Some 1-aroyl-4,4-dialkylsemicarbazides and their cyclization to afford 5-aryl-1,3,4-oxadiazol-2(3H)-ones

Some 1-aroyl-4,4-dialkylsemicarbazides have been prepared by reacting aroylhydrazides with dimethyl- or diethyl-carbamoyl chloride. In boilingDMF they lose dimethylamine or diethylamine to give 5-aryl-1,3,4-oxadiazol-2(3H)-ones.

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Einige 1-Aroyl-4,4-dialkylsemicarbazide und ihre Cyclisierung zu 5-Aryl-1,3,4-oxadiazol-2(3H)-onen (Kurze Mitteilung)

Zusammenfassung Es wurden mittels Reaktion von Aroyl-hydraziden mit Dimethyl- oder Diethyl-carbamidsäure-chlorid einige 1-Aroyl-4,4-dialkylsemicarbazide dargestellt. Diese verlieren in kochendemDMF Dimethylamin bzw. Diethylamin und geben 5-Aryl-1,3,4-oxadiazol-2(3H)-one.

     

Synthesis of 3-(3-Acetyl-5-aryl-2,3-dihydro-1,3,4-oxadiazol-2-yl)chromones

A method is proposed for the synthesis of 3-(3-acetyl-5-aryl-2,3-dihydro-1,3,4-oxadiazol-2-yl)chromones which consists of the conversion of 3-formylchromones to aroylhydrazones and their subsequent heterocyclization using acetic anhydride.     

Synthesis, structure and antifungal activity of new 3-[(5-aryl-1,3,4-oxadiazol-2-yl)methyl]benzo[d]thiazol-2(3H)-ones

A series of new 3-[(5-aryl-1,3,4-oxadiazol-2-yl)methy])benzo[d]thiazol-2(3H)-ones were synthesized by reaction of (5-substituted-2-oxobenzothiazolin-3-yl)-acetohydrazide with various aromatic acids in POCl(3) under reflux conditions. The structures of the title compounds were confirmed by 1H-NMR, 13C-NMR, IR, MS and elemental analysis. Furthermore, the structure of compound 4i was determined by single-crystal X-ray diffraction. The preliminary bioassy results indicated that some of them showed moderate inhibition activity against Colletotrichum orbiculare, Botrytis cinerea and Rhizoctonia solani.     

Efficient Synthesis of 1,4-Bis(5-aryl-1,3,4-oxadiazol-2-yl)-2,3,5,6-tetrafluorobenzenes

Russian Journal of Organic Chemistry - An efficient acid-catalyzed condensation between substituted benzohydrazides and 2,3,5,6-tetrafluoroterephthalic acid to form...     

N-1,3,4-(口恶)二唑基-N′-呋喃甲酰基硫脲的合成及杀菌活性研究

将呋喃环、1,3,4-(口恶)唑环2个杂环同时引入到酰基硫脲中,合成了10个未见报道的酰基硫脲类化合物. 所有化合物的结构均经元素分析、红外光谱、核磁共振氢谱和质谱确认. 抑菌法生物活性测试表明,各目标产物对黄瓜灰霉病菌的抑制效果较好,最高可达97%.     

Cyclic transformations of 5-aryl(or benzyl)-3-(2-bromoethyl- 1,3,4-oxadiazol-2(3H)-ones into 1-aminoimidazolidin-2-one and 5,6-dihydro-4H-1,3,4-oxadiazine derivatives

5-Aryl(or benzyl)-3-(2-bromoethyl)-1,3,4-oxadiazol-2(3H)-ones 3 have been prepared. They were reacted with secondary alkylamines without any change of the heterocycle to give amino derivatives 6 , but with primary alkylamines, cyclic transformation occurred to give 1-acylamino-3-alkylimidazolidin-2-ones 7 . In the presence of sodium alcoholate, bromo compounds 3 were transformed into 2-aryl(or benzyl)-4-alkoxycarbonyl-5,6-dihydro-4H-1,3,4-oxadiazines 9 .     

Synthesis of 3-(5-Aryl-1,3,4-oxadiazol-2-yl)chromones

A general method was proposed for the synthesis of 3-(5-aryl-1,3,4-oxadiazol-2-yl)chromones starting from 3-formylchromone. This aldehyde yields acylhydrazones, from which the corresponding unstable nitrile imines are generated. These intermediates undergo intramolecular 1,3-dipolar cycloaddition.     

