bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on 1,2,3‐triazoles. Part XI. A new entry to the benzopyrano[2,3‐D]‐1,2,3‐triazole system. Cyclization of 1‐benzyl‐5‐chloro‐4‐(2‐hydroxybenzoyl)‐1H‐1,2,3‐triazoles
Authors: Buckle Derek R.
Published: April 2009

The acylation of simple arenes such as benzene and alkylated benzenes with N‐protected 5‐chloro‐1H‐1,2,3‐triazole‐4‐carboxylic acid chlorides under Friedel‐Crafts conditions results in excellent yields of the corresponding ketones. Resorcinol dimethyl ethers undergo similar acylation reactions in somewhat lower yield with concomitant monodemethylation, and these derivatives undergo a facile base mediated cyclization to 9‐oxo‐3H,9H‐benzopyrano[2,3‐d]‐1,2,3‐triazoles.
Synthesis of spiro[3H‐indole‐3,2′‐tetrahydro‐1,3‐thiazine]‐2,4′(1H)‐diones
Authors: Rajopadhye Milind , Popp Frank D.
Published: April 2009

The title compounds have been prepared by the cyclocondensation of 3‐mercaptopropanoic acid with isat‐in‐3‐imines. The 1‐benzyl derivatives have been synthesized by simultaneously reacting 1‐benzylisatin, substituted anilines and 3‐mercaptopropanoic acid. Mannich condensation of the spiro thiazanones with secondary amines gave the corresponding 1‐aminomethyl derivatives.
Heterocyclic rearrangements. N,N‐diphenylhydrazones, oximes and O‐methyloximes of 3‐benzoyl‐5‐phenyl‐1,2,4‐oxadiazole
Authors: Vivona Nicolò , Frenna Vincenzo , Buscemi Silvestre , Ruccia Michele
Published: April 2009

The behaviour of (E)‐ and (Z)‐N,N‐diphenylhydrazones and O‐Methyloximes of 3‐benzoyl‐5‐phenyl‐1,2,4‐oxadiazole has been studied. When refluxed in benzene, or in dioxane‐water (1:1), the (Z)‐N,N‐diphenylhydrazone 8Z gave the indazole 11 or the substituted semicarbazide 12, respectively. The O‐methyloxime 14Z did not give any rearrangement. A criticism of the oximation reaction of 3‐benzoyl‐5‐phenyl‐1,2,4‐oxadiazole is also reported.
Some intramolecular michael additions of adenine derivatives
Authors: Brahme Nanda M. , Smith Walter T.
Published: April 2009

In our attempts to prepare polymerizable derivatives of nucleic acid bases, we investigated the reaction of adenine (1) and 9‐(cyanoethyl)adenine (4) with acrylic anhydride and acryloyl chloride. Reactions of adenine with methyl acrylate and vinyl acrylate were also examined. The results show that these reactions are solvent dependent and the intermediate acryloyladenine 3 can undergo a facile intramolecular Michael reaction to form 7.
A new synthesis of 5,7‐dicarboxy‐2,1‐benzisoxazolin‐3‐one
Authors: Kim C. K. , Krasavage B. A. , Maggiulli C. A.
Published: April 2009

Condensation of methyl 2‐isoxazolin‐5‐on‐3‐yl acetate (3) and 3‐(N,N‐dimethylamino)‐2‐ethoxycarbonylacrolein (6) gave 5‐ethoxycarbonyl‐7‐methoxycarbonyl‐2,1‐benzisoxazolin‐3‐one (7a). Simple hydrolysis of the diester 7a afforded 5,7‐dicarboxy‐2,1‐benzisoxazolin‐3‐one (7b).
Diels‐alder cycloadditions of diene‐substituted N‐ethoxycarbonyl‐2‐methyl‐1,2‐dihydropyridines with N‐phenylmaleimide
Authors: Krow Grant R. , Cannon Kevin C. , Carey James T. , Lee Yoon B. , Szczepanski Steven W. , Ramjit Harri G.
Published: April 2009

