bluuebunny/crossref_metadata_2025 huggingface dataset:
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

This 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

The 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

Cyclohepta[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

The 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

Studies 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

3,4‐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

The 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

5‐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

A 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

The 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

(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

The 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

1‐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

Various 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

Photocyclization 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.
Facile synthesis of N‐10 flavin disulfides
Authors: Kumar V. , Averill B. A.
Published: April 2009

A facile, high yield route to N‐10 flavin disulfides is described. The key feature is catalytic reduction of the nitro group to an amine function in an organic sulfide using platinum sulfide on charcoal.
1,3‐Dipolar cycloadditions of aryl nitrilimines to electron‐poor alkenes
Authors: Adembri Giorgio , Celli Angela M. , Scotton Mirella
Published: April 2009

The 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

The 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

The 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

A 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

Reduction 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

6‐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

3‐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

The 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

Reaction 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

The 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

Meso‐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

The 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

Oxidative 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.
Preparation of trimethylsilyl ethers of 3‐azetidinols. Scope and Limitations
Authors: Higgins Robert H. , Watson Monique R. , Faircloth William J. , Eaton Quentin L. , Jenkins Harvey
Published: April 2009

Preparation of the trimethylsilyl ethers of 1‐alkyl‐3‐azetidinols from non‐hindered primary amines and epichlorohydrin by conversion of the intermediate 1‐(alkylamino)‐3‐chloro‐2‐propanols to their trimethylsilyl ethers by either N‐(trimethylsilyl)acetamide or by 1‐(trimethylsilyl)imidazole followed by ring closure in acetonitrile is described. This sequence of reactions fails for aromatic amines, but appears to be general for all primary aliphatic amines, although the condensation of hindered amines with epichlorohydrin occurs slowly. Several novel azetidinols, in which the N‐alkyl substituent itself contains a second heterocyclic system, are reported. In addition, the pKA's of several m. and p‐substituted 1‐benzylazetidinols correlates well with the Hammett equation.
The synthesis and transformations of 9H‐imidazo[1,2‐b]pyrazolo[4,3‐d]‐pyridazine and 9H‐pyrazolo[4,3‐d]‐s‐triazolo[4,3‐b]pyridazine derivatives
Authors: Stanovnik Branko , Furlan Borut , Kupper Marko , Malež Lidija , Štimac Anton , Tišler Miha , Žličar Marko
Published: April 2009

The nucleophilic and electrophilic substitutions of 6‐substituted 9,9‐dimethyl‐9H‐imidazo[1,2‐b]pyrazolo‐ [4,3‐d]pyridazines 2, nucleophilic substitutions of 6‐substituted 9,9‐dimethyl‐9H‐pyrazolo[4,3‐d]‐s‐triazolo‐ [4,3‐b]pyridazines 7 and some other transformations to give compounds 3 and 8, respectively, were studied. It was shown that both heterocyclic systems are stable under the conditions employed in these transformations.
Reaction of ketenes with N,N‐disubstituted α‐aminomethyleneketones. XIX. Synthesis of N,N‐disubstituted 4‐amino‐3‐phenyl‐2H‐furo[2,3‐h]‐1‐benzopyran‐2‐ones (4‐amino‐3‐phenylangelicins). Crystal and molecular structure of 3‐Phenylangelicin
Authors: Mosti Luisa , Schenone Pietro , Menozzi Giulia , Sancassan Fernando , Baccichetti Francarosa , Benetollo Franco , Bombieri Gabriella
Published: April 2009

