由α-羰基一硫代半缩醛合成含氮杂环化合物

利用α-羰基一硫代半缩醛和含氨基的化合物反应,合成了六员含氮杂环化合物,其结构通过红外、核磁、质谱和元素分析得到了证实.     

α-羰基一硫代半缩醛与氨基脲的反应研究

利用α-羰基一硫代半缩醛与氨基脲反应，合成了6种未见文献报道的化合物，其结构经元素分析、红外、核磁和质谱得到了证实。     

α—羧基烯酮环二硫代缩醛化学（Ⅹ）—β,β—1,5—亚丙二硫…

β，β－１，５－亚丙二硫基－α，β－不饱和酮２ｂ和２－甲基烯丙基氯化镁加成可得醇３ｂ．在ＢＦ３·Ｅｔ２Ｏ催化下，３ｂ经分子内环合芳构化生成芳硫醚５ｂ．２和烯丙基溴化镁反应得醇４，４在ＢＦ３·Ｅｔ２Ｏ催化下经β－消除脱水生成共轭多烯类化合物６．二硫缩醛基以环和非环结构及环的大小对２与烯丙基Ｇｒｉｇｎａｒｄ试剂加成物在酸催化下的反应取向有重要影响。     

α—羰基烯酮式环二硫代缩醛类化合物的制备

从具有α-亚甲基的酮出发,利用溶液稀释的方法,提高了用Dieter法合成α-羰基烯酮式环二硫代缩醛类化合物的产率,并用改进方法合成了4个该类化合物。     

α,α二羰（酯）基烯酮二硫代缩醛化合物的碱性分解的反应

在乙硫醇钾或醇钠（钾）作用下，α，α－二羰（酯）基烯酮二硫代缩醛（１）可能经由逆Ｃｌａｉｓｅｎ缩合历程生成相应的β，β－双烷硫基丙烯酸酯或α－羰基烯酮二硫代缩醛类化物（２）。以醇钠（钾）为碱时２的产率较低。用乙硫钾为碱时，２的产率可达６６％以上，本实验为化合物体的合成提供了一条简单、有效的途径。     

α-羧基烯酮环二硫代缩醛化学(Ⅷ)——以叔丁醇钾为碱合成脂肪族α-羰基烯酮环二硫代缩醛类化合物

前文曾报道了以六甲基二硅氨基锂(LHMDS)为碱合成标题化合物的方法。进一步的实验表明,以叔丁醇钾为碱用于芳香族α-碳基烯酮环二硫代缩醛类化合物的合成效果较好。为此,本文以叔丁醇钾为碱合成了1_(a—j)等10个标题化合物,其中1_(d—j)为新化合物。实验表明,碱的浓度、反应所用溶剂对产物的产率有明显影响。叔丁醇钾的浓度以0.4 mol/L左右为宜,采用苯和DMF混合溶剂并以脂环酮为底物时产率较好。     

微波照射下膦酰基/硫甲基烯酮硫代缩醛和N-取代膦酰 基/硫甲基硫代碳酸酯的 合成

在微波照射下方便、高收率地合成了新奇的膦酰基杂环的合成子-膦酰基/硫甲基烯酮硫代缩醛和N-取代膦酰基/硫甲基硫代碳酸酯,实验表明微波照射大大加快了反应速率和提高了反应产率。     

α-羰基二硫缩烯酮类化合物在杂环合成中的应用进展

α-羰基二硫缩烯酮是一类重要的有机合成中间体,其官能团的多样性决定了反应的多样性.基于α-羰基二硫缩烯酮的主要反应有与亲核体的共轭加成、与金属有机试剂的选择性加成、环合、还原、缩合等反应以及作为代硫醇试剂的应用等.本文介绍了此类化合物的结构特征及合成方法,并着重按所合成杂环化合物的类型,分别对其在含氮、含氧、含硫及含多...     

Synthesis of Some New Heterocycles Derived from Arylmethylenemalononitriles

Arylmethylenemalononitriles 1 were treated with halo compounds under phase transfer catalysis (PTC) conditions to yield α-polyfunctional arylmethylene-malononitrile derivatives 2–4. The treatment of compounds 2–4 with hydrazine hydrate gave pyridinones 5,6 and pyridine 7, respectively. Triazines, triazepines, tetrazines, and triazoles 8–15 fused with pyridinone were synthesized by treating pyridinones 5 with a suitable reagent.     

Synthesis of Some New Heterocycles Derived from Phenylacetyl Isothiocyanate

Phenylacetyl isothiocyanate (1) was reacted with benzoyl hydrazine (2a) in acetonitrile to give thiosemicarbazide derivative 3 which was cyclized by polyphosphoric acid to give 1,2,4-triazoline-5-thione derivative 4. Treatment of 1 with thiosemicarbazide (2b) yielded another 1,2,4-triazoline-5-thione derivative 5. Similar treatment of 1 with phenyl hydrazine (2c) in acetonitrile gave a differently substituted 1,2,4-triazoline-5-thione derivative 6 in one pot-reaction. On the other hand, when the reaction was carried out in acetone, a mixture of 6 and thiadiazolidine derivative 7 was obtained. However, reaction of 1 with hydrazine hydrate (2d) gave hydrazine derivative 8. Reaction of isothiocyanate 1 with anthranilic acid (9) gave benzo[d][1,3,6]oxazin-1-one derivative 10. Treatment of 1 with 2-aminothiophenol (11a), 2-aminophenol (11b) or o-phenylenediamine (11c) produced benzothiazole derivative 12a, benzoxazole derivative 12b and benzimidazole derivative 12c, respectively. The structures of all the products were confirmed by micro-analytical and spectral data.     

