The electroreduction of pyrazolone glyoxalic ester derivatives in aqueous buffered media

Summary The polarographic reduction of two series of pyrazolone derivatives in alcoholic buffered media indicated that these molecules predominate in the hydrazone form and are reduced via a 4e^– irreversible process. The main eletrolysis products, 3,6-bis(pyrazoline-5-on-3yl)piperazine-2,5-dione (3), and 3,6-bis(1-phenyl-pyrazoline-5-on-3yl)piperazine-2,5-dione (4) were isolated and identified. A mechanism has been suggested and discussed.

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Die Elektroreduktion von Pyrazolon-Glyoxalester-Derivaten in wäßrigem, gepuffertem Medium

Zusammenfassung Die polarographische Reduktion zweier Serien von Pyrazolon-Derivaten in alkoholisch-wäßrigem, gepuffertem Medium zeigt, daß diese Moleküle bevorzugt in der Hydrazono-Form vorliegen und über einen irreversiblen 4e^–-Prozeß reduziert werden. Die Hauptprodukte der Elektrolyse, 3,6-bis(pyrazolin-5-on-3-yl)piperazin-2,5-dion (3) und 3,6-bis(phenylpyrazolin-5-on-3-yl)piperazin-2,5-dion (4) wurden isoliert und identifiziert. Ein Mechanismus wird vorgeschlagen und diskutiert.

     

Condensation reactions of a comenaldehyde derivative

Condensation reactions of comenaldehyde methyl ether (I) with malonic acid, ethyl cyanoacetate, and cyanoacetamide to give β-(5-methoxy-4H-pyran-4-on-2-yl)acrylic acid (II), ethyl 2-cyano-3-(5-methoxy-4H-pyran-4-on-2-yl)propenoate (III), and 2-cyano-3-(5-methoxy-4H-pyran-4-on-2-yl)propenamide (IV), respectively, are described. Ultraviolet absorption spectra for 2-hydroxymethyl-5-methoxy-4H-pyran-4-one, I and II are presented.     

SOME ASPECTS ON ACYCLO- 4-[QUINAZOLIN-3-YL]BENZENESULFONAMIDE NON-NUCLEOSIDES SYNTHESIS

The reaction of 4-[1,2,3,4-tetrahydroquinazolin-2,4-dion-3-yl]benze-nesulfonamide 4 and 4-[2-thioxo-1,2,3,4 tetrahydroquniazolin-4-on-3-yl]benznesulfonamide 5 with chloromethylethyl ether, chloromethylbenzyl ether, and (2-acetoxyethoxy)methyl bromide afforded compounds 7a–c, 8a,b, and 13 which are analogues to MKC-442, TNK 561, and HEPT.     

Mass spectroscopy of natural products. 20—Quinazoline carboxylic acids 4—Comparative positive and negative ion mass spectroscopic studies of 3,4-dihydroquinazolin-4-on-3-ylalkanoic acids and 3,4-dihydro-1,2,3-benzotriazin-4-on-3-ylalkanoic acids

The mass spectroscopic behaviour of 3,4-dihydroquinazolin-4-on-3-ylalkanoic acids and 3,4-dihydro-1,2,3-benzotriazin-4-on-3-ylalkanoic acids was studied under positive and negative ionization. The differences in fragmentation both between the ionization modes and between the two heterocyclic systems are discussed by using some ¹⁵N-labelled derivatives.     

The Utility of 2-(5,6,7,8-Tetrahydrobenzo[b]thieno-[2,3-d]pyrimidin-4-yloxy) Acethydrazide in Heterocyclic Synthesis

Because of being a versatile synthon, the title compound 2 was utilized to construct different heterocyclic systems including pyrazol-4-carbonitrile 3, pyrazolone 4, triazole-5(4H)-thione 7, aminotriazole 9, oxadiazoles 10 and 12, thiazolidine 13, and oxatriazole 14. All new synthesized compounds were structurally confirmed by elemental analyses and spectroscopic data.     

METAL CHELATES OF NEW LIGANDS: 1,2-BENZOTHIAZINE-1,1-DIOXIDE DERIVATIVES

Abstract

The novel chelates ML₂ (M = Co, Ni, Cu, Zn) were obtained by the interaction of 3-benzoyl-4-hydroxy-1,2-benzothiazine-4(3H)-on-1,1-dioxide and 2-methyl-3-benzoyl-4-hydroxy-1,2-benzo-thiazine-4(3H)-on-1,1-dioxide with elemental metals (direct electrochemical synthesis) or their acetates (chemical synthesis) in methanol. The tetrahedral or polymeric-octahedral structures with a β-diketonate fragment are assigned based on IR and ¹H NMR spectra. The studied ligands and their complexes are model compounds of molecules used as anti-inflammatory drugs.     

