Synthesis,Characterization, and Biological Screening of Some Novel Thiazolidin-4-One and α-Aminophosphonate Derivatives

Abstract

Synthesis of some new functionalized thiazolidin-4-ones and α-amino phosphonate derivatives has been reported. The imines were synthesized from the reaction of various substituted anilines with 1-phenyl-3-(pyridine-4-yl)-1H-pyrazole-4-carbaldehyde in ethanol at reflux condition. The corresponding thiazolidin-4-ones and α-aminophosphonates were prepared by reaction of imines with mercaptoacetic acid and triethyl phosphite, respectively. The structures of the newly synthesized compounds were confirmed by IR, ¹H NMR, and mass spectral data and were evaluated for their antimicrobial activities.

GRAPHICAL ABSTRACT      

HALOACETYLATED ENOL ETHERS: 16[5] REGIOSPECIFIC SYNTHESIS OF 5-TRICHLOROMETHYL-PYRAZOLES

ABSTRACT

The regiospecific synthesis and isolation of three series of 5-trichloromethyl-pyrazoles 2f–j, 3a–j and 4a–j from the cyclocondensation of 1,1,1-trichloro-4-alkoxy-3-alken-2-ones (1a–f) or trichloroacetyl containing β-diketones (1g–j) with dry hydrazine and phenyl-hydrazine is reported. It was established by ¹H- and ¹³C-NMR spectroscopy that the 5-hydroxy-5-trichloromethyl-4,5-dihydro-1H-pyrazole intermediates 2a–j were formed quantitatively.     

SYNTHESIS OF SOME 2-THIOXOPYRIDO[2,3-d]PYRIMIDINE RIBOFURANOSIDES AND THEIR ANTIMICROBIAL ACTIVITY

Abstract

2-Thioxc-3,5,7-trisubstitutcd-I-[2′.3′,5′-tri-O-benzoyl-β-D-ribofuranosyllpyrido [2,3-d]pyri midin-4(IH)-ones have been prepared by the condensation of trimethylsilyl derivative of 2-thioxo-3,5,7-trisubstituted pyrido[2,3-d]pyrimidin-4(IH)-ones with β-D-ribofuranose 1-acetate-2,3,5-tribenzoate in 65%-78% yield. The structure of the synthesized ribofuranosides and their precursors have been established by IR, ¹H NMR and elemental analysis. These derivatives have been screened for their antimicrobial activity.     

N-Methylpyridinium Tosylate Catalysed Green Synthesis,X-Ray Studies and Antimicrobial Activities of Novel (E)-3-Amino-2-(e)-(3, 4-Dihydronaphthalen-1(2H)-Ylidene)Hydrazono)Thiazolidin-4-Ones

Abstract

3,4-Dihydro-2H-naphthalen-1-ones 1,on reaction with thiocarbohydrazide, afforded monothiocarbohydrazones 2, which, on condensation with chloroacetic acid in the presence of an ionic liquid and bromotrimethylsilane furnish (E)-3-amino-2-(E)-(3,4-dihydronaphthalen-1-(2H)-ylidene)hydrazono)thiazolidin-4-ones 3 in quantitative yields. Acetyl derivatives 5 were obtained from 3 with acetic anhydride. Monothiocarbohydrazones 2 on condensation with benzaldehyde yield azomethines 4. The structure of compounds 2–5 has been established by elemental analysis, IR, ¹H NMR, and mass spectral data. The structure of compound 3a has been further confirmed by X-ray crystallographic data. The compounds 2–5 were screened for antimicrobial activity. The thiazolidinones 3a and 3b showed maximum antimicrobial activities.     

Synthesen von 5-Alkyl-2-aryl-pyrimidin-4(3H)-onen

The title substances with R²=H (type1) were synthesized by reductive desulfurization of corresponding 2-aryl-thieno-[2,3-d]pyrimidin-3(3H)-ones and 2-aryl-[1]benzothieno[2,3-d]-pyrimidin-4(3H)-ones (both:A), those with R²=CH₃ (type2) by cyclization of -alkyl-acetoacetates with benzamidines. Some derivatives of1 and2 were also prepared (type3). In some cases Raney-Ni desulfurization ofA gave 2-cyclohexylproducts (type4).

