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顺(反)-2,4,7-三芳基5-氧代4H-5,6,7,8-四氢苯并吡喃衍生物的合成 总被引:1,自引:1,他引:1
在酸或碱怀条件下,5,5-二甲基-1,3-环已二酮和5-芳基-1,3-环已二酮与 查尔酮首先进行Michael加成反应,进而环合为7,7-二甲基-2,4-二芳基-5-氧代- 4H-5,6,7,8-四氢苯并吡喃衍生物和含有两个手性原子的顺和反-2,4,7-三芳 基-5-氧代-4H-5,6,7,8-四氢苯并吡喃衍生物。讨论了反应机理并且通过~1H NMR光谱和NOE差谱确定其产物构型。所合成新的多氢苯并吡喃衍生物的分子结构 均经红外光谱、核磁共振光谱和元素分析予以证实。 相似文献
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以1-萘酚(6)为起始原料,经过Birch还原得到5,8-二氢-1-萘酚(7);7与乙酰 乙酸乙酯在不同条件下缩合合成了4-甲基-7,10-二氢苯并[h]香豆素(4).研究结 果表明,无氧和酸催化的反应条件对缩合反应是至关重要的.在没有酸催化的条件 下,反应生成3-乙酰基-2-羟基-6-甲基-吡喃-4-酮(8),并通过单晶X射线衍射分析 确定了产物的结构;在酸催化的条件下,除了生成产物4外,还伴随生成脱氢芳构 化产物4-甲基苯并[h]香豆素(5),而且在不同条件下二者的比例不同,其中以甲磺 酸为催化剂、在氮气保护下并加入抗氧化剂无水Na_2SO_3为最佳反应条件,化学选 择性约为70:30(4:5),收率49.1%. 相似文献
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异氰酸苯酯和N-[2-(4, 6-二甲基)-嘧啶基]-羟胺(5)反应生成1-[2-(4, 6-二甲基)-嘧啶基]-1-羟基-3-苯基脲(6)。化合物(6)在三乙胺存在下和氯甲酸乙酯反应生成2-[2-(4, 6-二甲基)-嘧啶基]-4-苯基-1, 2, 4-恶二唑烷-3, 5-二酮(1)。 相似文献
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ω-溴代芳香基乙酮与3-(D-葡萄糖-1-基)-4-氨基-5-巯基-1,2,4-三唑反应 合成了一系列新颖的3-(D-葡萄糖-1-基)-6-芳基-7H-1,2,4三唑并[3,4-b[1,3 ,4]噻二嗪.用元素分析,IR,NMR,MS对其结构进行了表征,研究了其NMR波谱特 征,并以^1H-^1H COSY,^13C-^1H COSY,COLOC二维NMR技术对其^1H NMR,^13C NMR的谱峰进行了全归属 相似文献
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A. A. Konarev 《Russian Journal of Electrochemistry》2007,43(10):1206-1210
The synthesis of 1,3-dimethyl-4-amino-5-formyluracyl, an intermediate of theophylline synthesis, was studied in an ammonium chloride medium using the electroreduction of 1,3-dimethyl-4-amino-5-nitrosouracyl to a diamino derivative with its further formylation. The electrolysis and formylation conditions were optimized. The reduction of 1,3-dimethyl-4-amino-5-nitrosouracyl was performed under the following conditions: its concentration was 12.0–13.5 %, the cathode was a Kh18N10T stainless steel gauze, the electrolysis was performed in the presence of ammonium chloride, the current density was 7.5–8.0 A/dm2, the electrolysis temperature was 40–45°C, and the formylation temperature was 71–72°C. The substance yield of overall formylaminouracyl was 81.2–83.3% and the current efficiency was 62.0–64.5%. The developed process of 1,3-dymethyl-4-amino-5-formyluracyl synthesis was evaluated at a scaled-up laboratory setup with a filter-press cell. 相似文献
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用对苯二甲醛或间苯二甲醛与5,5-二甲基-1,3-环己二酮反应,在不同条件下得到了含有双4(H)-吡喃、1,4_二氢吡啶结构单元的双一氧杂蒽衍生物、双-吖啶衍生物、以及双-AL羟基吖啶衍生物. 相似文献
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P. R. Sharma Vandana Gupta D. C. Gautam R. R. Gupta 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1483-1488
The synthesis of 7-bromo/5,6-dimethyl-4 H -1,4-benzothiazines and their conversion into sulfones is reported. The 7-bromo/5,6-dimethyl-4 H -1,4-benzothiazines were synthesized by the condensation and oxidative cyclization of 2-amino-5-bromo/3,4-dimethylbenzenethiol with g -diketones in dimethyl sulfoxide. The reaction is believed to proceed via an enaminoketone system. 4 H -1,4-Benzothiazine sulfones have been synthesized by the oxidation of 4 H -1,4-benzothiazines using 30% H 2 O 2 in glacial acetic acid. The structures of all newly synthesized compounds have been confirmed by elemental analysis and spectral studies. 相似文献
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A. A. Avetissian G. G. Tokmajian V. V. Karapetian 《Chemistry of Heterocyclic Compounds》2005,41(7):835-840
The reaction of 5,5-dimethyl-2-oxotetrahydrofuran-4-ylacetohydrazide with a series of aldehydes and ketones led to the synthesis
of systems which, according to the 1H NMR spectra, exist exclusively in the linear form. According to the mass spectra, however, in the gas phase some of the
compounds can also exist partly in the cyclic form.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 991–997, July, 2005. 相似文献