1,4‐Cycloaddition of phenylchloroketene to N,N‐disubstituted 5‐aminomethylene‐6,7‐dihydrobenzo[b]‐ furan‐4(5H)‐ones gave the corresponding adducts, namely N,N‐disubstituted 4‐amino‐3‐chloro‐3,4,5,6‐tetra‐ hydro‐3‐phenyl‐2H‐furo[2,3‐h]‐l‐benzopyran‐2‐ones II, which were dehydrochlorinated with DBN to N,N‐disubstituted 4‐amino‐5,6‐dihydro‐3‐phenyl‐2H‐furo[2,3‐h]‐1‐benzopyran‐2‐ones III. Compounds III afforded the title compounds IV by dehydrogenation with DDQ. In the cycloaddition step, 3‐phenylangelicin V, whose structure was confirmed by 1H‐nmr shift reagents data and by X‐ray crystal structure determination, was almost always formed, probably starting from II by dehydrochlorination, dehydrogenation and hydrogenolysis of the disubstituted amino group. Separation of V was achieved by alumina chromatography either in the cycloaddition step or, in most cases, in the dehydrochlorination step.

3‐Phenylangelicin crystallizes in the trigonal system, space group R3, with cell parameters (hexagonal axes) a = b = 41.021(10), c = 3.888(2) Å. The angelicin moiety forms a dihedral angle of 42.1(1)° with the phenyl substituent. Disordered solvent molecules of ethyl acetate are clathrated in channels in the direction of the crystallographic axis c.
Amidrazones 11. Rearrangement of 1‐allyl‐substituted‐4,5‐dihydro‐1‐methyl‐1H‐pyrazolium bromides
Authors: Smith Richard F. , Dennis Lisa A. , Ryan William J.
Published: April 2009

1‐Methyl‐2‐(2‐propenyl)‐3‐pyrazolidinimine (5) was obtained by treatment of 3‐amino‐4,5‐dihydro‐1‐methyl‐ 1‐(2‐propenyl)‐1H‐pyrazolium bromide (4) with ethanolic sodium ethoxide. Similar treatment of the analogous 2‐(2‐butenyl) and 2‐(3‐phenyl‐2‐propenyl)‐substituted salts 12 and 15 gave 1‐methyl‐2‐(1‐methyl‐2‐propenyl)‐3‐ pyrazolidinimine (13) and 1‐methyl‐2‐(1‐phenyl‐1‐propenyl)‐3‐pyrazolidinimine (16) respectively.
Synthesis, structural and conformational study of N‐β(or γ)‐acyloxyalkylnortropinones
Authors: Izquierdo M. L. , Gálvez E. , Burgos C. , Florencio F.
Published: April 2009

A series of N‐β(γ)‐acyloxyalkylnortropinones have been synthesized and studied by 1H and 13C nmr spectroscopy, and the crystal structure of N‐[γ‐(p‐chlorophenylcarbonyloxy)propyl]nortropinone 4 has been determined by X‐ray diffraction. The compounds studied display in deuteriochloroform solution the same preferred conformation. The pyrrolidine and piperidone rings adopt a flattened N‐8 envelope and distorted chair conformation, puckered at N‐8 and flattened at C‐3 respectively, with the N‐substituent in axial position with respect to the piperidone ring. These results are in close agreement with that found for compound 4 in the crystalline state.
Synthesis of some pyrrolobenzothiadiazonines
Authors: Cheeseman G. W. H. , Varvounis G.
Published: April 2009

Four pyrrolobenzothiadiazonines, compounds 6, 10, 16 and 24, have been prepared from 1‐substituted‐2‐ thiocyanatopyrrole intermediates.
A facile synthesis of 2,4,8,10‐tetrahalo‐6,12‐diaryldibenzo[b,f][1,5]diazocines
Authors: Boruah R. C. , Sandhu J. S.
Published: April 2009

3,5‐Dihalo‐2‐aminobenzophenones 2 on prolonged reflux in dry pyridine gave 2,4,8,10‐tetrahalo‐6,12‐ diaryldibenzo[b,f][1,5]diazocines 3 in high yields. Attempted condensation of 2 with glycine ester hydrochloride under identical reaction conditions failed to afford 1,4‐benzodiazepines.
Indole derivatives. 1. Synthesis of tetracyclic mesoionic pyrimido[3,2:2′,3′]‐as‐triazino[5′,6′‐b]indole‐2,4‐diones
Authors: Mbagwu Godwin O. , Bullock Boris , Greer Onza
Published: April 2009

