bluuebunny/crossref_metadata_2025_split huggingface dataset:
A convenient synthesis of novel spiro[benzoxazole‐2′,4(1H,3′H)‐pyrazolo[5,1‐c][1,2,4]triazines] by ring transformation of novel pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzoxazepines
Authors: Kurasawa Yoshihisa , Okiyama Mari , Kamigaki Yumiko , Kanoh Megumi , Okamoto Yoshihisa , Takada Atsushi 
Published: April 2009

AbstractNovel pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzoxazepines 5, 6 and 8 were synthesized, and these compounds were converted into novel spiro[benzoxazole‐2′,4(1H,3′H)‐pyrazolo[5,1‐c][1,2,4]triazines] 7 and 9 by ring transformation.
Synthesis of 2,2′‐dithiobis‐ and 2,2′‐trithiobis‐3‐pyridinecarboxylic acid derivatives as new potential radiosensitizers/radioprotectors
Authors: Monge A. , Martinez‐Merino V. , Fernández‐Alvarez E. 
Published: April 2009

AbstractThis paper reports the synthesis of dithio and trithio derivatives of 1,2‐dihydro‐2‐thioxopyridine, starting with 1,2‐dihydro‐2‐thioxo‐3‐pyridine carboxylic acid 1.This compound reacted with thionyl chloride to give the respective dithiobis (acyl chloride) 2, which hydrolyzed to the corresponding dithio acid 3. On the other hand, 1 reacted with sulfur dichloride to give trithio acid 4, which on treatment with thionyl chloride gave the trithiobis (acyl chloride) 5. Treatment of 2 and 5 with ethanol/pyridine, gave 8 and 12 respectively. Compounds 2–5, 8 and 12 were unstable in alkaline medium and they were degraded to 1.The bis(acyl chloride) 2 and 5 reacted with ammonia and primary and secondary amines to give the respective bis(amide) 9 and 13. Most of these amides (R = H, alkyl, aryl, R' = H) were found to be unstable in the presence of bases such as triethylamines, pyridine or excess of the starting amine, which promotes disproportion to give (see Scheme 3) the respective N‐substituted (R) 1,2‐dihydro‐2‐thioxo‐3‐pyridinecarboxamide 10 and the respective 2‐substituted (R)‐3‐oxo‐isothiazolo[5,4‐b]pyridine 11. On the other hand, compounds 11 were unstable to strong bases and they were transformed into the respective compounds 10 by an unknown mechanism. Boiling 11f with sodium hydroxide in ethanol gave 10f (50%). According to these last results, boiling 9h or 13d with sodium hydroxide in ethanol 10h (68%) and 10d (70%) were obtained.
On the oxidizability of 1‐methyl‐1,2,3,4‐tetrahydropyrimido[1,2‐a]indole‐10‐carboxaldehyde and its crystal structure
Authors: Andreani Aldo , Greci Lucedio , Tosi Giorgio , Sgarabotto Paolo , Ugozzoli Franco 
Published: April 2009

AbstractThe study of the molecular geometry of 1‐methyl‐1,2,3,4‐tetrahydropyrimido[1,2‐a]indole‐10‐carboxaldehyde as determined by X‐ray analysis and the electrochemical properties of that compound are reported. These are compared with those of a number of indole‐3‐carboxaldehyde, differently substituted at 1 and 2 position. This was done in order to understand the unsuccessful attempts to convert the title compound into the corresponding acid. The result indicate that this anomalous behaviour may be attributed to easy oxidizability of the pyrimido ring nitrogen.
Furan derivatives. Part 9. Synthesis and properties of cyclohepta[cd]benzofurans
Authors: Horaguchi Takaaki , Tanemura Kiyoshi , Suzuki Tsuneo 
Published: April 2009

AbstractCyclohepta[cd]benzofurans 1a‐c were synthesized by heating (5‐oxo‐5H‐benzocyclohepten‐4‐yloxy)acetic acids 7a‐c with sodium acetate in acetic anhydride or by irradiation of 7a‐c in acetonitrile. Several reactions such as protonation, catalytic hydrogenation, Diels‐Alder reaction, acylation, and photoreaction were examined for 1a‐b. The results show that cyclohepta[cd]benzofurans have both properties of heptafulvene and benzofuran. The carbon‐carbon double bond in the furan ring of 1a has aromatic character, however, the carbon‐carbon double bonds in the seven‐membered ring have olefinic character.
Studies on pyrrolidinones. Synthesis of N‐acylpyroglutamic esters with bactericide and fungicide properties
Authors: Rigo Benoǐt , Lespagnol Charles , Pauly Marc 
Published: April 2009

