3,3-二甲基-2-(3-甲基薁乙烯基)-3H-吲哚衍生物的合成

1-甲酰基薁-3-甲酸甲酯和2,3,3-三甲基-3H-吲哚衍生物发生缩合反应,合成了一系列3,3-二甲基-2-(3-甲基薁乙烯基)-3H-吲哚衍生物,收率48%～64%,其结构经~1H NMR,IR和元素分析表征.     

1-溴乙酰基薁-3-甲酸甲酯在离子液体中的亲核取代反应

在室温离子液体[Bm im BF4]中,亲核试剂与1-溴乙酰基薁-3-甲酸甲酯进行取代反应,高选择性、高收率地生成1-取代乙酰基薁类衍生物,其结构经1H NMR,IR和元素分析确认。     

3-(2-苯并呋喃酰基)薁-1-羧酸甲酯的有效合成

以苯基三甲铵三溴盐(PTAB)为溴化试剂, 对3-乙酰基薁-1-羧酸甲酯进行了溴代反应研究, 将其单溴代产物与水杨醛在温和反应条件下进行缩合, 以极优的收率高选择性得到3-(2-苯并[b]呋喃酰基)薁-1-羧酸甲酯类衍生物, 其结构经¹H NMR, IR及元素分析等得以证实.     

1-(香豆素-3-酰基)愈创兰烃薁的合成及其抗菌活性

在醋酸铵作用下,通过1-氰乙酰基愈创兰烃薁与2-羟基苯甲醛类化合物的缩合反应,合成了一系列1-(香豆素-3-酰基)愈创兰烃薁衍生物.该反应操作简单、条件温和、收率良好.产物结构经NMR,IR,MS及元素分析数据得以证实.对所得化合物进行了抗菌活性测试,初步表明它们具有一定的活性.     

三组分一锅法合成3-(2-喹啉基)薁甲酸甲酯衍生物

在质子酸作用下, 以1-甲酰基薁-3-甲酸甲酯、芳香胺和脂肪醛为原料, 三组分一锅法合成了一系列3-(2-喹啉基)薁甲酸甲酯衍生物. 该反应收率良好、操作简单、条件温和. 产物的结构通过红外光谱、核磁共振谱和元素分析证实, 同时给出了该反应可能的反应机理.     

3-(2-取代噻唑-4-基)愈创兰烃薁的合成及抗菌活性

以3-氯乙酰基愈创兰烃薁、硫脲或硫代酰胺为原料, 一锅法合成了一系列3-(2-取代噻唑-4-基)愈创兰烃薁衍生物. 该反应收率良好、操作简单、条件温和. 产物的结构通过红外光谱、核磁共振谱和元素分析证实. 对所合成化合物进行了抗菌活性测试, 初步表明具有活性.     

新型2-苯并呋喃取代薁类衍生物的合成

以溴乙酰溴为酰化剂,对2-甲基薁进行酰基化反应,其酰化产物通过与水杨醛缩合,溴代反应及硫代乙酰胺的环化反应,以较好的收率,高选择性合成了新型的1-(2-苯并[6]呋喃酰基)薁和3-(2-苯并呋喃基)薁类[1,2-c]噻吩类衍生物,其结构经1H NMR,IR及元素分析表征.     

1-(2-氨基-3,5-二氰基-4-芳基-4H-吡喃-6-基)愈创兰烃薁的合成

在醋酸铵作用下,通过1-氰乙酰基愈创兰烃薁、芳香醛、丙二腈的三组分反应,一锅法合成了一系列1-(2-氨基-3,5-二氰基-4-芳基-4H-吡喃-6-基)愈创兰烃薁衍生物.该反应操作简单、条件温和、收率良好.产物结构经NMR,MS,IR及元素分析等得以证实.     

新型薁类-1-酰腙化合物的合成及抗菌活性研究

为了合成和研究具有薁类结构物质的新的生物活性, 以1-薁类羧酸甲酯为起始原料, 经过酰肼化、与芳香醛及酮类化合物的缩合, 合成了含有酰腙类结构的薁类衍生物, 其结构经1H NMR, IR和元素分析确证. 对所得化合物进行了抗菌活性测试, 初步表明它们具有一定的活性.     