The ten possible substitution patterns for N‐Ethoxycarbonyl‐2‐methyl‐1,2‐dihydropyridines 5 in which one or two olefinic sites are alkyl substituted were synthesized and reacted with N‐phenylmaleimide 2 to provide cycloadducts 6. N‐Ethoxycarbonyl‐5,6‐cyclohexyl‐2‐methyl‐1,2‐dihydropyridine 51 provided the novel spirocycle 61.
Synthesis of some 7‐substituted 3‐chloro‐3,4‐dihydro‐1‐hydroxycarbostyrils by the reduction cyclization of α‐chloro‐β‐(4‐substituted‐2‐nitrophenyl)propionic acids
Authors: Mccord Tommy J. , Warner Michael R. , Shafer Paul L. , Disher Rose M. Davis , Davis Alvie L.
Published: April 2009

A new method was developed for the synthesis of some 7‐substituted 3‐chloro‐3,4‐dihydro‐l‐hydroxycarbostyrils 3c‐g in which α‐chloro‐β‐(4‐substituted‐2‐nitrophenyl)propionic acids 2c‐g were reductively cyclized by catalytic hydrogenation over platinum‐on‐carbon sulfided catalyst. In particular, this method was applied to α‐chloro‐β‐(2‐nitrophenyl)propionic acids bearing 4‐methyl 2c, 4‐ethyl 2d, 4‐ethoxy 2e, 4‐(n‐butyl 2f and 4‐phenyl 2g substituents to afford good yields of the corresponding 7‐methyl 3c, 7‐ethyl 3d, 7‐ethoxy 3e, 7‐(n‐butyl) 3f, and 7‐phenyl 3g substituted 3‐chloro‐3,4‐dihydro‐l‐hydroxycarbostyrils. The various 4‐substituted α‐chloro‐β‐(2‐nitrophenyl)propionic acids 2c‐q were synthesized by reacting the in situ diazotized salts of the appropriate 4‐substituted‐2‐nitroanilines in aqueous acetone with acrylic acid in the presence of cuprous chloride and hydrochloric acid. All compounds prepared in this study were characterized by microanalytical and ir and nmr spectral data.
Fluorinated heterocyclic compounds. 4‐fluoro‐2‐pyridone
Authors: Leznoff Clifford C. , Svirskaya Polina I. , Yedidia Varda , Miller Jack M.
Published: April 2009

The uracil analog, 4‐fluoro‐2‐pyridone was synthesized by ether cleavage of 4‐fluoro‐2‐methoxypyridine with trimethylsilyl iodide. Improved procedures for the preparations of 2‐methoxypyridine N‐oxide hydrochloride and 2‐methoxy‐4‐nitropyridine N‐oxide are described.
Fluorinated heterocyclic compounds. 2. 2,4‐difluoro and 4‐amino‐2‐fluoropyrimidines, nucleoside base analogs
Authors: Svirskaya Polina I. , Yedidia Varda , Leznoff Clifford C. , Miller Jack M.
Published: April 2009

Nucleoside base analogs in which fluoro substituents replace the enolic hydroxy groups of uracil, thymine and cytosine have been prepared. Improved methods for the preparation and isolation of the known 2,4‐di‐fluoropyrimidine, 2,4‐difluoro‐6‐methylpyrimidine and the new 2,4‐difluoro‐5‐methylpyrimidine, 2‐fluoro‐4‐aminopyrimidine, 4‐fluoro‐2‐aminopyrimidine, and other alkylaminofluoropyrimidines are described.
The reaction of enaminones with pentafluorobenzaldehyde. A novel route to substituted quinolines
Authors: Jiang Jack B. , Roberts Jerry
Published: April 2009

Reaction of enaminone 1 and pentafluorobenzaldehyde (2) in glacial acetic acid afforded quinoline skeleton 3 in good yield.
A one‐step synthesis of 2‐methylthio‐6‐oxopyrimidine derivatives: Preparation of fused pyrimidinones
Authors: Hussain S. M. , El‐Barbary A. A. , Mansour S. A.
Published: April 2009

