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1.
我们用CNDO/Ⅱ方法UI对四甲基乙烯,偏甲基乙氧基乙烯,三甲基乙烯和丙烯睛等四个烯烃分子作了量子化学计算,它们的几何参数均采用pople标准数据。  相似文献   

2.
本文研究了8-甲氧基呋喃并[3′,2′:6,7]香豆素(简称8-MOP)与烯烃的光环合加成反应。得到一系列头-尾相接的产物。反应速率的测定说明了它是由烯烃可极化率决定的。立体化学的研究和反应速率的比较说明该反应的机理是由8-MOP三线态中C_3位对烯烃的亲电进攻,经由双自由基中间体而得到产物。  相似文献   

3.
张曼华  安静仪 《化学学报》1983,41(2):182-186
The photocycloaddition of 8-methoxypsoralen to cyclothexene and to heptene-1 was found to give 3,4-dihydrobicyclo (4,2,0) octano (7",8":3,4) 8-methoxypsoralen (4) and a mixture of 3, 4-dihydro-(1-n-pentyl) cyclobutano-(2", 3":3,4) 8-methoxypsoralen (5) and the isomer 6 respectively. Stern-Volmer plot and quenching studies indicate that the reaction proceeds via psoralen triplet excited state.  相似文献   

4.
在溴和8-甲氧基呋喃并[3′,2′∶6,7]香豆素(1,8-MOP)及NBS与1的反应中发现,溴首先在C_5取代,其次加到C_(4′,5′)双键上,最后加到C_(3,4)双键上,得到新化合物3,4,5,4′,5′-五溴-3,4,4′,5′-四氢-8-MOP(4).比较了1和香豆素对NBS反应的活性,发现NBS对香豆素不发生加成反应.这是由于1中的甲氧基和呋哺环使其对亲电试剂的反应活性比香豆素高,并由~(13)C核磁共振谱的C_3化学位移及这两个化合物中各双键的可极化率得到证实.4与二乙胺和吡啶的消除反应分别得到新化合物5和6.  相似文献   

5.
我们曾研究了8-甲氧基呋喃并[3′,2′∶6,7]香豆素(8-MOP)与环己烯的光环合加成反应.本文进一步研究了8-MOP与2,3-二氢-γ-吡喃的光环合加成反应,并将上述两个反应的产物分离、鉴定,研究了其立体化学.  相似文献   

6.
2-氯-3-氰基吡啶与巯基乙酸乙酯经闭环反应制得3-氨基吡啶并[3,′2′∶4,5]噻吩-2-甲酸乙酯(1);1与甲酰胺第二次成环生成吡啶并[3,′2′∶4,5]噻吩并[3,2-d]嘧啶-4-酮(2);2经氯化后与取代苯酚反应合成了12个新型的4-芳氧基吡啶并[3,′2′∶4,5]噻吩并[3,2-d]嘧啶衍生物,其结构经1H NMR,13C NMR,IR和元素分析表征。  相似文献   

7.
The reaction of 1,3-dimethyl-5-chloro-6-nitropyrido[2,3-d]pyrimidine-2,4-dione with CH-acids yielded 5-substituted pyridol[2,3-d]pyrimidines which were used in the synthesis of pyrrolo(2,34,5)pyrido[2,3-d]pyrimidines.For Communication 7, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 800–803, June, 1993.  相似文献   

8.
《Tetrahedron letters》1988,29(51):6681-6684
The title compound (4) was synthesized by two sequential Friedlaender condensations between pentacyclic bis(ketoester) 2 and o-aminobenzaldehyde. The dihedral angle between the two quinoline rings in 4 is 76.4°; the nonbonded NXXXN interatomic distance in 4 is 4.32 Å.  相似文献   

9.
2-R-5-Imino-6H-1,3,4-thiadiazolo[3,2-a]pyrimidin-7-ones react with aromatic and heterocyclic aldehydes in the presence of Et3N to give condensation products on the methylene group, which react with carbon disulfide to yield the corresponding 2,6-disubstituted 8-thioxo-9,9a-dihydro-1,3,4-thiadiazolo[3′,2′∶1,2]pyrimidino[5,6-d]1,3-thiazin-5-ones. Deceased. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 366–368, February, 1999.  相似文献   