The synthesis of the title compounds 5 has been accomplished by the thermal cyclocondensation of bis(2,4,6‐trichlorophenyl) malonates with the appropriately substituted alkyl er arylalkylaminotriazinoindole.
C‐Nucleosides. 8. Synthesis of 5‐hydroxy‐2‐(β‐D‐ribofuranosyl)pyridine
Authors: Maeba Isamu , Suzuki Makoto , Takahashi Naoko , Iijima Takashi , Furukawa Hiroshi
Published: April 2009

The synthesis of 5‐hydroxy‐2‐(β‐D‐ribofuranosyl)pyridine (12) from 2‐(2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranosyl)furan (1) is described. Treatment of 1 with α‐methoxycarbamate in the presence of p‐toluenesulfonic acid in benzene at reflux temperature afforded furfurylcarbamate (2) and its α‐isomer in a 5/1 ratio. The anomerization was circumvented by treatment of 1 with α‐methoxycarbamate in the presence of boron trifluoride in benzene at room temperature. Compound 2 was electrochemically oxidized to give dihydrofuran 4. However, conversion of 4 into 11 was unsuccessful. Treatment of azide 8 with bromine and methanol afforded 9. Reduction of 9 with zinc powder gave dihydrofurfurylamine 10, in 80% yield. Treatment of this with concentrated hydrochloric acid in methanol yielded 11, which on deblocking with 5% sodium hydroxide aqueous solution gave 12.
Halogenated 3‐pyridylketones
Authors: Sutter Peter , Weis Claus D.
Published: April 2009

The oxidation of 2,6‐dichloro‐3‐benzylpyridines and bis(2,6‐dichloro‐3‐pyridyl)methanes, respectively, was accomplished using chromic trioxide in a highly acidic medium. The synthesis of several phenyl‐3‐(2,6‐dichloropyridyl)ketones and of bis(2,6‐dichloro‐3‐pyridyl)ketone are reported.
Synthesis of santonin related compounds
Authors: Tsuboi Sadao , Shinhama Koichi , Takeda Akira
Published: April 2009

(±)‐1‐Nordesmotroposantonin (2), a thermolysis product of santonin, and its isomer, α‐(1,2,3,4‐tetrahydro‐1,7‐dihydroxy‐α,6‐dimethyl‐2‐naphthalene)acetic acid γ‐lactone (3) were synthesized from 4‐(4‐methoxy‐3‐ethylphenyl)butanoic acid.
Synthèse d'oxaphénalènes substitués en position 2 par un groupement électro‐attractif
Authors: Buisson Jean‐Pierre , Royer René
Published: April 2009

Il est montré que la condensation de Rap [1] d'un composé halogéno‐méthylénique et d'un aldéhyde ortho‐ hydroxylé peut ětre effectuée en péri, avec les aldéhydes hydroxy‐8 naphtoïques‐1.
Reinvestigation of the condensation of 2‐hydrazinobenzothiazole with ethyl acetoacetate
Authors: Peet Norton P. , Sunder Shyam , Barbuch Robert J. , Whalon Michael R. , Huffman John C.
Published: April 2009

The reaction of 2‐hydrazinobenzothiazole (1) with ethyl acetoacetate has twice been reported to yield a fused triazepinobenzothiazolone, namely, 3‐methyl[1,2,4]triazepino[3,4‐b]benzothiazol‐5(4H)‐one (4). We have repeated this work and reassigned the reaction product as 2‐(2‐benzothiazolyl)‐1,2‐dihydro‐5‐methyl‐3H‐pyrazol‐3‐one (5) on the basis of X‐ray crystallography.
Some novel mesoionic bispurinone analogs: Studies on preparation and characterization
Authors: Mbagwu Godwin O. , Garland Rickie
Published: April 2009

