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1.
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
2.
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
3.
The photoinduced reaction of a mixture of (Z)‐α‐cyano‐β‐bromomethylcinnamide (1) and (E)‐α‐cyano‐β‐bromomethylcinnamide (2) with 1‐benzyl‐1, 4‐dihydronicotinamide produces a mixture of the (E)‐ and (Z)‐ isomers of α‐cyano‐β‐methylcinnamide (3 and 4). Using spin‐trapping technique for monitoring reactive intermediate, it is shown that the reaction proceeds via electron transfer‐debromination‐H abstraction mechanism. The thermal reaction of the same substrate with BNAH at 60°C in the dark gives three products: the (E)‐ and (Z)‐isomers of α‐cyano‐β‐methylcinnamide and a dehydrodimeric product; 2, 7‐dicyano‐3, 6‐diphenylocta‐2, 4, 6‐trien‐1, 8‐dioic amide (7). Based on product analysis, scavenger experiment and cyclic voltammetry, an electron transfer‐debromination‐disproportionation mechanism is proposed. 相似文献
4.
Christian Chapuis Michel Barthe Carole Cantatore Christine Saint‐Lger Patrick Wyss 《Helvetica chimica acta》2006,89(11):2638-2653
To complete our panorama in structure–activity relationships (SARs) of sandalwood‐like alcohols derived from analogues of α‐campholenal (= (1R)‐2,2,3‐trimethylcyclopent‐3‐ene‐1‐acetaldehyde), we isomerized the epoxy‐isopropyl‐apopinene (?)‐ 2d to the corresponding unreported α‐campholenal analogue (+)‐ 4d (Scheme 1). Derived from the known 3‐demethyl‐α‐campholenal (+)‐ 4a , we prepared the saturated analogue (+)‐ 5a by hydrogenation, while the heterocyclic aldehyde (+)‐ 5b was obtained via a Bayer‐Villiger reaction from the known methyl ketone (+)‐ 6 . Oxidative hydroboration of the known α‐campholenal acetal (?)‐ 8b allowed, after subsequent oxidation of alcohol (+)‐ 9b to ketone (+)‐ 10 , and appropriate alkyl Grignard reaction, access to the 3,4‐disubstituted analogues (+)‐ 4f,g following dehydration and deprotection. (Scheme 2). Epoxidation of either (+)‐ 4b or its methyl ketone (+)‐ 4h , afforded stereoselectively the trans‐epoxy derivatives 11a,b , while the minor cis‐stereoisomer (+)‐ 12a was isolated by chromatography (trans/cis of the epoxy moiety relative to the C2 or C3 side chain). Alternatively, the corresponding trans‐epoxy alcohol or acetate 13a,b was obtained either by reduction/esterification from trans‐epoxy aldehyde (+)‐ 11a or by stereoselective epoxidation of the α‐campholenol (+)‐ 15a or of its acetate (?)‐ 15b , respectively. Their cis‐analogues were prepared starting from (+)‐ 12a . Either (+)‐ 4h or (?)‐ 11b , was submitted to a Bayer‐Villiger oxidation to afford acetate (?)‐ 16a . Since isomerizations of (?)‐ 16 lead preferentially to β‐campholene isomers, we followed a known procedure for the isomerization of (?)‐epoxyverbenone (?)‐ 2e to the norcampholenal analogue (+)‐ 19a . Reduction and subsequent protection afforded the silyl ether (?)‐ 19c , which was stereoselectively hydroborated under oxidative condition to afford the secondary alcohol (+)‐ 20c . Further oxidation and epimerization furnished the trans‐ketone (?)‐ 17a , a known intermediate of either (+)‐β‐necrodol (= (+)‐(1S,3S)‐2,2,3‐trimethyl‐4‐methylenecyclopentanemethanol; 17c ) or (+)‐(Z)‐lancifolol (= (1S,3R,4Z)‐2,2,3‐trimethyl‐4‐(4‐methylpent‐3‐enylidene)cyclopentanemethanol). Finally, hydrogenation of (+)‐ 4b gave the saturated cis‐aldehyde (+)‐ 21 , readily reduced to its corresponding alcohol (+)‐ 22a . Similarly, hydrogenation of β‐campholenol (= 2,3,3‐trimethylcyclopent‐1‐ene‐1‐ethanol) gave access via the cis‐alcohol rac‐ 23a , to the cis‐aldehyde rac‐ 24 . 相似文献
5.