AbstractThe best method to prepare N‐acylpyroglutamic esters is to react N‐trimethylsilylpyroglutamic esters with acid chlorides or diketene. These acylesters possess bactericide and fungicide properties against several microorganisms.
Azabicyclo chemistry. 7. Ultra‐high field (600 MHz) NMR spectroscopy in solving conformational problems: cis‐Octahydroindoles
Authors: Mokotoff Michael , Hill Scott T. 
Published: April 2009

AbstractStudies using ultra‐high field (600 MHz) nmr spectroscopy has allowed us to assign the conformational preference of cis‐octahydroindoles, including the position of their nitrogen lone‐pair electrons. Lithium aluminum hydride reduction of cis‐octahydroindol‐2‐one (4) gave cis‐octahydroindole (5a) which showed three distinct nmr resonances, the C7a proton at δ 3.04 (apparent q, J = 5.3 Hz) and the two C2 protons at δ 3.10 and 2.94. The latter two resonances were absent in the C2 deuterated compound 5b. Deuteromethylation of 5a, via a urethane intermediate, gave 1‐deuteromethyl‐cis‐octahydroindole (8a) which showed resonances at δ 3.12 for the α‐faced C2 proton, the β‐faced C2 proton at δ 2.17, and the C7a proton at δ 2.15. The resonances at δ 3.12 and 2.17 are absent in the corresponding C2 deuterated compound 8b, and the C7a remains as a doublet of triplets (d, J = 5.5 Hz; t, J = 3.8 Hz). Interpretation of the above data led us to assign 8a as the cis compound with nitrogen axial, and the lone pair electrons in a pseudo‐axial position and antiperiplanar to the C7a and β‐faced C2 protons. The amine 5a is also cis and has the nitrogen axial, but the lone pair electrons are pseudo‐equatorial. Inspection of the Bohlmann band region in the ir of 5a and 8a supports the above assignments. These investigations thus suggest, in cis‐octahydroindoles, the following steric order: methyl > lone pair > H.
Bioactive heterocyclic analogs of the antitumor drug, podophyllotoxin
Authors: Jurd Leonard 
Published: April 2009

Abstract3,4‐Methylenedioxyphenol (sesamol) condenses with pyrrolidine and aromatic aldehydes to yield Mannich bases of type4. The Mannich bases react readily with ketonic reagents to form pyrrolidinylbenzopyran derivatives which provide a simple route to antimitotic and bioactive heterocyclic analogs of the anti‐cancer drug, podophyllotoxin.
Synthesis of certain 3,5,7‐disubstituted pyrazolo[3,4‐e][1,3]oxazines. Derivatives of a new heterocyclic ring system
Authors: Beylin Vladimir G. , Townsend Leroy B. 
Published: April 2009

AbstractThe synthesis of several 3,5,7‐trisubstituted pyrazolo[3,4‐e][1,3]oxazines by ring annulation of the appropriately substituted pyrazoles is described.
Synthesis of 4H‐pyrazolo‐ and 4H‐pyrrolophenothiazin‐4‐one derivatives
Authors: Nan'ya Seiko , Katsuraya Kaname , Ueno Yoshio , Maekawa Eturǒ 
Published: April 2009

Abstract5‐Methyl‐ and 6‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐diones were condensed with 2‐aminobenzenethiol or 6‐substituted‐3‐aminopyridine‐2(1H)thiones 4 to produce a new type of 5‐methyl‐2‐phenyl‐4H‐pyrazolophenothiazin‐4‐ones or 8‐substituted‐7‐aza‐5‐methyl‐2‐phenyl‐4H‐pyrazolophenothiazin‐4‐one derivatives. From 6‐bromo‐2,5‐dimethyl‐1,3‐diphenyl‐2H‐isoindole‐4,7‐dione and 4 8‐substituted‐7‐aza‐2,5‐dimethyl‐1,3‐diphenyl‐4H‐pyrrolophenothiazin‐4‐one derivatives were also prepared.
Preparation of 2‐aryl and 2‐aryloxymethyl imidazo[1,2‐a]pyridines and related compounds
Authors: Sundberg Richard J. , Dahlhausen D. J. , Manikumar G. , Mavunkel B. , Biswas Atanu , Srinivasan V. , King Fred , Waid Philip 
Published: April 2009