The preparation of the first examples of class II mesoionic bispurinones is described. Arylaminobithiazole 3 is cyclized by condensation with bis(2,4,6‐trichlorophenyl) methylmalonate to yield anhydro 3,3′‐bis(6‐methyl‐8‐aryl‐5‐hydroxy‐7‐oxothiazolo[3,2‐a]pyrimidinium hydroxide).
Conjugated systems derived from piperazine‐2,5‐dione
Authors: Katritzky Alan R. , Fan Wei‐Qiang , Szajda Maria , Li Qiao‐Ling , Caster Kenneth C.
Published: April 2009

The preparation of mono‐ and of symmetrical and unsymmetrical bis‐ylidine derivatives of piperazine‐ 2,5‐dione is described. The uv‐visible absorption of the products is correlated with acceptor/donor character of the substituents.
On the mechanism of a novel 3(2H)‐Furanone‐2(5H)‐furanone rearrangement
Authors: Mack Robert A. , Carroll Patrick J. , Georgiev Vassil St.
Published: April 2009

The isolation of a stable intermediate product and the mechanism of a novel 3(2H)‐furanone‐2(5H)‐furanone rearrangement that led to the facile preparation of a new class of γ‐lactone amides 2 and 4 are discussed.
A new regioselective synthesis of 2,3,4,5‐tetrahydro‐6H‐oxepino[3,2‐c]pyran‐6‐ones, and [1]benzopyran‐6‐ones
Authors: Bravo Pierfrancesco , Frigerio Massimo , Ticozzi Calimero
Published: April 2009

Through an anti‐Markovnikow hydration of some olefin derivatives of 4‐hydroxy‐2‐pyrones, and 4‐hydroxy‐coumarins, followed by a regioselective intramolecular dehydration, involving the primary alcohols obtained and the enolic oxygen of the rings, promoted by Amberlyst 15 in boiling toluene, the new heterocycles 2,3,4,5‐tetrahydro‐6H‐oxepino[3,2‐c]pyran‐6‐one (3) and [1]benzopyran‐6‐ones ba,c were obtained in fair yields.
Etude des voies d'accès aux aminométhyl benzo[g]isoquinoléinediones‐5,10. Mise en évidence d'une substitution anormale au cours de la réaction de Bischler‐Napieralski en série diméthoxy‐1,4 naphthalène
Authors: Croisy‐Delcey Martine , Huel Christiane , Bisagni Emile
Published: April 2009

Dans les conditions de la réaction de Bischler‐Napieralski, la cyclisation des acétamides dérivés des (diméthoxy‐1,4 et triméthoxy‐1,4,8 naphtyl)‐2 éthyl acétamides s'effectue principalement en position angulaire, par substitution du groupement méthoxy‐1. Les aminométhyl‐1 azaanthraquinones‐9,10 sont néanmoins accessibles à partir des aminométhyl‐1 isoquinoléinediones‐5,8, par condensation avec le diacétoxy‐1,4 butadiène‐1,3.
Potential cerebral perfusion agents. Synthesis and evaluation of a 1,4‐disubstituted dihydropyridine analogue
Authors: Srivastava Prem C. , Knapp Furn F. , Pruitt Carol D.
Published: April 2009

