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1.
Ho Sik Kim Yoshihisa Kurasawa Atsushi Takada 《Journal of heterocyclic chemistry》1989,26(5):1511-1513
The reaction of 2,6-dichloroquinoxaline 4-oxide 4 with methylhydrazine gave 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide 5, whose reaction with dimethyl acetylenedicarboxylate or 2-chloroacrylonitrile resulted in the 1,3-dipolar cycloaddition reaction to afford 7-chloro-3,4-bismethoxycarbonyl-1-methyl-1,2-dihydropyridazino[3,4-b]quinoxaline 6 or 6-chloro-3-hydroxymethylene-1-methyl-2,3-dihydro-1H-pyrazolo[3,4-b] quinoxaline hydrochloride 7, respectively. 相似文献
2.
Ho Sik Kim Yoshihisa Kurasawa Chiemi Yoshii Minako Masuyama Atsushi Takada Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1990,27(4):1111-1114
The pyridazino[3,4-b]quinoxalines 6a,b and pyrazolo[3,4-b]quinoxaline hydrochloride 9 were synthesized by the 1,3-dipolar cycloaddition reaction of 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide 5 with dimethyl or diethyl acetylenedicarboxylate and 2-chloroacrylonitrile, respectively. The reaction mechanisms were postulated for the formation of 6a,b and 9 . 相似文献
3.
Pei Wang Jia-Zhen Zhao Hong-Feng Li Xiang-Ming Liang Ya-Lun Zhang Chao-Shan Da 《Tetrahedron letters》2017,58(2):129-133
We successfully explored for the first time that trifluoroacetic acid (TFA) can effectively catalyze the oxa-Pictet-Spengler reaction of secondary tryptophols and acetals to synthesize 1,3-disubstituted 1,3,4,9-tetrahydropyrano[3,4-b]indoles in high yield (up to >99%) and diastereoselectivity (>20:1). The secondary tryptophols were synthesized from indole-3-acetic acid. The one-pot synthesis of tetrahydropyrano[3,4-b]indoles was successfully developed from secondary tryptophols and in situ prepared acetals from aldehydes and trimethylorthoformate and thus the cost-efficiency of the protocol was effectively enhanced. Finally, the catalytic asymmetric synthesis of the 1,3-disubstituted tetrahydropyrano[3,4-b]indole was also demonstrated after enantioselective achievement of highly enantiopure secondary tryptophols. 相似文献
4.
The synthesis of some pyrido[3,4-b]pyrano[3,4-b]indoles ( 3 ) from 3-hydroxy-4-(3-indolyl)piperidines ( 6 ) is reported. 相似文献
5.
I. B. Starchenkov V. G. Andrianov A. F. Mishnev 《Chemistry of Heterocyclic Compounds》1999,35(4):499-508
The reactions of 5,6-diamino- and 5,6-dihydrazinofurazano[3,4-b][yrazine that produce polycyclic or highly reactive compounds
are reviewed. The furazan ring has a deactivating effect on the amine functions of these compounds.
Dedicated to Professor Henk van der Plas on his 70th birthday.
For No. 6, see [1].
Latvian Institute of Organic Synthesis, Riga LV-1006
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 564–573, April, 1999. 相似文献
6.
4-Amino-5-ethyl-4H-1,2,4-triazole-3-thiol was used as a key intermediate for the synthesis of triazolo[3,4-b][1,3,4]thiadiazines, triazolo[4,3-b][1,2,4,5]tetrazines and Schiff’s base via reactions with various hydrazonoyl halides and salicyaldehyde, respectively. Moreover triazolyl-N-N′-triazole derivatives were prepared from reaction of Schiff’s base with various hydrazonoyl halides. The structures of all the newly synthesized heterocyclic compounds were established by considering elemental analysis and spectral data. 相似文献
7.
8.
(+)-pyrido[3,4- b]homotropane (PHT) was efficiently constructed in 12 steps from N, N-diisopropylisonicotinamide. The synthesis features (i) RCM reaction in installing the homotropane skeleton, (ii) Snieckus ortho-lithiation of N, N-diisopropylisonicotinamide followed by acylation, (iii) Myer reduction of bulky tertiary amide to alcohol with LiBH 3NH 2, and (iv) utilization of L-glutamic acid to introduce and establish the requisite stereogenic centers. 相似文献
9.
Cyclodehydration of tetrazolyl γ-keto sulfides, prepared by treatment of β-halo ketones with 5-mereapto-1-substituted-1,2,3,4-tetrazoles ( 1 ), gave 1,5-diaryl-7H-tetrazolo[5,4-6 ] [1,3] thiazinium salts in reasonable yields. Reaction of 1 with epoxy bromides afforded 6-hydroxy-1-substiluled-6,7-dihydro-5H-letrazolo[5,4-b] [ 1,3]thiazinium bromides. The spectral properties of the fused thiazinium salts are discussed. 相似文献
10.