Condensation of a ternary mixture of ethyl cyanoacetate, S‐methylisothiourea and aromatic aldehydes in pyridine afforded directly the 4‐aryl‐5‐cyano‐2‐methylthio‐6‐oxopyrimidines IV in good yields. Alkylation of IV with alkyl halides in alkaline medium yielded the 1‐alkyl derivatives V. The methylthio group in IV and V could be eliminated by aniline, hydrazine and phenylhydrazine and the corresponding 2‐anilino, VII, 2‐hydr‐azino, VIIIa,b, and 2‐phenylhydrazino, VIIIc,d, derivatives were obtained. Compounds VIIIa,b could be cyclised with nitrous acid to give the 3‐cyano‐4‐phenyltetrazolo[1,5‐a]pyrimidine‐2‐one (Xa) and the 1‐methyl analogue Xb, respectively. Some derivatives of VIII were prepared to help in elucidating the structures.
Reactions of ethyl 4‐chloro‐5‐pyrimidinecarboxylates with 2‐aminopyridine. Synthesis of 5H‐pyrido[1,2‐A]pyrimido[5,4‐e]pyrimidin‐5‐ones and 5H‐pyrido[1,2‐a]pyrimido[4,5‐d]pyrimidin‐5‐ones and rearrangement of the former to the latter
Authors: Kim Dong Han
Published: April 2009

5H‐Pyrido[1,2‐a]pyrimido[5,4‐e]pyrimidin‐5‐ones IVa,b and 5H‐pyrido[1,2‐a]pyrimido[4,5‐d]pyrimidin‐5‐ones Va,b were synthesized from ethyl 4‐chloro‐5‐pyrimidinecarboxylate and 2‐aminopyridine. The former compounds were obtained directly upon heating the reactants in ethanol, and the latter were prepared by the fusion of ethyl 4‐(2‐pyridylamino)‐5‐pyrimidinecarboxylates obtained as minor products from the above reaction. The angular fused cyclic compounds, IVa,b were rearranged to the linear tricycles, Vb‐f upon heating with amines.
Polycyclic N‐hetero compounds. XIX. Synthesis of novel meso‐ionic benz[h]imidazo[1,2‐c]quinazoline and benzo[h]pyrrolo[1′,2′:3,4]imidazo[1,2‐c]quinazoline derivatives
Authors: Hirota Takashi , Katsuta Kimiko , Namba Tetsuto , Sasaki Kenji , Hayakawa Shõhei
Published: April 2009

Benz[h]imidazo[1,2‐c]quinazolinium‐l‐olate (5) and benzo[h]pyrrolo[1′,2′:3,4]imidazo[1,2‐c]quinazolinium‐8‐olate (9) having novel meso‐ionic ring systems were synthesized by the reaction of N‐(5,6‐dihydrobenzo[h]‐quinazolin‐4‐yl)amino acids with acetic anhydride.
The chemistry of 3‐azaisotoic anhydrides. Synthesis and reactions of polyaza heterocycles
Authors: Coppola Gary M. , Fraser James D. , Hardtmann Goetz E. , Shapiro Michael J.
Published: April 2009

The preparation of a variety of N‐substituted 3‐azaisatoic anhydrides 3 and 8 is described. These anhydrides reacted with thiopseudoureas to give interesting bicyclic, tricyclic, and tetracyclic heterocycles many of which are new ring systems. One such heterocycle, the imidazo[1,2‐a]pyrido[2,3‐d]pyrimidine ring system, was studied further with respect to alkylation and reduction reactions. Alkylation of 12h occurred on the nitrogen in the central B ring, whereas, in the reduced species 33, alkylation took place in the C ring.