The synthesis of a 1,4‐disubstituted dihydropyridine, 1‐(E‐1[125I]iodo‐1‐penten‐5‐yl)‐4‐(β‐N‐acetylaminoethyl)‐1,4‐dihydropyridine ([125I]10), is described. Acetylation of 4‐(β‐aminoethylpyridine) with acetic anhydride followed by condensation with E‐1‐borono‐5‐iodo‐1‐pentene (7) gave 1‐(E‐1‐borono‐1‐penten‐5‐yl)‐4‐(β‐N‐acetylaminoethyl)pyridinium iodide (8). Chloramine‐T and sodium iodide iodination of 8 gave the corresponding E‐1‐iodo compound 9 which was reduced with sodium borohydride to furnish 1‐(E‐1‐iodo‐1‐penten‐5‐yl)‐4‐(β‐N‐acetylaminoethyl)‐1,4‐dihydropyridine (10). The corresponding radioiodinated compound was prepared similarly using Na[125I]. The tissue distribution studies in rats indicate that [125I]10 crosses the blood brain barrier (0.49% dose/g in the brain) but gradually washes out from the brain.
The synthesis of some alkylbenzocarbazoles
Authors: Katritzky Alan R. , Wang Zuoquan
Published: April 2009

The preparation is described of five known and eight novel carbazole derivatives, the latter including compounds with alkyl side‐chains.
Long range heteronuclear chemical shift correlation with one bond modulation decoupling: Phenanthro[1,2‐b]thiophene
Authors: Kruger Diana K. , Martin Gary E. , McKenney J. Dew , Castle Raymond N.
Published: April 2009

Long range heteronuclear chemical shift correlation has become an extremely useful technique for complex spectral assignment and structure elucidation. The sensitivity is higher than that afforded by 13C‐13C double quantum INADEQUATE experiment. The long range heteronuclear correlation provides the means of establishing connectivities across heteroatoms. Early attempts to use long range heteronuclear chemical shift correlation by simply optimizing the delays for long range couplings met with varied success. Long range coupling responses to protonated carbon resonances can be modulated by the one bond coupling of the protonated carbon. These modulations can lead to precipitous valleys in the response curve and a corresponding loss of connectivity information. A newly reported pulse sequence employing a BIRD pulse midway through the Δ2 refocusing delay “decouples” one bond modulation effects substantially increasing the likelihood of observing the desired connectivities. The application of this technique is reported for phenanthro[1,2‐b]thiophene. Unequivocal assignment of the title compound is reported using heteronuclear chemical shift correlation and long range correlation with modulation decoupling. The assignment took a total of < 15 hours of spectrometer time.
Preparations of 2‐azabicyclo[2.2.2]octa‐5,7‐dien‐3‐ones and 7‐azabicyclo[4.2.0]octa‐2,4‐dien‐8‐ones from addition reactions of 2‐pyridones
Authors: Somekawa Kenichi , Okumura Yasuo , Uchida Kunitomi , Shimo Tetsuro
Published: April 2009

The low temperature photoaddition of 2‐pyridone with dimethyl acetylenedicarboxylate gave a [4 + 2]‐cycloadduct and a [2 + 2]‐cycloadduct across the 5,6‐position of 2‐pyridone. Their formations were competing with a Michael reaction of the two substrates at the room temperature reaction. The reactions of other pyridones with dimethyl acetylenedicarboxylate gave [2 + 2]‐ and/or [4 + 2]‐cycloadducts. The [2 + 2]‐cycloadducts underwent an intriguing rearrangement to fused β‐lactams.
Synthèse et stéréochimie de perhydrocyclopenta[b]furannones‐3‐cis et perhydrocyclopenta[b]furannols‐3‐cis
Authors: Dolmazon René
Published: April 2009

Une voie d'accès à de nouveaux perhydrocyclopenta[b]furannols‐3‐cis et perhydrocyclopenta[b]furannones‐3‐cis est décrite. Leurs configurations et conformations sont établies par spectroscopie rmn 1H et 13C. Une certaine rigidité est observée au niveau de la jonction des deux cycles. Le cycle tétrahydrofurannone‐3 adopte une conformation mobile entre les formes C, et C2, dépendante du substituant en position 2.
A new improved synthesis and X‐ray crystal structure of [1,4]dithiino[2,3‐b]‐1,4‐dithiin
Authors: Varma K. S. , Sasaki N. , Clark R. A. , Underhill A. E. , Simonsen O. , Becher J. , Bøwadt S.
Published: April 2009

