bluuebunny/crossref_metadata_2025_split huggingface dataset:
Products from furans. VI. Synthesis of dihydro‐2‐disubstituted‐2H‐pyran‐3(4H)‐ones, tetrahydro‐3‐(aminomethyl)‐2‐(p‐methoxyphenyl)‐2‐methyl‐2H‐pyran‐3‐ol derivatives and 6‐(p‐methoxyphenyl ‐6‐methyl‐7‐oxa‐1,3‐diazaspiro[4,5]decane‐2,4‐dione
Authors: Georgiadis Minas P. 
Published: March 2009

AbstractHydrogenolysis of 5,6‐dihydro‐6‐(p‐methoxyphenyl)‐6‐methyl‐5‐oxo‐2H‐pyran‐2‐yl ethyl carbonate yielded dihydro‐2‐(p‐methoxyphenyl)‐2‐methyl‐2H‐pyran‐3(4H)‐one, 3. Subsequently cyanohydrin 4, derived from 3, on reduction afforded 3‐(aminomethyl)tetrahydro‐2‐(p‐methoxyphenyl)‐2‐methyl‐2H‐pyran‐3‐ol, 5. The synthesis of N‐dimethyl,N‐isopropyl,N‐imidazolyl as well as N‐oxazolinyl derivatives of 5 is presented. The synthesis of 6‐(p‐methoxyphenyl)‐6‐methyl‐7‐oxa‐1,3‐diazaspiro[4,5]decane‐2,4‐dione 10, a spiro hydantoin prepared from ketone 3 is also reported.
A new synthesis of novel 1‐aryl‐3‐heteroaryl‐1H‐pyrazolo[3,4‐b]quinoxalines via a Key Intermediate
Authors: Kurasawa Yoshihisa , Muramatsu Muneto , Yamazaki Kaoru , Tajima Setsuko , Okamoto Yoshihisa , Takada Atsushi 
Published: March 2009

AbstractThe chlorination of the α‐hydrazonoester 4 with phosphoryl chloride/pyridine gave 3‐[α‐(o‐chlorophenylhydrazono)methoxycarbonylmethyl]‐2‐chloroquinoxaline 5, whose cyclization with 1,8‐diazabicyclo[5,4,0]‐7‐undecene afforded 3‐methoxycarbonyl‐1‐(o‐chlorophenyl)‐1H‐pyrazolo[3,4‐b]quinoxaline 6. The reaction of 6 with hydrazine hydrate provided 3‐hydrazinocarbonyl‐1‐(o‐chlorophenyl)‐1H‐pyrazolo[3,4‐b]quinoxaline 7, whose reactions with methyl and allyl isothiocyanates furnished 3‐(2,3‐dihydro‐4‐methyl‐3‐thioxo‐4H‐1,2,4‐triazol‐5‐yl)‐1‐(o‐chlorophenyl)‐1H‐pyrazolo[3,4‐b]quinoxaline 2 and 3‐(4‐allyl‐2,3‐dihydro‐3‐thioxo‐4H‐1,2,4‐triazol‐5‐yl)‐1‐(o‐chloropheny)‐1H‐pyrazolo[3,4‐b]quinoxaline 8, respectively. Moreover, the reactions of 7 with triethyl orthoformate and orthoacetate gave 1‐(o‐chlorophenyl)‐3‐(1,3,4‐oxadiazol‐5‐yl)‐1H‐pyrazolo‐[3,4‐b]quinoxaline 9a and 1(o‐chlorophenyl)‐3‐(2‐methyl‐1,3,4‐oxadiazol‐5‐yl)‐1H‐pyrazolo[3,4‐b]quinoxaline 9b, respectively.
Synthesis of novel 3‐(α‐arylhydrazono‐1,3,4‐oxadiazol‐2‐ylmethyl)‐2‐oxo‐1,2‐dihydroquinoxalines and their characteristic tautomerism between the hydrazone imine and diazenyl enamine forms
Authors: Kurasawa Yoshihisa , Muramatsu Muneto , Okamoto Yoshihisa , Takada Atsushi 
Published: March 2009

