A convenient synthesis of ethyl 2-(4-nitrophenyl)-3,4-disubstituted and c-fused thiophene-5-carboxylates

A convenient one step synthesis of the hitherto unknown ethyl 2-(4-nitrophenyl)-3,4-disubstituted and c-fused thiophene-5-carboxylates was achieved by the condensation of ethyl 4-nitrobenzylthioacetate with a variety of 1,2-dicarbonyl compounds using sodium ethoxide in refluxing ethanol.     

Synthesis of Ethyl 4-(1,2,3-Selenodiazol-4-yl)-5-alkylsulfanyl- and -5-Phenylsulphonylmethylfuran-2-carboxylates

Russian Journal of General Chemistry - By means of the reactions of ethyl 4-acetyl-5-bromomethylfuran-2-carboxylate with butanethiol, ethyl sulfanylacetate and sulfanylethanol the corresponding...     

Solid-state synthesis of poly(3',4'-dimethoxy-2,2':5',2"- terthiophene): comparison with poly(terthiophene) and poly(3',4'-ethylenedioxy-2,2':5',2"- terthiophene)

A new terthiophene monomer: 3',4'-dimethoxy-2,2':5',2"-terthiophene (TMT) was synthesized and characterized by 1H-NMR, 13C-NMR and FTIR. The solid-state oxidative polymerizations of TMT were performed in various ratios of oxidant (FeCl?) to monomer (TMT). The resulting polymers were characterized by 1H-NMR, FTIR, UV-vis-NIR, GPC, X-ray diffraction, CV, as well as TGA and conductivity measurements. The structure and properties of poly (TMT) were compared with those of polyterthiophene [poly(TT)] and poly (3',4'-ethylenedioxy-2,2':5',2"-terthiophene) [poly(TET)] prepared under the same polymerization conditions. After comparative analysis with poly(TT) and poly(TET), the effects of the dimethoxy substituent and FeCl? on the structural and physicochemical properties of the poly(TMT)s were discussed in depth. The comparison suggested that the dimethoxy-substituted polymer did not display higher crystallinity, thermal stability, conductivity and electrochemical activity than ethylenedioxy substituted one. The results also showed that the effect of FeCl? on poly(TMT) was similar that seen with the poly(TT), in which the oxidation degree, electrochemical activity and conductivity increased steadily with increasing [FeCl?/[TT] ratio. Furthermore, the poly(TMT) and poly(TT) are mostly made up of dimers with a small amount of higher molecular weight components.     

Synthesis and anti-inflammatory-analgesic activity of 2'',4''-difluoro-3-(carbamoyl)biphenyl-4-yl benzoates

Eighteen 2',4'-difluoro-3-(carbamoyl)biphenyl-4-yl benzoates were synthesized from diflunisal in three steps with total yields from 72% to 86%. All compounds were identified by IR, 1H NMR, MS and elemental analysis. The anti-inflammatory activity and analgesic activity for 18 compounds were evaluated. The preliminary assay results showed that compounds 4a and 4p exhibited potent anti-inflammatory-analgesic activity.     

Synthesis of new 1-substituted 4-(2-phenylquinazolin-4-yl)-and 4-(2-phenylquinazolin-4-ylidene) thiosemicarbazides

Two new 1-substituted 4-(2-phenylquinazolin-4-yl)-and 4-(2-phenylquinazolin-4-ylidene) thio-semicarbazides were formed by a multistep domino reaction of imidoyl isothiocyanate derivative with 1,1-di-R-hydrazine in acetone solution. Application of hydrazine hydrate under the same reaction conditions afforded 4-(2-phenylquinazolin-4(3H)-ylidene)-2-(propen-2-yl)-1-(propan-2-ylidene) thio-semicarbazide via a six-step triple-component domino reaction. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1688–1693, November, 2008.     

Synthesis of antimicrobial agents of tetra-substituted thiophenes from ethyl 5-(2-bromoacetyl)-4-phenyl-2-(phenylamino)thiophene-3-carboxylate

5-(2-Bromoacetyl)-2,3,4-trisubstituted-thiophene was used as a synthetic intermediate to prepare a series of thiophene derivatives and thiophene incorporating oxazole, imidazole, thiazole, pyrrole, and pyridine rings via substitution and cyclo-condensation reactions. The data were extracted from the spectra of the resulting products confirmed their suggested structures. The newly synthesized compounds were screened to evaluate their in vitro antimicrobial activity vs several positive and negative gram bacteria and fungi. The screening data revealed that the thiophene derivative 7a , incorporating a thiazole ring, displayed strong activity against all tested microorganisms when compared with the antibiotics used.     

