Selenium heterocycles. XXXVII . Synthesis of 4-(thiazol-4-yl)-1,2,3-selenadiazoles and 4-(selenazol-4-yl)-1,2,3-selenadiazoles

Starting from readily available 2-substituted-4-formylthiazoles and selenazoles, a series of 4-(2-aryl-4-selenazolyl)-1,2,3-selenadiazoles I and 4-(2-substituted-4-thiazolyl)-1,2,3-selenadiazoles II were prepared. Pyrolysis of compound II afforded (2-substituted-4-thiazolyl) acetylenes VII. Addition of potassium hydroxide pellets to an alcoholic solution of II gave 2-substituted-1,4-diselenafulvenes VIII. Decomposition of compound II with base followed by the addition of carbon disulfide gave 5-substituted 2-thioxo-1,3-thiaselenoles XI.     

5-(Thiazol-4-yl)-1,2,4-triazoles

By reaction of arylhydrazones of benzoyl chloride with 4-aminomethylthiazole in the presence of triethylamine, the corresponding amidrazones were obtained, which upon oxidation gave 5-(thiazol-4-yl)-1,2,4-triazoles with fungicidal and bactericidal activity.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2111–2112, September, 1991.     

Alternative Synthesis of 5-(1H-Pyrazol-4-yl)-2-{6-[(2,2,6,6-tetramethylpiperidin-4-yl)oxy]pyridazin-3-yl}phenol

A scalable and environmentally benign route to the free base of branaplam, a small molecule splicing modulator, was identified and developed. This alternative approach circumvented the inherent risk of dioxin formation associated with ortho-halo phenol derivatives present in the previous route. A Friedel–Crafts approach provided a reliable access to the key intermediate, subsequently followed by a Suzuki–Miyaura cross-coupling. Multiple process aspects of the synthetic approach were evaluated, and a robust process for its large-scale synthesis was developed and successfully demonstrated.     

Synthesis of Geminally Activated 4-(Furan-2-yl)- and 4-(Thiophen-2-yl)-1-nitrobuta-1,3-dienes

The condensation of 3-(furan-2-yl)- and 3-(thiophen-2-yl)prop-2-enals with nitro-substituted CH acids, namely ethyl nitroacetate, nitroacetone, nitroacetophenone, and nitroacetonitrile, afforded a series of geminally activated nitro dienes, 4-(furan-2-yl)- and 4-(thiophen-2-yl)-1-nitrobuta-1,3-dienes. The product structure was confirmed by NMR and IR spectroscopy.

     

Crystal Structure and Theoretical Energy Gap of 2-(2-((4-(Pyridin-2-yl)pyrimidin-2-yl)disulfanyl)pyrimidin-4-yl) pyridinium Hexafluorophosphate

The crystal structure of 2-(2-((4-(pyridin-2-yl)pyrimidin-2-yl)disulfanyl)pyrimidin-4-yl)pyridinium hexafluorophosphate was obtained by X-ray single-crystal diffraction. This molecule crystallizes in monoclinic P2/c space group with a=6.219(1), b=13.103(2), c=13.059(2) ?, β=97.567(2)°, Z=2, the final R=0.0525 and w R=0.1434. The title compound was prepared successfully from 1,2-bis(4-(pyridin-3-yl)pyrimidin-2-yl)disulfane(BPPD). TD-DFT computational studies on energy gaps and UV-Vis spectra of BPPD and the title compound have been carried out for comparisons. The resultant HOMO-LUMO gap of the BPPD compound is 4.45 e V, while that for the corresponding hexafluorophosphate salt is much smaller at 2.46 e V, which are in agreement with their UV-Vis absorptions.     

Synthesis of 6-Methyl-4-(1-methyl-2-buten-1-yl)-2-(2-cyclohexen-1-yl)- and 6-Methyl-4-(1-methyl-2-buten-1-yl)-2-(1-cyclohexen-1-yl)anilines

Alkenylation of 6-methyl-2-(2-cyclohexen-1-yl)- and 2-(1-cyclohexen-1-yl)anilines with piperylene in the presence of AlCl₃ and transformation of the resulting cyclohexenylanilines into carbazole structures were studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 441–443.Original Russian Text Copyright © 2005 by Gataullin, Ishberdina, Sotnikov, Abdrakhmanov.     

Nitrilimine cycloaddition to 4-(pyrazol-5-yl)carbonyl-2-azetidinone and 4-(pyrazol-4-yl)carbonyl-2-azetidinone

The higly stereoselective nitrilimine cycloaddition onto the novel 3(R*)-phenyl-4(S*)-cinnamoyl-2-azetidinone 2 gave 4-(4,5-dihydropyrazol-5-yl)carbonyl-2-azetidinone 5 as the major product and 4-(4,5-dihydropyrazol-4-yl)carbonyl-2-azetidinone 6 as the minor one. Ceric ammonium nitrate (CAN) oxidation of the cycloadducts gave the title compounds with good overall yield.     

Convenient synthesis of N-(4-(2-aminopyridin-4-yl)thiazol-2-yl)-2-phenylacetamides

We report a facile one-pot, three-step synthesis of N-(4-(2-aminopyridin-4-yl)thiazol-2-yl)-2-phenylacetamides via condensation of 2-p-methoxybenzylamino-4-acetylpyridine with phenylacetylthioureas.     