AbstractThe reactions of 3‐(α‐arylhydrazono)hydrazinocarbonylmethyl‐2‐oxo‐1,2‐dihydroquinoxalines 1a,b with triethyl orthoesters resulted in the intramolecular cyclization to give the 3‐(α‐arylhydrazono‐1,3,4‐oxadiazol‐2‐ylmethyl)‐2‐oxo‐1,2‐dihydroquinoxalines 4a–d, but not the 1,2,4,5‐tetrazepinylquinoxalines 5a–d. The cyclization mode into the 1,3,4‐oxadiazole ring was confirmed by the alternate syntheses of 4a,c from the reactions of 3‐(1,3,4‐oxadiazol‐2‐ylmethylene)‐2‐oxo‐1,2,3,4‐tetrahydroquinoxalines 6a,b with o‐chlorophenyl diazonium salts, respectively. Moreover, 4a–d exhibited an interesting tautomerism between the hydrazone imine form A and diazenyl enamine form B.
A comparative study on the synthesis of the 1H[1]benzothieno[2,3‐d]‐imidazole and 1H[1]benzothieno[2,3‐d]‐v‐triazole
Authors: Guerrera Francesco , Siracusa Maria Angela , Santagati Natale Alfredo , Tornetta Benedetto 
Published: March 2009

AbstractAlternate routes for the synthesis of the new title compounds are described. The experimental procedure for the isolation of the unstable 2,3‐diaminobenzo[b]thiophene as the dichloride salt is presented.
Obtention de dialkylamino‐2 cyano‐3 2H‐chromènes
Authors: Auzou Gilles , René Loïc 
Published: March 2009

AbstractLes dialkylamino‐2 cyano‐3 chromènes‐2H sont obtenus en un seul stade par condensation de β‐cyanoenamines et d'aldéhydes salicyliques substitués ou non, en présence d'acide para toluéne sulfonique.
A new method for the synthesis of novel 1‐aryl‐3‐heteroaryl‐1H‐pyrazolo[3,4‐b]quinoxalines
Authors: Kurasawa Yoshihisa , Muramatsu Muneto , Yamazaki Kaoru , Tajima Setsuko , Okamoto Yoshihisa , Takada Atsushi 
Published: March 2009

AbstractThe reaction of 3‐(2,3‐dihydro‐4‐methyl‐3‐thioxo‐4H‐1,2,4‐triazol‐5‐ylmethylene)‐2‐oxo‐1,2,3,4‐tetrahydroquinoxaline 4 with o‐chlorobenzenediazonium chloride gave 3‐[α‐(o‐chlorophenylhydrazono)‐2,3‐dihydro‐4‐methyl‐3‐thioxo‐4H‐1,2,4‐triazol‐5‐ylmethyl]‐2‐oxo‐1,2‐dihydroquinoxaline 6, whose refluxing in phosphoryl chloride/pyridine afforded 1‐(o‐chlorophenyl)‐3‐(2,3‐dihydro‐4‐methyl‐3‐thioxo‐4H‐1,2,4‐triazol‐5‐yl)‐1H‐pyrazolo[3,4‐b]quinoxaline 7. The reactions of 6 and 7 with nitrous acid resulted in sulfur extrusion to provide 1‐(o‐chlorophenyl)‐3‐(4‐methyl‐4H‐1,2,4‐triazol‐5‐yl)1H‐pyrazolo[3,4‐b]quinoxaline 8 and 3‐[α‐(o‐chlorophenylhydrazono)‐4‐methyl‐4H‐1,2,4‐triazol‐5‐ylraethyl]‐2‐oxo‐1,2‐dihydroquinoxaline 9, respectively.
3‐[(Z)‐2‐t‐Butoxyethenyl]‐4‐hydroxy‐2(5H)‐furanone, an interesting byproduct obtained from reaction of 4‐t‐butoxy‐2‐butenoate with the alkoxide anion of methyl glycolate
Authors: Arora S. K. , Cho B. S. , Chadha V. K. , Bauer A. J. , Venton D. L. , Lim C. T. , Le Breton G. C. 
Published: March 2009