AbstractA series of substituted 2‐aryl imidazo[1,2‐a]pyridines has been prepared in which a variety of substituents are introduced on the 4′‐position of the phenyl ring and on the 3, 5, 6 or 7 position of the heterocyclic ring. Most examples have acetamido, bromo, cyano, or formyl substituents at the 4′‐position. Analogous imidazo‐[2,1‐b]fhiazoles and imidazo[1,2‐a]pyrimidines have also been prepared. Another series of compounds consisting of 4′‐formylphenoxymethyl derivatives of imidazole, the three positional isomers of pyridine, thiazole, benzimidazole and ring‐substituted imidazo[1,2‐a]pyridines has been prepared. 2‐(4′‐Formylphenylethenyl) derivatives of imidazole and imidazo[1,2‐a]pyridine were also prepared.
The synthesis and some NMR properties of 2,3‐bis(diphenylphosphino)‐6‐phenyl‐λ3‐phosphinine
Authors: Holah David G. , Hughes Alan N. , Knudsen Karen L. , Perrier Richard 
Published: April 2009

AbstractThe synthesis, from 1,2,5‐triphenylphosphole and bis(diphenylphosphino)acetylene, of 2,3‐bis(diphenylphosphino)‐6‐phenyl‐λ3‐phosphinine, the first example of a λ3‐phosphinine bearing phosphorus‐containing side chains, is reported. This compound shows in its nmr spectrum the largest value of 3Jpp (178 Hz) yet reported for a system containing the PIII‐C‐C‐PIII linkage. Evidence is presented which supports the idea that this extraordinarily large coupling arises as a result of geometrical factors which place the non‐bonding electron pairs of the two side‐chain P atoms in very close proximity to one another. Reactions of the λ3‐phos‐phinine with Ni(II) and Pt(II) compounds are briefly discussed in the context of the nmr properties of both the ligand and the complexes formed.
Syntheses of apogalanthamine analogs as α‐adrenergic blocking agents. IX. Syntheses of optically active 8‐hydroxy‐6‐methyl‐5,6,7,8‐tetrahydrodibenz[c,e]azocines
Authors: Kihara Masaru , Ohnishi Kuniyoshi , Kobayashi Shigeru 
Published: April 2009

Abstract(8R) and (8S)‐Hydroxy‐6‐methyl‐5,6,7,8‐tetrahydrodibenz[c,e]azocines (R‐ and S‐1) were synthesized by oxidative kinetic resolution of N‐(2‐iodobenzyl)‐β‐(2‐iodophenyl)ethanolamine (8), followed by cyclization of the optically active acetates (R‐ and S‐6) of R‐ and S‐8 with zero‐valent nickel to (8R)‐ and (8S)‐acetoxyazocines (R‐ and S‐7), and by hydrolysis of the acetates (R‐ and S‐7).
Crystal structure and reactivity of 2‐chloro‐3,5‐dinitrothiophene and of 2‐phenylsulphonyl‐3,5‐dinitrothiophene with nucleophiles
Authors: Mugnoli Angelo , Spinelli Domenico , Consiglio Giovanni , Noto Renato 
Published: April 2009

AbstractThe geometry obtained by a crystal structure determination of the title compounds, as compared with that of the analogous benzene derivatives, along with results of ab initio calculations, is used to interpret the different SNAr reactivities in some thiophene and benzene compounds. The smaller rotation of the nitro groups with respect to the aromatic rings observed in thiophene derivatives should be considered a relevant factor in the higher reactivity in the thiophene series.
Synthesis of 1‐azacycl[3.2.2]azine and 1‐azabenzo[h]cycl[3.2.2]azine
Authors: Tominaga Yoshinori , Shiroshita Yoshihide , Kurokawa Tomohiko , Matsuda Yoshiro , Hosomi Akira 
Published: April 2009