Synthesis of 3(2- and 4-Pyridinyl)-1,3,4-oxadiazol-2(3H)ones

The synthetic objective of preparing halo- and halo- plus alkoxy-substituted pyridyloxadiazolones was achieved by allowing an alkali metal salt of an oxadiazolone to displace a leaving group on a halo- or halo- plus alkoxy-substituted pyridine, respectively. Other routes failed to give the desired compounds, and they are briefly discussed.     

Synthesis of 3-(5-Aryl-1,3,4-oxadiazol-2-yl)chromones

A general procedure was proposed for the synthesis of 3-(5-aryl-1,3,4-oxadiazol-2-yl)chromones by reaction of 3-formylchromone with aroylhydrazines, transformation of the corresponding acylhydrazones into 1,3-dipoles by the action of bromine in the presence of sodium acetate, and intramolecular ring closure.     

A facile synthesis of 2-substituted-4-(substituted)phenyl-Δ2-1,3,4-oxadiazolin-5-ones

The title compounds, 3, are formed at ambient temperature from 4,4-dimethyl-2-(substituted)-phenylsemicarbazides (1) and carboxylic acid chlorides in the presence of triethylamine. 2-Dimethylamino-4-(substiluted)phenyl-Δ²-1,3,4-oxadiazolin-5-ones are formed from 1 and dialkyl-carbamoyl chlorides at elevated temperature (about 15° ). Acylation of 1 with carboxylic acid anhydrides, also at elevated temperature, is accompanied by loss of dimethylamine from the intermediate l-acyl-4,4-dimethyl-2-(substituted)phenylsemicarbazides, 2, to give 3.     

含1,3,4-(口恶)二唑取代的酰基硫脲的合成及杀菌活性

大量文献报道了1,3,4-(口恶)二唑的合成及广泛的生物活性[1-3],酰基硫脲类化合物也因其广谱的生物活性引起了人们浓厚的研究兴趣[4-5].根据活性因子叠加的原理,本文将一系列1,3,4-(口恶)二唑引入到酰基硫脲中,从对氯苯氧乙酸出发,得到的酰基异硫氰酸酯再与一系列2-氨基-5-芳基-1,3,4-(口恶)二唑反应,合成了10个酰基硫脲类化合物.所有化合物均经元素分析、红外光谱、核磁共振谱和质谱确认.同时对所有化合物进行了生物活性测试.合成路线如下.     

含1，3，4-噁二唑取代的酰基硫脲的合成及杀菌活性

大量文献报道了1，3，4-噁二唑的合成及广泛的生物活性，酰基硫脲类化合物也因其广谱的生物活性引起了人们浓厚的研究兴趣。根据活性因子叠加的原理，本文将一系列1，3，4-噁二唑引入到酰基硫脲中，从对氯苯氧乙酸出发，得到的酰基异硫氰酸酯再与一系列2-氨基-5-芳基-1，3，4-噁二唑反应，合成了10个酰基硫脲类化合物。所有化合物均经元素分析、红外光谱、核磁共振谱和质谱确认。同时对所有化合物进行了生物活性测试。合成路线如下。     

3-N-丙酰基-2-芳基-5-(2-碘苯基)-1,3,4-噁唑啉类化合物的合成

2-碘苯甲酰肼与芳醛反应得到相应的酰腙(1),1再与丙酸酐脱水环化合成了3-N-丙酰基-2-芳基-5-(2-碘苯基)-1,3,4-噁唑啉类化合物,其结构经1H NMR,IR,MS和元素分析表征。     

Reaktionen von 3-substituiertem 5-Trifluormethyl-1,3,4-oxadiazol-2(3H)-on mit Nucleophilen

Reactions of 3-Substituted 5-Trifluoromethyl-1,3,4-oxadiazol-2(3H)-one with Nucleophiles The 3-substituted 5-trifluoromethyl-1,3,4-oxadiazolones 3, 4, 13 , and 15 are attacked by N- and S-nucleophiles either at the ring C-atom C(2) or C(5). Depending on the nature of the substituent and the nucleophile, the ring-opening products 7, 10, 12 , and 14 or the ring-enlargement products 16 are formed. The reaction of 4 with thiols is a novel variant of the Grob-type fragmentation. The reactivity of the 1,3,4-oxadiazolones is compared with that of the analogous 1,3,4-thiadiazolones. The structures of the new compounds were elucidated by ¹H- and ¹³ C-NMR spectroscopy.     