10.
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12.
以1,4-萘醌为原料,合成了含硫的醌构稠杂环化合物苯并[b]萘并[2′,3′∶5,6][1,4]二噻英并[2,3-i]噻蒽-5,7,9,14,16,18-六酮(4),其结构经1HNMR和IR确证。采用波长为800nm,脉宽为80fs的Ti∶Sapphire飞秒激光,运用双光束简并四波混频法测定了4的三阶非线性光学性能,结果表明,4的三阶非线性光学极化率χ(3),非线性折射率n2,分子二阶超极化率γ和响应时间分别为2.89×10-13esu,5.31×10-12esu,3.14×10-31esu和101fs。并分析了4的分子结构对其三阶非线性光学性能的影响。  相似文献   

13.
报道了氨基磺酸作用下,通过Pictet-Spengler反应合成苯并噻吩并[3′,2′:2,3]吡啶并[4,5-d]噻唑并[3,2-a]嘧啶酮衍生物的有效合成方法.其中,该反应关键中间体7-(3-氨基苯并噻吩-2-基)噻唑并[3,2-a]嘧啶-5-酮,经由7-氯甲基噻唑并[3,2-a]嘧啶-5-酮与2-巯基苯甲腈的烷基化及Thorpe-Ziegler环化制得.该合成过程原料易得,反应条件温和,收率高,为新型稠杂环嘧啶类化合物的合成提供了简便的新途径.  相似文献   

14.
Russian Journal of Organic Chemistry - 6′,7′-Dimethoxy-N-methyl-2′,3′-dihydro-1′H-spiro[cyclopentane-1,4′-isoquinoline]-1′-carboxamide reacted with...  相似文献   

15.
New derivatives of pyrano[3,45,6]pyrido[2,3-d]pyrimidines were synthesized from ethyl 2-amino-7,7-dimethyl-7,8-dihydro-5H-pyrano[4,3-b]pyridine-3-carboxylate.A. L. Mndzhoyan Institute of Fine Organic Chemistry, National Academy of Sciences of the Republic of Armenia, Erevan. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1239–1241, September, 1999.  相似文献   

16.
The reaction of 8-hydroxy-1,3-dimethyl-4H-cyclohepta[c]furan-4-one with the ethoxymethylene derivatives of malononitrile or ethyl cyanoacetate in the presence of KOH gave noncyclic cyanovinyl derivatives as their potassium salts rather than the expected α-pyrone derivatives. They are smoothly cyclized to the target α-pyrones by refluxing with acid. The corresponding 3-benzamido-2H-pyran-2-ones can be obtained in a single vessel from the 2-aryl-4-ethoxymethylene-4H-1,3-oxazol-5-ones using the same scheme. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1632–1638, November, 2008.  相似文献   

17.
Representatives of new heterocyclic systems were obtained — pyrido[3,25,6][1,4]thiazino[3,4-c]- and pyrimido[5,45,6][1,4]thiazino[3,4-c][1,2, 4]triazines. Hydrazides of N-(pyrid-3-yl)- and N-(pyrimid-5-yl)oxamic acids were isolated and characterized. Their acylation products were investigated.For communication 45, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 559–562, April, 1993.  相似文献   

18.
本文阐明了1,3-环己二烯(1,3-CHD)与二苯并[a,j]蒽(DBA[a,j])在溶液中进行光环化加成反应时的光化学行为,并应用反应部位节点结构相关原理,提出了该反应是按对称性允许的协同过程进行的机理。我们首次观察到n4s+n4s光加成产物可以重排成n4s+n2s的光加成产物,在这个重排过程中,三线态双自由基是一个可能的中间体。  相似文献   

19.
Methods for the synthesis of 2,4-dithioxo-6,6-dimethyl-5,6-dihydro-8H-pyrano(thiopyrano)[4,34,5]thieno[2,3-d]pyrimidines have been developed.For Communication 10 see [1].A. L. Mndzhoyan Institute of Technical Organic Chemistry, National Academy of Sciences of the Republic of Armenia, Erevan 375014. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 803–804, June, 1998.  相似文献   

20.
4-羟基-6-甲基-2-吡喃酮分别与原甲酸三氯乙酯,三(溴甲基)氧磷和1,3,5-三(溴甲基)苯经取代反应制得三-2-吡喃酮(3a~3c);3a和3b分别与二苯酮(4)通过经历4的三线激发态,横穿3的C5-C6,C5'-C6'和C5″-C6″双键经固相[2+2]光环加成反应,高位置、高配向选择性地合成了4个新型的氧杂类化合物(5a,5a',5b和5b'),其结构经1H NMR,13C NMR,IR,LR-MS和HR-MS表征。  相似文献   

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