Sergey A. Komykhov Konstantin S. Ostras Alvard R. Kostanyan Sergey M. Desenko Valery D. Orlov Herbert Meier 《Journal of heterocyclic chemistry》2005,42(6):1111-1116
The reactions of α,β‐unsaturated nitriles ( 1, 9, 12 ) as bielectrophiles with aminoazoles ( 2, 4, 6 ) as binu‐cleophiles were investigated. Acrylonitrile ( 1 ) reacts almost exclusively in a chemoselective Michael‐type addition yielding the substituted azoles 3, 5 and 7 , respectively. Cinnamonitriles 9a,b behave in a similar way, but the free CN group adds a second molecule 4 yielding 10a,b and its cyclocondensation product 11a,b as minor component. The attempted formation of azolopyrimidines is best achieved by the reaction of the benzylidenemalononitriles 12a ‐ f with 2 or 4 . The process is chemo‐ and regioselective. The structure determinations were based on NMR measurements including DEFT, COSY, ROESY, HMQC and HMBC techniques and correct earlier suggestions. 相似文献
6.
Ahmed Ahmed El‐Barbary Yehia Ahmed Hafiz Mohamed Shaker Abdel‐Wahed 《Journal of heterocyclic chemistry》2011,48(3):639-644
Thiation of 1 by LR gave the corresponding 3,5‐dithioxo derivative 2 and the trimer 3 . Methylation of 1 afforded the S‐methyl derivative 4 . Compound 1 was fused with 6‐bromo‐2‐phenyl‐benzo[1,3‐d]oxazin‐4‐one ( 5 ) and gave 6 . Condensation of 1 with some acid derivatives 7a , 7b , 7c , 7d and/or 8a , 8b , 8c yielded thiadiazolo‐triazine derivatives 9a , 9b , 9c , 9d and 10a , 10b , 10c . Compounds 9a , 9c and 10c were hydrolyzed to furnish 11a , 11b , 11c Acetylation of 14 afforded mono‐ and diacetyl‐derivatives 15 and 16 . Benzoylation of 14 afforded mono‐ and dibezoyl‐derivatives 17 and 18 . 14 with some aromatic aldehydes yielded 9a , 9b , 9c . Reacting 14 with phenyl (iso‐ and/or isothio‐) cyanate gave the urea derivatives 20a , 20b . Thiation of 14 with P4S10 furnished 21 . The newly synthesized compounds were tested as antimicrobial agents. J. Heterocyclic Chem., (2011) 相似文献
7.
Joanna Borowiecka 《Heteroatom Chemistry》1999,10(6):465-470
The first examples of S‐thiophosphate derivatives of 2‐bromo‐2‐deoxy sugars 7–12 were synthesized by reacting alkyl ammonium salts 1–4 of thiophosphoric acids with α‐1,2‐cis (5) or α‐1,2‐trans dibromo sugars (6) and addition of free thiophosphoric acids 1a or 2a to 2‐bromo‐D‐glucal (13). It was observed that the solvent determines formation of either the O‐ or S‐glycosyl compound. β‐Thiophosphates can be transformed to the α‐configuration in the presence of acid in quantitative yield. The structures of the synthesized derivatives of 7–12 were confirmed by spectroscopic methods. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 465–470, 1999 相似文献
8.
