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1.
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. 相似文献
2.
We report here a one-step synthesis of the 4,5,6,7-tetrahydro-1H- 1,2,4,-triazolo[4,3-d][1,4]diazepine, 4-6, and 1,2,4-oxadiazolo[4,5-d][1,4]-diazepine, 7-10, by 1,3-dipolar cycloaddition of nitrile imines and nitrile oxides with 2,3-dihydro-H-1,4-diazepine, 1. In all cases these cycloaddition are peri- and regioselectives (the C ? N bond is sole affected) and occures with high yields. Structure and conformations of cycloadducts have been assigned by means of nmr analysis 相似文献
3.
The fragmentation pathways of nineteen 1,3a,5-trisubstituted 3a,4,5,11-tetrahydro- 1,2,4-oxadiazolo[5,4-d][1,5]benzothiazepines have been studied with the aid of mass-analyzed ion kinetic energy spectrometry and exact mass measurements using fast-atom bombardment ionization. All compounds show a tendency to eliminate a neutral propene, or substituted or unsubstituted styrene, from the thiazepine ring to yield 1,2,4-oxadiazolo[5,4-b][1,3]benzothiazole ions, and further undergo reverse 1,3-dipolar cycloadditions to give benzothiazole ions. The formation of stable conjugated fused tetracyclic systems, substituted 1,2,4-oxadiazolo[5,4-f]phenanthridine ions, was also observed. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
4.
Yoshihisa Kurasawa Tomoyoshi Hosaka Yuko Matsumoto Aiko Ishikura Kazue Ikeda Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1994,31(6):1697-1700
The reaction of 7-chlorotetrazolo[1,5-α]quinoxaline 5-oxide 6a with acetic anhydride gave 7-chloro-5-(7-chlorotetrazolo[1,5-α]quinoxalin-4-yl)-4,5-dihydro-4-oxotetrazolo[1,5-α]quinoxaline 7a , while the reaction of 7-chloro-1,2,4-triazolo[4,3-α]quinoxaline 5-oxide 6b with acetic anhydride afforded 7-chloro-5-(7-chloro-1,2,4-triazolo[4,3-α]quinoxalin-4-yl)-4,5-dihydro-4-oxo-1,2,4-triazolo[4,3-α]quinoxaline 7b and 7-chloro-4,5-dihydro-4-oxo-1,2,4-triazolo[4,3-α]quinoxaline 8b . The reaction of compound 6a or 6b with acetic anhydride/acetic acid provided 7-chloro-4,5-dihydro-4-oxo-tetrazolo[1,5-α]quinoxaline 8a or compound 8b , respectively. 相似文献
5.
Mamdouh A. M. Taha 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2525-2533
4-Amino-4H-3-methylthio{7H-1,2,4-triazolo[1,5-d]tetrazol-6-yl}-1,2,4-triazole-5thi-ol (1) was condensed with various substituted aromatic aldehydes or acid chlorides to yield a series of arylideneamines 2 or aroylamines 3. These were easily cyclized to the corresponding 6-aryl-3-methylthio7H-1,2,4-triazolo[1,5-d]tetrazol-6-yl-1,2,4-triazolo [3,4-b]-1,3,4-thiadiazoles (4) on treatment with palladium-on-charcoal or phosphorus oxychloride. Compounds 4 were also prepared directly via the reaction of 1 with aromatic carboxylic acids in the presence of phosphorus oxychloride. Cyclocondensation of 1 with a variety of two-carbon cyclizing reagents, namely chloroacetone, pyruvic acid, benzoylformic acid, and benzoin led to the formation of 3-methylthio{7H-1,2,4-triazolo[1,5-d]tetrazol-6-yl}-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines (5?8). Some of the newly synthesized compounds were tested for their antibacterial and antifungal activity against a variety of microorganisms. 相似文献
6.
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. 相似文献
7.
The carbodiimides 2, obtained from aza-Wittig reactions of iminophosphorane 1 with aromatic isocyanates, reacted with hydrazine to give selectively 6-amino-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-ones 5. Compounds 5 were further transformed to iminophosphoranes 6 by reaction with triphenylphosphine, hexachloroethane and triethylamine. A tandem aza-Wittig reaction of iminophosphorane 6 with isocyanate or acyl chloride generated previously unreported 3,5-dihydro-1,2,3-triazolo[4,5-d]-1,2,4-triazolo[1,5-a]pyrimidin-9-ones 10 or 12 in satisfactory yield. X-ray structure analysis of 10 g verified the proposed structure and the reaction selectivity. 相似文献
8.