短柄雪胆中的三萜葫芦素及其皂苷

从短柄雪胆的块根中分离得到了14个三萜葫芦素类化合物. 经波谱分析及化学方法鉴定了它们的结构, 其中有新化合物5个, 分别命名为短柄雪胆苷A～E (1～5), 以及肉花雪胆苷元A (6), 藤三七雪胆苷R8 (7), 肉花雪胆苷I (8), 肉花雪胆苷II (9), 肉花雪胆苷III (10), 雪胆甲素(11), 雪胆乙素(12), 雪胆甲素苷(13), 藤三七雪胆苷R1 (14)等9个已知化合物. 6是首次从自然界中得到的化合物.     

Zum verhalten konjugierter diene gegenüber C6H5J(OAc)2-(CH3)3SiN3

IR-spectroscopic measurements between ?60° and 0°C show the existence of C₆H₅J(OAc)_2-n(N₃)_n generated by the reaction of C₆H₅J(OAc)₂ with (CH₃)₃SiN₃. C₆H₅J(OAc)_2-n(N₃)_n reacts with 2,3-dimethylbutad to give substances C₁₂H₂₀N₆ (1), having the probable structure of 2,3,5-trimethyl-3,6-di-azidomethyl-heptadiene-1,5 and 3,4-diazido-3-methylbutanone-2 (2). Likewise we get from 1,3-cyclohexadiene the diazide C₁₂H₁₆N₆ (3), and 4-azido-cyclohexene-2-on-1 (4). Analogously from cyclopentadiene we get the carbonylcompound 4-azido-cyclopentene-2-on-1 (5). E-5-azido-hexene-3-on (8) results from 2,4-E,Z-hexadiene. 1,3-cyclooctadiene gives as main product 6 (4-azido-cyclooctene-2-on-1) but also some 7 (8-azido-cyclooctene-2-on-1) emerging from an attack on positions 1 and 2.Δ^1,3, Δ^3,5 and Δ^4,6-cholestadiene yield in a regio- and stereo-specific manner the products 9 (1α-azidocholestene-2-on-4), 10 (6β-azidocholestene-4-on-3) and 11 (4β-azidocholestene-5-on-7). These last examples confirm our suggestions from the preponderance of the 1,4-functionalisation.     

Chinazolincarbonsäuren, 5. Mitt.: Synthese von 1,4-Dihydro-chinazolin-4-on-1-yl-essigsäuren und Estern

1,4-Dihydro-quinazoline-4-on-1-yl-acetic acids5 were prepared by reaction of 3,1-benzoxazine-2,4-diones1 with ammonia to2. Cyclisation of2 gave4 and their hydrolysis lead to5. 2-Substituted quinazolinones9 could be obtained by reaction of2 with acid chlorides or by reaction of1 with amidines. Quinazolinone8 was synthesized in a similar way. The substituted 2-aminobenzamide10 showed a reaction behaviour different from that of2.

Dem Andenken von Dr.Wolfgang Truppe ( 24. 11. 1984) gewidmet.     

REACTIONS WITH THIAZOLINONES: A NEW ROUTE FOR THE SYNTHESIS OF THIAZOLONYLPYRIDAZONE AND THIAZOLYLPYRAZOLONE DERIVATIVES

Abstract

2-Amino-1.1.3-tricyanoprop-l-ene (1) reacted with thioglycollic acid to afford the key compound for this study namely: 2-amino-I,I-dicyano-3(2-thiazolin-4-on-2-yl)prop-1-ene 2. 2 reacted with hydrazines to afford the thiazolylmethylaminopyrazole derivatives 3 and 4. The reaction of 2 with diazotised primary aromatic amines afforded coupling products which were cyclised to the hydrazothiazolonylpyridazine derivatives 7. The reaction with aromatic aldehydes gave the his-ylidene derivatives 8. Structures are assigned based on elemental and spectroscopic analysis.     