The reaction of 3‐azaisatoic anhydrides with carbanions was also investigated. Reactions occur with anions generated from nitromethane, diethylmalonate, ethyl nitroacetate, ethyl isocyanate, and ethyl o‐fluorobenz‐oylacetate.
The 1,3,4‐oxadiazole moiety, a protective synthon for indirect radioiodination
Authors: Heindel Ned D. , Van Dort Marcian , Cahn Maurice , Schneider Richard , Burns H. Donald
Published: April 2009

2‐(4‐Hydroxyphenyl)‐1,3,4‐oxadiazole can readily be iodinated/radioiodinated to 2‐(3,5‐diiodo‐4‐hydroxy‐phenyl)‐1,3,4‐oxadiazole which in a one‐step hydrolysis‐condensation serves as an indirect prosthetic moiety for iodination of carbonyl compounds.
Synthesis of the isomeric monomethyl derivatives of the novel naphtho[2′,1′:4,5]thieno[2,3‐c]quinoline ring system
Authors: Kudo Hirotaka , Castle Raymond N. , Lee Milton L.
Published: April 2009

The synthesis of the novel naphtho[2′,1′:4,5]thieno[2,3‐c]quinoline (11) ring system and four of the isomeric monomethyl derivatives is described.
Assignment of the 13C‐NMR spectrum of phenanthro[4,3‐A]dibenzothiophene through the utilization of two‐dimensional relayed coherence transfer and double quantum coherence spectroscopy
Authors: Musmar M. J. , Martin Gary E. , Gampe Robert T. , Lee Milton L. , Hurd Ralph E. , Tedjamulia Marvin L. , Kudo Hirotaka , Castle Raymond N.
Published: April 2009

Total assignment of the 13C‐nmr spectrum of the helical molecule phenanthro[4,3‐a]dibenzothiophene at 125.762 MHz is reported. Assignments were made by the combined application of 13C‐13C autocorrelated double quantum coherence and heteronuclear relayed coherence transfer (RELAY) experiments.
Synthesis of substituted, 2,2,5,5‐tetramethylpyrrolidin‐l‐oxyl spin labels–PH sensitivity studies
Authors: Mathew Abraham E. , Dodd John R.
Published: April 2009

The synthesis of derivatives of 2,2,5,5‐tetramethylpyrrolidine nitroxide spin labels aspH sensitive probes is reported. The data on thepH sensitivity studies of these compounds indicate that the amino group increases thepH sensitivity of a nitroxide to a greater degree than a cyano, carboxyl or amido group.
Benzofurano derivatives of coumarins as possible antifertility agents
Authors: Sinha Sunil , Tyagi Anil , Pandey R. K. , Joshi B. C.
Published: April 2009

Synthesis and medicinal importance of 4‐methyl‐6‐nitro‐8,9,10,11‐tetrahydro‐2H‐benzofuro[2,3‐b]‐1‐benzo‐pyran‐2‐one (I), 4‐ethyl‐11‐nitro‐6,7,8,9‐tetrahydro‐2H‐benzofuro[3,2‐g]‐1‐benzopyran‐2‐one (II), and 6,7‐di‐hydro‐4,13‐dimethylbis‐1‐benzopyrano[6,7‐d:7′,6′‐d']‐2H,11H‐benzo[1,2‐b:3,4‐b']difuran‐2,11‐dione (III) is presented. The structures of these compounds were confirmed by elemental analysis and spectral studies.
Polycondensed heterocycles. I. Synthesis of 11‐oxo‐5H, 11H‐pyrrolo[2,1‐c][1,4]benzothiazepine, Derivative of a novel ring system
Authors: Nacci V. , Garofalo A. , Fiorini I.
Published: April 2009

The synthesis of the title compound 4 by cyclization of 1‐(2‐ethoxycarbonylthiobenzyl)pyrrole 9, prepared by treating with ethyl chloroformate the 1‐(2‐mercaptobenzyl)pyrrole 7 previously obtained by debenzylation of 1‐(2‐benzylthiobenzyl)pyrrrole 6, failed. On the other hand 4 was successfully synthesized by intramolecular cyclization of 1‐(2‐mercaptobenzyl)pyrrole‐2‐carboxylic acid 15 by DMAP‐catalyzed DCC method. The pyrrole 6 and 1‐(2‐benzylthiobenzyl)pyrrole‐2‐carboxaldehyde 11 were useful as starting materials to obtain 1‐(2‐benzylthiobenzyl)pyrrole‐2‐carbonitrile 13, which was hydrolyzed to corresponding amide 16. Debenzylation of 16 afforded 1‐(2‐mercaptobenzyl)pyrrole‐2‐carboxyamide 17, whose hydrolysis led to required acid 15.
Diazapolycyclic compounds. XXVI. Reactivity of epoxy‐ and dihydroxy derivatives of diazaquinone adducts
Authors: Alarcón P. , Pardo M. , Soto J. L.
Published: April 2009