Wolf-Diethard Pfeiffer Anja Bodtke Jana Mücke Annemarie Hetzheim Pavel Pazdera 《Journal of heterocyclic chemistry》1999,36(5):1327-1336
The preparation of 1,2,4-triazolo[1,5-c]quinazolines 4a-d , 5 , 8a-d by cyclocondensation of 1a-c with carboxylic acids and carboxylic anhydrides, respectively, is described. By different pathways, the 5-thioxo-5,6-dihydro-1,2,4-triazolo[1,5-c]quinazolines 4a-d react with hydrazine hydrate or amines with the formation of 5-substituted 1,2,4-triazolo[1,5-c]quinazolines 9 and 10a-d . Cyclocondensation of 9 with carboxylic acids, carboxylic anhydrides, and nitrous acid, respectively, leads to the new anellated heterocycles bis-1,2,4-triazolo[4,3-a:1,5-c]quinazoline 13 and tetrazolo [1,5-a]-1,2,4-triazolo[1,5-c]quinazoline ( 14 ). 相似文献
9.
Chebanov VA Muravyova EA Desenko SM Musatov VI Knyazeva IV Shishkina SV Shishkin OV Kappe CO 《Journal of combinatorial chemistry》2006,8(3):427-434
Multicomponent reactions (MCRs) and microwave-assisted organic synthesis (MAOS) have been used as key methods for the synthesis of fused dihydropyrimidine derivatives. The three-component condensation of 3-amino-5-alkylthio-1,2,4-triazoles with aromatic aldehydes and acetoacetamides under microwave irradiation was developed as a rapid and efficient solution-phase method for the high-yielding preparation of 7-aryl-2-alkylthio-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine-6-carboxamide libraries. In addition, the selective reduction of the formed dihydrotriazolopyrimidines to trans-trans-2-alkylthio-7-aryl-4,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]pyrimidine-6-carboxamides was established. The described synthetic protocols provide rapid access to novel and diversely substituted dihydroazolopyrimidine libraries. 相似文献
10.
将取代色满酮(1)与芳肼反应生成的腙与HNCO发生[3+2]环加成反应,加成产物(2)经氧化得到偕偶氮异氰酸酯(3).化合物3在HBF4的催化下发生环化-重排反应,得到新颖的三环系2-氧代-1,2,4-三唑并[3,2-d][1,5]苯并氧氮杂化合物5a~5g. 相似文献
11.
A. Sh. Oganisyan A. S. Noravyan M. Zh. Grigoryan 《Chemistry of Heterocyclic Compounds》2004,40(1):75-78
Novel dihydro-5H-pyrano[3',4':5',6']pyrido[2,3-d]-1,2,4-triazolo[4,3-c]pyrimidines and 1,2,3,4-tetrazolo[1,5-c]pyrimidines have been synthesized from 2-amino-3-cyano-7,7-dimethyl-7,8-dihydro-5H-pyrano[4,3-b]pyridine. 相似文献
12.
V. M. Chernyshev A. N. Sokolov D. A. Khoroshkin V. A. Taranushich 《Russian Journal of Organic Chemistry》2008,44(5):715-722
The hydrogenation of 2-amino-5-R-7-R′-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidines with NaBH4 led to the formation of 2-amino-5-R-7-R′-4,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]pyrimidines. Acylation, sulfonylation, and alkylation of these compounds depending on conditions and the reagent character occur at the amino group, atoms N3 or N4. The treatment with alkali of 2-amino-3-benzyl-5-R-7-R′-4,5,6,7-tetrahydro-1,2,4-triazolo-[1,5-a]pyrimidinium bromide resulted in 2-amino-3-benzyl-5-R-7-R′-3,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]-pyrimidine, similar reaction of 2-acetamido-3-benzyl-5-R-7-R′-4,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]-pyrimidinium bromide gave a mesoionic product of a hydrogen elimination from the amide nitrogen atom. 相似文献
13.