Synthesis of derivatives of <Emphasis Type="Italic">o</Emphasis>-aminoacetophenone and <Emphasis Type="Italic">o</Emphasis>-aminobenzyl alcohol

Oxidation of 2′-hydroxy-8-methylspiro[4H-benz-1,3-oxazin-2-one-6,1′-cyclopentane] or N-mesyl-2-(cyclopent-1-en-1-yl)-6-methylaniline provided the corresponding ketones. The rearrangement of these ketones oximes under treatment with thionyl chloride gave rise to nitriles of 5-(2-amino-3-methylphenyl)-5-oxopentanoic or 5-(2-methanesulfamido-3-methylphenyl)-5-hydroxypentanoic acids. By heating 5-(2-acetylamido-3-methylphenyl)-5-oxopentanoic acid with LiH in THF3-(2,8-dimethylquinol-4-on-3-yl)propanoic acid was obtained.     

An Efficient Synthesis of Thiazolidine‐4‐ones with Antitumor and Antioxidant Activities

Reaction of 3‐aroyl‐1‐arylthioureas with dimethyl but‐2‐ynedioate in dichloromethane and catalyzed by triphenylphosphine at ?5°C led to (Z)‐methyl 2‐[(Z)‐2‐(4‐aroylimino)‐4‐oxo‐3‐aryl‐1,3‐thiazolidin‐5‐ylidene]acetates in good yields. The mechanism is discussed. X‐ray structure analysis of one thiazolidine derivative is described. Antitumor and antioxidant activities have been investigated. One derivative of 1,3‐thiazolidine showed moderate antiproliferative in vitro activity against hepatocellular carcinoma Hep‐G2, whereas another 1,3‐thiazolidine introduced effective antioxidant activity compared to ascorbic acid.     

Addition compounds of nucleophiles and 3-ethylthio-6-oxo-6H-1,2-dithiolo[4,3-c]1,2-dithiolium tetrafluoroborate. Synthesis of 3H,6H-1,2-dithiolo[4,3-c]1,2-dithiole-3-one-6-thione

Summary A smooth method of synthesizing 3H, 6H-1,2-dithiolo[4,3-c]1,2-dithiole-3,6-dithione (3), and also its partial desulfuration to yield 3H, 6H-1,2-dithiolo[4,3-c]1,2-dithiole-3-one-6-thione (4) is presented. The ethylation product5 of the monothione4 reacts with various nucleophilic reagents to form remarkably stable adducts. The adducts of5 with methanol,tert-butyl mercaptan, and with aniline could be isolated and characterized by their¹H-NMR spectra.

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Anlagerungsverbindungen von Nukleophilen an 3-Ethylthio-6-oxo-6H-1,2-dithiolo[4,3-c]1,2-dithioliumtetrafluoroborat. Synthese von 3H,6H-1,2-Dithiolo[4,3-c]1,2-dithiol-3-on-6-thion

Zusammenfassung Eine glatte Synthese für 3H,6H-1,2-Dithiolo[4,3-c]1,2-dithiol-3,6-dithion (3) und für dessen partielle Entschwefelung zu 3H,6H-1,2-Dithiolo[4,3-c]1,2-dithiol-3-on-6-thion (4) wird angegeben. Das Ethylierungsprodukt5 des Monothions4 reagiert mit unterschiedlichen Nukleophilen zu bemerkenswert stabilen Addukten. Die Addukte mit Methanol,tert.-Butylmercaptan und mit Anilin wurden isoliert und durch ihr¹H-NMR-Spektrum charakterisiert.

     

Synthesis,Antimicrobial, and Anthelmintic Activities of Some New 3-Chlorobenzothiophene-2-Carbonylchloride Derivatives

3-Chlorobenzothiophene-2-carbonylchloride 1 was prepared from cinnamic acid and then converted into the acid hydrazide 2. Reaction of 3-chloro-1-benzothiophene-2-carbohydrazide 2 with the appropriate isothiocyanate yielded the substituted thiosemicarbazides 3a–b, which are cyclized into thioxotetrahydropyrimidine 4a–b, 1,3,4-thiadiazoles 5a–b, thiazolidine 6a–b, 1,3,4-oxadiazole 7a–b, triazoles 8a–b, 1,2,4-triazole substitutedthioate 9a–f, and 1,3-thiazolylidenes 10a–b, respectively. The structures of the newly synthesized compounds were elucidated on the basis of elemental analyses, IR, ¹H NMR, and mass spectral data and have been screened for antimicrobial and anthelmintic activities.     

Synthesis of Thiazolidine and Thiophene Derivatives for Evaluation as Anticancer Agents

The non-isolated adducts (3a,b) were used as key intermediates to synthesize some novel thiazolidine and thiophene derivatives. Compound (4) exhibited a remarkable antitumor activity against EAC cells compared with the Doxorubicin as a positive control.     