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Teilweise unter Mitarbeit vonMorteza Baradar.     

SYNTHESIS AND CHEMISTRY OF SOME NEW 2-MERCAPTOIMIDAZOLE DERIVATIVES OF POSSIBLE ANTIMICROBIAL ACTIVITY

4,5-Diaryl-2,3-dihydro-2-mercaptoimidazoles (2a–e) were synthesized. They reacted with chloroacetic acid in gl. acetic acid/Ac ₂ O in presence of anhyd. sodium acetate afforded 5,6-diaryl-2,3-dihydro-imidazo[2,1-b]thiazol-3-ones (3a–d). Also these compounds were prepared by the action of chloroacetyl chloride on compounds (2) in pyridine. Compounds (3a–d) on condensation with aromatic aldehydes yield 2-arylmethylene-5,6-diaryl-2,3-dihydroimidazo[2,1-b]-thiazol-3-ones (4a–q). The latter compounds were prepared directly by the reaction of (2) with chloroacetic acid and the aromatic aldehydes. Compounds (3a–d) coupled with aryldiazonium salts in pyridine to give 2-arylhydrazono-5,6-diaryl-2,3-dihydroimidazo[2,1-b]thiazol-3-ones (5a–r). Also compounds (2) when reacted with 2 or 3-bromopropionic acid afford 2,3-di-hydro-5,6-diaryl-2-methylimidazo[2,1-b]thiazol-3-ones (6a–d) and 2,3-di-hydro-6,7-diaryl imidazo-[2,1-b]-1,3-thiazin-4-ones (7a–d), respectively. Compounds (3, 6, and 7) have been cleaved by aromatic amines to give the corresponding 2-(4′,5′-diaryl-2′,3′-dihydroimidazol-2′-yl)thioacetanilide (8a–f), 2-(2′,3′-dihydro-4′,5′-diaryl imidazol-2′-yl)thiopropionamide (9a–c), and 3-(2′,3′-dihydro-4′,5′-diaryl-imidazol-2′-yl)thiopropionamide (10a–d) respectively. All the prepared compounds show considerable antimicrobial activity against bacteria, yeast, and fungi.     

Synthesis and Antioxidant Activity Evaluation of Novel 5,7-dimethyl-3H-Thiazolo[4,5-B]Pyridines

Abstract

5,7-Dimethyl-3H-thiazolo[4,5-b]pyridine-2-one was obtained under the reaction of 4-iminothiazolidin-2-one with acetylacetone. Further structural modifications include the introduction of diversity at the N³ and C⁶ positions. The antioxidant activity of the synthesized compounds was evaluated in vitro by the method of scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals.

[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 following free supplemental files: Additional figures]     

COPPER-CATALYSED REARRANGEMENT OF 4-SUBSTITUTED-2,3-1H-BENZOXAZINE-1-THIONES

Abstract

4-Substituted-2,3-1H-benzoxazine-1-thiones were prepared by the treatment of the corresponding benzoxazine-1-ones with P₂S₅. The thermal rearrangement of 4-substituted-2.3-1H-benzoxazine-1-thiones, catalysed by metallic copper, yielded 4-substituted-2.3-1 H-benzthiazine-1-ones.     

Synthesis of Some Novel 5-(Arylidene)-2-imino-3(pyridin-2-yl)thiazolidin-4-one Derivatives

Treatment of 2-aminopyridine ( 1 ) with chloroacetyl chloride in dry benzene gave 2-chloro-N-(pyridin-2-yl)acetamide ( 3 ), which on further reaction with potassium thiocyanate gave 2-imino-3-(pyridin-2-yl)thiazolidin-4-one ( 4 ) as an intermediate compound for the synthesis of pyridin-2-yl substituted 2-imino-thiazolidine-4-one derivatives. Cyclocondensation reaction of ( 4 ) with a series of aromatic aldehydes gave 5-arylidene derivatives of pyridin-2-yl substituted 2-imino-thiazolidine-4-ones 5a–j . ¹ H and ¹³C NMR spectroscopy, as well as elemental analyses, were used for the identification of these new compounds.     

