共查询到20条相似文献,搜索用时 62 毫秒
1.
Addition of various amines to the 3,3‐bis(trifluoromethyl)acrylamides 10a and 10b gave the tripeptides 11a – 11f , mostly as mixtures of epimers (Scheme 3). The crystalline tripeptide 11f 2 was found to be the N‐terminal (2‐hydroxyethoxy)‐substituted (R,S,S)‐ester HOCH2CH2O‐D ‐Val(F6)‐MeLeu‐Ala‐OtBu by X‐ray crystallography. The C‐terminal‐protected tripeptide 11f 2 was condensed with the N‐terminus octapeptide 2b to the depsipeptide 12a which was thermally rearranged to the undecapeptide 13a (Scheme 4). The condensation of the epimeric tripeptide 11f 1 with the octapeptide 2b gave the undecapeptide 13b directly. The undecapeptides 13a and 13b were fully deprotected and cyclized to the [5‐[4,4,4,4′,4′,4′‐hexafluoro‐N‐(2‐hydroxyethoxy)‐D ‐valine]]‐ and [5‐[4,4,4,4′,4′,4′‐hexafluoro‐N‐(2‐hydroxyethoxy)‐L ‐valine]]cyclosporins 14a and 14b , respectively (Scheme 5). Rate differences observed for the thermal rearrangements of 12a to 13a and of 12b to 13b are discussed. 相似文献
2.
Sciji Yamaguchi Hideo Saitoh Masahide Kurosaki Hajime Yokoyama Yoshiro Hirai Shunsaku Shiotani 《Journal of heterocyclic chemistry》1999,36(1):1-9
Bromination of α‐cyanopyridine derivatives of furopyridines 1a‐d gave the 2,3‐dibromo‐2,3‐dihydro compounds 2a‐d in excellent yields. Treatment of 2a‐d with sodium hydroxide in methanol yielded compounds formed through the dehydrobromination and solvolysis of the nitrile. N‐Oxidation of 1a and 1b gave N‐oxide in much poor yield, while 1c and 1d gave the N‐oxide 13c and 13d in good yields. The nucleophilic reactions (cyanation, chlorination and acetoxylatoin) of 13c through a Reissert‐Henze type reaction gave poor results, which would be caused by the strong electron withdrawing effect of the cyano group. 相似文献
3.
Quinolone Analogs 14: Synthesis of Antimalarial 1‐Aryl‐3‐(4‐quinolon‐2‐yl)ureas and Related Compounds
下载免费PDF全文
![点击此处可从《Journal of heterocyclic chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yoshihisa Kurasawa Kiminari Yoshida Naoki Yamazaki Kenji Sasaki Yoshito Zamami Zhao Min Atsumi Togi Hideyuki Ito Eisuke Kaji Haruhiko Fukaya 《Journal of heterocyclic chemistry》2014,51(Z1):E241-E248
The 4‐quinolone‐2‐carbohydrazide 6a was converted into 1‐aryl‐3‐(4‐quinolon‐2‐yl)ureas 5a , 5b , 5c , 5d , 5e , 1‐aryl‐3‐(4‐quinolon‐2‐yl)imidazolidine‐2,4‐diones 9a , 9b , and N‐(4‐quinolon‐2‐yl)carbamates 10a , 10b via 4‐quinolone‐2‐carbonylazide 7a . The 4‐methoxyquinoline‐2‐carbohydrazide 6b was also transformed into 1‐aryl‐3‐(4‐methoxyquinolin‐2‐yl)ureas 11a , 11b , 11c , 11d , 1‐aryl‐3‐(4‐methoxyquinolin‐2‐yl)imidazolidine‐2,4‐diones 12a , 12b , and N‐(4‐methoxyquinolin‐2‐yl)carbamates 13a , 13b via 4‐methoxyquinoline‐2‐carbonylazide 7b . Some of the 1‐aryl‐3‐(4‐quinolon‐2‐yl)ureas 5a , 5b , 5c , 5d , 5e showed the in vitro antimalarial activity to chloroquine‐resistant Plasmodium falciparum, wherein IC50 was 0.93 to 4.00 μM. 相似文献
4.