Abstract1‐Azacycl[3.2.2]azines were synthesized from 2‐methylthioimidazo[1,2‐a]pyridines, 2a and 2b, by using [2 + 8] cycloaddition reaction with dimethyl acetylenedicarboxylate as the key step. Synthesis of 1‐azabenzo‐[h]cycl[3.2.2]azine was also described.
Synthesis and structure determination of N‐(alkoxycarbonylsulfenyl)‐s‐triazine herbicides
Authors: Pilgram K. H. , Gale Laird H. 
Published: April 2009

AbstractVarious 2‐substituted‐4,6‐bis(alkylamino)‐1,3,5‐triazines, 1, have been found to react with alkoxycarbonylsulfenyl chlorides, 2, to give the title compounds, 3. The structural characterization of 3a in the solid state by single X‐ray crystallographic analysis established that it is the isomer wherein the methoxycarbonylthio group is attached to the less sterically hindered, exocyclic nitrogen bearing the ethyl group.
A short and efficient synthesis of 4a‐substituted cis‐hexahydro‐1,2,3,4,4a,9a‐carbazol‐4‐ones
Authors: Gramain J.‐C. , Troin Y. , Husson H.‐P. 
Published: April 2009

AbstractPhotocyclization of tertiary aryl enaminones 1 gave trans‐hexahydrocarbazol‐4‐ones 2 which were subsequently alkylated with a series of electrophiles via the corresponding thermodynamic anion. The 4a‐substituted derivatives formed were shown to have the cis‐hexahydrocarbazol‐4‐one structure by comparison with the previously prepared trans isomer.
1,3‐Dipolar cycloadditions of aryl nitrilimines to electron‐poor alkenes
Authors: Adembri Giorgio , Celli Angela M. , Scotton Mirella 
Published: April 2009

AbstractThe 1,3‐dipolar cycloadditions of aryl nitrilimines to 1,2‐diacetylethylene gave along with the 1,2‐diaryl‐4,5‐diacetyl‐4,5‐dihydropyrazoles 5 and the corresponding dehydrogenated pyrazoles 6, the unexpected 1,3‐diaryl‐4‐acetylpyrazoles 7. As for tetrasubstituted alkenes, whereas 1,2‐diacetyl‐1,2‐dicarbethoxyethylene gave a stable cycloadduct 8, 1,2,3,4‐tetraacetylethylene yielded a mixture of pyrazoles 6 and 7.
Chemotherapeutical agents. VII. Synthesis and pesticidal activities of sulphides and sulphones derived from bis[4‐aryl‐1,2,4‐triazoline‐5‐thione‐3‐yl]alkane and 5‐phenyl‐1,3,4‐oxadiazole‐2‐thione
Authors: Ram Vishnu J. , Vlietinck Arnold J. 
Published: April 2009

AbstractThe bis[4‐aryl‐3‐alkylthio‐1,2,4‐triazol‐5‐yl]alkanes 4 were prepared by the action of alkyl halides on bis[4‐aryl‐1,2,4‐triazoline‐5‐thione‐5‐yl]alkanes in aqueous sodium hydroxide (5%). The prepared sulphides 4 were oxidised to give the corresponding sulphones 5 either with acidic potassium permanganate or hydrogen peroxide. Similarly, sulphides 8 were prepared from 5‐phenyl‐1,3,4‐oxadiazole‐2‐thione by reaction with different alkylhalides in alkaline medium. Mannich bases 9 from 5‐phenyl‐1,3,4‐oxadiazole‐2‐thione (7) were also prepared by stirring an equimolar solution of 6 in ethanol with formaldehyde (38%) and an amine in an ice‐cold bath. All the compounds were screened for their pesticidal activities but none showed any significant activity.
The regioselectivity in the reactions of N‐aryl‐C‐ethoxycarbonylnitrilimines with acrylic acid derivatives
Authors: Ezmirly Saleh T. , Shawali Ahmad S. 
Published: April 2009