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V. P. Perevalov M. A. Andreeva L. I. Baryshnenkova Yu. A. Manaev G. S. Yamburg B. I. Stepanov V. A. Dubrovskaya 《Chemistry of Heterocyclic Compounds》1983,19(12):1326-1330
3-Bromo-1,5-dimethyl-4-nitropyrazole does not react upon heating with aqueous ammonia, while 1,5-dimethyl-3,4-dinitropyrazole under the same conditions yields 3-amino-1,5-dimethyl-4-nitropyrazole, which is formed from 3-bromo-1,5-dimethyl-4-nitropyrazole in the presence of a copper catalyst. The amination of 1-methyl-3,4-dinitropyrazole-5-carboxylic acid is accompanied by decarboxylation, which is characteristic for 4-substituted 1-methylpyrazole-5-carboxylic acids upon heating in aqueous ammonia or water. 相似文献
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L. G. Delyatitskaya M. V. Petrova S. Grinberga N. N. Tonkikh A. Ya. Strakov 《Chemistry of Heterocyclic Compounds》2000,36(6):728-732
Treatment of 3,6,6-trimethyl-4-oxo-1-(2-pyridyl)-4,5,6,7-tetrahydroindazole with sodium azide in acids gives 3,7,7-trimethyl-5-oxo-1-(2-pyridyl)-5,6,7,8-tetrahydro(4H)pyrazolo[4,3-b]azepine. Heating 1-(2-pyridyl)-3,6,6-trimethyl- and 1-phenyl-6,6-dimethyl-4-hydroxyimino-4,5,6,7-tetrahydroindazoles in polyphosphoric acid gives 1-phenyl-5,6-dimethyl- and 1-(2-pyridyl)-3,5,6-trimethyl-4-aminoindazole respectively: The reactions of the latter with 4-dimethylaminobenzaldehyde gave the 4-(4-dimethylaminobenzalamino) derivative and with 2-formyldimedone the 4-(4,4-dimethyl-2,6-dioxocyclohexylidenemethylamino) derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 830–834, June, 2000. 相似文献
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Angel Alberola Felisa Alonso Purificacin Cuadrado María Carmen Saudo 《Journal of heterocyclic chemistry》1988,25(1):235-240
4-Acyl- and 4-alkenyl-3,5-dimethylisothiazole derivatives, not available by direct electrophilic substitution [1–5] have been prepared from 3,5-dimethyl-4-isothiazolylcarbonitrile 1 and the corresponding aldehyde 2 in satisfactory yields. Both compounds, 1 and 2 , are readily obtained from 3,5-dimethyl-4-iodoisothiazole, whose preparation we have previously reported [6]. 相似文献
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N. N. Tonkikh M. V. Petrova A. F. Mishnev K. V. Ryzhanova F. M. Avotin'sh A. Ya. Strakov 《Chemistry of Heterocyclic Compounds》2000,36(7):822-829
The corresponding 2,3-substituted 4(3H)-quinazolinones were obtained in the reactions of 2-methyl- and 2-phenyl-4-oxo-3,1-benzoxazines with 1-amino-1,2,4-triazole, 4-amino-2,3-dimethyl-1-phenyl-5-pyrazolone, 2-amino-5-ethyl-1,3,4-thiadiazole, 3-amino-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazole, 1-amino-3-cyano-4,6-dimethyl-2-pyridone, and 1-amino-3-cyano-6-phenyl-4-trifluoromethyl-2-pyridone. The formation of N-benzolyanthranilamides in the reactions of 2-phenyl-4-oxo-3,1-benzoxazine with 2-amino-5-ethyl-1,3,4-thiadiazole and 1-amino-3-cyano-6-phenyl-4-trifluoromethyl-2-pyridones was exceptional. The structures of two of the products have been confirmed by X-ray crystallography.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 936–943, July, 2000. 相似文献
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K. A. Krasnov V. G. Kartsev A. S. Gorovoi V. N. Khrustalev 《Chemistry of Natural Compounds》2002,38(5):450-457
The three-dimensional structure of 1,3-dimethyl-5-(4-allyloxybenzyl)-5-cytisylmethylbarbituric acid was found by x-ray structure analysis. A conformation with proximal cytisine and 2,4,6-trioxopyrimidine moieties was observed. Analogous structures for other synthesized 1,3-dimethyl-5-arylmethyl-5-cytisylmethylbarbituric acids and their 2-thio analogs were proved and the intramolecular effects caused by mutual magnetic shielding of spatially proximal groups were studied using PMR. 相似文献