Aromatic aldehydes react with indole-2-carboxylic acid azides under acid catalysis conditions to give the corresponding 3-(-halobenzyl)indoles, which react with aliphatic and aromatic amines to give the corresponding aminobenzylindoles. The latter undergo intramolecular cyclization to dihydropyrrolo[3,4-b]indoles at room temperature and are converted to dihydropyrimido[4,5-b]indoles through the Curtius rearrangement when they are heated to 80-110°C. Acetylation of the latter products gives N- and O-acetyl derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 935–939, July, 1982. 相似文献
11.
I. B. Starchenkov V. G. Andrianov A. F. Mishnev 《Chemistry of Heterocyclic Compounds》1998,34(9):1081-1085
The reduction of 1,2,3-triazolo[4,5-e]furazano[3,4-b]pyrazine 6-oxide was investigated. By means of data from x-ray crystallographic analysis it was shown that there is a relation between the aromaticity and the structure of the obtained triazoles.For communication 5, see [1].Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1259–1264, September, 1998. 相似文献
12.
Thieno[3,4-b]pyrazines: synthesis,structure, and reactivity 总被引:1,自引:0,他引:1
Kenning DD Mitchell KA Calhoun TR Funfar MR Sattler DJ Rasmussen SC 《The Journal of organic chemistry》2002,67(25):9073-9076
A general synthetic route has been developed for the efficient preparation of 2,3-disubstituted thieno[3,4-b]pyrazines. These methods eliminate problems in the preparation of the precursor 3,4-diaminothiophene and utilize alpha-diones prepared through the reaction of the appropriate organocuprates with oxalyl chloride. This combination allows the convenient preparation of thieno[3,4-b]pyrazine and its 2,3-disubstituted analogues (where substituent = methyl, hexyl, octyl, decyl, dodecyl, and phenyl) in high yield. Characterization of the structure and reactivity of this class of compounds is also described, including the results of structural, electrochemical, and pK(a) studies. 相似文献
13.
Augusto Colombo Jordi Frigola Juan Parés Blas Andaluz 《Journal of heterocyclic chemistry》1989,26(4):949-955
The synthesis and structure elucidation of new pyrazolo[3,4-b][1,4]diazepines and pyrazolo[3,4-b]pyrazines are reported and the characterisation of isomers and tautomers by proton and carbon-13 nmr are discussed. In some case only NOE experiments allow us to identify the isomeric structure. 相似文献
14.
《Tetrahedron: Asymmetry》2004,15(12):1949-1955
Olefinic diols, prepared from (R)-(+)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde via olefination and hydrolysis, were converted into enantiomerically pure hydroxy substituted tetrahydrofuran derivatives by cyclization using N-phenylselenophthalimide and BF3. The PhSe group in the C-4 position of these tetrahydrofurans was then substituted by an allyl group using allyltributylstannane in the presence of AIBN. The selenium promoted cyclizations of the allyl tetrahydrofurans in which the OH and the allyl groups are trans to each other formed the enantiopure perhydrofuro[3,4-b]pyrans, while the cyclization of the allyl tetrahydrofurans in which the OH and the allyl groups are cis gave rise to the perhydrofuro[3,4-b]furans. These bicyclic products were finally deselenenylated with triphenyltin hydride and AIBN. 相似文献
15.
16.
Starting from the readily available 2-methyl-3-benzoylfuran, 1-phenylthieno[3,4-b]furan and 1-phenyl-seleno[3,4-b]furan were prepared. Also, starting from phenyl 3-methylindol-2-yl ketone and aryl 2-methyl-indole-3-yl ketones a series of substituted thieno[3,4-b]indoles and substituted seleno[3,4-b]indoles were prepared. 相似文献
17.
18.
A. Shafiee M. A. Ebrahimzadeh J. Shahbazi S. Hamedpanah 《Journal of heterocyclic chemistry》1998,35(1):71-75
Starting from the readily available aryl 2-methyl-5-phenyl-3-furyl ketones, 5-methyl-1H-1-phenylpyrazole-4-yl ketones and 4-methyl-2-phenyl-5-thiazolylcarboxaldehyde, a series of 2-phenyl-4-arylthieno[3,4-b]-furan, 2-phenyl-4-(p-methoxyphenyl)selenolo[3,4-b]furan, 4-aryl-1H-1-phenylthieno[3,4-c]pyrazole and 5-benzyl-2-phenylpyrrolo[3,4-d]thiazole were prepared in high yield. 相似文献
19.
20.
Yoshihisa Kurasawa Harumi Arai Kiyoko Arai Atsushi Satoh Satoyuki Ninomiya Yoshihisa Okamoto Atsushi Takada 《Journal of heterocyclic chemistry》1987,24(4):1219-1220
Novel 4-chlorophenylhydrazono-3-oxo-1,2,3,4-tetrahydropyridazino[3,4-b]quinoxalines 10a-c were synthesized by the cyclization of the α-hydrazonohydrazides 8a-c. The chlorination of 10a with phosphoryl chloride afforded 3-chloro-4-[2-(o-chlorophenyl)hydrazino]pyridazino[3,4-b]quinoxaline 12. 相似文献