Reaction of oxalyl and malonyl chloride with 1,1-dimethyl-2-substituted hydrazides

Recently we reported the reaction of 1,1-dimethyl-4-substituted semicarbazides with phosgene to occur with formation of several new heterocyclic ring systems. Here we report the reaction of several semicarbazides, thiosemicarbazides and related acyl substituted hydrazides with oxalyl chloride and malonyl chloride. These reactions occur with the formation of heterocyclic products which are oxadiazolinones, imidazolidinetriones, 2-thioxoimidazolindine-4,5-diones, and 2-thioxo-1,3-diazine-4,6-diones (2-thioxopyrimidine-4,6-diones).     

Heterocycles from substituted semicarbazides and thionyl chloride. 1-oxo-1, 2,3,5-thiatriazolidin-4-one

Reaction of thionyl chloride and semicarbazides or thiosemicarbazides produces the novel 1-oxo-1,2,3,5-thiatriazolidin-4-one or 4-thione ring system.     

Phase Transfer Catalyzed Synthesis of Thiosemicarbazide Derivatives of 2-ethoxybenzoic Acid

A series of 1,4-disubstitued thiosemicarbazides and their related heterocyclic compounds have been found to possess important biological activities[1]. Some thiosemicarbazides have been found to be useful as herbicides, insecticides and plant-growth regulators [1]. In view of these and in continuation of our earlier work on the synthesis and biological activity of thiosemicarbaides derivatives [2], we now report a convenient and efficient method for the preparation of thiosemicarbazides derivatives of 2-ethoxybenzoic acid under the condition of solid-liquid phase transfer catalysis using PEG-400 as the catalyst.     

Synthesis of pyridazinone‐substituted 1,3,4‐thiadiazoles, ‐1,3,4‐oxadiazoles and ‐1,2,4‐triazoles

Several 1‐(1‐aryl‐1,4‐dihydro‐3‐carboxy‐6‐methylpyridazin‐4‐one)‐4‐aryl thio‐semicarbazides and their corresponding oxadiazole, thiadiazole and triazole derivatives were prepared and characterized by their spectral data. The preliminary biological tests showed that some new compounds exhibit good anti‐fungal activity.     

22-降-豆甾-22-含氮化合物的合成及抗肿瘤活性

通过结构改造,合成了不同支链的甾体化合物并测定了它们的抗肿瘤细胞增殖活性,探讨了不同支链对抗肿瘤活性的影响。     

A study of the behaviour of 2,4-substituted thiosemicarbazides toward orthoesters: Formation of mesoionic compounds

The reactions beetwen 2,4-disubstituted thiosemicarbazides and orthoesters in refluxing xylene led to the formation of the 1,2,4-triazoline-5-thione ring and to the 1,2,4-triazolium-5-thiolate ring. The formation of the mesoionic componds is due to rearrangement of the easily available 2,4-disubstituted thiosemicarbazides to 1,4-disubstituted thiosemicarbazides under the reaction conditions adopted. This method can be usefully used for the synthesis of mesoionic compounds, especially in the case of the 2-methyl-4-phenylthiosemicarbazide.     

1-取代苯基-1,4-二氢-6-甲基-4-哒嗪酮-3-酰氨基硫脲的合成及其抗烟草花叶病毒活性

用1－芳基－1，4－二氢－6－甲基－4－氧哒嗪－3－酰肼与取代苯基异硫氰酸酯反应合成了系列新型取代－1，4－二氢－6－甲基－4－哒嗪酮－3－酰氨基硫脲化合物，其结构经IR，1H NMR及元素分析确认，生物活性测定表明，该类化合物对烟草花叶病毒具有很高的抑制活性。     

N-Substituted benzoxazolyl ureas and thioureas in Biginelli reaction promoted by trifluoromethane sulfonic acid:An efficient and convenient synthesis of substituted benzoxazolyl 3,4-dihydropyrimidine(1H)-(thio)-ones

An efficient synthesis of 3,4-dihydropyrimidine 2(1H)-ones and thiones(3,4-DHPMs) core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid.The classical Bignelli reaction has been extended by the use of N-substituted benzoxazolyl semicarbazides and thiosemicarbazides and this method has the advantage of excellent yields and short reaction times.     