沙库必曲中间体(R)-2-(叔丁氧羰基氨基)-3-(联苯-4-基)丙醇的合成

采用D-酪氨酸衍生物为原料,与苯磺酰氯反应制得叔丁氧羰基保护的D-苯丙氨醇苯磺酸酯,经还原,再在5 mol% N-杂环卡宾(NHC)钯催化剂(IMes)Pd(Py)Cl作用下与苯硼酸经过Suzuki-Miyaura偶联反应得到沙库必曲重要中间体(R)-2-(叔丁氧羰基氨基)-3-(联苯-4-基)丙醇,总产率大于57%,ee值大于99%。     

Synthesis of 2-and 6-chloro-3-(5-methyl-1,3,4-oxadiazol-2-yl)pyridines

A convenient synthesis of 2- and 6-chloro-3-(5-methyl-1,3,4-oxadiazol-2-yl)pyridines, 3 and 10 , utilizing the readily available amide 7 is described. Incorporation of the 3-t-butylamino-2-hydroxypropoxy side chain onto 3 provided 2 , a potential bioisostere of 1 . The antihypertensive activities of 2 and 12 were evaluated in the spontaneously hypertensive rat model.     

Synthesis,Crystal Structure and Anticoagulant Activity of 5-Chloro-N-[[（5S）-2-oxo-3-[4-（2- oxopyridin-1 （2H）-yl）phenyl] oxazolidin-5- yl] methyl] thiophene-2-carboxamide①

The title compound(zifaxaban 2, C20H16ClN3O4 S, Mr = 429.87) was synthesized and its crystal structure was determined by single-crystal X-ray diffraction. Zifaxaban crystallizes in monoclinic, space group P21 with a = 5.7900(12), b = 13.086(3), c = 12.889(3) A, β = 100.86(3)°, V = 959.1(3) A3, Z = 2, Dc = 1.489 g/cm3, F(000) = 444, μ = 0.342 mm-1, the final R = 0.0320 and wR = 0.0640 for 2717 observed reflections(I 2σ(I)). The absolute configuration of the stereogenic center in the title compound was confirmed to be S by single-crystal X-ray diffraction. Four existing intermolecular hydrogen bonds help to stabilize the lattice and the molecule in the lattice to adopt an L-shape conformation. Zifaxaban was slightly more active than rivaroxaban 1 in in vitro assay against human FXa and therefore is promising as a drug candidate.     

Synthesis of 2-and 5-(1,1-Dimethyl-1,2,5,6-tetrahydropyridinium-3-yl)oxadiazoline Iodides

ＩｎｔｒｏｄｕｃｔｉｏｎＲｅｃｅｎｔｌｙ ,ｔｈｅｉｎｃｒｅａｓｉｎｇｄｅｍａｎｄｆｏｒｅｆｆｅｃｔｉｖｅｔｒｅａｔ ｍｅｎｔｏｆｎｅｕｒｏｄｅｇｅｎｅｒａｔｉｖｅｄｉｓｅａｓｅｓ ,ｐａｒｔｉｃｕｌａｒｌｙＡｌｚｈｅ ｉｍｅｒ’ｓｄｉｓｅａｓｅ (ＡＤ) ,ｉｓｂｅｃｏｍｉｎｇｍｏｒｅａｎｄｍｏｒｅｕｒ ｇｅｎｔ.ＡｍｏｎｇｔｈｅｒｅｓｅａｒｃｈｅｓｉｎｔｈｅｒａｐｅｕｔｉｃｓｆｏｒＡＤ ,ｍａｎｙｍｕｓｃａｒｉｎｉｃｃｏｍｐｕｎｄｓｎｏｔｏｎｌｙａｒｅｂｅｎｅｆｉｃｉａｌｉｎｔｈｅｔｒｅａｔ ｍｅｎｔｏｆＡ…     

Synthesis of ethyl 4-(1,2,3-thiadiazol-4-yl)-5-(bromomethyl)furan-2-carboxylate and its reactions with nucleophiles

By cyclization of carboethoxyhydrazone of ethyl 4-acetyl-5-methylfuran-2-carboxylate under the conditions of Hurd–Mori reaction ethyl 4-(1,2,3-thiadiazol-4-yl)-5-methylfuran-2-carboxylate was synthesized. The ester obtained was brominated with N-bromosuccinimide at the methyl group in the furan ring. This bromide reacts with various N-, S-, O-, and P-nucleophiles to form the corresponding substitution products. Furylthiadiazole fragment remains stable in the course of these transformations.     