AbstractTreatment of methyl 4‐t‐butoxy‐2‐butenoate (1) with the alkoxide anion of methyl glycolate gives, in addition to the previously reported (Fried, et al. [2]) 2,3‐disubstítuted‐2,3‐dihydro‐4‐furanone 2, an equivalent amount of the interestingly substituted 3‐[(Z)‐2‐t‐butoxyethenyl]‐4‐hydroxy‐2(5H)furanone 3. Isolation, structure proof and possible mechanism of formation are presented
Synthesis of imidazo[1,5‐c]pyrimidine derivatives
Authors: Wade James J. 
Published: March 2009

AbstractTwo complementary procedures, each starting from 6‐aminomethyluracil (2), have been used to prepare imidazo[1,5‐c]pyrimidines with a variety of substituents at positions 3, 5, 6, and 7. The starting material,2, can be readily prepared from commercially available 6‐chloromethyluracil by reaction with anhydrous ammonia. In the first procedure,2is acylated and then cyclodehydrated by reaction with phosphorus oxychloride to give a separable mixture of a 3‐substituted 5,7‐dichloroimidazo[1,5‐c]pyrimidine and a 3‐substituted 7‐chloroimidazo[1,5‐c]pyrimidin‐5(6H)‐one. The relative product distribution is subject to some control by the choice of the acyl substituent on the starting uracil. The resulting dichloro compounds were derivatized by reaction at the 5‐position with various nucleophiles, although the 7‐chloro substituent is unreactive. An alternative synthetic method proceeds from2in six efficient steps (protection as the phthalimide, chlorination, nucleophilic substitution, deprotection, acylation, and cyclodehydration) to 3‐substituted‐5,7‐bis(methylthio)imidazo[1,5‐c]pyrimidines. These compounds may also be derivatized by nucleophilic substitution at the 5‐position.
Synthesis and reactions of an open‐chain bis‐reissert salt analog
Authors: Iyer Radhakrishnan P. , Ratnam Rakesh K. , Kulkarni Subodh P. , Sonaseth Mariam S. 
Published: March 2009

AbstractAn open‐chain bis‐Reissert salt analog 5 has been synthesized and fully characterized. The reaction of the salt analog with methyl acrylate yields the pyrrole 7 which exists in solution in the azafulvene form 7a. The reaction of the salt analog with dimethylacetylene dicarboxylate (DMAD) affords the bispyrrole 9.
Reaction of o‐aminophenol and p‐benzoquinone in acetic acid
Authors: Bolognese Adele , Scherillo Giulia , Schäfer Wolfram 
Published: March 2009

AbstractThe reaction of o‐aminophenol and p‐benzoquinone in acetic acid yields phenoxazinones 1, 5 and 6, phenoxazine 7, triphenodioxazine 2, ditriphenodioxazine 3 and the phenoxazinonyltriphenodioxazine 4.
1‐Azadienes in heterocyclic synthesis. Reaction of 1‐N‐alkyl‐1‐azapenta‐1,3‐dienes with mesoionic oxazolones
Authors: Sain B. , Sandhu J. S. 
Published: March 2009

Abstract1‐N‐Alkyl‐1‐azapenta‐1,3‐dienes 2 smoothly reacted with various mesoionic oxazolones 1 to afford 3,4‐di‐hydro‐2‐pyridones 3 in excellent yields and there was no evidence for the formation of any products arising from the cycloaddition on the carboncarbon double bond or on the azomethine function.
Reaction of N‐(4‐pyridylmethyl)benzamide N‐oxides with ethyl cyanoacetate in the presence of acetic anhydride
Authors: Braña Miguel F. , Rodríguez María L. López , Rodríguez Concepción , Garrido‐Pertierra Amando 
Published: March 2009

