芳基肟胺菊酯类化合物和1,2,4—恶二唑衍生物的合成及其…

芳基肟胺化合物与取代环丙烷羧酸酰氯在Ｅｔ３Ｎ作用下室温反应得到芳基肟胺菊酯类化合物，在甲苯中回流反应则得到含取代环丙烷基的１，２，４－恶二唑衍生物，前者在甲苯中回流，ＨＯＡｃ作催化剂时发生环化反应也生成１，２，４－恶二唑衍生物，初步生物活性测试表明这些化合物具有的杀菌和除草活性。     

2－氯／2－甲磺酰基－5－（2－苯基－4－喹啉基）－1，3，4－噁二唑化合物的合成及其亲核取代的研究

借处理２－羟基－５－（２－苯基－４－喹啉基）－１，３，二唑同ＰＣｌ＿５／ＰＯＣｌ＿３之间的反应合成了２－氯－５－（２－苯基－４－喹啉基）－１，３，４－二唑（３）和通过２－基－５－（２－苯基－４－喹啉基）－１，３，４－二唑的甲基化，然后氧化制得２－甲磺酰基－５－（２－苯基－４－喹啉基）－１，３，４－二唑（６）．并分别研究了３和６同胺、叠氮及肼的反应，得到２，５－二取代的二唑新衍生物．初步观察了部分化合物的抗菌活性．     

1－对甲苯磺酰基－2－氧代－2－苯氧基－3－芳基－1，4，2－二氮磷杂环戊－5－硫酮的合成及其除草活性

通过１－苯基－３－对甲苯磺酰基硫脲（１）与亚磷酸三苯酯和取代苯甲醛在甲苯中进行的类Ｍａｎｎｉｃｈ反应合成１－对甲苯磺酰基－２－氧代－２－苯氧基－３－芳基－１，４，２－二氮磷杂环戊－５－硫酮（２）．本文对合成过程中所涉及到的副反应进行了初步探讨，初步的生物活性测定结果表明，化合物２具有一定的除草活性。     

1－对甲苯磺酰基－3－芳基－4－苯基－1，4，2－二氮磷杂环戊－5－酮的合成及除草活性

通过１－苯基－３－对甲苯磺酰基脲与亚磷酸三苯酯和取代苯甲醛在甲苯中进行的类Ｍａｎ－ｎｉｃｈ反应合成１－对甲苯磺酰基－２－苯氧基－２－氧代－３－芳基－４－苯基－１，４，２－二氮磷杂环戊－５－酮．化合物的结构经元素分析、ＮＭＲ、ＭＳ及部分化合物的红外光谱所证实，对合成过程中所涉及到的副反应进行了初步探讨，生物测定实验表明，某些产物具有良好的选择性除草活性。     

1,2,3-三取代贫电子环丙烷衍生物与甲醇反应的研究

环丙基的化学性质类似于烯键,亲电试剂对环丙基的反应已研究得较多［１－４］．由于带多个吸电子官能基的环丙烷衍生物的合成较为困难,因此,有关亲核试剂对环丙基的反应报道较少．作者通过肿叶立德 １与米氏酸衍生物 ２的反应,简便地合成了一系列 １,２,３一三取代贫电子环丙烷衍生物３［５,６］．并用此方法高立体选择性地合成了一系列二氢呋喃衍生物［７］及γ－丁酸内酯衍生物［８］等．为弄清亲核试剂对贫电子环丙烷衍生物的反应情况,作者对亲核试剂与环丙烷类衍生物化合物３的反应作了研究．本文报道顺－１－苯甲酰基－２－对…     

利用手性N-氰乙基-2-羟基蒎烷-3-酮亚胺合成光学活性2-乙基环丙烷氨基酸

以２－羟基蒎烷－３－酮（１）与氨基乙腈缩合得到的手性酮亚胺（２）为中间体，经去质子化，在Ｐｄ（０）催化下与１，４－二氯－２－丁烯（３）发生串联反应，得到光学活性环丙烷衍生物（４），产率约为７０％，反应的非对映立体选择性（ｄ．ｅ．）为１００％．化合物４经选择性还原后水解，即可制得光学活性２－乙基环丙烷氨基酸，产物的对映体过量（ｅ．ｅ．）为３３％．     

2,5—取代—1,3,4—恶二唑化合物库的固相合成

本文使用组合化学方法以聚苯乙烯亚磺酸钠树脂为载体合成了２，５－取代－１，３，４－恶二唑化合物库。树脂１首先与溴代乙酸乙酯反应聚合物支载的乙酸酯。肼解后所得的肼树脂进一步与取代的苄氯反应得双酰肼树脂。树脂４与三氯氧磷回流得聚合物支载的２，５－取代－１，３，４－恶二唑。     