Fawzy A. Attaby Ahmed H. H. Elghandour Hussein M. Mustafa Yasser M. Ibrahem 《中国化学会会志》2002,49(4):561-569
Cyanothioacetamide ( 1 ) reacted with but‐2‐enal ( 2 ) to give the corresponding 4‐methyl‐2‐sulfanylpyridine‐3‐carbonitrile ( 7 ) which was used as a good starting material for the synthesis of 1‐(3‐amino‐4‐methylthieno[2,3‐b]pyridin‐2‐yl)ethan‐1‐one ( 10 ), 3‐amino‐4‐methylthieno[2,3‐b]pyridine‐2‐carboxamide ( 15 ), 3‐amino‐4‐methylthieno[2,3‐b]pyridine‐2‐carboxylate ( 18 ) and 3‐amino‐4‐methylthieno[2,3‐b]pyridin‐2‐ylarylketone 25a‐c through its reactions with each of (1‐chloroacetone ( 8 ), 3‐chloropentane‐2,4‐dione ( 11 ) or ethyl 2‐chloro‐3‐oxo‐butanoate ( 19 )), 2‐chloroacetamide ( 13 ), ethyl 2‐chloroacetate ( 16 ) and 2‐bromo‐1‐arylethan‐ 1 ‐one 23a‐c , respectively. Considering the data of elemental analyses, IR, 1HNMR, mass spectra and theoretical calculations, structures of the newly synthesized heterocyclic compounds were elucidated. 相似文献
9.
Grzegorz Mlostoń Katarzyna Urbaniak Małgorzata Domagała Arno Pfitzner Manfred Zabel Heinz Heimgartner 《Helvetica chimica acta》2009,92(12):2631-2642
The thermal reaction of trans‐1‐methyl‐2,3‐diphenylaziridine (trans‐ 1a ) with aromatic and cycloaliphatic thioketones 2 in boiling toluene yielded the corresponding cis‐2,4‐diphenyl‐1,3‐thiazolidines cis‐ 4 via conrotatory ring opening of trans‐ 1a and a concerted [2+3]‐cycloaddition of the intermediate (E,E)‐configured azomethine ylide 3a (Scheme 1). The analogous reaction of cis‐ 1a with dimethyl acetylenedicarboxylate ( 5 ) gave dimethyl trans‐2,5‐dihydro‐1‐methyl‐2,5‐diphenylpyrrole‐3,4‐dicarboxylate (trans‐ 6 ) in accord with orbital‐symmetry‐controlled reactions (Scheme 2). On the other hand, the reactions of cis‐ 1a and trans‐ 1a with dimethyl dicyanofumarate ( 7a ), as well as that of cis‐ 1a and dimethyl dicyanomaleate ( 7b ), led to mixtures of the same two stereoisomeric dimethyl 3,4‐dicyano‐1‐methyl‐2,5‐diphenylpyrrolidine‐3,4‐dicarboxylates 8a and 8b (Scheme 3). This result has to be explained via a stepwise reaction mechanism, in which the intermediate zwitterions 11a and 11b equilibrate (Scheme 6). In contrast, cis‐1,2,3‐triphenylaziridine (cis‐ 1b ) and 7a gave only one stereoisomeric pyrrolidine‐3,4‐dicarboxylate 10 , with the configuration expected on the basis of orbital‐symmetry control, i.e., via concerted reaction steps (Scheme 10). The configuration of 8a and 10 , as well as that of a derivative of 8b , were established by X‐ray crystallography. 相似文献
10.