1-{2-咪唑[1,2-a]吡啶基}愈创兰烃薁的合成

以1-氯乙酰基愈创兰烃薁和取代2-氨基吡啶为原料,一锅法合成了一系列未见文献报道的1-{2-咪唑[1,2-a]吡啶基}愈创兰烃薁衍生物,收率47%～74%,其结构经1H NMR,IR和元素分析表征。     

1,3,3-三甲基-2-亚甲基吲哚啉合成新工艺

报道了一种以N－甲基苯肼和3－甲基－2－丁酮为原料一步合成1，3，3－三甲基－2－亚甲基吲哚啉的新工艺。讨论了影响产品收率的各种因素。该新工艺具有原料易得，工艺路线较短，减少环境污染等特点。     

Synthesis of 3H[1,2]diazepino[5,6-b]indole and 3H[1,2]diazepino[4,5-b]indole derivatives

The synthesis of two new derivatives of 3H[1,2]diazepino[5,6-b]indole, 5 and 11 , and one new derivative of 3H[1,2]diazepino[4,5-b]indole, 16 , are described. Compound 5 was obtained by the reaction of methyl 2-(3-methoxycarbonyl-1-methylindole)acetate 2 , with hydrazine. Compound 11 was obtained in two ways from ethyl 2-(1-methylindole)acetate ( 8 ) by formylation and reaction with hydrazine. Compound 16 was obtained treating 3-(2-ethoxycarbonylindole)acetonitrile ( 14 ) with hydrazine.     

Haloacetylated enol ethers. 11. Synthesis of 1-methyl- and 1-phenyl pyrazole-3(5)-ethyl esters. A one-pot procedure

A one-pot synthesis of 1-methyl- and 1-phenylpyrazole-3(5)-ethyl esters 2,3a-e by the cyclocondensation of β-alkoxyvinyl trichloromethyl ketones 1a-e with methyl and phenyl hydrazine hydrochloride under mild conditions, is reported. A study using compounds 1a-e with different substituents proved that these are versatile building blocks for the synthesis of pyrazole derivatives, having a 3(5)-ethoxycarbonyl substituent in good yields (60–89%). The hydrazine and β-alkoxyvinyl trichloromethyl ketone substituent effects on the reaction regiochemistry on the formation of the 1,3- and 1,5-isomer were observed.     

Pyridazine Derivatives and Related Compounds,Part 1. Some Reactions with 4-Cyano-5,6-Diphenyl-2,3-Dihydropyridazine-3-One

4-Cyano-5,6-diphenyl-2,3-dihydropyridazine-3-onc 1 reacts with phosphorous oxychloride to give 70% of the corresponding 3-chloro derivative 2. Treating 2 with anthranilic acid in butanol, 4-cyano-2,3-diphenyl-10H-pyridazino[6,1-b]quinoxaline-10-one, 3 was obtained. Compound 1 reacts with phosphorous pentasulphide to give 3-mercapto derivative 4, which was converted by acrylonitrile to S-(2-cyanoethyl)pyridazine derivative 5. Compound 4 reacts with ethyl bromoacetate and with phenacyl bromide gave the corresponding thieno[2,3-c] pyridazine derivatives 8, 9, Alkylation of 1 with ethyl chloroacetate afforded 3-0-carbethoxymethyl derivative 10. Compound 10 reacts with amines (aniline, hydrazine) to give the corresponding amide and acid hydrazide 13, 12 respectively. Hydrolysis of 10 with sodium hydroxide gave the corresponding acid derivative 11. Treating 1 with methyl iodide, 3-0-methyl derivative 14 was obtained, which was converted by ammonium acetate/acetic acid to 3-amino-4-cyano-5,6-diphenyl pyridazine 15. Compound 1 reacts with methyl magnesium iodide gave 4-acetyl derivative 16, which was reacted with hydrazine, phenyl hydrazine and with hydroxylamine to give the substituted I H pyrazolo [3,4-c] pyridazine 17 a,b and isoxazolo [5,4-c] pyridazine 18 derivatives respectively.     

Synthesis of 4-[Alkylsulfanyl(sulfonyl)methyl]isoxazoles and -1<Emphasis Type="Italic">H</Emphasis>-pyrazoles from 3-[(Alkylsulfanyl)methyl]- pentane-2,4-diones

New 4-[(alkylsulfanyl)methyl]- and 4-[(alkanesulfonyl)methyl]isoxazoles and -1H-pyrazoles were synthesized by reactions of 3-[(alkylsulfanyl)methyl]- and 3-[(alkanesulfonyl)methyl]pentane-2,4-diones with hydroxylamine and hydrazine, phenylhydrazine, semicarbazide, or thiosemicarbazide, respectively. The heterocyclization of 3-[(alkylsulfanyl)methyl]pentane-2,4-diones with thiosemicarbazide and semicarbazide hydrochloride was accompanied by elimination of amide or thioamide group. 3-[(Alkanesulfonyl)methyl]pentane- 2,4-diones were found to exist in solution as enol tautomers; they were prepared by oxidation of the corresponding 3-[(alkylsulfanyl)methyl]pentane-2,4-diones with hydrogen peroxide in acetic acid in the presence of a catalytic amount of sulfuric acid.     