2，4－二羟基－3－芳氨基甲基苯乙酮和8－乙酰基－3－芳基－3，4－二氢－5－羟基－2H－1，3－苯并■嗪的合成及其相互转化

研究了在氯化氢－乙醇溶液或乙醇溶液中，２，４－二羟基苯乙酮与甲醛和芳胺的Ｍａｎｎｉｃｈ反应，分别得到了５个２，４－二羟基－３－芳氨基甲基苯乙酮和５个８－乙酰基－３－芳基－３，４－二氢－５－羟基－２Ｈ－１，３－苯并嗪新化合物。用元素分析、ＩＲ、１ＨＮＭＲ、ＭＳ、ＵＶ确定了它们的结构，并成功地实现了２，４－二羟基－３－芳氨基甲基苯乙酮和８－乙酰基－３－芳基－３，４．二氢－５－羟基－２Ｈ－１，３－苯并嗪二类化合物的转化。     

2—氯／2—甲磺酰基—5—（2—苯基—4—喹啉基）—1,3,4—恶二唑…

借处理２－羟基－５－（２－苯基－４－喹啉基）－１，３，４－恶二唑同ＰＣｌ５／ＰＯＣｌ３之间的反应合成了２－氯－５－（２－苯基－４－喹啉基）－１，３，４－恶二唑（３）和通过２－Ｙｕ基－５－（２－苯基－４－喹啉基）－１，３，４－恶二唑的甲基化，然后氧化制得２－甲磺酰基－５－（２－苯基－４－喹啉基）－１，３，４－恶二唑（６）。并分别研究了３和６同胺、叠氮及肼的反应，得到２，５－二取代的恶二唑新衍生物。初     

半合成头孢菌素和青霉素新衍生物的研究

将５－芳基－２Ｈ－四唑乙酰氯分别和头孢菌素母体７－ＡＣＡ，７－ＡＤＣＡ以及青霉素母体６－ＡＰＡ反应制得９种７β（５－芳基－２Ｈ－四唑乙酰胺基）头孢菌素衍生物和１种６β（５－芳基－２Ｈ－四唑乙酰胺基）青霉素衍生物，将２－苯基－４－喹啉甲酰氯分别和７－ＡＣＡ、７－ＡＤＣＡ及６－ＡＰＡ反应制得２种７β（２－苯基－４－（喹啉甲酰胺基）头孢菌素化合物，１种６β（２－苯基－４－喹啉甲酰胺基）青霉素衍生物。粗产     

Reactions of 1,2,4-Oxadiazole[4,5-a]piridinium Salts with Alcohols: the Synthesis of Alkoxybutadienyl 1,2,4-Oxadiazoles

1,2,4-Oxadiazole[4,5-a]piridinium salts add alcohols and alkoxides to undergo electrocyclic ring opening affording alkoxybutadienyl 1,2,4-oxadiazole derivatives. The pyridinium salts represent a special class of Zincke salts that are prone to rearrange to give alkoxybutadienyl 1,2,4-oxadiazoles when treated with suitable nucleophiles or, alternatively, to give pyridones in the presence of bicarbonate. The pivotal tuning of the experimental conditions leads to a straightforward synthesis of valuable 1,2,4-oxadiazole derivatives. The mechanism is also discussed in the light of previous observations.     

On the dichotomic behavior of the Z-2,4-dinitrophenylhydrazone of 5-amino-3-benzoyl-1,2,4-oxadiazole with acids in toluene and in dioxane/water: rearrangement versus hydrolysis

The mononuclear rearrangement (MRH) of the Z-2,4-dinitrophenylhydrazone (4a) and of the Z-phenylhydrazone (4b) of 5-amino-3-benzoyl-1,2,4-oxadiazole into the relevant triazoles 5a and 5b in toluene has been quantitatively investigated in the presence of trichloroacetic acid (TCA) and of piperidine at 313.1 K. While the behavior in the presence of piperidine recalls the one previously evidenced for some Z-hydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole, the study of the reactivity in the presence of TCA has most interestingly evidenced a general-acid-catalyzed rearrangement for "both" 4a and 4b. Thus, 4a offers the first example of a solvent-dependent dichotomic behavior in MRH processes on 1,2,4-oxadiazole derivatives as far as it undergoes an "acidic hydrolysis" in dioxane/water and a "rearrangement" in toluene.     

Electrocyclic Ring-Opening of 1,2,4-Oxadiazole[4,5-a]piridinium Chloride: a New Route to 1,2,4-Oxadiazole Dienamino Compounds

1,2,4-Oxadiazole[4,5-a]piridinium chloride adds nucleophiles to undergo electrocyclic ring opening affording 1,2,4-oxadiazole dienamino derivatives. These pyridinium salts represent a special class of Zincke salts that are prone to rearrange when treated with primary amines or in the presence of bicarbonate to give the pyridones. The pivotal tuning of the experimental conditions leads to a straightforward synthesis of valuable 1,2,4-oxadiazole dienamine derivatives. The mechanism is also discussed in the light of NMR experiments and theoretical calculations.     

