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1.
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
2.
Yoshihisa Kurasawa Tomomi Kureyama Noriko Yoshishiba Ritsuko Katoh Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1993,30(2):537-541
The reaction of 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide 8 with furfural, 3-methyl-2-thiophene-carbaldehyde, 2-pyrrolecarbaldehyde, 4-pyridinecarbaldehyde and pyridoxal hydrochloride gave 6-chloro-2-[2-(2-furylmethylene)-1-methylhydrazino]quinoxaline 4-oxide 5a , 6-chloro-2-[1-methyl-2-(3-methyl-2-thienyl-methylene)hydrazino]quinoxaline 4-oxide 5b , 6-chloro-2-[1-methyl-2-(2-pyrrolylmethylene)hydrazino]quinoxa-line 4-oxide 5c , 6-chloro-2-[1-methyl-2-(4-pyridylmethylene)hydrazino]quinoxaline 4-oxide 5d and 6-chloro-2-[2-(3-hydroxy-5-hydroxymethyl-2-methyl-4-pyridylmethylene)-1-methylhydrazino]quinoxalme 4-oxide 5e , respectively. The reaction of compound 5a or 5b with 2-chloroacrylonitrile afforded 8-chloro-3-(2-furyl)-4-hydroxy-1-methyl-2,3-dihydro-1H-1,2-diazepino[3,4-b]quinoxaline-5-carbonitrile 6a or 8-chloro-4-hydroxy-1-methyl-3-(3-methyl-2-thienyl)-2,3-dihydro-1H-1,2-diazepino[3,4-b]quinoxaline-5-carbonitrile 6b , respectively, while the reaction of compound 5e with 2-chloroacrylonitrile furnished 11-chloro-7,13-dihydro-4-hydroxy-methyl-5,14-methano-1,7-dimethyl-16-oxopyrido[3′,4′:9,8][1,5,6]oxadiazonino[3,4-b]quinoxaline 7. 相似文献
3.
Yoshihisa Kurasawa Ho Sik Kim Tae Kawano Ritsuko Katoh Atsushi Takada Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1991,28(1):199-201
The reaction of the 1,2-diazepino[3,4-b]quinoxalines 2a,b or 3a,b with N-bromosuccinimide/water resulted in ring transformation to give the 1,4-dihydro-4-oxopyridazino[3,4-b]quinoxalines 4a,b , respectively. 相似文献
4.
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
5.
Ho Sik Kim Yoshihisa Kurasawa Chiemi Yoshii Minako Masuyama Atsushi Takada Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1990,27(4):1119-1122
The isoxazolo[2,3-a]quinoxalines 11a,b and pyrrolo[1,2-a]quinoxalines 12a,b were selectively synthesized from the 2-substituted 6-chloroquinoxaline 4-oxides 10a,b . The pyrrolo[1,2-a]quinoxalines 12a,b were clarified to be produced by the ring transformation of the isoxazolo[2,3-a]quinoxalines 11a,b . The pyrrolo[1,2-a]quinoxalines 14a,b were obtained from both 2,6-dichloroquinoxaline 4-oxide 9 and compounds 12a,b . 相似文献
6.
Yoshihisa Kurasawa Ho Sik Kim Ritsuko Katoh Tae Kawano Atsushi Takada Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1991,28(3):787-792
The reaction of the hydrazones 5a-c with 2-chloroacrylonitrile produced the 1,2-diazepino[3,4-b]quinoxaline hydrochlorides 6a-c , which were transformed into the 5,6,7,13-tetrahydro-5,14-methano-16-oxo-1,5,6-benzoxadiazonino[3,4-b]quinoxalines 7a-c , respectively. The oxidation of 7a-c with diethyl azodicarboxylate afforded the 7,13-dihydro-5,14-methano-16-oxo-1,5,6-benzoxadiazonino[3,4-b]quinoxalines 8a-c , respectively. Compounds 7a-c and 8a-c were also obtained by a one-pot synthesis from 5a-c and 6a-c , respectively. 相似文献
7.
Yoshihisa Kurasawa Kaoru Yamazaki Setsuko Tajima Yoshihisa Okamoto Atsushi Takada 《Journal of heterocyclic chemistry》1986,23(1):281-282
The reactions of 3-methyl-2-oxo-1,2-dihydroquinoxaline 3 with chlorophenyl diazonium salts afforded the hydrazones 4a-c , whose chlorinations with phosphoryl chloride gave the dichlorides 5a-c . Refluxing of the dichlorides 5a-c and base in N,N-dimethylformamide provided the 1-aryl-1H-pyrazolo[3,4-b]quinoxalines 6a-c . 相似文献
8.
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
9.
Yoshihisa Kurasawa Noriko Yoshishiba Tomomi Kureyama Tomoko Okano Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1992,29(6):1653-1656
The reaction of 6-chloro-2-hydrazinoquinoxaline 4-oxide 5 with triethyl orthoformate gave 7-chloro-1,2,4-triazolo[4,3-a]quinoxaline 5-oxide 6. The reaction of compound 6 with phenyl isocyanate afforded 7-chloro-4-phenylamino-1,2,4-triazolo[4,3-a]quinoxaline 7 , while the reaction of compound 6 with phenyl isothiocyanate resulted in deoxygenation to provide 7-chloro-1,2,4-triazolo[4,3-a]quinoxaline 8. However, the reaction of compound 6 with allyl isothiocyanate effected the 1,3-dipolar cycloaddition reaction, but not deoxygenation, to furnish 9-chloro-4,5-dihydroisoxazolo[2,3-a][1,2,4]triazolo[3,4-c]quinoxalin-5-ylmethylisothiocyanate 9. Moreover, the reduction of compound 9 with iron/acetic acid resulted in ring transformation to give 11 -chloro-7-hydroxy-4-thioxo-4,5,6,7,8,9-hexahydro-1,2,4-triazolo[4,3,2- o,p][1,3]diazocino[4,5-b]quinoxaline 10 , whose acetylation afforded 5-acetyl-11-chloro-7-hydroxy-4-thioxo-4,5,6,7,8,9-hexahydro-1,2,4-triazolo[4,3,2-o,p][1,3]diazocino[4,5-b]quinoxaline 11. 相似文献
10.