Mohamed G. Assy Mohamed H. Sherif Abd El‐Galil E. Amr Osama I. Abdelsalam Mohamed A. Al‐Omar Mohamed M. Abdalla Islam Ragab 《Journal of heterocyclic chemistry》2013,50(4):766-773
In continuation of our previous work, a series of novel thiophene derivatives 4 , 5 , 6 , 8 , 9 , 9a , 9b , 9c , 9d , 9e , 10 , 10a , 10b , 10c , 10d , 10e , 11 , 12 , 13 , 14 , 15 , 16 were synthesized by the reaction of ethyl 2‐amino‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carboxylate ( 1 ) or 2‐amino‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carbonitrile ( 2 ) with different organic reagents. Fusion of 1 with ethylcyanoacetate or maleic anhydride afforded the corresponding thienooxazinone derivative 4 and N‐thienylmalimide derivative 5 , respectively. Acylation of 1 with chloroacetylchloride afforded the amide 6 , which was cyclized with ammonium thiocyanate to give the corresponding N‐theinylthiazole derivative 8 . On the other hand, reaction of 1 with substituted aroylisothiocyanate derivatives gave the corresponding thiourea derivatives 9a , 9b , 9c , 9d , 9e , which were cyclized by the action of sodium ethoxide to afford the corresponding N‐substituted thiopyrimidine derivatives 10a , 10b , 10c , 10d , 10e . Condensation of 2 with acid anhydrides in refluxing acetic acid afforded the corresponding imide carbonitrile derivatives 11 , 12 , 13 . Similarly, condensation of 1 with the previous acid anhydride yielded the corresponding imide ethyl ester derivatives 14 , 15 , 16 , respectively. The structures of newly synthesized compounds were confirmed by IR, 1H NMR, 13C NMR, MS spectral data, and elemental analysis. The detailed synthesis, spectroscopic data, LD50, and pharmacological activities of the synthesized compounds are reported. 相似文献
5.
Anja Siegemund Christine Hartung Sven Baumann Brbel Schulze 《Helvetica chimica acta》2004,87(2):376-381
2‐Aryl‐4,5,6,7‐tetrahydro‐1,2‐benzisothiazol‐3(2H)‐ones 1a – e were synthesized by cyclocondensation of 2‐(thiocyanato)cyclohexene‐1‐carboxanilides 9 as a convenient new method. Their S‐oxides 10 were prepared by two routes, either by oxidation of 1 or dehydration of rac‐cis‐3‐hydroperoxysultims 11 . Furthermore, compounds 1 have been identified by HPLC? API‐MS‐MS as intermediates in the oxidation process of the salts 6 . The hydroperoxides 12b and rac‐trans‐ 11b have been unambiguously detected by HPLC? MS investigations and in the reaction of rac‐cis‐ 13b with H2O2 to the hydroperoxides rac‐trans‐ 11b and rac‐cis‐ 11b . 相似文献
6.
Twelve compounds unknown in the literature N‐(E)‐2‐stilbenyloxymethylenecarbonyl substituted hydrazones of 2‐, 3‐ and 4‐pyridinecarboxaldehydes, as well as methyl‐3‐pyridylketone have been prepared. The stereochemical behavior of these compounds in dimethyl‐d6 sulfoxide solution has been studied by 1H NMR technique. The E geometrical isomers and cis/trans amide conformers have been found for N‐substituted hydrazones 1–12. EI induced mass spectral fragmentation of these compounds were also investigated. The data obtained create the basis for distinguishing isomers. 相似文献
7.
Kazimieras Anusevicius Rita Vaickelioniene Vytautas Mickevicius Gema Mikulskiene 《Journal of heterocyclic chemistry》2013,50(2):309-314
A new potentially biologically active N‐(4‐chloro/iodophenyl)‐N‐carboxyethyl‐β‐alanine derivatives ( 2 , 2a , 2b , 3 , 3a , 3b , 4 , 4a , 4b , 8 , 8a , 8b , 9 , 9a , 9b ) and products of their cyclization 6 , 6a , 6b , 7 , 7a , 7b , 10 , 10a , 10b , 11 , 11a , 11b were obtained and characterized by the methods of 1H‐NMR, 13C‐NMR, IR, mass spectroscopy, and elemental analysis. 相似文献
8.