Chemistry of biureas—I: Cyclisation of ethoxycarbonyl derivatives of thiobiureas and bithioureas

The interaction of ethoxycarbonyl isothiocyanate with semicarbazides or thiosemicarbazides produces 1-ethoxycarbonyl-2-thiobiureas or bithioureas, respectively. The former are cyclisable to 2-ethoxycarbonamido-5-hydroxy-l,3,4-thiadiazole in acid, or to 2(H)-carbamoyl-3-hydroxy-5-alkylthio-1,2,4-triazoles, and thence to 3-hydroxy-5-mercapto-1,2,4-triazole in alkaline media. The ring-closure of the 1-ethoxycarbonylbithioureas proceeds similarly affording, under the influence of acids, 5-amino (or mercapto)-2-ethoxycarbonamido-1,3,4-thiadiazoles. The action of alkali produces compounds derived from 3-hydroxy-5-mercapto-1,2,4-triazole; the isolation, in a selected example, of the 2(H)-phenylthiocarbamoyl-derivative, elucidates the course of this reaction. Hydrazinolysis of 1-ethoxycarbonylbithiourea yields 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole.     

Parallel solid-phase syntheses of 1,3,4-thiadiazolium-2-aminides

An efficient and advantageous solid-phase strategy has been developed to synthesize 1,3,4-thiadiazolium-2-aminides. The title compounds were prepared in parallel fashion according to the following compact route: (i) anchoring of aromatic aldehydes to the solid support; (ii) solution preparation of 1,4-disubstituted thiosemicarbazides from hydrazines plus isothiocyanates; (iii) trimethylsilyl chloride-promoted cyclization between the resin-bound aldehydes and 1,4-disubstituted thiosemicarbazides; and (iv) removal of the products from the solid support by acid treatment. The products (17 made in all) were cleaved with high initial purities (90-98%) and obtained in generally good isolated yields (53-94%, with one exception).     

乙烯类单体自由基聚合的阻聚效应——Ⅻ.酰氨基硫脲及某些杂环衍生物对醋酸乙烯酯聚合的影响

众所周知,酚类、胺类、醌类、硝基以及亚硝基化合物对烯类单体的自由基聚合有阻聚作用。一些杂原子化合物如RNHNHR′,RSR(RNHCSS)₂M等对烯类单体的自由基聚合也能产生阻聚^[1-5]。     

Synthesis of some new 4,5-substituted-4H-1,2,4-triazole-3-thiol derivatives

In this study appropriate hydrazide compounds, furan-2-carboxylic acid hydrazide (1) and phenylacetic acid hydrazide (2) were converted into 1,4-substituted thiosemicarbazides 4a-e and 5a-e and 4-amino-5-(furan-2-yl or benzyl)-4H-1,2,4-triazole-3-thiols 7 and 10. The 1,4-substituted thiosemicarbazides were then converted into 5-(furan-2-yl or benzyl)-4-(aryl)-4H-1,2,4-triazole-3-thiols 8a-e and 9a-e. In addition, the azomethines 11a-d and 12a-d were prepared from the corresponding arylaldehydes and the 4-amino-5-(furan-2-yl or benzyl)-4H-1,2,4-triazole-3-thiols 7 and 10. The structures of all the synthesized compounds were confirmed by elemental analyses, IR, (1)H-NMR and(13) C-NMR spectra.     

Synthesis and Biological Screening of Novel Thiadiazoles,Selenadiazoles, and Spirocyclic Benzopyran by Ultrasonic and Microwave Irradiation

We describe the synthesis of novel thiadiazole, selenadiazole, and spirocyclic benzopyrans via the semicarbazides 3 and thiosemicarbazides 3 of 2-ethyl-2-methyl-4H-chromen-4-ones 1 by conventional and nonconventional methods. The microwave and ultrasonic irradiation methods form the respective products in excellent yields in very short reaction time as compared to the conventional method. The synthesized compounds were tested for antimicrobial screening against bacteria and fungi show moderate activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and Antimicrobial Activity of New Derivatives of 1,3,4‐Thiadiazoles and 1,2,4‐Triazoles with 5‐Nitroindazole as Support

The synthesis of new derivatives of 1,3,4‐thiadiazoles and 1,2,4‐triazoles was achieved using the 1,4‐disubstituted thiosemicarbazides as intermediaries.     

