共查询到20条相似文献,搜索用时 484 毫秒
1.
The 15N NMR spectra of the O-inside cis-fused conformer of perhydropyrido[1,2-c][1,3]thiazine shows a shielding of the nitrogen of 23.0 ppm relative to the trans-fused conformer. In contrast, 15N shifts for the cis-and trans-fused conformers of perhydro-oxazolo[3,4-a]pyridine and perhydrothiazolo[3,4-a]pyridine show corresponding shieldings of only 0.6 and 2.5 ppm, respectively. 相似文献
2.
Trevor A. Crabb Roger F. Newton Janet Rouse 《Magnetic resonance in chemistry : MRC》1982,20(2):113-116
The 1H NMR parameters of the NCH2O protons in the spectrum of perhydropyrrolo[1,2-c][1,3]oxazine show its existence in solution at room temperature in the O-inside cis-fused conformation. rel-(3aS,6aS,6bR,10aS,11aS)-6a-Methylperhydroindolo[3,2,1-i,j]benzoxazine and rel-(3aS,6aS,6bS,10aR,11aS)-6a-methylperhydroindolo[3,2,1-i,j]benzoxazine are shown to adopt cis- and trans-fused conformations, respectively, for the corresponding bicyclic moiety. 相似文献
3.
The 1H NMR parameters of the NCH2O protons of the reduced pyrrolo[1,2-c][1,3]oxazine moiety in rel-(3aS,6aS,11aS)-1,3,3a,4,5,6,6a,11a-octahydro-6a-methylindolo[3,2,ij][3, 1]benzoxazine and in the alkaloid rosibiline indicate a trans ring fusion for the grouping. The O-inside cis-fused moiety is present in the related rel-(3aR,6aS,11aS)-octahydro-6a-methylindolo[3,2,1-ij][3, 1]benzoxazine and in Wieland–Gumlich glycol formal. 相似文献
4.
A series of perhydropyrido[1,2-c][1,6,3]dioxazocines and 2-alkylperhydropyrido[1,2-c][1,3,6]oxdiazocines have been prepared. 6-p-Nitrophenyl-3,4-dimethylperhydropyrido[1,2-c][1,6,3]-dioxazodioxazocine is shown to adopt the cis fused ring conformation in solution with the nitrogen lone pair axial with respect to the piperidine ring. The 2-alkylperhydropyrido[1,2-c][1,3,6]oxdiazocines adopt a similar cis fused ring conformation and with increasing steric requirement of the 2-alkyl substituent the 8-membered ring increasingly favours the chair-chair conformation, rather than the chair–boat conformation favoured by the 2-methyl substituted compound. 相似文献
5.
The reaction of 3-allylthio-5-phenyl-4H-1,2,4-triazole with iodine to give a mixture of 5,6-dihydro-5-iodomethyl-3-phenyl[1,3]thiazolo[2,3-c][1,2,4]triazole, 6,7-dihydro-6-iodo-3-phenyl-5H-[1,2,4]triazolo[3,4-b][1,3]thiazine, 5,6-dihydro-6-iodomethyl-2-phenyl[1,3]thiazolo[3,2-b][1,2,4]triazole, and 6,7-dihydro-6-iodo-2-phenyl-5H-[1,2,4]triazolo[5,1-b][1,3]thiazine has been studied. The structure of the products obtained was established using 1H NMR spectroscopy of their dehydriodination products. 相似文献
6.
From an analysis of nmr spectral data, 1,6,7,12b-tetrahydro-2H,4H-[1,3 ]oxazino[3′, 4′ :1,2]-pyrido[ 3,4-b ]indole is shown to exist in solution at room temperature almost entirely in the cis-fused ring conformation with the nitrogen lone pair bisecting the C4 methylene group whereas under the same conditions 1,2,3,6,7,12b-hexahydro-3-methyl-4H-pyrimido[3′,4′:1,2] pyrido-[3,4-b ]indole exists as an approximately 50:50 equilibrium mixture of the cis and trans-fused ring conformations. 相似文献
7.
cis(4-H,11b-H)-4-Aryl-1,6,7,11b-tetrahydro-2H,4H-[1,3]oxazino [4,3-a]isoquinoline and the related thiazino compound preferentially adopt in solution the O (or S) inside cis-conformation in contrast to cis(1-H,4a-H)-1-arylperhydropyrido[1,2-c][1,3]oxazine which adopts the trans fused conformation. 1-(β-Hydroxy-ethyl)-1,2,3,4-tetrahydro-β-carboline condenses with benzaldehyde to give the 1,3-oxazine derivative rather than the dimeric structure reported in the literature. 相似文献
8.