AbstractThe cycloaddition of a series of C‐ethoxycarbonyl‐N‐arylnitrilimines 5a‐f to acrylic acid derivatives namely acrylamide, acrylonitrile and ethyl acrylate has been studied. Under thermal conditions 1,3‐dipolar cycloadditions proceed with complete regioselectivity to give 5‐R substituted 2‐pyrazolines 8–10 in high yield. The structures of the cycloadducts 8–10 were confirmed by 13C nmr, 1H nmr and ir spectra. The regioselectivity is interpreted in terms of HOMO(nitrilimine)‐LUMO(dipolarophile) interaction.
Synthesis and anticonvulsant activity of some novel 3‐aminoquinazolines
Authors: Tita Terence T. , Kornet Milton J. 
Published: April 2009

AbstractA number of novel 3‐aminoquinazolines were obtained via two synthetic pathways. In the first method o‐aminobenzoylhydrazines were prepared either by reacting an isatoic anhydride and a hydrazine or by reacting o‐nitrobenzoic acid with a hydrazine, followed by catalytic reduction. Subsequent cyclization with an appropriate orthoester provided 3‐aminoquinazolines and 2‐methyl‐3‐aminoquinazolines. The second pathway involved condensation of o‐aminoacetophenone with a hydrazine to form hydrazones which were reduced to aminohydrazines and cyclized as above to yield 4‐methyl‐3‐aminoquinazolines and 2,4‐dimethyl‐3‐aminoquinazolines. The title compounds were evaluated in mice in MES and sc Met seizure models for anticonvulsant activity, and in the rotorod test for neurotoxicity. They were generally toxic. However, 4‐methyl‐3‐(N‐piperidino)‐3,4‐dihydroquinazoline hydrochloride exhibited activity comparable to that of methaqualone.
The reduction of 6‐methoxy‐9‐methyl‐11‐oxoechiboline using lithium aluminium hydride
Authors: Cox Brian , Robinson Brian 
Published: April 2009

AbstractReduction of 6‐methoxy‐9‐methyl‐11‐oxoechiboline 1a using lithium aluminium hydride in boiling tetrahydrofuran under reflux affords 6‐methoxy‐9‐methylechiboline. However, attempts to effect a similar reduction of a suspension of compound 1a in boiling diethyl ether under reflux, in which it is only very slightly soluble, were unsuccessful and when, under these conditions, a Soxhlet apparatus was employed to effect dissolution, an unexpected reductive ring scission occurred along with reduction of the carbonyl group to afford 4a‐(2‐aminoethyl)‐6‐methoxy‐9‐methyl‐1,2,3,4,4a,9a‐hexahydrocarbazole 3.
Synthesis, reactions and biological evaluation of some 1,2,4‐triazine derivatives
Authors: Mansour A. K. , Eid Mohga M. , Hassan R. A. , Haemers A. , Pattyn S. R. , Vanden Berghe D. A. , Van Hoof L. 
Published: April 2009

Abstract6‐Substituted benzyl‐4‐phenyl‐3‐thioxo‐2,3,4,5‐tetrahydro‐1,2,4‐triazin‐5‐ones 3a‐d were prepared and converted into their corresponding 3‐methylthio derivatives 4a‐d. Reaction of compounds 4a‐d with hydrazine hydrate gave the corresponding 4‐amino‐3‐anilino‐4,5‐dihydro‐1,2,4‐triazin‐5‐ones 5a‐d. 6‐Substituted benzyl‐4‐phenyl‐2,3,4,5‐tetrahydro‐1,2,4‐triazin‐3,5‐diones 9a‐c were synthesized and allowed to react with hydrazine hydrate to give the corresponding 6‐substituted benzyl‐4‐amino‐2,3,4,5‐tetrahydro‐1,2,4‐triazin‐3,5‐diones 10a‐c. The biological evaluation of some of these triazines is described. All compounds were screened for antiviral, antibacterial, antimycobacterial, antifungal and antiyeast activity. No important biological activity was found.
Synthesis and reactions of halo‐, nitro‐, and arylazo‐substituted 3‐aminotropolones. Formation of 8H‐cyclohept[d]oxazol‐8‐one derivatives
Authors: Zhang Luo‐Cheng , Yin Bing‐Zhu , Jin Zhong‐Tian , Imafuku Kimiaki 
Published: April 2009

