Diazepines—XXII : 13C NMR spectra of 2,3-dihydro-1,4-diazepinium salts

The ¹³C NMR spectra of a number of 2,3-dihdyro-1,4-diazepinium salts, like ¹H NMR spectra, confirm shape, and charge distribution for these compounds. The ring has a half-chair shape which is inverting rapidly at room temperature. The atoms in the conjugated portion of the ring show alternating polarity, and phenyl groups attached to these positions act, respectively, as electron-donors or electron-acceptors. A methyl substituent in the saturated portion of the ring shows equal preference for quasi-equatorial and quasi-axial conformations. Some comparisons are drawn between present results and similar results obtained with related benzene derivatives.     

1,4-氧硫杂萘-4,4-二氧化物含氟衍生物的合成

以含氟的2-(2-氯-4-硝基苯磺酰基)-1-劳基乙酮为原料,在K_OCO_3/TEBA/DMF体系中,与烷基化试剂发生烷基化-环化反应。合成六种未经文献报道的1,4-氧硫杂萘-4,4-二氧化物的含氟衍生物,利用元素分析、IR、~1H NMR、MS对其结构进行了表征。     

Über arsen-haltige heterocyclen : III. Kristalistruktur von 2,6-dimethyl-4,4-diphenyl-1,4-oxarsenaniumbromid-monohydrat

The crystal structure of the title compound has been determined from single crystal X-ray data and refined to a conventional R factor of 0.046. The coordination of the As atom is tetrahedral with a mean As—C distance of 1.92 Å. The six-membered heterocycle has chair conformation with two equatorial methyl and one equatorial and one axial phenyl substituent. The transannular 1,4-As?O distance is 3.11 Å, interactions are discussed. The connection of the structure is more van der Waals than ionic type. Some unspecific gaps are statistically occupied by one molecule of crystal water.     

Über Arsen-haltige Heterocyclen. IV. Kristallstruktur von 2,6-Dimethyl-4,4-diphenyl-1,4-oxarsenaniumnitrat

On Heterocyclic Systems Containing Arsenic. IV. Crystal Structure of 2,6-Dimethyl-4,4-diphenyl-1,4-oxarsenanium Nitrate The crystal structure of the title compound 2 has been determined from single crystal X-ray data and refined to a conventional R of 0.037. The coordination of the As atom is tetrahedral with a mean As? C distance of 191 pm. The six-membered heterocycle has chair conformation with a transannular 1,4-As…O distance of 310 pm. The conformation of the cation of 2 is quantitatively barely different from the analogous bromide compound and can be accepted as standard conformation for this type of cation. In the crystal structure the cations are connected partly by tridental bridgeing nitrate anions and mostly by VAN DER WAALS contacts.     

Synthesis of a library of 3-oxopiperazinium and perhydro-3-oxo-1,4-diazepinium derivatives and identification of bioactive compounds

The design and synthesis of a library of novel families of 3-oxopiperazinium and perhydro-3-oxo-1,4-diazepinium derivatives is reported. The library was composed of 44 3-oxopiperazinium derivatives (11 of these compounds had a spiranic skeleton) and 22 perhydro-3-oxo-1,4-diazepinium compounds. The synthetic procedure involved a 6-step sequence carried out in solution, along with the use of solid-phase linked scavengers and microwave activation for the rapid removal of the excess of amine reagents. A final cyclization step performed under mild conditions led to the charged heterocyclic moiety. Screening of this library in two biological assays identified active compounds that inhibit the activity of the vanilloid receptor TRPV1 and modulators of the multidrug resistance phenomenon. Thus, this synthetic sequence represents a facile and convenient entry to unprecedented libraries of this sort of tetraalkylammonium derivatives that may be of use for identification of novel scaffolds of diverse biological activity.     

Synthesis of 1-substituted-7-hydroxyquinolinium salts

The reaction of 7-acetoxyquinoline with trifluorosulfonate esters of primary alcohols in methylene chloride or acetonitrile, followed by acid hydrolysis, provides a general synthesis of 1-substituted-7-hydroxyquinolines, whose phenolate anions are fluorescent.     

Synthesis of N-butyloxycarbonylalanyl-1,4dioxa-7-azaspiro[4,4]nonane-8(S)-carboxylic acid ethyl ester

A four-step method has been developed for the synthesis of N-buryloxycarbonylalanyl-1,4-dioxa-7-azaspiro[4,4]nonane-8(S)-carboxylic acid ethyl ester through the formation of N-benzyloxycarbonyl-1,4-dioxa-7-azaspiro[4,4]nonane-8(S)-carboxylic acid ethyl ester.Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 663–665, May, 1996. Original article submitted January 31, 1996.     

A New and Easy Method for the Synthesis of 2-ARYL-3-ALKYL-7-NITRO-1,4-Benzoxathiin-4,4-Dioxides

Eleven new title compounds were synthesized by treatment of 1-aryl-2-(2-chloro-4-nitrophenylsulfonyl) ethanone with several alkylating reagents in K₂CO₃/TEBA/DMF system. The possible mechanism of the reaction was suggested.     

Synthesis of linear polyquaternary salts derived from 4,4′-Bipyridine

1,1″-(1,3-Propanediyl)bis-4,4′-bipyridinium dibromide is converted to 1,1″-(1,3-propanediyl)bis[1′-(3-hydroxypropyl)-4,4′-bipyridinium] tetrabromide by reaction with 1,3-dibromopropane in hot aqueous dimethylformamide. The tetraquaternary salt participates in a dequaternization and coupling reaction on treatment with hot aqueous hydrobromic acid to afford an octaquaternary salt, which is readily converted to decaquaternary and dodecaquaternary derivatives. The 1,4-butanediyl analogue participates in a similar sequence of reactions.     

Unusual cleavage of phenacyl-substituted benzimidazolium salts. Synthesis of 1,4-diarylimidazoles

The action of ammonium acetate in acetic acid on 1-alkyl(aralkyl)-3-phenacylbenzimidazolium bromides leads, in addition to the formation of a new imidazole ring, to cleavage of the benzimidazole fragment of the molecule at the 1,2 bond to give 1-alkyl(aralkyl)aminoaryl-4-arylimidazoles. 1,2-Dimethyl-3-(p-nitrophenacyl)benzimidazolium bromide is converted under similar conditions to the corresponding 2-methylimidazole. 4,4-Dimethyl-2,2-bis(p-nitrophenyl)-1,1-dipyrrolo[1,2-a]benzimidazole was isolated as a side product of this reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 388–392, March, 1982.     

Synthesis of 1,4-diphenyl-3-phenylimino-1,2-dihydro-1,2,4-triazolium hydroxide (Nitron)

1,4-Diphenyl-3-phenylimino-1,2-dihydro-1,2,4-triazolium hydroxide (Nitron) is prepared by the reaction of Pb₃O₄ with diphenylthiourea, followed by the reaction of the obtained diphenylcarbodiimide with phenylhydrazine to form triphenylaminoguanidine, whose heterocyclization yields 1,4-diphenyl-3-phenylimino-1,2-dihydro-1,2,4-triazole, which is subsequently oxidized.