11.
Ho Sik Kim Yoshihisa Kurasawa Chiemi Yoshii Minako Masuyama Atsushi Takada Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1990,27(4):1115-1117
The reaction of the 2-substituted 6-chloroquinoxaline 4-oxides 1a or 1b with 2-fold molar amount of methyl propiolate resulted in the 1,3-dipolar cycloaddition reaction to give 8-chloro-1,3-bismethoxycarbonyl-4-(piperidin-1-yl)pyrrolo[1,2-a]quinoxaline 4a or 8-chloro-1,3-bismethoxycarbonyl-4-(morpholin-4-yl)pyrrolo-[1,2-a]quinoxaline 4b , respectively. Compound 4a or 4b was transformed into 8-chloro-3-methoxycarbonyl-4-(piperidin-1-yl)pyrrolo[1,2-a]quinoxaline 5a or 8-chloro-3-methoxycarbonyl-4-(morpholin-4-yl)pyrrolo[1,2-a]-quinoxaline 5b , respectively. The structure of 4a,b was confirmed by the NOE measurement among the C1 -H , C 2-H and C 9-H proton signals of 5a,b . An additional reaction mechanism was proposed for the ring transformation of isoxazolo[2,3-a]quinoxalines into pyrrolo[1,2-a]quinoxalines. 相似文献
12.
Ho Sik Kim Eun Kyoung Kim Sung Sik Kim Yong Tae Park Young Seuk Hong Yoshihisa Kurasawa 《Journal of heterocyclic chemistry》1997,34(1):39-42
The pyridazino[3,4-b]quinoxaline 12 was synthesized by the cyclization of the α-arylhydrazonoacyl-hydrazide 11. The reaction of compound 12 with phosphoryl chloride gave pyridazino[3,4-b]quinoxaline 13, whose reactions with sodium azide or cyclic secondary amines provided pyridazino[3,4-b]quinoxalines 14,17 and 18, respectively. The acylhydrazide 15 was also cyclized to pyridazino[3,4-b]quinoxaline 16. 相似文献
13.
《Tetrahedron letters》1986,27(27):3181-3182
A simple and large scale approach to the synthesis of muscimol 7 has been developed starting from the easily available dibromoformaldoxime 1. 相似文献
14.
A facile one-pot synthesis of chromene bearing novel spiropyrrolidine-oxindoles has been accomplished by the [3+2]-cycloaddition reaction of 3-acetyl-2H-chromen-2-ones with azomethine ylides derived in situ from isatin or N-methyl isatin with sarcosine. 相似文献
15.
A. Poursattar Marjani J. Khalafy R. H. Prager 《Chemistry of Heterocyclic Compounds》2012,48(6):931-935
Several new derivatives of imidazo[1,2-a]quinoxalines have been synthesized in good to excellent yields starting from arylaminoisoxazol-5(2H)-ones and 2,3-dichloroquinoxaline through a rearrangement under mild base-catalyzed conditions. 相似文献
16.
Kwai Ming J. Cheung 《Tetrahedron letters》2010,51(45):5915-5918
We describe the synthesis of diverse pyrazoles by 1,3-dipolar cycloaddition of ethyl diazoacetate with various acetylenes in refluxing toluene. The product pyrazoles are useful starting points for preparing a diverse collection of trisubstituted pyrazole carboxamides. For aryl and heteroaryl alkynes a single product is obtained while alkyl alkynes afford a ca. 6:1 mixture of regioisomers. The observed regioselectivity for the cycloaddition step and the ease of reaction are consistent with predictions derived from computing the HOMO-LUMO energies of the reactants. 相似文献
17.
Yoshihisa Kurasawa Muneto Muramatsu Kaoru Yamazaki Setsuko Tajima Yoshihisa Okamoto Atsushi Takada 《Journal of heterocyclic chemistry》1986,23(5):1391-1394
The novel 1H-pyrazolo[3,4-b]quinoxalines (flavazoles) 9–15 were synthesized from 3-methoxycarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxaline 6 via a convenient hydrazone synthesis, and these flavazoles were clarified to have the antifungal activity. 相似文献
18.
[reaction: see text] Condensation of N-substituted glycines with chiral 3-allyl-2-formyl perhydro-1,3-benzoxazines forms an azomethine ylide that cyclizes to give octahydropyrrolo[3,4-b]pyrrole derivatives. The [3 + 2] dipolar cycloadditions are stereoespecific leading to a single diastereoisomer. The chemical yields are dependent on the reaction temperature and the presence or absence of a base. 相似文献
19.
A. Shaabani A. Rahmati A. H. Rezayan H. R. Khavasi 《Journal of the Iranian Chemical Society》2011,8(1):24-30
A one-pot, catalyst- and solvent-free approach has been developed for the stereoselective synthesis of fluorinated tetrahydropyrimido[1,2-b]benzothiazoles. The three-component condensation reaction of an aldehyde and a trifluoromethyl ??-dicarbonyl compound in the presence of 2-aminobenzothizole occurs in high yields at 90 °C. 相似文献
20.
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