PREPARATION OF 6-THIA-3,8-DIAZABICYCLO/3,2,1/OCTAN-2-ONES

Abstract

Study of the isomerisation of penilloic acid in aprotic solvents revealed the epimerisation at position C-4, when opening of thiazolidine ring was prevented by N-acetyl group(I).     

Synthesis of C-functionalized acetylacetone and its europium complex. Preparation and study of luminescence of europium-containing sol-gel films

New fuctionalized ligand 3-(3′-triethoxysilylpropylaminocarbonyl)pent-2-on-3-en-4-ol (EtO)₃SiCH₂·CH₂CH₂NHC(O)-C[C(O)CH₃][=C(OH)CH₃] (I) containing ketoenol and triethoxysilyl groups is synthesized from 3-triethoxysilylpropyl isocyanate (EtO)₃SiCH₂CH₂CH₂N=C=O and acetylacetone. The reaction is accompanied by the formation of 2-(3′-triethoxysilylpropylaminocarboxy)-pent-2-en-4-one (EtO)₃SiCH₂CH₂·CH₂NHC(O)-OC(CH₃)=CH-C(O)CH₃ (II), the product of addition of acetylacetone enol form to isocyanate group. The ratio of amide I and urethane II forms is 7:3. Europium(III) tris[3-(3′-triethoxysilylpropylaminocarbonyl) pent-2-on-3-en-4-olate] is prepared from I and Eu(i-OPr)₃. An alternative pathway consists in the reaction of europium tris(acetylacetonate) with 3-triethoxysilylpropyl isocyanate. Conditions of formation of transparent europium-containing sol-gel films were developed. Thermal stability and photoluminescence of the films were investigated.     

Reaction of 2-imino-3-aryl-4-oxothiazolidines with phenyl isothiocyanate

2-Phenylthiocarbamoylimino-3-aryl-4-oxothiazolidines, which are hydrolyzed at the C=N and N₃=C₄ bonds of the thiazolidine ring to give 3-arylthiazolidine-2,4-diones, N-phenylthiocarbamoylarylpseudothiohydantoic acids, and 3-phenylthiocarbamoylthiazolidine-2,4-dione, were synthesized by reaction of 2-imino-3-aryl-4-oxothiazolidines with phenyl isothiocyanate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 903–905, July. 1976.     

Selective aziridination of olefinic esters

Summary Oxidation of 3-amino-2-isobutylquinazoline-4-one (2) with lead tetraacetate at –20°C gave N-acetoxyamino-2-isobutylquinazolin-4-one (3), which selectively aziridinated olefinic esters to yield substituted 1-(2-isobutylquinazolin-4-one-3-yl)-aziridine-2-carboxylates5a–q.

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Selektive Aziridinierung von olefinischen Estern

Zusammenfassung Oxidation von 3-Amino-2-isobutylchinazolin-4-on (2) mit Bleitetraacetat bei –20°C ergab N-Acetoxyamino-2-isobutylchinazolin-4-on (3), welches mit verschiedenen olefinischen Estern selektiv substituierte 1-(2-Isobutylchinazolin-4-on-3-yl)-aziridin-2-carbonsäureester5a–q lieferte.

     

Synthesis and Biological Study of Some 4-oxo-Thiazolidine Derivatives of 2-Aminothiazole

Conventional and microwave assisted synthesis of new series of N‐[2‐{2‐(substituted phenyl)‐4‐oxo‐5‐(substituted benzylidene)‐1,3‐thiazolidine}‐iminoethyl]‐2‐aminothiazole 5a–5m have been developed. The cycloaddition reaction of thioglycolic acid with N‐{2‐(substituted benzylidenehydrazino)‐ethyl}‐2‐aminothiazole 3a–3m in the presence of anhydrous ZnCl₂ afforded new heterocyclic compounds N‐[2‐{2‐(substituted phenyl)‐4‐oxo‐1,3‐thiazolidine}‐iminoethyl]‐2‐aminothiazole 4a–4m . The later product on treatment with several selected substituted aromatic aldehydes in the presence of C₂H₅ONa undergoes Knoevenagel reaction to yield 5a–5m . The structures of compounds 1 , 2 , 3a–3m , 4a–4m and 5a–5m were confirmed by IR, ¹H NMR, ¹³C NMR, FAB‐Mass and chemical analysis. All above compounds were screened for their antimicrobial activities against some selected bacteria and fungi and antituberculosis study against M. tuberculosis.