AbstractReaction of N‐(4‐pyridylmethyl)benzamide N‐oxides 2a‐f with ethyl cyanoacetate in the presence of acetic anhydride yield dimerization compounds 3a‐f and (E)‐ethyl 2‐cyano‐3‐(4‐pyridyl)‐3(benzoylamino)acrylates 4a‐f, which react with hydrazine to give 4‐cyano‐3‐(4‐pyridyl)‐3‐pyrazolin‐5‐one 9 and the corresponding benzamides 10a‐f.
Adamantylazoles. 5. The molecular structure of 1‐(1‐adamantyl)pyrazoles
Authors: Cabildo P. , Claramunt R. M. , Sanz D. , Foces‐Foces M. C. , Cano F. Hernández , Fayet J. P. , Vertut M. C. , Elguero J. 
Published: March 2009

AbstractThe crystal structures of 1‐(1‐adamantyl)‐3,5‐dimethylpyrazole 1 and 1‐(1‐adamantyl)‐3,4,5‐trimethylpyrazole 2 were studied by X‐ray analysis. The space groups and cell parameters are: 1, Cc, 13.4452(4), 14.9407(4), 7.1119(2) Å, 90, 111.944(2), 90°, with Z = 4. 2, P21/c, 6.7466(1), 21.2565(7), 10.1462(2) Å, 90, 106.368(2), 90°, with Z = 4. The final disagreement factors were 0.069 and 0.061, for 721 [2σ(I)] and 1950 [2σ(I)] observed reflexions, respectively. Compound 1 presents the adamantyl residue disordered between the two usual conformations. The experimental dipole moments and the carbon‐13 chemical shifts (both in hexadeuteriodi‐methylsulfoxide and in the solid state) were measured and discussed in connection with the structure of these compounds.
Novel synthesis of pyrido[1,2‐a]benzimidazoles via reaction of N‐acyl arylhydroxylamines with pyridine
Authors: Anderson David J. , Taylor Arlen J. 
Published: March 2009

AbstractThe reduction of 4‐chloro‐3,5‐dinitrobenzonitrile via catalytic hydrogenation and/or titanium trichloride produced three successive hydroxylamines 6,7, and 8 that were fully characterized during complete reduction to the diamine 9. The nitrohydroxylamine 6 was acetylated to the mono‐N‐acetyl and bis‐acetyl derivatives 10 and 11 which reacted with pyridine to afford the pyrido[1,2‐a]benzimidazole 13. An analoguous series of reactions was executed with 4‐chloro‐3,5‐dinitrobenzotrifluoride to afford the pyrido[1,2‐a]benzimidazole 21. Structure confirmation of 21 was established via an x‐ray determination. The mechanism of the transformation is discussed.
Synthesis of 2‐substituted benzimidazole‐5‐carbamates as potential antifilarial agents
Authors: Ram Siya , Wise Dean S. , Townsend LeRoy B. 
Published: March 2009

AbstractA number of 2,5‐disubstituted benzimidazoles have been prepared from 2‐benzyl‐5‐nitrobenzimidazole (5) and 2‐p‐fluorobenzyl‐5‐nitrobenzimidazole (6), and evaluated as potential antifilarial agents. None of the compounds prepared in this study have demonstrated any significant antifilarial activity.
The crystal and molecular structure of 9‐methylphenanthro[4,3‐a]dibenzothiophene
Authors: Quast Michael J. , Martin Gary E. , Lynch Vincent M. , Simonsen Stanley H. , Stuart John G. , Tedjamulia Marvin L. , Castle Raymond N. , Lee Milton L. 
Published: March 2009