The positions of conformational equilibria in 1,5-, 1-6- and 1,8-dimethylperhydro-oxazolo[3,4-a]pyridines were determined by 1H NMR spectroscopy. The cis-(H-5, H-8a)-1,6-dimethyl-perhydro-oxazolo[3,4-a]pyridine. In contrast, r-1,t-6,t-8a-1,6-dimethylperhydro-oxazolo[3,4- a]pyridine preferred the cis-fused conformation. Three of the 1,8-dimethylperhydro-oxazolo[3,4-a]pyridines adopted the trans-fused conformations (with distortion of the system in the case of the r-1,c-8,c-8a derivative) and the r-1,c-8,t-8a-1,8-dimethyl derivative adopted the cis-fused conformation. 相似文献
9.
The 1H- and 13C-nmr spectra of [1]benzothieno[2,3-c]naphtho[1,2-h]quinoline and [1]benzothieno[2,3-c]-naphtho[1,2-h][1,2,4]triazolo[4,3-a]quinoline were totally assigned using a combination of two-dimensional nmr techniques. After correlation of the proton signals by a COSY spectrum and one-bond heteronuclear correlation, complete assignment of the 1H- and 13C-nmr spectra of the novel heterocyclic compounds required the application of long-range CH coupling information particularly for quarternary resonance assignments and the orientations of individual spin systems relative to one another. 相似文献
10.
Trevor A. Crabb Jacqueline S. Mitchell Christopher H. Turner 《Magnetic resonance in chemistry : MRC》1981,16(2):141-147
Seven of the possible diastereoisomeric perhydronaphthaleno[3,4-e]pyrido[1,2-c][1,3]oxazines have been synthesized and the configurations and preferred conformations of these assigned on the basis of IR and 1H NMR spectroscopy and the application of conformational principles. 相似文献
11.
P. Metzger C. Cabestaing E. Casadevall A. Casadevall 《Magnetic resonance in chemistry : MRC》1982,19(3):144-147
The 13C NMR spectra of trans- and cis-fused bicyclo[4.n.0]alkanes, where n=4, 3 and 2, were determined. The distortion of the six membered ring, which is due to the strain arising from the 1,2 fusion of cyclohexane with a smaller ring, is apparent mainly for the chemical shifts of the ring junction carbons. Both for the trans-and for the cis-fused hydrocarbons the results support a cyclohexane in a chair conformation, distorted to a different degree according to the size of the other ring. The geometries of the different compounds in the series were calculated. 相似文献
12.
Octahydroimidazo[1,5-a]pyridine is shown to preferentially adopt the trans-fused ring conformation in solution at room temperature. The NMR spectra of the rotational isomers of some N-acetyloctahydroimidazo[1,5-a]pyridines and N-acetyloctahydro-1H-pyrido[1,2-c]pyrimidine are described, and the stereochemistry about the N-acetyl bonds and the cis or trans nature of the ring fusion defined. 相似文献
13.
Britsun V. N. Esipenko A. N. Kudryavtsev A. A. Lozinskii M. O. 《Russian Journal of Organic Chemistry》2004,40(2):232-238
A new procedure for preparation of 2-R-5-aryl-5,6-dihydro-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones by condensation of 5-R-1,2,4-triazole-3-thiones with 3-arylacryloyl chlorides was developed. The thiazine ring of the [1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones is easily cleaved by treating with ammonia and hydrazine affording amides and hydrazides of 3-aryl-3-(1H-1,2,4-triazol-5-ylsulfanyl)propanoic acids. The latter react with isothiocyanates furnishing carbamoyl thiohydrazides of 3-aryl-3-(1H-1,2,4-triazol-5-ylsulfanyl)propanoic acids that in alkaline media undergo cyclization into 4-aryl-5-[2-(4H-1,2,4-triazol-5-ylsulfanyl)-2-phenylethyl]-2,4-dihydro-3H-1,2,4-triazole-5-thiones. 相似文献
14.
The reaction of the 2-(ω-aminoalkyl)imidazoles 4a-f with N-cyanodi-phenylimidocarbonate ( 7 ) leads to appropriately hydrogenated imidazo-[1,5-a]imidazoles, imidazo[1,2-c][1,3]diazepines and imidazo[1,2-c][1,3]diazocines ( 9a-f ), which are similar to (7,8-dihydroimidazo)[1,2-c]pyrimidin-5-yl)cyanamides ( 3 )[1] in respect to their chemical and spectroscopic properties. 相似文献
15.
A series of substituted hexahydropyrido [2,1-c][1,4]oxazin-4(3H)-ones has been prepared by reaction of the sodio derivative of the appropriate piperidyl carbinol with ethyl chloroacetate. From a study of their NMR spectra the configurations of these compounds have been assigned and the conformation of the perhydro-1, 4-oxazinone moiety shown to be that with the ring oxygen atom and the angular hydrogen on the same side of the plane defined by C3? C(O)? N. The synthesis and NMR spectra of hexahydro-2H-pyrido [1,2-d][1,4]oxazepin-5(4H)-one, 1,6,11,11a-tetrahydro [1,4]-oxazino [4,3-b]isoquinolin-4(3H)-one and of hexahydropyrido [2,1-c][1,4]thiazin-4(3H)-one are also discussed. cis-6,9a-H-6-Methyl-hexahydropyrido[2,1-c][1,4]oxazin-4(3H)-one is shown to exist in a conformation containing a deformed perhydropyridine ring. 相似文献
16.