Abstract3‐Acetamidotropolone (1a) reacted with bromine and fuming nitric acid to afford respectively 3‐acetamido‐7‐bromo‐ (1b) and ‐5,7‐dibromotropolone (1c) and 3‐acetamido‐5‐nitrotropolone (1d). Azo‐coupling reaction of 1a gave 3‐acetamido‐5‐(4‐methylphenylazo)tropolone (1f). Bromination of 1d and 1f gave 7‐bromo‐substituted compounds 1e and 1g, respectively. The compounds 1b‐g were hydrolyzed to afford 3‐aminotropolones 4b‐g, which reacted with triethyl orthoformate to give the corresponding 8H‐cyclohept[d]oxazol‐8‐ones 5b‐g. Heating of 3‐acetamidotropolones 1a‐d with polyphosphoric acid gave 2‐methyl‐8H‐cyclohept[d]oxazol‐8‐ones 6a‐d.
A facile synthesis of 1‐alkylthio and acylthio‐2,3‐dihydro‐1H‐naphtho[2,1‐b]thiopyrans and 4‐alkylthio and acylthio‐3,4‐dihydro‐2H‐naphtho[1,2‐b]thiopyrans
Authors: Nakazawa Toshikatsu , Itabashi Kunio 
Published: April 2009

AbstractThe reaction of 3‐(2‐naphthylthio)propionaldehyde (3)and its (1‐naphthylthio)isomer (7)with a variety of thiols and thio acids in the presence of sulfuric acid at room temperature afforded 1‐alkylthio and acylthio‐2,3‐dihydro‐1H‐naphtho[2,1‐b]thiopyrans 5 and 4‐alkylthio and acylthio‐3,4‐dihydro‐2H‐naphtho[1,2‐b]thiopyrans 9 in excellent yield.
Synthesis and structure determination of isomeric 7‐ and 8‐chloro‐1,5‐benzodiazepine derivatives
Authors: Pennini R. , Cerri A. , Tajana A. , Nardi D. , Giordano F. 
Published: April 2009

AbstractReaction of 4‐chloro‐1,2‐benzenediamine with 3,3‐dimercapto‐1‐phenyl‐2‐propen‐1‐one afforded, as expected, a mixture of 7‐chloro and 8‐chloro‐1,3‐dihydro‐4‐phenyl‐2H‐1,5‐benzodiazepine‐2‐thione. After separation of the two components and further reaction, their structure was established by chemical degradation of 7‐chloro‐2‐(2‐diethylaminoethylthio)‐4‐phenyl‐3H‐1,5‐benzodiazepine to 5‐chloro‐1,3‐dihydro‐1‐methyl‐2H‐benzimidazol‐2‐one. The structure was also confirmed by single X‐ray analysis of 7‐chloro‐2‐(2‐diethylaminoethylthio)‐4‐phenyl‐3H‐1,5‐benzodiazepine.
Studies on the synthesis of heterocyclic compounds. XVI. Cleavage of 1,3‐benzodioxoles and ‐benzoxathioles by sodium iodide‐acyl chloride
Authors: Corda Luciana , Fadda Anna Maria , Maccioni Antonio , Maccioni Anna Maria , Podda Gianni 
Published: April 2009

AbstractThe cleavage reaction of ethereal and thioethereal bonds with sodium iodide and acyl chloride has been studied. In all the 1,3‐benzodioxoles and ‐benzoxathioles studied, the opening of the heterocyclic ring with formation of 1,2‐diacetoxybenzene or 2‐hydroxythiophenol diacetic ester and gem‐diiodoalkanes and iodoalkenes has been observed. The structure of newly prepared compounds has been determined by analytical and spectroscopic data or comparison with authentic samples.
Porphyrin system containing [2.2]paracyclophane units
Authors: Czuchajowski Leszek , Lozynski Marek 
Published: April 2009

AbstractMeso‐tetrakis([2.2]paracyclophanyl)porphyrin was obtained from [2.2]paracyclophanecarbaldehyde and pyrrole. Replacement of phenyl groups in meso‐tetraphenylporphyrin by paracyclophanyl substituents remarkably influences the electronic structure of the molecule, causing bathochromic shifts of all uv‐vis absorption bands, and changing the ring current of the porphyrin core. The shifts in the electron spectrum are substantially greater than those observed for other porphyrin derivatives characterized by their extended π‐electron systems, such as meso‐tetrakis(2‐phenylethenyl)porphyrin and meso‐tetrakisbiphenylporphyrin.
Synthesis of 2′‐deoxyribofuranosyl indole nucleosides related to the antibiotics SF‐2140 and neosidomycin
Authors: Girgis Nabih S. , Cottam Howard B. , Robins Roland K. 
Published: April 2009