Synthesis of Some New Pyrimidothienopyridazines and Related Heterocycles

5‐Amino‐3,4‐diphenylthieno[2,3‐c]pyridazine‐6‐carbonitrile 2a was reacted with propylene diamine to give tetrahydropyrimidinyl derivative 3 . The latter compound ( 3 ) underwent certain cyclocondensation reactions to produce pyrimidothienopyridazines 4–6 . Also, the reactions of 5‐amino‐3,4‐diphenylthieno[2,3‐c]pyridazine‐6‐carboxamide with heterocyclic aldehydes and/or cycloalkanones were carried out and their products were identified. Moreover, some novel pyridazinothienopyrimidobenzimidazoles 14–17 were synthesized.     

Synthesis and Antibacterial Acivity of Some Novel Pyrimidine-Based Heterocycles

Russian Journal of General Chemistry - Cyclization of 1,2-diamino-4(4-chlorophenyl)-6-oxo-1,6-dihydropyrimidine-5-carbonitrile 2 with a variety of electrophilic reagents results in formation of a...     

Novel Approaches to the Synthesis of Some Heterocycles Containing Nitrogen

Some syntheses of heretofore unknown pyrimidines, tetrahydroquinazolines, and quinazolines are described. These methods are uniquely simple one- or two-step reactions, general and versatile in scope, and give high yields. Some interesting chemistry associated with these heterocyclic systems is discussed.     

Synthesis of Heterocycles from 2-Acylbenzoic Acids

Heterocyclics are the crucial scaffolds present in pharmaceuticals, natural products, biologically active compounds and agrochemicals. Consequently, the development of simple and practical methods for constructing heterocyclics has always been a fascinating field in organic synthesis. Recently, 2-acylbenzoic acids, highly reactive and versatile synthons, have been broadly applied in the construction of heterocycles due to their multiple reaction sites. In this review, we summarized recent progress in the application of 2-acylbenzoic acids for the synthesis of heterocycles including phthalides, isochromanones, isoindolines, phthalazinones, and quinolones. The substrate scopes, proposed mechanisms, and product application of different types of reactions are discussed.     

Synthesis and Biological Activity Test of Some New Five Membered Heterocycles

A new series of 1,3,4‐oxadiazoles, 1,2,4‐triazoles, 1,3,4‐thiadiazoles were synthesized using alkylhydrazides as the starting materials, and then 1,2,4‐triazoles were used to synthesize [1,2,4]triazolo[3,4‐b][1,3,4]thiadiazoles. All the compounds were evaluated for in vitro antibacterial activity and antitumor activity.     

Design and Synthesis of Some New Quinoxaline‐Based Heterocycles

Considering quinoxaline as a privileged structure for developing probes of impressive therapeutic potentials, some new azole and azine conjugates of quinoxaline were synthesized. Thus, ethyl 3‐amino‐1,4‐dihydroquinoxaline‐2‐carboxylate ( 2 ) was prepared as one‐pot three‐component product and incorporated in a series of manipulations including cyclocondensation reactions to afford a series of pharmacophoric motif conjugates 8–12 , 14, 15–17 , 20–23 , 24–29 , 30 – 37 , and 38–43 in fair yields. The newly synthesized were characterized by IR, ¹H NMR, ¹³C NMR, and mass spectral data.     

Synthesis of Some New Folic Acid-Based Heterocycles of Anticipated Biological Activity

To date, no fused heterocycles have been formed on folic acid molecules; for this reason, and others, our target is to synthesize new derivatives of folic acid as isolated or fused systems. Folic acid 1 reacted with ethyl pyruvate, triethyl orthoformate, ethyl chloroformate, thioformic acid hydrazide, and aldehydes to give new derivatives of folic acid 2–6a,b. Moreover, It reacted with benzylidene malononitrile, acetylacetone, ninhydrin, ethyl acetoacetate, ethyl cyanoacetate, and ethyl chloroacetate to give the pteridine fused systems 10–15, respectively. Ethoxycarbonylamino derivate 5 reacted with some nucleophiles containing the NH₂ group, such as aminoguanidinium hydrocarbonate, hydrazine hydrate, glycine, thioformic acid hydrazide, and sulfa drugs in different conditions to give the urea derivatives 16–20a,b. Compound 4 reacted with the same nucleophiles to give the methylidene amino derivatives 21–24a,b. The fused compound 10 reacted with thioglycolic acid carbon disulfide, malononitrile, and formamide to give the four cyclic fused systems 25–30, respectively. The biological activity of some synthesized showed moderate effect against bacteria, but no effect shown towards fungi.     

Synthesis of Some New Spiro Heterocycles from the Reaction of Cycloalkylidenemal Ononitriles with Active Methylene Reagents

The reaction of cycloalkylidenemalononitriles 1a–c with some active methylene reagents as well as cycloalkanones in boiling ethanol containing piperidine catalyst affords a series of new spiro heterocyclic systems.