Fabrizio Melani Lucia Cecchi Giovanna Palazzino Guido Filacchioni 《Journal of heterocyclic chemistry》1985,22(4):1109-1112
The synthesis of pyrazolo[4,5-c][1]benzazepin-10-ones 10 and 13 and pyrazolo[4,3-c][1]benzazepin-10-ones 11 and 12 is reported. The structure of compounds 10-13 and that of their parent compounds 2-5 ensues from a 13C nmr study. 相似文献
17.
Giovanna Palazzino Lucia Cecchi Vittoria Colotta Fabrizio Melani Guido Filacchioni 《Journal of heterocyclic chemistry》1989,26(1):71-75
The synthesis of 1,2,3,4-tetrahydropyrazolo[4,3-c][1]benzazepin-1-ones 1 and that of its 10-methyl derivative 2 is reported. The preparation of the latter from 3-(2-aminobenzyl)3-pyrazolin-5-one and triethyl ortho-formate gave as the main product a derivative of the new tricyclic ring system, pyrazolo[1,5-c][1,3]benzo-diazepine. The structures of the new compounds synthesized were assigned by means of a 13C nmr study. 相似文献
18.
Annarella Costanzo Fabrizio Bruni Gabriella Guerrini Silvia Selleri Petra Malmberg Aiello Claudia Lamberti 《Journal of heterocyclic chemistry》1992,29(6):1499-1505
The synthesis of derivatives of pyrazolo[1,5-a]pyrrolo[1,2-c][1,3,6]benzotriazocine was obtained by the reaction of arylaldehydes with some 1-(2-aminophenyl)-5-(pyrrol-1-yl)pyrazoles, as hydrochlorides. Characterization of this new class of compounds was effected with ir, pmr and 13C nmr spectral data. 相似文献
19.
A Facile Synthesis of Oxoindenothiazine and Dioxospiro(indene‐2,4′‐thiazine) Derivatives from (Substituted ethylidene)hydrazinecarbothioamides
下载免费PDF全文
![点击此处可从《Journal of heterocyclic chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alaa A. Hassan Yusria R. Ibrahim Essmat M. El‐Sheref Mahmoud A. A. Ibrahim Stefan Bräse 《Journal of heterocyclic chemistry》2015,52(4):1201-1207
(E)‐2‐[2‐(1‐Substituted ethylidene)hydrazinyl]‐5‐oxo‐9b‐hydroxy‐5,9b‐dihydroindeno[1,2‐d][1,3]‐thiazine‐4‐carbonitriles and (E)‐5‐oxo‐[(E)‐(1‐substituted ethylidene)hydrazinyl]‐2,5‐dihydroindeno[1,2‐d][1,3]thiazine‐4‐carbonitriles have been obtained from the reaction of 2‐(substituted ethylidene)hydrazinecarbothioamides with 2‐(1,3‐dioxo‐2,3‐dihydro‐1H‐inden‐2‐ylidene)propanedinitrile ( 1 ) in ethyl acetate solution. However, (Z)‐6′‐amino‐1,3‐dioxo‐3′‐substituted‐2′‐[(E)‐(1‐phenylethylidene)hydrazono]‐1,2′,3,3′‐tetrahydrospiro(indene‐2,4′‐[1,3]thiazine)‐5′‐carbonitriles were observed during the reaction of N‐substituted‐2‐(1‐phenylethylidene)hydrazinecarbothioamides with ( 1 ). The structure assignment of products has been confirmed on the basis of 1H‐, 13C‐NMR, and mass spectrometry, as well as theoretical calculations. 相似文献
20.
9,10-Dimethoxy-1,2,3,4,12,13-hexahydro-1-oxoquino[1,2-c]quinazolinium perchlorate, 1,2,3,4,13,24-hexahydro-1-oxo[1,3]dioxolo[4,5-g]quino[1,2-c]quinazolinium perchlorate, 6-methyl-2,3,9,10-tetramethoxyquino-[1,2-c]quinazolinium perchlorate and 2,3-dimethoxy-13-methyl[1,3]dioxolo[4′,5′:6,7]quino[1,2-c]quinazolinium perchlorate were synthesized as analogs of the potent antitumor benzo[c]phenanthridine alkaloids nitidine and fagaronine. The related 2,3,8,9-tetramethoxyindazolo[2,3-a]quinoline and 2,3-dimethoxy[1,3]dioxolo-[4,5-g]indazolo[2,3-a]quinoline were also synthesized. Further, the novel formation of 6,7-dimethoxy-2-(2-ethylamino-4,5-dimethoxyphenyl)quinoline via reductive alkylation with Raney nickel in refluxing ethanol is also reported. 相似文献