AbstractThe crystal structure of 9‐methylphenanthro[4,3‐a]dibenzothiophene, C25H16S, Mr = 348.47, has been determined. Monoclinic, P21/c, a = 11.364(3), b, = 14.257(3), c = 11.575(2)Å, β = 116.26(2)°, V = 1681.9(7)Å3, Z = 4, Dx = 1.38 g/cc, MoKα radiation λ = .71069 Å, F(000) = 728, T = 163K, R = .0458 for 2330 reflections. The structure compares favorably with that of hexahelicene and methylated derivatives. The thiophene moiety increases the helical core radius and decreases the pitch with respect to hexahelicene and its derivatives.
Mass spectral fragmentation pattern of 3‐methyl‐ and 3‐phenyl‐4‐(N‐methylarylhydrazono)isoxazol‐5‐ones
Authors: Keats Neil G. , Singh Shyam K. , Summers Lindsay A. 
Published: March 2009

Abstract3‐Methyl‐4‐(N‐methylarylhydrazono)isoxazol‐5‐ones and 3‐phenyl‐4‐(N‐methylarylhydrazono)isoxazol‐5‐ones undergo considerable fragmentation on electron impact involving rupture of the isoxazolone ring and bonds in the N‐methylarylhydrazono side chain.
Studies on furan derivatives. XIV. Nucleophilic substitution of methyl 5‐nitro‐2‐furancarboxylate and 5‐Nitrofuran‐2‐nitrile
Authors: Shimadzu Masaji , Ishikawa Nobuko , Yamamoto Katsumi , Tanaka Akira 
Published: March 2009

AbstractMethyl 5‐alkoxy‐2‐furancarboxylates, methyl 5‐alkylthio‐2‐furancarboxylates and methyl 5‐phenylthio‐2‐furancarboxylate were prepared by nucleophilic substitution of methyl 5‐nitro‐2‐furancarboxylates. Also, 5‐phenoxyfuran‐2‐nitriles and 5‐phenylthiofuran‐2‐nitriles were prepared.
Preparation and some spectral properties of benzo‐fused 1,4‐dimethyl‐2(1H)‐quinolinones
Authors: Ito Keiichi , Maruyama Junko , Shimamori Takako 
Published: March 2009

AbstractThe preparation of the angular and linear isomers of benzo‐fused 1,4‐dimethyl‐2(1H)‐quinolinones 3a–5a and their spectral data including 13C‐nmr data are reported. Structural difference among 3a–5a is confirmed from the proximity effect in 1H‐ and 13C‐nmr data and from the uv spectral pattern.
Triazole phosphonates. Electrophilic substitution of 1‐substituted‐1H‐1,2,4‐triazoles via lithiated triazole intermediates
Authors: Anderson D. Keith , Sikorski James A. , Reitz David B. , Pilla Linda T. 
Published: March 2009

AbstractThe metalation chemistry of several 1‐substituted‐1H‐1,2,4‐triazoles has been investigated. When various alkyl groups were incorporated in the 1‐position, lithiation proceeded exclusively at C‐5. The 1‐trityl‐, 1‐methyl‐, and 1‐benzyl‐5‐lithio‐1,2,4‐triazoles were stable at −78° and reacted cleanly with a variety of electrophiles. The 1‐benzyl and 1‐methyl derivatives were synthetically more versatile and could be successfully utilized to prepare several examples of the previously unknown 1,2,4‐triazol‐5‐yl phosphonates.
The syntheses of pteridin‐2‐one derivatives from diaminomaleonitrile (DAMN)
Authors: Tsuzuki Koichi , Tada Masaru 
Published: March 2009

Abstract1,3‐Dimethyl‐4‐iminopteridin‐2‐one, 1,3‐dimethylpteridine‐2,4‐dione, 1‐methylpteridine‐2,4‐dione, 4‐alkoxy‐1‐methylpteridin‐2‐one, and 4‐alkylamino‐1‐methylpteridin‐2‐one were synthesized from diaminomaleonitrile (DAMN) through pyrazine‐2,3‐dicarbonitrile. The synthetic procedures consist of the condensation of DAMN with glyoxal, the nucleophilic substitution of pyrazine‐2,3‐dicarbonitrile with methylamine, the reaction of 3‐methylaminopyrazine‐2‐carbonitrile with electrophiles such as methyl isocyanate and methyl chloroformate in the presence of sodium hydride, and the transformation of 3‐(methoxycarbonylmethyl)aminopyrazine‐2‐carbonitrile into the pteridine derivatives.
Imino‐bridged heterocycles. VII.N‐aminobenzocycloheptapyridinimines
Authors: Brenner Daniel G. , Pitzenberger Steven M. , Shepard Kenneth L. , Varga Sandor L. 
Published: March 2009