Synthesis and Characterization of New Thiazolidin-4-one Derivatives

The synthesis of some new functionalized thiazolidin-4-one derivatives has been described. The N-substituted-thiosemicarbazides 3a-3i were obtained though the reaction of alkylamines 2a–2i , carbon disulfide, and hydrazine hydrate. The condensation reaction between 3a–3i and 4-amino-2-methanesulfanylpyrimidine-5-carboxaldehyde 1 afforded the thiosemicarbazones 4a–4i . The corresponding thiazolidin-4-ones 5a–5i were prepared by cyclization of 4a–4i with ethyl bromoacetate. The structures of the final products were confirmed by IR, ¹ H NMR, ¹³ C NMR, and HRMS.     

Reactions with pyrrolidine-2,4-diones,II: New approaches to the synthesis of substituted 5,6-dihydropyrrolo[3,4-d][1,2,3]triazol-4(2H,4H)ones

Summary Approaches leading to 5,6-dihydro-5,6-diphenyl-2-substituted-pyrrolo[3,4-d][1,2,3]-triazol-4(2H,4H)-ones (10) are described. The first approach consists of cyclodehydrating 3(or 4)-hydroxyimino-1,5-diphenyl-4(or 3)-(4-substituted phenylhydrazono)pyrrolidin-2-ones (4,7) with boiling acetic anhydride. The second approach involves cyclization of 3(or 4)-acetoxyimino-1,5-diphenyl-4(or 3)-(4-substituted phenylhydrazono)pyrrolidin-2-ones (8,9) with elimination of acetic acid upon treatment with sodium hydroxide.Part of the work has been presented at the 8^th International Congress of Heterocyclic Chemistry (August 1981), Graz, Austria     

The One Step Synthesis of 2-(2-Bromo-5- methoxyphenyl)-5-(3-arylidene)-1,3-thiazolo[3,2-b]- 1,2,4-triazol-6-(5H)-ones and the Evaluation of the Anticonvulsant Activity

A smooth one-step synthesis of 2-(2-bromo-5-methoxyphenyl)-5-(3-arylidene)-1,3-thiazolo[3,2-b]-1,2,4-triazol-6-(5H)-ones (4a–n) is described. The newly prepared compounds are characterized by analytical and IR, ¹ H NMR, ¹³ C NMR, and FABMS spectral analysis. A few compounds are screened for anticonvulsant activity. Compounds 4i and 4n exhibit promising anticonvulsant activity and are recommended for further studies.     

4,5-二氢咪唑并[1,2-b]-1',2',4'-三唑-4-酮衍生物的合成与杀菌活性

应用芳基异氰酸酯与烯基膦亚胺1的氮杂Wittig反应, 得到的碳二亚胺2, 再与水合肼作用得到氨基咪唑啉酮衍生物4. 而后用4与芳基异氰酸酯(或酰氯)、三苯基膦、六氯乙烷和三乙胺“一锅”反应, 得到4,5-二氢咪唑并[1,2-b]-1',2',4'-三唑-4-酮衍生物6或7. 探讨了所合成新型稠杂环化合物的生物活性, 结果表明部分化合物表现出良好的杀菌活性. 如7c在50 mg/L浓度时, 对棉花枯萎菌、稻瘟菌、黄瓜灰霉菌和油菜菌核菌的抑制率均达100%.     

A Convenient One-Pot Synthesis of Some New 3-(2-Phenyl-6-(2-thienyl)-4-pyridyl)hydroquinolin-2-ones Under Microwave Irradiation and Their Antimicrobial Activities

A series of 3-(2-phenyl-6-(2-thienyl)-4-pyridyl)hydroquinolin-2-ones 4a–o were synthesized in high yields by a one–pot cyclocondensation reaction under Kröhnke's reaction conditions using 2-chloro-3-formyl quinoline 1a–c, 2-acetyl thiophene 2, and various N-phenacylpyridinium bromides 3a–e in a mixture of ammonium acetate and acetic acid by microwave irradiation. All the compounds have been characterized by elemental analysis, FT-IR, ¹H NMR, and ¹³C NMR spectral analysis. These compounds have been screened for their antimicrobial activities.

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.     