Reaction of ethyl γ-bromo-β-methoxycrotonate with carbonyl compounds. Synthesis of 4-methoxy-6-substituted-5,6-dihydro-2H-pyran-2-ones and 3-substituted 3-pyrazolin-5-ones

Ethyl β-methoxycrotonate I reacts with substituted carbonyl compounds II in benzene to give 4-methoxy-6-substituted-5,6-dihydro-2H-pyran-2-ones III. The reaction of IIIa and j with hydrazine hydrate in ethanol leads to 3-[(1′-thienyl-1-hydroxy)methyl]-5-hydroxy-1H-pyrazole (IVa) and 3-[1′-styryl-1′-hydroxy)methyl]-5-hydroxy-1H-pyrazole (IVj) in good yields. The structure of the products were assigned and confirmed on the basis of their elemental analysis and the electronic absorption, infrared and nmr spectra.     

Synthesis of some 5,6,7,8-tetrahydro-4-cinnolone derivatives and 1-methyl-3-arylacetyl-4,5,6,7-tetrahydroindazoles

2-Arylidene-3-oxo-2,3,4,5,6,7-hexahydrobenzo[b]furans 2 react with hydrazine hydrate to afford 5,6,7,8-tetrahydro-4-cinnolones. By methylation, these compounds gave the corresponding N-1 and N-2 methyl derivatives. The mesoionic compounds are obtained, accompanied by 3-arylacetyl-4,5,6,7-tetrahydroindazoles upon reaction of 2 with methylhydrazine.     

Synthesis,Characterization and Biological Activities ofN-Acyl-3-(3-pyridyl)-5-aryl-pyrazoles

Ten novel N-acyl-3-(3-pyridyl)-5-aryl-pyrazoles were synthesized by Claisen condensation of the aryl methyl ketones with ethyl nicotinate, the cyclization with hydrazine hydrate and the N-acylation with acyl chloride in turn. The structures of all the compounds synthesized were confirmed by means of Fourier transform infrared(FTIR), ¹H NMR, mass spectroscopy and elemental analysis. The biological activities of the title compounds were examined by disc diffusion method against Escherichia coli, Staphylococcus aureus, Pyricularia oryzae and Rhizoctnia solani. All the N-acyl-3-(3-pyridyl)-5-aryl-pyrazoles exhibited a certain degree of antibacterial and antifungal activities. Comparatively, compounds 3c and 3d exhibited much significant antibacterial and antifungal activities than the other pyrazole derivatives.     

Surface reaction mechanisms of hydrazine on Si(100)-2 x 1 surface: NH3 desorption pathways

Multireference as well as single-reference wave functions were adopted to study the surface reaction mechanisms of hydrazine. The initial surface mechanisms resemble those of ammonia and its methyl derivatives. MRMP2 values indicate that the lifetime of initial molecularly adsorbed species should be longer than previously suggested. High energy path as well as low energy path of subsequent surface reactions were found. The theoretical initial surface product of low energy path is consistent with the experimentally suggested structure. Both paths eventually lead to very stable surface products, which are also consistent with the experimentally suggested structures. The reaction channels of the experimentally observed NH3 desorptions were also revealed. It was shown that the high reactivity of hydrazine as compared to ammonia and its methyl derivatives is due to the high nucleophilic ability of the additional nitrogen atom of hydrazine.     

Rearrangements in the formation of pyrazolines from alkyl hydrazines and unsaturated carbonyl compounds

The isomeric composition of the 2-pyrazolines obtained by the condensation of croton aldehyde and methyl vinyl ketone with C₁–C₄ monoalkyl hydrazines has been studied by the GLC method. It has been shown that in the reaction of croton aldehyde with isopropyl hydrazine, isobutyl hydrazine, and, to a smaller extent, with methyl hydrazine, in addition to the 1-alkyl-5-methyl-2-pyrazolines the 1, 3-isomers are formed. In other cases, only one pyrazoline, corresponding to the structure of the carbonyl compound, is formed. Eight previously-unknown dialkyl-2-pyrazolines are described.