Synthesis,Crystal Structure and Biological Activity of 5-(2-Methylphenyl)-1,3,4-oxadiazol-2(3H)-one Derivatives

3-Methyl-5-(2-methylphenyl)-1,3,4-oxadiazol-2(3H)-one(6) and N,N-diethyl-2-(2-methylbenzoyl)-hydrazinecarboxamide(7) were designed and synthesized from 5-(2-methylphenyl)-1,3,4-oxadiazol-2(3H)-one(5) by substituting and ring-opening, respectively. The target compounds were confirmed by IR, 1H NMR spectroscopy, MS, elemental analysis and single-crystal X-ray diffraction. Compound 6(C10H10N2O2, Mr = 190.20) crystallizes in the triclinic system, space group P 1 with a = 7.4645(16), b = 10.868(2), c = 12.970(3) A, α= 110.542(2), β= 98.142(2), γ=99.766(2)°, V = 947.7(3) A3, Z = 4, F(000) = 400, Dc = 1.333 g/cm3, μ= 0.095 mm-1, the final R =0.0550 and wR = 0.1483 for 2956 observed reflections with I 2γ(I). Compound 7(C13H19N3O2, Mr= 249.31) crystallizes in the monoclinic system, space group C2/c with a = 18.926(3), b =12.1853(17), c = 14.740(2) o,(I) = 125.6380(10)°, V = 2762.7(7) A3, Z = 8, F(000) = 1072, Dc=1.199 g/cm3, μ= 0.083 mm-1, the final R = 0.0554 and w R = 0.1468 for 2395 observed reflections with I 2σ(I). The preliminary bioassay results indicate that compound 6 exhibits notable fungicidal activities against Fusarium graminearum, Botrytis cinerea, Rhizoctonia cerealis and Colletotrichum capsici at the concentration of 100 μg/mL.     

2-(2-三氟苯基)-5-芳基-1,3,4-噁二唑类化合物的合成

2-三氟苯甲酰肼与芳酰氯反应制得N,N′-二酰肼(2)。2在三氯氧磷存在下脱水闭环,合成了一系列2-(2-三氟苯基)-5-芳基-1,3,4-噁二唑类化合物,其结构经1H NMR,IR,MS和元素分析表征。     

2-芳基-3-N-丙酰基-5-(4-溴苯基)-1,3,4-噁唑啉类化合物的合成

噁唑啉类化合物是重要的杂环族化合物,在农药化学和医药化学中应用及其广泛。在现有的文献中已报道的大多是3-N乙-酰基-1,3,4噁-唑啉类化合物的合成[1-6],而3-N乙-酰基-1,3,4噁-唑啉类化合物的合成却很少见。为了深入研究同一分子中聚集不同骨架杂环化合物的合成以及开发新型高     

Reaction of 6-methyl-2-methylthio-3-(2-thioxo-1,3,4-oxadiazol-5-yl)methyl-4(3H)-pyrimidinone with amines

The reaction of 6-methyl-2-methylthio-3-(2-thioxo-1,3,4-oxadiazol-5-yl)methyl-4(3H)-pyrimidinone with butyland benzylamine and also with piperidine and morpholine has been studied. It was found that the primary amines not only open the 1,3,4-oxadiazole ring to form the corresponding thiosemicarbazides but also substitute the methylthio group at position 2 in the pyrimidine ring. Morpholine can only open the 1,3,4-oxadiazole ring but piperidine can also substitute the methythio group to give an oxadiazolethione piperidinium salt.Vilnius University, Vilnius 2734, Lithuania. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1125–1129, August, 1998.     

3-（3-乙酰基-5-芳氧亚甲基-2,3-二氢-1,3,4-噁二唑-2-基）色酮类化合物的合成

3-（3-乙酰基-5-芳氧亚甲基-2;3-二氢-1;3;4-噁二唑-2-基）色酮类化合物的合成;噁二唑啉;色酮;合成