[1,4]Dithiino[2,3‐b]‐1,4‐Dithiin (3) has been synthesised in high yield by a one‐step procedure starting with sodium 1,3‐dithiole‐2‐thione‐4,5‐dithiolate (2). The X‐ray crystal structure shows non‐planarity of the fused ring system as well as short intermolecular S ⃜S contacts.
Synthesis of 5,6‐dihydro‐4H‐thiopyran‐4‐ones
Authors: Becher Jan , Brøsndum Klaus , Hansen Poul , Jacobsen Jens Peter Jan
Published: April 2009

The anions of 1,4‐diaryl‐3‐buten‐2‐ones 1 reacts with arylisothiocyanates, yielding intermediates 4 which can ring close to 5,6‐dihydro‐4H‐thiopyran‐4‐ones 5. Under similar reaction conditions ethyl 3‐oxo‐4‐pentenoates 7 gives the 6‐spiropyrans 9. Methylation of 3 gives the S‐methylated open form 6.
Synthesis of dimethoxy‐ and dioxano‐annellated benzofuroxans from o‐dinitroarenes
Authors: Eswaran S. V. , Sajadian S. K.
Published: April 2009

Thermolysis of 4,5‐dinitroveratrole 1a in the presence of sodium azide and dimethylsulfoxide gives the new 5,6‐dimethoxybenzofuroxan, 2a, whereas 3,4,5‐trinitroveratrole led to the new 5(7),6‐dimethoxy‐4‐nitrobenzofuroxans 2e, 3e via a nucleophilic substitution of a nitro group by azide ion and pyrolytic ring closure. This method provides a simpler route to the known 1,3‐benzodioxano[5,6‐c]furoxan, 2b and 1,4‐benzodioxano[6,7‐c]furoxan 2c, as well.
Ambident anion chemistry: The reaction of sterically‐hindered phenolate anions with 1H‐pyrrole‐2,5‐diones
Authors: Pastor Stephen D. , Hessell Edward T.
Published: April 2009

The reaction of N‐phenylmaleimide, 4a, with sodium 2,6‐di‐t‐butylphenolate, 5a, in dimethylsulfoxide (DMSO) resulted a complex oligomeric mixture. The dimer 8 was isolated from the reaction of the N‐alkyl‐maleimide 4b with 5a in DMSO. The reaction of 4a with 5a in tetrahydrofuran (THF), which is an aprotic solvent that is known to promote ion pairing, resulted in the isolation of a low yield of 6a. The reaction of 4a with 5a in the hydrogen‐bonding solvent t‐butyl alcohol gave 6a in slightly higher yield. The N‐alkylpyrrolidine‐2,5‐diones 6c‐f were obtained by the reaction of the maleimides 4c‐e with the corresponding sodium phenolate 5a‐b in t‐butyl alcohol reaction medium. The isolated yield of product increased with the size of the N‐alkyl substituent of the maleimide. Surprisingly, the reaction of the 2,6‐dimethylphenolate 5c with 4d led to the isolation of the dimer 10 with the formation of a quaternary carbon atom. The yield of 6a was observed to counterion dependent, increasing in the order Na+ < Li+ < MgBr+ in t‐butyl alcohol. The bismaleimides 12 and 14 were obtained by the reaction of either 11 or 13 with 5d in THF.
Reactions of furoxano[3,4‐b]quinoxaline with alkynes and alkenes. Synthesis of pyrazino[2,3‐b]quinoxaline 1,4‐dioxides
Authors: Vrettou Maria S. , Gallos John K. , Nicolaides Demetrios N.
Published: April 2009