AbstractCondensation of anhydrous hydrazine with a variety of benzocycloheptapyridinones led to N‐aminobenzocycloheptapyridinimines. Regiospecific ring closures occurred in all the systems investigated.
Synthesis and in vitro antimicrobial and antifungal properties of some novel 1,3,4‐thiadiazole and s‐triazolo[3,4‐b][1,3,4]thiadiazole derivatives
Authors: Omar A.‐Mohsen M. E. , Aboulwafa Omaima M. 
Published: March 2009

AbstractA novel series of 2‐arylthiocarbamoylhydrazino‐5‐phenyl‐1,3,4‐thiadiazoles III‐VII was synthesized and cyclodesulfurized into the corresponding 3‐arylamino‐6‐phenyl‐s‐triazolo[3,4‐b][1,3,4]thiadiazoles VIII‐XII with DCCD. Some of the products were found to be only moderately active against Staphylococcus aureus and Candida albicans.
Nitriles in heterocyclic synthesis. A novel synthesis of spiropyran‐4‐ylindolidene derivatives
Authors: Hafez Ebtisam Abdel Aziz , Abdul Galil Fathy M. , Sherif Sherif M. , Elnagdi Mohamed H. 
Published: March 2009

AbstractThe structure of the products of reaction of 2‐oxo‐3‐dicyanomethylidene‐2,3‐dihydroindole (1a) and 2‐oxo‐3‐cyanoethoxycarbonylmethylidene‐2,3‐dihydroindole (1b) with the pyrazolin‐5‐one derivatives 2a,b could be established via 13C nmr and high resolution 1H nmr to be the spiropyranylindolone derivatives 5a‐d.
Synthesis of pyrido[1′,2′:1,2]imidazo[4,5‐b]pyrazines from 2,3‐dichloro‐5,6‐dicyanopyrazine with 2‐aminopyridines
Authors: Suzuki Toshinobu , Nagae Yasushi , Mitsuhashi Keiryo 
Published: March 2009

AbstractNovel synthesis of the title compounds by the facile cyclization between 2,3‐dichloro‐5,6‐dicyanopyrazine and various 2‐aminopyridines under relatively mild conditions is described. The reactivity depended on the basicity of 2‐aminopyridines.
Synthesis and spectral behavior of 5‐methyl‐3‐phenyl‐1,3‐oxazolidin‐2‐ones using NMR
Authors: Nishiyama Tomihiro , Matsui Shigeki , Yamada Fukiko 
Published: March 2009

AbstractHeterocyclic compounds of four 5‐methyl‐3‐phenyl‐1,3‐oxazolidin‐2‐ones have been synthesized by the reaction of N‐2‐hydroxyethyl‐ or N‐2‐hydroxypropylanilines with phosgene in the presence of pyridine. From the spectral behavior, the title compounds are found to exist in the trans and cis forms.
Novel eight‐membered heterocycles. Synthesis of dithiazolo[4,5‐d:5′,4′‐g][1,3]diazocine derivatives
Authors: Rahman Loay K. A. 
Published: March 2009

AbstractA number of derivatives of dithiazolo[4,5‐d:5′,4′‐g][1,3]diazocine have been prepared by the ring closure of the diaminodithiazole derivatives 7–8 or by replacement of the corresponding alkylthio‐function of 9–10.
Synthesis of pyrimidino[4,5‐b][1,5]benzodiazepin‐2‐ones and pyrimidino[1,6‐a]benzimidazol‐1‐ones from 4‐ethoxycarbonylamino‐1H‐1,5‐benzodiazpine‐3‐carbonitrile via 4‐(2‐aminoanilino)pyrimidin‐2(1H)‐one‐5‐carbonitriles
Authors: Takagi Kaname , Aotsuka Tomoji , Morita And Hikari , Okamoto Yoshihisa 
Published: March 2009