Martin S. Seyfried Anthony Linden Grzegorz Mlostoń Heinz Heimgartner 《Helvetica chimica acta》2009,92(9):1800-1816
The reactions of 5‐benzylidene‐3‐phenylrhodanine ( 2 ; rhodanine=2‐thioxo‐1,3‐thiazolidin‐4‐one) with diazomethane ( 7a ) and phenyldiazomethane ( 7b ) occurred chemoselectively at the exocyclic C?C bond to give the spirocyclopropane derivatives 9 and, in the case of 7a , also the C‐methylated products 8 (Scheme 1). In contrast, diphenyldiazomethane ( 7c ) reacted exclusively with the C?S group leading to the 2‐(diphenylmethylidene)‐1,3‐thiazolidine 11 via [2+3] cycloaddition and a ‘two‐fold extrusion reaction’. Treatment of 8 or 9b with an excess of 7a in refluxing CH2Cl2 and in THF at room temperature in the presence of [Rh2(OAc)4], respectively, led to the 1,3‐thiazolidine‐2,4‐diones 15 and 20 , respectively, i.e., the products of the hydrolysis of the intermediate thiocarbonyl ylide. On the other hand, the reactions with 7b and 7c in boiling toluene yielded the corresponding 2‐methylidene derivatives 16, 21a , and 21b . Finally, the reaction of 11 with 7a occurred exclusively at the electron‐poor C?C bond, which is conjugated with the C?O group. In addition to the spirocyclopropane 23 , the C‐methylated 22 was formed as a minor product. The structures of the products (Z)‐ 8, 9a, 9b, 11 , and 23 were established by X‐ray crystallography. 相似文献
11.
Xi Cun Wang Fang Wang Zheng Jun Quan Zhang Zhang Man Gang Wang 《Journal of heterocyclic chemistry》2006,43(6):1473-1477
12.
Andrew Solovyov Sergey Cherenok Ivan Tsymbal Salvatore Failla Giuseppe A. Consiglio Paolo Finocchiaro Vitaly Kalchenko 《Heteroatom Chemistry》2001,12(2):58-67
By the reaction of para‐formylcalix[4]arenes 1–6 with trialkyl phosphites in the presence of dry hydrogen chloride, calix[4]arenes 7–13 possessing dialkylphosphoryl‐hydroxymethyl groupings at the upper rim were synthesized. Calix[4]arenes 18–23 functionalized with dialkylphosphoryl‐alkyl(aryl)aminomethyl groups were obtained by sodium‐promoted addition of dialkyl phosphites to C=N bonds of para‐iminocalix[4]arenes 14–17 . The consecutive treatment of α‐hydroxy‐ or α‐aminophosphonic acid dialkyl esters of calix[4]arenes 7, 10, 18 , and 21 with bromotrimethylsilane and methanol gave dihydroxyphosphoryl derivatives of calix[4]arenes 24–27 . It was shown that calix[4]arenes bearing at the macrocyclic upper rim hydroxymethylphosphonic fragments, as well as bis‐hydroxymethyl(aminomethyl)phosphonic fragments, are able to undergo self‐assembly with formation of dimeric OH···O=P hydrogen bonded associates. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:58–67, 2001 相似文献
13.
Vladimir V. Kouznetsov Diego F. Amado Ali Bahsas Juan Amaro‐Luis 《Journal of heterocyclic chemistry》2006,43(2):447-452
14.
Abdelwareth A. O. Sarhan Hassa N. A. H. Elsherif Abdalla M. Mahmoud Osama M. A. Habib 《Journal of heterocyclic chemistry》2008,45(3):897-907
15.
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
16.
Andrzej Maślankiewicz Ewa Michalik Zbigniew Ciunik 《Journal of heterocyclic chemistry》2008,45(2):527-532
17.
The behavior of ethyl 2‐phenylthiocarb‐ amoyl acetate 1 toward a variety of several α‐halo‐ carbonyl compounds was investigated. Thus, reaction of 1 with α‐bromoketones, hydrazonoyl bromides, and 2‐chloro‐N‐arylacetamides afforded the corresponding dihydrothiazole, 1,3,4‐thiadiazole, and thiophene derivatives, respectively. The synthesis of thiazolidin‐4‐one 11 , thiazolidin‐5‐one 12 , and some azo derivatives of thiazolidin‐5‐one were described. 5‐Arylazothiazoles 17 and 19 were synthesized by condensation of hydrazonoyl bromides 3 with different thiourea derivatives. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:299–305, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20206 相似文献
18.