Pyrazino[2,3‐b]quinoxaline 1,4‐dioxides 3a‐e were prepared by reacting Furoxano[3,4‐b]quinoxaline with alkynes and alkenes.
Some novel reactions of 2‐amino‐4‐methyloxazole with aldehydes: Aryl and alkyl hydoxymethylation at C‐5
Authors: Khan Humaid R. , Crank G. , Jesdapaulpaan S.
Published: April 2009

2‐Amino‐4‐methyloxazole reacts with aldehydes to give products having a hydroxymethyl function at C–5. No Schiff's bases were formed. Reactions seem to be confined to 4‐alkyl substituted‐2‐aminooxazoles as 2‐aminooxazole and its 4‐phenyl and 2‐acetomido derivatives fail to react with aldehydes. The nature of the aldehyde affects the amount of the product formed.
Synthesis of 4‐vinylquinoline: Pyrolytic rearrangement of the 4‐(1‐hydroxyethyl)quinoline and related derivatives
Authors: Rodriguez J. G. , Benito Y.
Published: April 2009

The synthesis of 4‐vinylquinoline has been carried out by means of the Wittig reaction between 4‐quino‐linecarbaldehyde and the methyl triphenylphosphonium ylide in dimethyl sulphoxide in good yield. Dehydration of the 4‐(1‐hydroxyethyl)quinoline and their xanthate derivative, give equimolar amounts of 4‐ethylquinoline and 4‐acetylquinoline while small amounts of 4‐vinylquinoline were found. Dehydrochlorination of 4‐(1‐chloroethyl)quinoline in ethanol‐sodium hydroxide provides 4‐ethyl‐3‐ethoxyquinoline in good yield, but 4‐vinylquinoline is a minor reaction product.
Novel synthesis of (−)‐trans‐Δ9,11‐tetrahydrocannabinol
Authors: Banijamali Ali R. , Makriyannis Alexandros
Published: April 2009

Addition of hydrogen chloride gas to a solution of Δ8‐tetrahydrocannabinol in dry dichloromethane at ‐60° in the presence of zinc chloride results in the formation of a higher concentration of 9‐α‐chlorohexa‐hydrocannabinol (75%) than the thermodynamically more stable 9‐β‐chlorohexahydrocannabinol (25%). The two isomers can be separated by reverse‐phase hplc. Elimination of hydrogen chloride from 9‐α‐chlorohexa‐hydrocannabinol using potassiumt‐amylate under anhydrous conditions gives exclusively Δ9,11‐tetrahydrocannabinol in overall yield of 65%.
A new and improved synthesis of 6‐aryl‐1,2,4‐triazolo[4,3‐b]pyridazines
Authors: Lieberman Daniel F. , Albright J. Donald
Published: April 2009

A new and improved synthesis of 6‐aryl‐1,2,4‐triazolo[4,3‐b]pyridazines is described. This methodology provides the title compounds under mild conditions and in high yields. The first step comprises the condensation of an aryl methyl ketone with a 4‐amino‐1,2,4‐triazole in toluene heated at reflux. The second step involves the condensation of that imine and t‐butoxybis(dimethylamino)methane in tetrahydrofuran at ambient temperature. The third step constitutes the pyridazine ring closure to the title compounds in acetic acid heated at reflux.
The oxidative‐rearrangement of nitrogen heterocycles with lead tetraacetate and t‐butyl hypochlorite
Authors: Zey Robert L.
Published: April 2009

Mechanisms for the lead tetraacetate and t‐butyl hypochlorite oxidation of 1,4‐dihydro‐3(2H)‐cinnolinones and 1‐amino‐2‐indolinones are discussed. Evidence for the lack of a nitrene intermediate is given.
Reaction of 5H‐dibenz[b,f]azepine with t‐butyl hypochlorite: An aromatic nitrenium ion intermediate?
Authors: Cann Michael C. , Lezinsky David
Published: April 2009