AbstractThe 2′‐deoxyribofuranose analog of the naturally occurring antibiotics SF‐2140 and neosidomycin were prepared by the direct glycosylation of the sodium salts of the appropriate indole derivatives, with 1‐chloro‐2‐ deoxy‐3,5‐di‐O‐p‐toluoyl‐α‐D‐erythropentofuranose (5). Thus, treatment of the sodium salt of 4‐methoxy‐1H‐ indol‐3‐ylacetonitrile (4a) with 5 provided the blocked nucleoside, 4‐methoxy‐1‐(2‐deoxy‐3,5‐di‐O‐p‐toluoyl‐β‐ D‐erythropentofuranosyl)‐1H‐indol‐3‐ylacetonitrile (6a), which was treated with sodium methoxide to yield the SF‐2140 analog, 4‐methoxy‐1‐(2‐deoxy‐β‐D‐erythropentofuranosyl)‐1H‐indol‐3‐ ylacetonitrile (7a). The neosidomycin analog (8) was prepared by treatment of the sodium salt of 1H‐indol‐3‐ylacetonitrile (4b) with 5 to obtain the blocked intermediate 1‐(2‐deoxy‐3,5‐di‐O‐p‐toluoyl‐β‐D‐erythropentofuranosyl) −1H‐indol‐3‐ylace‐tonitrile (6b) followed by sodium methoxide treatment to give 1‐(2‐deoxy‐β‐D‐erythropentofuranosyl)‐1H‐ indol‐3‐ylacetonitrile (7b) and finally conversion of the nitrile function of 7b to provide 1‐(2‐deoxy‐β‐D‐ erythropentofuranosyl)‐1H‐indol‐3‐ylacetamide (8). In a similar manner, indole (9a) and several other substituted indoles including 1H‐indole‐4‐carbonitrile (9b), 4‐nitro‐1H‐indole (9c), 4‐chloro‐1H‐indole‐2‐carboxamide (9d) and 4‐chloro‐1H‐indole‐2‐carbonitrile (9e) were each glycosylated and deprotected to provide 1‐(2‐deoxy‐β‐D‐erythropentofuranosyl)‐1H‐indole (11a), 1‐(2‐deoxy‐β‐D‐erythropentofuranosyl)‐1H‐indole‐4‐ carbonitrile (11b), 4‐nitro‐1‐(2‐deoxy‐β‐D‐erythropentofuranosyl)‐1H‐indole (11c), 4‐chloro‐1‐(2‐deoxy‐β‐D‐ erythropentofuranosyl)‐1H‐indole‐2‐carboxamide (11d) and 4‐chloro‐1‐(2‐deoxy‐β‐D‐erythropentofuranosyl)‐ 1H‐indole‐2‐carbonitrile (11e), respectively.The 2′‐deoxyadenosine analog in the indole ring system was prepared for the first time by reduction of the nitro group of 11c using palladium on carbon thus providing 4‐amino‐1‐(2‐deoxy‐β‐D‐erythropentofuranosyl)‐ 1H‐indole (16, 1,3,7‐trideaza‐2′‐deoxyadenosine).
Synthesis of unsymmetrical arylthiophenes and bithienyls via oxidative cyclization of 1,3‐butadiene‐1‐thiols
Authors: Campaigne E. , White R. L. 
Published: April 2009

AbstractOxidative cyclization of 2‐mercapto‐5‐aryl‐2,4‐pentadienoic acids with iodine produced the respective 5‐aryl‐2‐thenoic acids. The method was also suitable for the synthesis of unsymmetrical substituted 2,2′‐bithienyls, and 2,3′‐bithienyls. The synthesis of 5‐carboxy‐2′‐bromo‐5′‐phenyl‐2,3′‐bithienyl from benzal‐acetone demonstrated that oxidative cyclization of 1,3‐butadiene‐1‐thiols is a useful procedure for preparing 5′‐aryl‐2,3′‐bithienyls from simple carbonyl compounds. Preferential ring bromination of 2‐phenyl‐4‐methyl‐thiophene with N‐bromosuccinimide and a radical catalyst was also observed.