The reaction of 3‐benzoylcyanomethylidine‐1(H)‐indole‐2‐one ( 1 ) with a variety of active methylene compounds, thioglycolic acid, glycine, hydrazine hydrate and phenyl hydrazine led to the formation of compounds 4a‐d‐10 . 3‐Thiosemicarbazide‐1(H)‐indole‐2‐one 2 on reaction with α‐halocarbonyl compounds gave compounds 11a‐c, 12a‐c . The latter compounds on heating with phosphoryl chloride, cyclization takes place via losing water to give the angular tetracyclic compounds 13a,b and 14a‐c . Cyanoacetic hydrazone derivative 3 readily cyclized upon heating in triethyl orthoformate to give the tricyclic system, oxopyridazino indole 15 . On the other hand, the reaction of 3 with benzylidine malononitrile and benzylidene ethylcyanoactate gave the pyranyl hydrazone derivatives 16a,b . 相似文献
19.
The reactions of thiobenzamide 8 with diazo compounds proceeded via reactive thiocarbonyl ylides as intermediates, which underwent either a 1,5‐dipolar electrocyclization to give the corresponding five membered heterocycles, i.e., 4‐amino‐4,5‐dihydro‐1,3‐thiazole derivatives (i.e., 10a, 10b, 10c , cis‐ 10d , and trans‐ 10d ) or a 1,3‐dipolar electrocyclization to give the corresponding thiiranes as intermediates, which underwent a SNi′‐like ring opening and subsequent 5‐exo‐trig cyclization to yield the isomeric 2‐amino‐2,5‐dihydro‐1,3‐thiazole derivatives (i.e., 11a, 11b, 11c , cis‐ 11d , and trans‐ 11d ). In general, isomer 10 was formed in higher yield than isomer 11 . In the case of the reaction of 8 with diazo(phenyl)methane ( 3d ), a mixture of two pairs of diastereoisomers was formed, of which two, namely cis‐ 10d and trans‐ 10d , could be isolated as pure compounds. The isomers cis‐ 11d and trans‐ 11d remained as a mixture. In the reactions of the thioxohydrazone 9 with diazo compounds 3b and 3d , the main products were the alkenes 18 and 23 , respectively. Their formation was rationalized by a 1,3‐dipolar electrocyclization of the corresponding thiocarbonyl ylide and subsequent desulfurization of the intermediate thiiran. As minor products, 2,5‐dihydro‐1,3‐thiazol‐5‐amines 21 and 24 were obtained, which have been formed by 1,5‐dipolar electrocyclization of the thiocarbonyl ylide, followed by a 1,3‐shift of the dimethylamino group. 相似文献
20.
Jnos Kovcs Nra Balzsdi Szab Zoltn Nagy Krisztina Ludnyi Gyrgy Keglevich 《Heteroatom Chemistry》2005,16(5):320-326
Novel 7‐phosphanorbornene derivatives, such as 4, 5, 10 , and 11 were synthesized utilizing 1‐phenyl‐2‐methyl‐2,5‐dihydro‐1H‐phosphole oxide ( 1 ) and 1‐cyclohexyl‐3‐methyl‐2,5‐dihydro‐1H‐phosphole oxide ( 7 ) as the starting materials. Products 4 and 10 were prepared by trapping the corresponding phosphole oxide intermediates ( 3 and 9 , respectively) by N‐phenylmaleimide, while 5 and 11 were obtained by the dimerization of 3 and 9 , respectively. The trapping reaction was studied in details; on one hand, bromo‐2,3‐dihydro‐1H‐phosphole oxides ( 6‐1 and 6‐2 ) were pointed out as the intermediates, on the other hand, the trapping reaction was optimized. Bri‐ dged P‐heterocycles 4, 5, 10 , and 11 were tested in the fragmentation‐related phosphorylation of methanol. Hydrogenation of phosphanorbornenes 4 and 5 led to the corresponding phosphanorbornanes ( 12 and 14 , respectively) and to a reductive type of retro cycloaddition. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:320–326, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20097 相似文献