Synthesis,Crystal Structure,and Antibacterial Activity of 1,2,4‐Triazoles and 1,2,4‐Triazol‐3‐one
下载免费PDF全文
![点击此处可从《Journal of heterocyclic chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Bochra Ben Salah Najla Chaari Awatef Rekik Anis Ben Hsouna Mohamed Trigui Mohamed Kossentini 《Journal of heterocyclic chemistry》2015,52(6):1769-1775
A straightforward method has been developed for the synthesis of 1,2,4‐triazol‐3‐one 3 and 1,2,4‐triazoles 6a , 6b , 6c , 6d starting from N1‐substituted‐N1‐tosylhydrazonates 2 and hydrazine monohydrate. This methodology affords a number of 1,2,4‐triazol‐3‐one 3 and 1,2,4‐triazoles 6a , 6b , 6c , 6d in reasonable yields. The structures of all new compounds were elucidated using infrared, 1H and 13C NMR, high‐resolution mass spectrometry, elemental analysis, and the X‐ray crystallography (for compounds 3 and 6a ). Some of the newly synthesized compounds were screened for their antibacterial activity. 相似文献
9.
Ahmed Abdou O. Abeed 《Journal of heterocyclic chemistry》2015,52(4):1175-1184
A novel series of pyrazoline and thiazole derivatives incorporating 2‐pyrazolin‐5‐one moiety were synthesized starting from α,β‐unsaturated ketones under the effect of hydrazine derivatives and thiosemicarbazide. The obtained pyrazolines 4a , 4b were treated with different reagents to afford N‐substituted pyrazolines 5a , 5b , 6a , 6b , 7a , 7b , 8a , 8b . N‐Thiocarbamoyl pyrazolines 12a , 12b were cyclized using phenacyl bromide, 2,3‐dichloroquinoxaline, and monochloroacetic acid afforded the novel pyrazolinyl thiazoles 13a , 13b , 14a , 14b , 15a , 15b , 16a , 16b , 16c , 16d , 16e , 16f . The newly synthesized compounds were characterized by analytical and spectral data. 相似文献
10.
A series of 7‐fluorinated 7‐deazapurine 2′‐deoxyribonucleosides related to 2′‐deoxyadenosine, 2′‐deoxyxanthosine, and 2′‐deoxyisoguanosine as well as intermediates 4b – 7b, 8, 9b, 10b , and 17b were synthesized. The 7‐fluoro substituent was introduced in 2,6‐dichloro‐7‐deaza‐9H‐purine ( 11a ) with Selectfluor (Scheme 1). Apart from 2,6‐dichloro‐7‐fluoro‐7‐deaza‐9H‐purine ( 11b ), the 7‐chloro compound 11c was formed as by‐product. The mixture 11b / 11c was used for the glycosylation reaction; the separation of the 7‐fluoro from the 7‐chloro compound was performed on the level of the unprotected nucleosides. Other halogen substituents were introduced with N‐halogenosuccinimides ( 11a → 11c – 11e ). Nucleobase‐anion glycosylation afforded the nucleoside intermediates 13a – 13e (Scheme 2). The 7‐fluoro‐ and the 7‐chloro‐7‐deaza‐2′‐deoxyxanthosines, 5b and 5c , respectively, were obtained from the corresponding MeO compounds 17b and 17c , or 18 (Scheme 6). The 2′‐deoxyisoguanosine derivative 4b was prepared from 2‐chloro‐7‐fluoro‐7‐deaza‐2′‐deoxyadenosine 6b via a photochemically induced nucleophilic displacement reaction (Scheme 5). The pKa values of the halogenated nucleosides were determined (Table 3). 13C‐NMR Chemical‐shift dependencies of C(7), C(5), and C(8) were related to the electronegativity of the 7‐halogen substituents (Fig. 3). In aqueous solution, 7‐halogenated 2′‐deoxyribonucleosides show an approximately 70% S population (Fig. 2 and Table 1). 相似文献
11.
A series of double armed diaza‐15‐crown‐5 ethers (9a ‐ 16a) and diaza‐18‐crown‐6 ethers (9b ‐ 16b) have been prepared by the Mannich reaction of 2,6‐disubstituted phenols with the corresponding N,N'‐dimethoxymethyldiaza‐crown ethers in benzene. The crystal structures of the diaza‐18‐crown‐6 ethers having iso‐propyl (10b) , tert‐butyl (11b) , and mixed methyl and tert‐butyl groups (12b) at positions 3′ and 5′ of the phenolic side arms were determined using X‐ray diffraction methods. Competitive transport by these ligands for sodium, potassium and cesium cations were measured under basic‐source phase and acidic‐receiving phase conditions. 相似文献
12.