AbstractReactions of 4‐ethoxycarbonylamino‐1H‐1,5‐benzodiazepine‐3‐carbonitrile (2) with aliphatic primary amines gave 1‐substituted 4‐(2‐aminoanilino)pyrimidin‐2(1H)‐one‐5‐carbonitriles 3. Analogous reactions of 2 with aromatic primary amines afforded 2‐(2′‐anilino‐1′‐cyanovinyl)benzimidazoles 5 and 6. Upon treatment with triethylamine, 3 underwent intramolecular cyclization to give 3‐substituted 5‐aminopyrimidino[4,5‐b]‐[1,5]benzodiazepin‐2(3H,11H)‐ones 8. Heating of 3 with p‐toluenesulfonic acid in ethanol gave 2‐substituted pyrimidino[1,6‐a]benzimidazol‐1(2H)one‐4‐carbonitriles 9. Reactions of 2 with hydrazines were also described. Mechanistic pathways are proposed to account for the products.
Synthesis of heterocycles. Part VI. Synthesis and antimicrobial activity of some 4‐amino‐5‐aryl‐1,2,4‐triazole‐3‐thiones and their derivatives
Authors: Eweiss N. F. , Bahajaj A. A. , Elsherbini E. A. 
Published: March 2009

Abstract4‐Amino‐5‐aryi‐1,2,4‐triazole‐3‐thiones I react with acid chlorides to yield 4‐acylamino‐5‐aryl‐1,2,4‐triazole‐3‐thiones II. Compounds I also react with methylene iodide, chloroacetonitrile and methyl bromoacetate to give bis‐(4‐amino‐5‐aryl‐1,2,4‐triazol‐3‐ylthio)methanes III, 4‐amino‐5‐aryl‐3‐cyanomethylthio‐1,2,4‐triazoles IV and 4‐amino‐5‐aryl‐3‐carbomethoxymethylthio‐1,2,4‐triazoles V, respectively. Compounds V react with hydrazine hydrate to give the corresponding acid hydrazides VI which in turn condenses with acid chlorides and aldehydes to afford respectively 1‐[(4‐amino‐5‐aryl‐1,2,4‐triazol‐3‐ylthio)acetyl]‐2‐aroylhydrazines VII and aryl methylene (4‐amino‐5‐aryl‐1,2,4‐triazol‐3‐ylthio)acethydrazones VIII. The antimicrobial activities of the above compounds were screened against different strains of bacteria and fungi.
Rearrangements of 4‐(2‐Aminophenyl)‐1,4‐dihydro‐2,6‐dimethyl‐3,5‐pyridinedicarboxylic acid diethyl ester
Authors: Kim Dong H. 
Published: March 2009

AbstractThe treatment of 4‐(2‐aminophenyl)‐1,4‐dihydro‐2,6‐dimethyl‐3,5‐pyridinecarboxylic acid diethyl ester (III) with refluxing toluene or pyridine afforded 1,2,3,6‐tetrahydro‐2,4‐dimethyl‐2,6‐methano‐1,3‐benzodiazocine‐5,11‐dicarboxylic acid diethyl ester (IV) as the major product. In addition, the following minor products were isolated: 2‐methyl‐3‐quinolinecarboxylic acid ethyl ester (V), 3‐(2‐aminophenyl)‐5‐methyl‐6‐azabicyclo[3,3,1]‐hept‐1‐ene‐2,4‐dicarboxylic acid diethyl ester (VI), and 5,6‐dihydro‐2,4‐dimethyl‐5‐oxobenzo[c][2,7]naphthyridine‐1‐carboxylic acid ethyl ester (VII). In contrast, acidic conditions caused the conversion of III into V in a 95% yield. The formation of the latter appears to involve IV as an intermediate, since IV degraded rapidly in acid to give V in a quantitative yield.
13C NMR spectra of 1,3‐oxathiolane, 1,3‐oxathiolane 3‐oxide and 1,3‐oxathiolane 3,3‐dioxide derivatives
Authors: Teodori E. , Melani F. , Gualtieri F. 
Published: March 2009