Reactions with heterocyclic amidines 1. Cyanoethylation of cyclic amidines

2-Amino-5-phenyl-1,3,4-oxadiazole ( 1a ) and 2-amino-1,3,4-thiadiazole ( 1b ) reacted with acrylonitrile to yield β-cyanoethylamino derivatives. On the other hand, 2-amino-4-phenylthiazole ( 2 ) reacted with acrylonitrile under the same experimental conditions to yield a di-β-cyanoethylaminothiazole derivative. 3-Phenyl-Δ²-1,2,4-triazoline-5-thione reacted with acrylonitrile to yield the corresponding adduct. The structure of the adduct was established by its conversion into the acid 13 which could be synthesised via another independent route.     

Examination of the dipolarophilicity of ethylene and nitrile functions in the cycloaddition of mesitonitrile oxide to isopropylidenemalononitrile

Mesitonitrile oxide reacts with isopropylidenemalononitrile to give mono- and bis-1,2,4-oxadiazole derivatives 2 and 3 and Δ²-soxazolines 4 and 5 in moderate yields. The dipolarophilic character of the ethylene and nitrile functions in these cycloadditions is examined.     

Synthesis,characterisation and mesomorphic behaviours of non-symmetrically substituted 1,2,4- and 1,3,4-oxadiazole derivatives

Two series of non-symmetrically substituted bent-core mesogens derived from the central 3,5 and 2,5 cores of the 1,2,4- and 1,3,4-oxadiazole derivatives, respectively, containing ether and ester linkage have been synthesised by several straightforward synthetic procedures, and their mesomorphic behaviour was studied by optical polarising microscopy (OPM) and differential scanning calorimetry (DSC). The last five homologues of the 1,2,4-oxadiazole series exhibit a monotropic nematic phase on cooling, while the 1,3,4-oxadiazole derivatives do not show any liquid crystalline properties but rather a crystal to isotropic transition is observed by OPM. We show that the bent angles of the 1,2,4- and 1,3,4-oxadiazole rings are crucial in observing the liquid crystal (LC) phases formed, and also that the length of the alkyl substituent is observed to have a significant effect on the nature of the LC phases.     

A New Route to Synthesis of 3,6-Diaryl-1,2,4- triazolo [ 3,4-b ] 1,3,4-oxadiazoles

Various 1,2,4-triazoles and 1,3,4-oxadiazole derivatives have been reported to possess diverse biological activities.In addition to above biological activity, we coupled these two rings together to get 1,2,4-triazolo[3,4-b] 1,3,4-oxadiazole derivatives. This ring system was first reported in 1961[1] and synthesized in 1971.     

Synthesis of some N-alkylated 1,2,4-triazoles, 1,3,4-oxadiazoles,and 1,3,4-thiadiazoles based on N-(furan-2-yl-methylidene)-4,6-dimethyl-1H-pyrazolo-[3,4-<Emphasis Type="Italic">b</Emphasis>]pyridine-3-amine

N-(Furan-2-ylmethylidene)-4,6-dimethyl-1H-pyrazolo[3,4-b]pyridine-3-amine was prepared and alkyla- ted with the corresponding halo compounds to afford N-alkylated products. 2-[3-(Furan-2-ylmethy- lideneamino)-4,6-dimethyl-1H-pyrazolo[3,4-b]pyridin-1-yl]acetohydrazide was converted into the key intermediate thiosemicarbazide, which undergoes cyclization reactions under acidic and basic conditi- ons to give 1,2,4-triazole, 1,3,4-oxadiazole, and 1,3,4-thiadiazole derivatives. Condensation of the hyd- razide with monosaccharide aldoses gave the corresponding sugar hydrazones, which on treatment with acetic anhydride readily undergo cyclization reaction to afford oxadiazoline derivatives.     

Oxidation of aldehyde semicarbazones with lead dioxide: Application to the syntheses of 2-amino-1,3,4-oxadiazoles and 2,4-dihydro-1,2,4-triazol-3-ones

The oxidation of aldehyde semicarbazones with lead dioxide in acid media was effected. The 4,4-disubstituted semicarbazones of aromatic aldehydes afford 2-amino-1,3,4-oxadiazole derivatives. The 2,4-disubstituted semicarbazones give 2,4-dihydro-1,2,4-triazol-3-ones, often in higher yields than the known methods. The mechanisms for the formation of these compounds are proposed.     

1,2,4-噁二唑类化合物的合成及抗菌活性研究

以对溴苯腈为原料,通过多步反应合成了一系列3-(吗啉苯基)-5-取代-1,2,4-异噁唑类化合物和3-(吗啉苯基)-5-取代-4,5-二氢-1,2,4-噁二唑类化合物,并用1HNMR、13C NMR和MS进行了结构确证。这些化合物对测试的部分革兰氏阳性菌,如金黄色葡萄球菌、耐甲氧西林金黄色葡萄球菌、表皮葡萄球菌、粪肠球菌显示出一定的抗菌活性,但与噁唑烷酮类上市药物利奈唑胺相比,抗菌活性有明显下降。这一结果表明对于化合物的抗菌活性,1,2,4-噁二唑杂环不如噁唑烷酮结构有效。