Yoshihisa Kurasawa Kiminari Yoshida Naoki Yamazaki Eisuke Kaji Kenji Sasaki Yoshito Zamami Yasuhiro Sakai Takatoshi Fujii Hideyuki Ito 《Journal of heterocyclic chemistry》2012,49(2):288-292
The reaction of the 6‐substituted 1‐methyl‐4‐quinolone‐3‐carboxylates 10a , 10b with hydrazine hydrate gave the 3‐carbohydrazides 7a , 7b , respectively, whose reaction with 2‐, 3‐, and 4‐pyridinecarbaldehydes afforded the 3‐(N2‐pyridylmethylene)carbohydrazides 8a , 8b , 8c and 9a , 9b , 9c . The Curtius rearrangement of compound 7b provided the N,N′‐bis(4‐quinolon‐3‐yl)urea 14 presumably via the 3‐carboazide 11 and then 3‐isocyanate 12 . Compounds 7a , 8a , and 9a were found to possess antimalarial activity from the in vitro screening data. J. Heterocyclic Chem.,(2011). 相似文献
13.
Malcolm A. Halcrow Colin A. Kilner Mark Thornton‐Pett 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):213-214
The title compound, C13H7F6N5, is one of a series of hindered tris‐imine ligands for meridonial coordination to transition metals. The molecule has crystallographic C2 symmetry, the pyrazole and pyridine rings adopting a near‐coplanar transoid conformation. 相似文献
14.
One‐pot Synthesis of 1,2,3,4‐Tetrahydropyrimidin‐2(1H)‐thione Derivatives and their Biological Activity
下载免费PDF全文
![点击此处可从《Journal of heterocyclic chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mounir A. I. Salem Magda I. Marzouk Marwa S. Salem Ghazala A. Alshibani 《Journal of heterocyclic chemistry》2016,53(2):545-557
2‐Thioxo/oxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylate derivatives 2a , 2b , 2c , 2d were prepared by the reaction of ethyl acetoacetate and thiourea or urea with aldehydes using NH4Cl as a catalyst. Compounds 2a and 2c reacted with mono and bihalogenated compounds such as ethyl iodide, chloroacetonitrile, epichlorohydrin, acetyl chloride, ethyl bromoacetate, chloroacetic acid, chloroacetylchloride, and/or oxalyl chloride to afford compounds 3 , 4a , 4b , 5 , 6a , 6b , 7 , 8 , 9 and 10 , respectively. Compounds 2a , 2c , and 7 were allowed to react with p‐fluorobenzaldehyde to yield the corresponding products 11a , 11b , and 12 , respectively. Oxidation of 2a and 2c gave 2b , 13a , 13b , 14 , 15 , 16 dependent on the oxidizing agent used. Vilsmeiere‐Haack formylation of 2a and 2b with POCl3/DMF afforded 17a and 17b . Chlorination of 2b and 2d gave the chlorinated derivative 18a and 18b , which reacted with thiourea to give thioureidopyrimidine 19a and 19b . Reactions of 2a with hydrazine monohydrate, semicarbazide hydrochloride, and sodium hydroxide gave compounds 20 , 21 , 22 , respectively. The cytotoxicity and in vitro anticancer evaluation of some prepared compounds have been assessed against two different human tumor cell lines including breast adenocarcinoma MCF‐7 and human hepatocellular carcinoma HepG2. Antimicrobial and antioxidant activities of some compounds were investigated. The newly synthesized compounds were characterized by IR, 1H‐NMR, 13C‐NMR, and mass spectral data. 相似文献
15.
16.
Shaaban K. Mohamed Ahmed M. Soliman Mahmoud A. A. El Remaily H. Abdel‐Ghany 《Journal of heterocyclic chemistry》2013,50(6):1425-1430
The reaction of 4‐oxo‐3,4‐dihydroquinazolinyl‐2‐guanidine 1 with several active methylene compounds has revealed formation of the corresponding hydropyrimidine and dihydropyrimidnone (DHPMs) derivatives via cycloaddition reaction mechanism. Satisfactory results were obtained with good yields, short time, and simplicity in the experimental procedure. Reaction with ketones in DMF proceeded via (5+1) heterocyclization and resulted in the formation of 2‐amino‐4‐(het)aryl‐4,6‐dihydro‐1(3)(11)H‐[1,3,5]triazino[2,1‐b]quinazolin‐6‐ones 8 , 9 , 10 , 11 , 12 , 13 , respectively. All compounds have been characterized based on IR, 1H‐NMR, and mass spectrum. 相似文献
17.