4-(4-吗啉)哌啶盐酸盐的合成

4-甲酸乙酯哌啶与溴苄反应,再经酰胺化和氨化反应制得关键中间体4-氨基-1-苄基哌啶(5);5与2,2-二溴二乙醚经环化反应制得N-苄基-4-(4-吗啉)哌啶,再经成盐,加氢合成了4-(4-吗啉)哌啶盐酸盐(1,总收率24.9%),1的结构经1HNMR,IR和GC-MS确认。     

Synthesis of stereoisomeric 4-(2-methylindolin-1-yl)- and 4-(2-methylindol-1-yl) derivatives of glutamic acid

The reaction of dimethyl (2S,4RS)-N-phthaloyl-4-bromoglutamate with 2-methylindoline afforded diastereomeric 4-(2-methylindolin-1-yl)-(S)-glutamic acid derivatives, whose oxidation gave rise to 4-(2-methylindol-1-yl)-(S)-glutamic acid derivatives.     

Asymmetric Synthesis of （-）-（4R, 5R）-4-[5-（Benzo[1, 3]dioxol-5-yl）-4- hydroxyl- 1-（pyridin-2-yl）-4, 5-dihydro- 1H-pyrazol-3-yl]benzamide

For discovering novel small molecule inhibitors of transforming growth factor-β1(TGF-β1)type-I receptor(ALK5),we designed1,3,5-triaryl-4-hydroxyl-4,5-dihydro-1H-pyrazole(1)as target compound,mimic the structure of SB-431542which is a2-pyridyl substituted triarylimiazole inhibitor of ALK51.Racemic compound1showed moderate ALK5inhibitory activity in luciferase reporter assays[inhibition(%control):0.1umol/L8.79%;1umol/L19.05%].To investigate the influence of the absolute configuration of…     

New 4-(benzotriazol-1-yl)-1,2,3-triazole derivatives

A new 4-(benzotriazol-1-yl)-1,2,3-triazole structure was obtained by the diazotization reaction of either of 1-(2-aminophenyl)-4-carboxamido-5-amino-1H-1,2,3-triazole ( 1c ) or of the corresponding Dimroth isomer 1d . It underwent some common reactions to evaluate its chemical behaviour and structure. An analogous reaction sequence was carried out from the 2-nitro-4-methylphenyl azide, to assign the structure to the nitro derivatives prepared. The structure of the new compounds prepared was confirmed by chemical and spectroscopic methods.     

5-Phenyl-2-(pyrazol-4-yl)-1,3,4-thiadiazoles

By recyclization of 2-R-6-ethyl-7-hydroxy(methoxy)-3-(5-phenyl-1,3,4-thiadiazol-2-yl)chromones when treated with hydrazine hydrate and phenylhydrazine, we synthesized 5-phenyl-2-(3-R-5-R1-1H-pyrazol-4-yl)-1H-1,3,4-thiadiazoles and 2-(3-R-5-R1-1-phenyl-1H-pyrazol-4-yl)-5-phenyl-1H-1,3,4-thiadiazoles. We confirmed the structure of the latter from ¹H NMR spectra.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 781–787, May, 2005.     

Heterocyclizations of 1-(Benzothiazol-2-yl)-4-phenylthiosemicarbazide

1-(Benzothiazol-2-yl)-4-phenylthiosemicarbazide reacted with methyl iodide in the presence of sodium acetate in boiling ethanol to give 2,2′-dithiobis[N-(5-methylsulfanyl-4-phenyl-4H-1,2,4-triazol-3-yl)-benzenamine]. The reaction of the title compound with dimethyl acetylenedicarboxylate in dioxane led to the formation of methyl 3-(benzothiazol-2-yl)-2-(2-methoxy-2-oxoethyl)-2,3-dihydro-1,3,4-thiadiazole-2-carboxylate.     

Synthesis of 2-(pyrimidin-4-yl)indoles

The synthesis of 2-substituted isomers of the meridianins, a familiy of bioactive indole alkaloids isolated from the tunicate Aplidium meridianum, was undertaken. The synthetic route comprises six steps, with a microwave promoted Fischer cyclization as the key reaction.     

Synthesis of 3-[4-(1-Benzofuran-2-yl)-1,3-thiazol-2-yl]-2-(4-aryl)-1,3-thiazolidin-4-one Derivatives as Biological Agents

A protocol for the synthesis of 3-[4-(1-benzofuran-2-yl)-1,3-thiazol-2-yl]-2-(4-aryl)-1,3-thiazolidin-4-one derivatives (5a–e) has been developed from 1-(1-benzofuran-2-yl)-2-bromoethanone (2),which served as a key intermediate for the synthesis of the title compounds. The reaction of compound 2 with thiourea furnished 4-(1-benzofuran-2-yl)-1,3-thiazol-2-amine 3, which upon further reaction with various aromatic aldehydes, gave Schiff bases 4a–e. These Schiff bases, when treated with thioacetic acid in the presence of catalytic amount of anhydrous ZnCl₂, yielded thiazolidinone derivatives 5a–e. All the newly synthesized compounds have been characterized by analytical and spectral data and screened for their antimicrobial and analgesic 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.