AbstractCarbon‐13 nmr spectra of several 1,3‐oxathiolane, 1,3‐oxathiolane‐3‐oxide and 1,3‐oxathiolane‐3,3‐dioxide derivatives are reported. Relationships between some stereochemical features and chemical shift are discussed.
Reactions of triacetic acid lactone with carbonyl compounds. X‐Ray structure determination of 3‐acetoacetyl‐2‐chromenone and 3,6,9,12‐tetramethyl‐1H,6H,7H,12H‐6,12‐methanodipyrano[4,3‐b:4,3‐f]‐dioxocin‐1,7‐dione
Authors: De March P. , Moreno‐Mañas M. , Roca J. L. , Germain G. , Piniella J. F. , Dideberg O. 
Published: March 2009

AbstractThe structure of 3‐acetoacetyl‐2‐chromenone has been definitely assigned to the product resulting from the reaction of 4‐hydroxy‐6‐methyl‐2‐pyrone, 1, with 2‐hydroxybenzaldehyde. Also, the reaction of the pyrone 1 with pentane‐2,4‐dione in a 2:1 molar ratio gives 3,6,9,12‐tetramethyl‐1H,6H,7H,12H‐6,12‐methanodypirano[4,3‐b:4,3‐f]dioxocin‐1,7‐dione. X‐Ray analyses of both products are presented.
The reaction of pyridazinones with nucleophiles. An unusual reaction with cyanide
Authors: Badger Edward W. , Moos Walter H. 
Published: March 2009

AbstractStudies on the synthesis of pyridazinone analogues of pyridone cardiotonics are reported. The synthetic scheme involves the reaction of pyridazinones and chloropyridazinones with nucleophiles. Addition occurred twice with cyanide as the nucleophile, thus providing a novel dicyanopyridazinone.
Synthesis of new spirobenzazolines including a furo[3,4‐b]pyran ring system
Authors: Coudert P. , Couquelet J. M. , Tronche P. 
Published: March 2009

AbstractA series of 4,5‐dihydrofuro[3,4‐b]pyran‐6‐spiro‐2′‐benzazolines 3 were prepared by reaction of 4,4‐dimethyl‐2,6‐dioxo‐4,5‐dihydrofuro[3,4‐b]pyran 1 with o‐phenylenediamine, o‐aminophenol, o‐aminothiophenol or their derivatives. Most of these compounds exhibited a significant analgesic activity.
Nitrations of 4′,5′‐dihydropsoralens: A route to radiopharmaceutical precursors
Authors: Heindel Ned D. , Foster Natalie , Varkey Thankamma 
Published: March 2009

AbstractUnlike the nitration of the fully‐aromatic furocoumarin, methoxsalen, which yields a single nitration product, the nitration of the 4′,5′‐dihydro compound generates a condition‐variant mixture of three nitro products. Reduction, diazotization, and pyrrolidine‐trapping of one of these, the 4′,5′‐dihydro‐5‐nitro‐8‐ methoxypsoralen, provides a pyrrolidine triazene precursor for radioiodination of the dihydropsoralen system.
Assignment of the 1H‐ and 13C‐NMR spectra of congested helicenes using two‐dimensional NMR methods: Phenanthro[3′,4′:3,4]phenanthro[2,1‐b]thiophene
Authors: Zektzer Andrew S. , Stuart John G. , Martin Gary E. , Castle Raymond N. 
Published: March 2009

AbstractPhenanthro[3′,4′:3,4]phenanthro[2,1‐b]thiophene has been prepared and its highly congested proton and carbon nmr spectra assigned. The nmr assignments required concerted utilization of two‐dimensional nmr techniques which included: COSY, direct and long range optimized heteronuclear chemical shift correlation and heteronuclear relayed coherence transfer.