Treatment of epoxy and dihydroxy derivatives of diazaquinone adducts with concentrated sulfuric acid yields the respective oxo derivatives, while the reaction of the epoxides with boron trifluoride etherate affords trans‐fluorohydrines.
3‐(1‐imidazoyl)‐6‐methoxy‐2‐benzoxazolinone. A byproduct of the synthesis of 6‐MBOA With 1,1′‐carbonyldiimidazole
Authors: Nachman Ronald J.
Published: April 2009

Previously unknown 3‐(1‐imidazolyl)‐6‐methoxy‐2‐benzoxazolinone was isolated as a byproduct of the synthesis of reproductive‐stimulant 6‐methoxybenzoxazolinone (6‐MBOA) with 1,1′‐carbonyldiimidazole. Concomitant with byproduct formation was a 34% reduction in the yield of the desired 6‐MBOA. A brief discussion of the formation of this byproduct and maximization of the yield of 6‐MBOA is included.
Synthesis of 4‐substituted 5,6‐diphenylmorpholine‐2,3‐diones with two or three chiral centers
Authors: Alcaide Benito , López‐Mardomingo Carmen , López‐Sáez Berta , Pérez‐Ossorio Rafael , Plumet Joaquín
Published: April 2009

Chiral α‐aminoalcohols obtained by stereoselective reduction of α‐iminoketones have been condensed with oxalyl chloride to afford 4‐substituted 5,6‐diphenylmorpholine‐2,3‐diones having two or three chiral centers.
Synthesis of novel imidazo[1,2‐a]pyrrolo[2,1‐c][1,4]benzodiazepines and pyrimido[1,2‐a]pyrrolo[2,1‐c][1,4]benzodiazepines
Authors: Duceppe Jean‐Simon , Gauthier Jean
Published: April 2009

Several 1 1‐amino‐5H‐pyrrolo[2,1‐c][1,4]benzodiazepines have been used as starting material to prepare a number of derivatives of 9H‐imidazo[1,2‐a]pyrrolo[2,1‐c][1,4]benzodiazepines and 10H‐pyrimido[1,2‐a]pyrrolo[2,1‐c][1,4]benzodiazepines. The imidazole nucleus was built by reaction of amidines with ethyl bromopyruvate or aminoacetaldehyde dimethylacetal. Several derivatives of imidazo[1,2‐a]pyrrolo[2,1‐c][1,4]benzodiazepine have been prepared by formylation of the pyrrole ring followed by formation of thioamides. Condensation of 11‐amino‐5H‐pyrrolo[2,1‐c][1,4]benzodiazepines with diethyl ethoxymethylenemalonate afforded intermediate diesters which were transformed into the corresponding 10H‐pyrimido[1,2‐a]pyrrolo[2,1‐c]‐benzodiazepines.
New reactions of deoxyvasicinone. Part 3
Authors: Dunn A. D. , Kinnear K. I.
Published: April 2009

The reaction of deoxyvasicinone 1 with benzoic anhydride, bis(dimethylamino)methane and amyl nitrite are reported. Metallation of 1 is also described.
The reaction of cycloalkanonhydrazones with mercaptoacetic acid. Synthesis of novel N‐aminospirothiazolidinones
Authors: Reddy R. Raji , Iyengar D. S. , Bhalerao U. T.
Published: April 2009