INVESTIGATION OF THE THIAZOLE SERIES 7. SYNTHESIS,STRUCTURE AND PROPERTIES OF 2-HYDROXIMINO-1,3-THIAZOLIDINE-4-ONES

Abstract

Several 2-hydroximino-1,3-thiazolidine-4-ones have been prepared by reaction of the respective α-thiocyanatocarbonic acid esters with hydroxylamine. They have been characterized by ir, uv and ¹H-nmr. The chemical structure was determined unequivocally by the crystal structure analysis of 5-ethyl-2-hydroximino-1,3-thiazolidine-4-one, space-group: P2₁/c, a = 10.0382(7), b = 5.2903(4), c = 19.305(1) Å, β = 134.233(4) at T = 24(1)°C. The structural model was refined with 3196 data to give R = 0.044. Analysis of the bonding geometry has lead to characterization of the 2-amino-1,3-thiazolidine-4-ones as cyclic N-thiaiminoamides.     

ELEGANT SYNTHESIS OF SOME NOVEL SPIRO [BENZOTHIAZEPINE-INDOLE] DERIVATIVES

Abstract

The synthesis of some novel sulfur-containing spiroindole derivatives is reported, 2,3-Dihydrospiro [cycloalka[3,4][1,5] benzothiazepine-2,3′-[3H]indole]-2′-(1′H)-ones (V) were prepared by the reaction of 1,3-dihydro-3-(2-oxocycloalkylidene)indole-2(1H)-one (II) with 2-aminothiophenol in dry toluene. The compounds have been characterized on the basis of elemental and spectral studies.     

SYNTHESIS OF 4,9-DIMETHYL-8- (6-ARYL-2-THIOXO-1,2,3,6-TETRAHYDRO PYRIMIDIN-4-YL)-FURO[2,3-H]CHROMEN-2-ONES AS ANTIMICROBIAL AGENTS UNDER MICROWAVE IRRADIATION

Acrolyl furochromen-2-ones (3a–i) obtained in good yields on microwave irradiation of furochromen-2-one (1) with various simple and substituted aromatic aldehydes (2a–i). 3a–g on cyclo dehydration with thiourea in domestic microwave oven furnished tetrahydro thiaxopyrimidine furochromen-2-ones 4a–i in high yields. The structures of the newly synthesized compounds were established on the basis of analytical and spectral data, IR, and ¹H NMR.     

Synthesis of 2-[mercapto(cyano)methylene]-1,2,3,4-tetrahydro-quinazolin-4-ones and 2-amino-4-methylpyrazolo-[1,5-a]quinazolin-5(4H)-one

A series of 2-[mercapto(cyano)methylene]-1,2,3,4-tetrahydroquinazolin-4-ones and 2-amino-4-methylpyrazolo[1,5-a]quinazolin-5(4H)-one were prepared from 2-cyanomethylquinazolin-4(3H)-ones via α-bromo derivatives 4 and amide oxime 8, respectively. The new compounds have been characterized by elemental analyses and ¹H-nmr, in some cases by ir and ¹³C-nmr investigations.     

A new synthetic route to aminothiazolinones

Novel 2-(5-R-1,3,4-thiadiazol-2-yl)aminothiazolin-4-ones 6a—h and 2-imino-3-(5-R-1,3,4-thiadiazol-2-yl)thiazolidin-4-ones 7a—h were prepared by treating N-(5-R-1,3,4-thiadiazol-2-yl)thioureas 4a—h with chloroacetic acid on various solid supports under microwave irradiation. Tautomeric mixtures of compounds 6a—h and 7a—h were obtained in all cases. In alkaline and neutral media, compounds 6a—h were the major products, while in acid media, 7a—h were the major products.     

1,4-PENTADIEN-3-ONES. A SOURCE FOR SELENANO 1,2,3- SELENA AND THIADIAZOLES

The 4-Selenanols (2,3) and 4-selenanones (4) were obtained by the reaction of 1,4-pentadien-3-ones (1) with sodium hydrogen selenide under different conditions. The fused 1,2,3-selenadiazoles (6) and 1,2,3-thiadiazoles (7) were prepared from 4 on oxidative cyclization with SeO₂ and Hurd–Mori reaction with SOCl₂.