H)(+)()] by detection of the characteristic signals below delta 250 for carbenium ions. Unquestionably, the urazole ring significantly influences the radical cation reactivity of the housanes 3. Thus, in contrast to the corresponding homocyclic tricyclooctane derivatives, stoichiometric instead of catalytic amounts of CET oxidant are needed, the two nitrogen atoms of the hydrazino bridge stabilize the radical cation 3(*)(+)() by conjugation, and the carbonyl groups of the urazole moiety assist the deprotonation to the exocyclic double bonds to prevent 1,2 alkyl migration.     

Synthesis of new imidazo[4,5-d][1,3]diazepine derivatives from 5-amino-4-(cyanoformimidoyl)imidazoles

N¹-[(Z) -2- Amino-1,2-dicyanovinyl]formamidines 1a-d react readily with tosyl isocyanate to form novel 8-amino-3-substituted-5-oxo-7-tosylaminoimidazo[4,5-d][1,3]diazepines 6a-d rather than the 6-cyano-2-oxopurine derivatives 5a-d expected. Compound 5a has been synthesized from 1a by reaction with ethyl chloroformate and base-catalyzed cyclization of the resultant 5-ethoxycarbonylamino-4-(cyanoformimidoyl)imidazole. Treatment of the 5-amino-4-cyanoimidazoles 7a and b with tosyl isocyanate under similar conditions gives the 4-cyano-5-(3′-tosylureido)imidazoles 8a and b , which on treatment with ethanolic ammonia cyclizes to the corresponding isoguanines 10a and b .     

Platinum(II) complexes of 2-alkoxy-dibenzo[c.e][1,2]oxaphosphorines

2-Alkoxy-dibenzo[c.e][1,2]oxaphosphorines were prepared by the reaction of chloro-dibenzooxaphosphorine with alcohols and were converted to the cyclic phosphonates by oxidation and to the corresponding phosphonous boranes by reaction with borane-dimethylsulfide. Interaction of the alkoxy-dibenzooxaphosphorines with dichlorodibenzonitrileplatinum led to bis(dibenzooxaphosphorino)dichloroplatinum complexes exhibiting the P-ligands in the cis disposition. Relative energetics for the prepared cis and the theoretically possible trans isomers of the complexes along with their stereostructures were investigated by quantum chemical calculations.     

Synthesis of [1,2,5]selena(or thia)diazolo[3,4‐e][1,4]diazepines, [1,2,5]selena(or thia)diazolo[3,4‐e][1,4]oxazepines and [1,2,5]selena(or thia)diazolo[3,4‐c] [1,2,6]thiadiazines

Novel heterocycles [1,2,5]selenadiazolo[3,4‐e][1,4]diazepines 3a‐c , [1,2,5]thiadiazolo[3,4‐e]‐[1,4]diazepines 7a‐c , [1,2,5]selenadiazolo[3,4‐e][1,4]oxaepines 4a,b , [1,2,5]thiadiazolo[3,4‐e]‐[1,4]oxazepines 9a‐c and [1,2,5]selena(or thia)diazolo[3,4‐c][1,2,6]thiadiazines 10a,b were synthesized starting form 4,6‐dimethyl[1,2,5]se]enadiazolo[3,4‐d]pyrimidine‐5,7(4H,6H)‐dione 1 or 4,6‐dimethyl‐[1,2,5]thiadiazolo[3,4‐d]pyrimidine‐5,7(4H,6H)‐dione 5 .     

Heterocycles containing nitrogen and sulfur. Part 49. Synthesis of derivatives of new heterocyclic systems: 1,2-Dioxocyclopenta(hexa)[g]oxazolidino-[3,2-f] pyrimido[4,5-b][1,4]thiazine, 1,2-dioxocyclopenta(hexa)-[g] imidazolidino[3,2-f]pyrimido[4,5-b][1,4]thiazine, and 1,2-oxazino[5,4-g]pyrimidino[4,5-b][1,4]thiazine