Cycloalkanone hydrazones undergo condensation with mercaptoacetic acid to give predominantly the spirothiazolidinones. The structures of the products have been established on the basis of physico‐chemical data. These compounds have shown promising antibacterial and antifungal activity.
Reactions of indoles with ortho esters, N,N‐dimethylformamide and N,N‐dimethylacetamide dialkyl acetals
Authors: Bergman Jan
Published: April 2009

Indole and N‐methylindole react with oxa stabilized carbocations generated in situ from orthoformates to yield tris(3‐indolyl)methane. The unsymmetrical isomers, e.g. 2‐(N‐methyl‐3‐indolyl)di(N‐methyl‐3‐indolyl)‐methane (4), were not formed as established by an independent synthesis. N,N‐Dimethylacetamide dimethyl‐acetal reacted with 2‐alkyl substituted indoles to produce 1,1‐bis(3‐indolyl)ethanes (3).
On the chichibabin amination of quinoline and some nitroquinolines
Authors: Tondys Hanna , van der Plas Henk C. , Woźniak Marian
Published: April 2009

Quinoline is aminated into 2‐aminoquinoline (55‐60%) when treated with potassium amide/liquid ammonia/potassium permanganate at −65°. When the amination is carried out by allowing the solution of quinoline in potassium amide/liquid ammonia to raise from −60° to + 15° before addition of potassium permanganate, the main product is 4‐aminoquinoline. Using as reagent liquid ammonia/potassium permanganate (thus without the presence of potassium amide) 3‐nitroquinoline is exclusively aminated at −40° into 4‐amino‐3‐nitroquinoline. Using the same conditions, from 4‐nitroquinoline 3‐amino‐4‐nitroquinoline is obtained. The mechanism of these amination reactions is discussed.
Cycloadditions of ketenes with cyclic carbodiimides
Authors: Brady William T. , Shieh C. H.
Published: April 2009

The cycloaddition of ketenes with cyclic carbodiimides yields β‐lactams in good to excellent yields. The cycloaddition of equal molar amounts of diphenyl‐, phenylethyl‐ and phenylketenes with cyclic carbodiimides produced a 1:1 cycloaddition product, the expected β‐lactams. However, the cycloaddition of a 2:1 molar ratio of diphenyl‐ and phenylketenes with 1,3‐diazacycloocta‐1,2‐diene respectively, gave the 2:1 cycloadducts, the tricyclodi‐β‐lactams. The cycloaddition of methylchloro‐ and dichloroketenes yielded β‐lactams that were very susceptible to hydrolysis to the N‐substituted cycloureas. A trapping experiment suggests that these reactions proceed through a stabilized dipolar intermediate.
Ring closure of thiosemicarbazides with sulfuric acid. A structure correction
Authors: Sard Howard , Meltzer Peter C. , Razdan Raj K.
Published: April 2009

The dehydration of 2a with sulfuric acid at ambient tempeature produces the sulfonated product 3a.
Triazoles. III. The alkylation of 3‐R′‐thio‐5‐amino‐1,2,4‐triazoles
Authors: Reiter J. , Somorai T. , Dvortsák P. , Bujtás Gy.
Published: April 2009

The alkylation of 3‐R′‐thio‐5‐amino‐1H‐1,2,4‐triazoles 1 or their sodium salt with alkyl and aralkyl halides 2, respectively, to yield all the four possible monoalkylated derivatives 3, 4, 5 and 6 was studied. The comparison of the spectral data of different type isomers 3, 4, 5 and 6 isolated and their Schiff bases 8, 9 and 10, respectively, was unequivocal evidence in support of their structure which was then further supported by independent synthesis and ring closure reactions. According to an hplc study the main product of the alkylation is derivative 3, the by‐product is derivative 4, while derivatives 5 and 6 are formed only in insignificant amounts.
Synthesis and reactions of N‐Aryl‐C‐arylsulfonylformohydrazidoyl bromides
Authors: Hassaneen Hamdi M. , Abdelhamid Abdou O. , Fahmi Abdelgawad A. , Shawali Ahmad S.
Published: April 2009