Yoshihisa Kurasawa Tomomi Kureyama Noriko Yoshishiba Tomoko Okano Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1993,30(3):781-787
The reaction of 7-chlorotetrazolo[1,5-a]quinoxaline 5-oxide 4a or 7-chloro-1,2,4-triazolo[4,3-a]quinoxaline 5-oxide 4b with 2-chloroacrylonitrile gave 7-chloro-4-(2-cyano-2-hydroxyvinyl)tetrazolo[1,5-a]quinoxaline 5a or 7-chloro-4-(2-cyano-2-hydroxyvinyl)-1,2,4-triazolo[4,3-a]quinoxaline 5b , respectively. Alcoholysis of compound 5a or 5b afforded 7-chloro-4-ethoxycarbonylmethylene-4,5-dihydrotetrazolo[1,5-a]quinoxaline 6a or 7-chloro-4-ethoxycarbonylmethylene-4,5-dihydro-1,2,4-triazolo[4,3-a]quinoxaline 6b , respectively. Compounds 5a,b were found to exist as a syn and anti mixture of the enol form, while compounds 6a,b occurred as the enamine and methylene imine forms. The tautoraeric character and/or D-H exchange of the vinyl protons are described for compounds 5a,b and 6a,b . 相似文献
14.
L. Kosychova Z. Stumbreviciute L. Pleckaitiene R. Janciene B. D. Puodziunaite 《Chemistry of Heterocyclic Compounds》2004,40(6):811-815
A one-pot synthetic approach to the novel 5,6-dihydro-4H-[1,2,4]triazolo[4,3-a][1,5]benzodiazepines by thermal cyclization of 4-acylhydrazino-2,3-dihydro-1H-1,5-benzodiazepines is described. 相似文献
15.
XU Jia-xi~** ZUO Gang LIANG Bo Key Laboratory of Bioorganic Chemistry Molecular Engineering of Ministry of Education Department of Chemical Biology College of Chemistry Molecular Engineering Peking University Beijing P. R. China 《高等学校化学研究》2005,21(3)
Introduction Mostimportantantibioticspossessarepresen- tativestructureofaβ-lactamfusedfive-orsix- memberedheterocyclicringcontainingnitrogenand sulfuratoms.Forinstance,theeffectiveantibi- otics,penicillin,penamandpenem,havefusedthi- azolidine-β-lactam,andtheeffectiveantibiotics, cephalosporinandcephem,arefuseddihydroth- iazine-β-lactams[1].Recently,someβ-lactam derivativeshavealsobeenrecognizedasthein- hibitorsofhumanleukocytaseelastase[2]andserine protease[3].Thesynthesisofbicyclicβ-lact… 相似文献
16.
Yoshihisa Kurasawa Yuko Matsumoto Aiko Ishikura Kazue Ikeda Tomoyoshi Hosaka Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1993,30(5):1463-1468
The reaction of 7-chloro-4-(2-cyano-2-hydroxyvinyl)tetrazolo[1,5-α]quinoxaline 2a with 4-aminopyridine, p-toluidine or p-aminophenol gave 7-chloro-4-(4-pyridylcarbamoylmethylene)-4,5-dihydrotetrazolo[1,5-α]-quinoxaline 7a , 7-chloro-4-(p-tolylcarbamoylmethylene)4, 5-dihydrotetrazolo[1,5-α]quinoxaline 8a or 7-chloro-4-(p-hydroxyphenylcarbamoylmethylene)-4,5-dihydrotetrazolo[1,5-α]quinoxaline 9a , respectively. The reaction of 7-chloro-4-(2-cyano-2-hydroxyvinyl)-1,2,4-triazolo[4,3-α]quinoxaline 2b with 4-aminopyridine, p-toluidine or p-aminophenol afforded 7-chloro4-(4-pyridylcarbamoylmethylene)-4,5-dihydro-1,2,4-triazolo-[4,3-α]quinoxaline 7b , 7-chloro-4-(p-tolylcarbamoylmethylene)-4,5-dihydro-1,2,4-triazolo[4,3-α]quinoxaline 8b or 7-chloro-4-(p-hydroxyphenylcarbamoylmethylene)-4,5-dihydro-1,2,4-triazolo[4,3-α]quinoxaline 9b , respectively. The reaction of compound 2a with 2-aminopyridine or 3-aminopyridine provided 7-chloro-4-(2-pyridyl-carbamoylmethylene)-4,5-dihydrotetrazolo[1,5-α]quinoxaline 10 or 7-chloro-4-(3-pyridyl-carbamoylmethylene)-4,5-dihydrotetrazolo[1,5-α]quinoxaline 11 , respectively. Compounds 7a,b (4-pyridylcarbamoyl) predominated as the enamine tautomer A in a trifluoroacetic acid solution, while compounds 8a,b (p-tolylcarbamoyl) and compounds 9a,b (p-hydroxyphenylcarbamoyl) coexisted as the enamine A and methylene imine B tautomers in a trifluoroacetic acid solution. Moreover, the ratio of the enamine tautomer A elevated in an order of compound 11 (3-pyridylcarbamoyl), compound 10 (2-pyridylcarbamoyl) and compound 7a (4-pyridylcarbamoyl), reflecting an order of the increase in the pKa values of the aminopyridine side chain moieties. In general, the ratio of the enamine tautomer A was higher in the basic carbamoyl derivatives 7–11 than in the neutral ester derivatives 3a,b . From these results, the basic side chain moiety of the tetrazolo[1,5-α]quinoxalines 7a-11 or 1,2,4-triazolo[4,3-α]quinoxalines 7b-9b was found to increase the ratio of the enamine tautomer A in trifluoroacetic acid media. 相似文献
17.
XUJia-xi ZUOGang LIANGBo 《高等学校化学研究》2005,21(3):274-279
Mass spectrometric behaviour of 2,2a, 3,4-tetrahydro-4-methyl-2a-phenyl-2- (thiophen-2-yl)- 1H-azeto [-2,1-d-J1-1,5-]benzothiazepin-l-one-5-oxide and 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-l-oxide/-1,1-dioxide have been studied with the aid of mass-analyzed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization. The monooxide derivatives showed a tendency to eliminate an alkene or an oxygen atom. 1H-Azeto[-2,1-d][1,5]benzothiazepin-1-one-5-oxide could also eliminate the thiophen- 2-ylketene molecule via a reverse [-2 q- 2 ~ cycloaddition. 2,3-Dihydro-2,4-diphenyl- 1,5-benzothiazepine-1-oxide/-1, 1-dioxide could eliminate SO2 or SO, respectively. The structure of 2,2a, 3, 4-tetrahydro-4-methyl-2a-phenyl-2- (thiophen-2-yl)-1H-azeto 1-2,1-d-] [1,5 -] benzothiazepin-1-one-5-oxide was identified on the basis of its fragmentation. The identification was supported by the fragmentations of model compound, 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide. 相似文献
18.
含肟醚的新型三唑并嘧啶衍生物的合成及除草活性研究 总被引:1,自引:0,他引:1
2-巯基-5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶(6)与氯乙醛或氯丙酮反应生成5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶-2-硫丙酮(硫乙醛) (7). 中间体7与O-烷基(芳基)羟胺(5)反应得到目标化合物1-(5,7-二甲基-1,2,4三唑[1,5-a]嘧啶-2-硫)乙醛-O-烷基肟醚(9), 2-(5,7-二甲基-1,2,4三唑[1,5-a]嘧啶-2-硫)丙酮O-烷基肟醚(10). 初步生物活性测试结果表明部分化合物具有较好的除草活性. 相似文献
19.
Maksim A. Kolosov Elena H. Shvets Dmitriy A. Manuenkov Sergey A. Vlasenko Irina V. Omelchenko Svetlana V. Shishkina Valeriy D. Orlov 《Tetrahedron letters》2017,58(12):1207-1210
6-Unsubstituted 7-R-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidines (R = H or Me) were synthesized via two pathways: (a) deacylation of the corresponding 5-acetyl Biginelli-like precursors in KOH/H2O and (b) reduction of the corresponding 1,2,4-triazolo[1,5-a]pyrimidines using LiAlH4. The products could be easily formylated at position 6, which is promising for the further synthesis of functionalized 6-substituted derivatives of 4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidines. In contrast, 6-acetyl-7-(4-(N,N-dimethylaminophenyl))-5-methyl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine undergoes a cascade process in KOH/H2O, leading to the formation of a 4,5,8,9-tetrahydro[1,2,4]triazolo[5,1-b]quinazoline derivative. 相似文献
20.
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. 相似文献