The reaction of 5H‐dibenz[b,f]azepine with t‐butyl hypochlorite and this same reaction in the presence of silver(I) were studied in an attempt to generate dibenz[b,f]azatropylium, an aromatic nitrenium ion. Analysis of the product mixture from this reaction mitigate against formation of this ion. An alternate mechanism is presented.
Pyridazines. XXXVII. Novel triazanaphthalene derivatives via intramolecular cyclization reactions of vic‐disubstituted pyridazines
Authors: Boamah Philip Yaw , Haider Norbert , Heinisch Gottfried , Moshuber Jöran
Published: April 2009

8‐Phenylpyrido[3,4‐d]pyridazines bearing various amino substituents at C‐5 (7a‐d, 8) were prepared from ethyl 5‐benzyl‐4‐pyridazinecarboxylate 1 via the fused pyridone 5. The isomeric 4‐phenylpyrido[2,3‐d]pyridazines having the amino functions attached to C‐2 (10a‐f) were obtained by a one‐pot cyclization of the amino ketone 1 with appropriate acetamide acetals. These novel triazanaphthalene derivatives are of interest as analogues of diuretic and antithrombotic agents.
The synthesis of XTT: A new tetrazolium reagent that is bioreducible to a water‐soluble formazan
Authors: Paull Kenneth D. , Shoemaker Robert H. , Boyd Michael R. , Parsons Jack L. , Risbood Prabhakar A. , Barbera William A. , Sharma Mahenda N. , Baker David C. , Hand Elli , Scudiero Dominic A. , Monks Anne , Alley Michael C. , Grote Manfred
Published: April 2009

A new tetrazolium salt, XTT, has been synthesized. XTT is reduced by a considerable variety of cell lines to a water‐soluble formazan. XTT appears to merit further investigation as a reagent for broader application to cell culture assay systems.
Preparation of hydrogenated azepino[3,2,1‐hi]indoles
Authors: Katayama Hajime , Maeda Kaijiro , Kaneko Kimiyoshi
Published: April 2009

A general method for the preparation of 4,5‐dihydro‐, 1,2,4,5‐tetrahydro‐, 4,5,6,7‐tetrahydro‐ and 1,2,4,5,6,7‐hexahydroazepino[3,2,1‐hi]indoles was established by using intramolecular Friedel‐Crafts alkylation of chloromethylthioacetamide as a crucial step.
On the reaction of α‐(2‐hydroxyphenoxy)alkylketones with dimethylsulphoxonium methylide. A novel route to 2‐substituted‐2,3‐dihydro‐2‐hydroxymethyl‐1,4‐benzodioxins
Authors: Salimbeni Aldo , Manghisi Elso , Arnone Alberto
Published: April 2009

A new route to 2‐substituted‐2,3‐dihydro‐2‐hydroxymethyl‐1,4‐benzodioxins 3 based on the reaction of α‐(2‐hydroxyphenoxy)alkylketones 1 with dimethylsulphoxonium methylide in dimethylsulphoxide is reported. Besides the desired compounds 3, the isomeric 2H‐3,4‐dihydro‐1,5‐benzodioxepines 4 were also isolated, generally as minor products. The concurrent formation of 3 and 4 has been interpreted as occurring through the intermediate oxiranes 2, which can undergo intramolecular nucleophilic attack at either of the carbon atoms of the epoxy ring.
Coupling reactions of aryl and heteroaryl halides with a trimethylsilylethynylpyrazine
Authors: Akita Yasuo , Kanekawa Hideta , Kawasaki Tatsuya , Shiratori Ikuko , Ohta Akihiro
Published: April 2009

By the coupling reactions of trimethylsilylacetylene and 2‐chloro‐3,6‐diisobutylpyrazine, 3,6‐diisobutyl‐2‐trimethylsilylethynylpyrazine or 1,2‐bis(3,6‐diisobutylpyrazin‐2‐yl)acetylene was obtained, depending on the solvent used. The former substance coupled with various aryl and heteroaryl halides to give 1‐aryl‐2‐pyrazin‐ylacetylenes.