Elena I. Klimova Tatiana Klimova Marcos Flores Alamo José M. Méndez Stivalet Lena Ruíz Ramírez Leon V. Backinowsky Marcos Martínez García 《Journal of heterocyclic chemistry》2011,48(2):441-448
The reactions of α‐ferrocenylmethylidene‐β‐oxocarboxylates ( 1 , 2 , 3a , and 3b ) with N‐methyl‐ and N‐(2‐hydroxyethyl)hydrazines ( 5a , 5b ) afford ethyl 1‐alkyl‐5‐aryl(methyl)‐3‐ferrocenylpyrazole‐4‐carboxylates ( 6a , 6b , 6c , 6d , 6e ) (~50%) and N‐alkylhydrazine insertion products, viz., ethyl (N′‐acyl‐N′‐alkylhydrazino)‐3‐ferrocenylpropanoates ( 7a , 7b , 7c , 7d , 7e ) (~20%) and 1‐acyl‐2‐(N′‐alkyl‐N′‐ethoxycarbonylhydrazino)‐2‐ferrocenylethanes ( 8a , 8b , 8c , 8d , 8e ) (~10%). The structures of the compounds obtained were established based on the spectroscopic data and X‐ray diffraction analysis (for pyrazoles 6a and 6b ). J. Heterocyclic Chem., (2011). 相似文献
18.
Yoshihisa Kurasawa Waka Satoh Izumi Matsuzaki Yuka Maesaki Yoshihisa Okamoto Ho Sik Kim 《Journal of heterocyclic chemistry》2003,40(5):837-843
The reaction of the quinoxaline N‐oxides 7a,b with diethyl ethoxymethylenemalonate gave the 1‐methylpyridazino[3,4‐b]quinoxaline‐4,4‐dicarboxylates 8a,b , whose reaction with N‐bromosuccinimide or N‐chlorosuccinimide afforded the 3‐halogeno‐1‐methylpyridazino[3,4‐b]quinoxaline‐4,4‐dicarboxylates 9a‐d. The reaction of compounds 9a‐d with hydrazine hydrate resulted in hydrolysis and decarboxylation to provide the 3‐halogeno‐1‐methylpyridazino[3,4‐b]quinoxaline‐4‐carboxylates 10a‐d , whose reaction with nitrous acid effected oxidation to furnish the 3‐halogeno‐4‐hydroxy‐1‐methylpyridazino[3,4‐b]quinoxaline‐4‐carboxylates 11a‐d , respectively. The reaction of compounds 11a‐d with hydrazine hydrate afforded the 3‐halogeno‐1‐methylpyridazino[3,4‐b]quinoxalin‐4‐ols 12a‐d , whose oxidation provided the 3‐halogeno‐1‐methylpyridazino[3,4‐b]quinoxalin‐4(1H)‐ones 6a‐d , respectively. Compounds 6a‐d had antifungal activities in vitro. 相似文献
19.
Eleonora Freire Sergio Baggio Juan Carlos Muoz Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):o259-o262
The structures of the mono‐ and sesquihydrates of 2,6‐bis(1H‐benzimidazol‐2‐yl)pyridine (bbip) are reported. Phase (I), C19H13N5·H2O, has one water and one bbip molecule in the asymmetric unit, while phase (II), C19H13N5·1.5H2O, has three water molecules and two bbip molecules in the asymmetric unit. The compounds exhibit very similar molecular geometries but different packing organizations, which result from intricate hydrogen‐bonding schemes. 相似文献
20.
In an attempt to establish novel candidate with promising anticancer activity, two derivatives of (benzo[d]thiazol‐2‐yl)thiophene backbone 1 and 14 were synthesized, and they further reacted with various chemical reagents to afford the corresponding substituted thiophene derivatives 6 , 8 , 10 , 15 , 17 , and 20 , thieno[3,2‐d]pyrimidine derivatives 2 – 5 , 7 , 9 , 16 , 21 , 23 , and 24 , thieno[3,2‐b]pyridine derivatives 11 – 13 , and thieno[3,2‐e][1,4]oxazepine derivative 18 . Structures of prepared compounds were affirmed via spectral and elemental data. Among the obtained compounds, seven derivatives 2 , 3 , 4 , 5 , 11 , 12 , and 13 were chosen by National Cancer Institute, USA. Such compounds were screened for their antitumor activity versus 60 cancer cell lines in one‐dose (10 μmol) screening assay. The outcomes showed that all selected compounds exhibited moderate to high anticancer activity towards many cancer cell lines among which compounds 5 and 11 exerted potent antitumor activity against numerous malignant growth cell lines particularly Ovarian Cancer IGROV1. 相似文献