Synthesis,film-forming properties,and photosensitivity of 4-alkoxy(acyloxy)-3-alkoxyphenylmethylene-(biphenyl-4-yl)amines

The reactions of ethers and esters of the vanillin series with biphenyl-4-ylamine in absolute methanol yielded previously unknown E isomers of biphenyl-substituted azomethines (Schiff bases). The film properties and photosensitivity of the new compounds were examined.     

The synthesis and photoactivated cytotoxicity of novel 5-phenyl-3- （2,2＇：5＇,2″-terthien-5-yl）-4,5-dihydro-lH-pyrazolines

A series of novel 5-phenyl-3-（2,2＇：5＇,2″-terthien-5-yl）-4,5-dihydro-lH-pyrazolines were synthesized in this report. Their photoactivated cytotoxicities on the 5podoptera litura （SL） cell line were evaluated using the MTT method. It was noticed that the inhibitory activities of all the conjugates was enhanced when irradiated with UV-A light. Compounds 4, 6 and 8 were found to be most effective with inhibition rates of 88.1%, 88.0%, and 90,5%, respectively, For compound B, the inhibition rate value was only slightly enhanced under the irradiation treatment （78.3%） compared to the dark treatment （74.8%）. The relationship analysis between structure and activity showed that the middle thiophene ring played an important role on the inhibitory activities. It was shown that these compounds could be the potential candidates for new photoactivated pesticides.     

Synthesis of ethyl 5-aryl-5-(trifluoromethyl)-4,5-dihydroisoxazole-3-carboxylates,exhibiting plant growth-regulating properties

Russian Chemical Bulletin - A convenient method for the synthesis of high-boiling-point α-(trifluoromethyl)styrenes was proposed. The regioselective synthesis of a series of ethyl...     

Synthesis,studies and in vitro antibacterial activity of some 5-(thiophene-2-yl)-phenyl pyrazoline derivatives

In the present investigation, a novel series of pyrazolines 2a–2d were synthesized by the cyclization of various -1-[2-(alkoxy) phenyl]-3-(thiophen-2-yl) prop-2-en-1-one 1a–1d with N-substituted phenyl hydrazine and thiosemicarbazide in the presence of CH₃COOH and NaOH in ethanol which lead to the formation of new pyrazolines. The structures of these compounds were elucidated by, IR, ¹H-NMR, ¹³C-NMR, ESI-MS spectral data and their purities were confirmed by elemental analyes. The in vitro antibacterial activity of these compounds was evaluated against two Gram-positive and two Gram-negative bacteria Aeromonas hydrophila, Yersinia enterocolitica, Listeria monocytogenes, and Staphylococcus aureus by microdilution method and then the minimum inhibitory concentration (MIC) of these compounds was determined. The results showed that compounds 1-[2-(benzyloxy) phenyl]-5-(thiophen-2-yl)-1-phenyl-4,5-dihydro-1H-pyrazol-4-yl (2b) and 1-[2-(naphthalen-2-ylmethoxy) phenyl]-5-(thiophene-2-yl)-1-phenyl-4,5-dihydro-1H-pyrazole-4-yl (2d) showed most promising antibacterial activity as compared to the antibiotics gentamicin and tetracycline in (Table 1, Table 2).     

新型1-取代-2-(1′,3′-二氧五环-4′-基)苯并咪唑的合成

以地沟油水解副产物甘油和多聚甲醛为原料,经醇醛缩合和次氯酸钠催化氧化反应制得1,3-二氧杂环戊-4-酸(DIC); DIC与邻苯二胺或其衍生物进行酰胺化-环化反应高效地合成了3种新型的1-取代-2-(1′,3′-二氧五环-4′-基)苯并咪唑类化合物,其结构经UV-Vis, ¹H NMR, ¹³C NMR, IR和GC-MS表征。     

Synthesis and pharmacological activity of 2-(biphenyl-4-yl)imidazo[1,2-a]benzimidazoles

Russian Chemical Bulletin - An efficient method for the synthesis of novel 9H-imidazo[1,2-a]benzimidazole derivatives containing a biphenyl substituent at position 2 was developed. These compounds,...