An Efficient Solid-State Synthesis of N-Aryl-2-phenyldiazenecarboxamides

The subject of organic solid-state synthesis is a fascinating one. It has many advantages such as high efficiency and selectivity, easy separation and purification, mild reaction conditions, and environmental acceptability1. In recent years, this method has been widely used in a variety of organic reactions including substitution2, condensation3, oxidation-reduction4, rearrangement5 and elimination6. However, the solid state reaction using K3Fe(CN)6/KOH to oxidize substituted semicarbazides…     

Synthesis and antimicrobial activity of some new 1,3,4-thiadiazole and 1,2,4-triazole compounds having a D,L-methionine moiety

New 1,3,4-thiadiazole, 5a-e, and 1,2,4-triazolecompounds 6a-c, containing a D,L-methionine moiety were synthesized by intramolecular cyclization of 1,4-disubstituted thiosemicarbazides 4a-e in acid and alkaline media, respectively. The potential antimicrobial effects of the synthesized compounds were investigated using the Staphylococcus aureus ATCC 25923, Bacillus antracis ATCC 8705, Bacillus cereus ATCC 10987, Sarcina lutea ATCC 9341 and Escherichia coli ATCC 25922 strains. The newly synthesized compounds exhibited promising activities against Bacillus antracis and Bacillus cereus.     

Dimroth rearrangement “thiadiazole-triazole”: synthesis and exploration of 3-sulfanyl-1,2,4-triazolium salts as NHC-proligands

Russian Chemical Bulletin - The reaction of 1,4-disubstituted thiosemicarbazides with N,N-dimethylformamide dimethyl acetal afforded 1,4-disubstituted 1,2,4-triazolium-3-thiolates. Heating of the...     

Does dehydrocyclization of 4-benzoylthiosemicarbazides in acetic acid lead to s-triazoles or thiadiazoles?

Ever since the recognition of strong pharmaceutical activities of triazoles and thiadiazoles, these scaffolds have been the subject of vigorous studies. One of the best strategies for synthesis of these azoles is dehydrocyclization of 1,4-disubstituted thiosemicarbazides, which leads to s-triazoles in alkaline media, whereas in strong acidic media 1,3,4-thiadiazoles are formed. However, the literature is riddled with contradictory communications regarding the nature of the products of such reactions under mild acidic conditions. As these compounds are not amenable to X-ray analysis, we have resorted to NMR and theoretical modelling to resolve this discrepancy. In this article, we present arguments indicating that dehydrocyclization of 4-benzoylthiosemicarbazides in glacial acetic acid leads to thiadiazole derivatives. These structural findings are augmented by studies of bioactivity of a few members of the studied class of compounds.     

Synthese et reaction de diacyl-1,4 alkyl-4 dihydropyridines

The action of zinc and acetic, propionic or butyric anhydride on C-4 substituted pyridines gives 1,4-diacyl 4-alkyl dihydropyridines, which can also be obtained by a free radical reaction. The 1-acetyl 4-methylene 5-methyl 4,5-dihydro azepine 24 has been prepared by solvolysis of tosylate 23 prepared from 1,4-diacetyl 4-methyl dihydropyridine. The 4-methyl quinuclidinone 28 was prepared from 1,4-diacetyl 4-methyl dihydropyridine 4 by hydrogenation, hydrolysis, bromination and cyclisation.     

Synthesis and evaluation of AChE inhibitory activity of 5,6-diaryl-1,2,4-triazinyloxyacetyl-4-substituted thiosemicarbazides,triazoles and N-benzylidene derivatives

A series of 1,2,4-triazinyl thiosemicarbazides, triazoles and N-benzylidene derivatives have been synthesized by condensation of 5,6-diphenyl-1,2,4-triazin-3-yloxyacetyl hydrazine with aromatic aldehydes and aryl isothiocyanates. Subsequent ring closure of thiosemicarbazides yielded the triazoles. All the compounds were subjected to in vitro testing of cholinesterase inhibitory action. Percentage inhibition was found to be moderate to good in a few of the compounds.