The reaction of 4-methoxy-5-amino-6-mercaptopyrimidine with 2-oxo-1-chlorocyclopentyl(hexyl)glyoxalate esters gave derivatives of the previously unknown tetracyclic systems 1,2-dioxocyclopenta (hexa)[g]oxazolidino[3,2-f]pyrimido[4,5-b][1,4]thiazines, which are transformed by ammonium acetate into derivatives of 1,2-dioxocyclopenta(hexa) [g]imidazolidino[3,2-f]pyrimido[4,5-b]-[1,4] thiazines. Derivatives of the new tricyclic 1-oxazino [5,4-g]pyrimido[4,5-b][1,4]thiazine system were obrtained by reaction of 6-carbethoxy-7-acetylpyrimido [4,5-b] [1,4] thiazines with hydroxylamine.     

First Total Synthesis of (Z)-11-(2-oxopropylidene)-2,3,11,11a-tetrahydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepin-5(10H)-one

The first total synthesis of naturally occurring (Z)-11-(2-oxopropylidene)-2,3,11,11a-tetrahydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepin-5(10H)-one,a unique cycloanthranilylproline derivative, has been achieved from readily available anthranilic acid in five steps.     

Mass Spectral Fragmentation Patterns of 11-(o- and p-R-Anilino)-5H-dibenzo[b,e][1,4]diazepines. IV

The mass spectral fragmentation patterns of eleven 11-(o- and p-R-anilino)-5H-dibenzo[b,e][1,4]diazepines obtained by electron impact have been studied. All the spectra analyzed contain molecular ions, which are base peak for para isomers and the principal fragmentation routes takes place either from the molecular ion, or from (M⁺ - 1) ion. There are, however, some deviations from the general fragmentation pattern in the case of 1,4-dibenzodiazepines with o-amino and p-methoxy substituents caused by direct interaction of these groups with the dibenzodiazepine ring.     

Preparation of a discotic 2,4,7,9-tetraaryl-6H-dibenzo[c,e][1,2]thiazine and generation of a persistent Radical 1

6H-Dibenzo[d,e][1,2]thiazine substituted with four 3,4-dioctyloxyphenyl groups forms a room temperature discotic phase with a clearing temperature of 104°C. Oxidation of the thiazine 2b with either metal oxides (PbO₂ or AgO) or SO₂Cl₂ gave a moderately stable radical 1b (a _N = 0.95 mT, g = 2.0045). Full conversion of 2b to 1b was observed with AgO in a toluene/MeCN mixture or with SO₂Cl₂. The radical 1b was isolated in the neat form with the latter oxidant. It shows sensitivity to molecular oxygen, which hampered its purification and subsequent thermal and magnetic studies.     

Two routes to (11,12)-dihydrodibenzo[c,g][1,2]dithiocine

The title compound is made by two routes. One route features the separate introduction of two sulfur atoms and a double Pummerer reaction while the other route contains a direct introduction of both sulfur atoms using disulfur diimidazole.     

用核磁共振方法表征6(8)氨基-3H苯[1,2]氧嗪-1,4-二酮

用一维1HNMR、13CNMR方法研究了6(8)氨基-3H苯[1,2]氧嗪-1,4二-酮的结构,并通过二维1H-1H同核相关谱(COSY)、13C-1H异核相关谱(HMQC)及13C-1H异核远程相关谱(HMBC)进一步确定了该类化合物的1H谱和13C谱中各谱峰的归属,为研究同类化合物表征提供了依据。     

Tetracyclic systems: Synthesis of isoindolo[1,2-b]thieno-[2,3(3,2 or 3,4)-e][1,3]thiazocines and Isoindolo[2,1-a]thieno-[2,3(3,2 or 3,4)-f][1,4] and [1,5]diazocines

Cyclization of thioglycolic acids derivatives 3a-d gave isoindolo[1,2-b]thieno[2,3(3,2 or 3,4)-e][1,3]-thiazocines 4a-d . Isoindolo[2,1-a]thieno[2,3(3,2 or 3,4)-f][1,4] or [1,5]diazocines 10b or 11a-c were synthesized from Beckmann or Schmidt rearrangement of the ketones 7a-c .