Bromination of 1‐arylsulfonyl‐1,2‐propanedione‐1‐aryl‐hydrazones 7 in a mixture of acetic acid and acetic anhydride in the presence of sodium acetate gave N‐aryl‐C‐arylsulfonylformohydrazidoyl bromides 5. Treatment of 5 with dibenzoylmethane, acetylacetone, ethyl acetoacetate and ethyl benzoylacetate in ethanol in the presence of sodium ethoxide yielded the pyrazole derivatives 8‐11, respectively. Reaction of 5 with potassium thiocyanate afforded the thiadiazoline derivative 14. The bromides 5 also react with nucleophiles such as morpholine, piperidine, phenoxide, thiophenoxide and benzenesulfinate anions to give the corresponding substitution products 19‐23, respectively. The structures of the products 8‐23 were assigned and confirmed on the basis of their spectral and elemental analyses, their chemical behaviour and alternate synthesis wherever possible.
Imidazolyl derivatives of the chroman ring. 2
Authors: Cozzi Paolo , Pillan Antonio
Published: April 2009

The synthesis of 3‐(1H‐imidazol‐1‐yl)‐4H‐1‐benzopyran‐4‐ones 2 and of 2‐(1H‐imidazol‐1‐yl)‐4H‐1‐benzopyr‐an‐4‐ones 11 are described. The former proceeds through chroman ring closure from 2‐(1H‐imidazol‐1‐yl)‐2′‐hydroxyacetophenones, the latter occurs reacting 3‐bromo‐4H‐1‐benzopyran‐4‐ones with imidazole and represents an example of a new synthesis of 2‐heteroarylchromones. Compounds 2 can be easily reduced to the corresponding chromanones and chromanols previously described in Part 1.
Synthesis of 1,2‐disubstituted isoindoles from o‐phthalaldehyde and primary amines
Authors: Nan'ya Seiko , Tange Toshiaki , Maekawa Eturô
Published: April 2009

2‐Alkyl‐1(2‐formylphenyl‐N‐alkyliminomethyl)isoindoles were prepared by the reaction of o‐phthaldehyde with primary amines in 99% ethanol at 0°. 2‐Alkyl‐3‐alkyliminoisoindolinones were isolated from the reaction mixture as by‐products. Their formation mechanism is proposed.
Methylation of 3‐methyl‐ and 3‐phenyl‐4‐arylhydrazonoisoxazol‐5‐ones with methyl iodide and dimethyl sulfate
Authors: Singh Shyam K. , Summers Lindsay A.
Published: April 2009

Methylation of 3‐methyl‐4‐arylhydrazonoisoxazol‐5‐ones with methyl iodide affords both 2,3‐dimethyl‐4‐arylazoisoxazol‐5‐ones and 3‐methyl‐4‐(N‐methylarylhydrazono)isoxazol‐5‐ones but with dimethyl sulfate only the former products are formed. 3‐Phenyl‐4‐arylhydrazonoisoxazol‐5‐ones behave in a similar way on methylation with methyl iodide and dimethyl sulfate.
Studies of amine‐induced ring opening of some mesoionic xanthines
Authors: Mbagwu Godwin O. , Bass R. Gerald , Glennon Richard A.
Published: April 2009

The ring‐opening reactions of seven mesoionic thiazolo[3,2‐a]pyrimidine‐5,7‐diones by a series of primary and secondary amines have been investigated. The rates of the ring fission of five N(8)‐substituted mesoionic xanthines with benzylamine were measured and found to follow second order kinetics. The Hammett relationship is followed with ϱ value of + 0.48 in p‐dioxane as solvent. The dependence of rates on temperatures has been studied for the N(8)‐ethyl derivative; the energy of activation (ΔE*) is 25.3 kcals mol−1, the enthalpy of activation (ΔH*) is 24.7 kcals mol−1 and the entropy of activation (ΔS*) is — 4.9 e.u. A slight increase in rate of reaction was observed when the solvent was changed from p‐dioxane to dimethyl sulfoxide. In p‐dioxane at constant mesoionic xanthine concentration, the rate constant for ring opening decreased with increasing benzylamine concentration. These results are consistent with a bimolecular nucleophilic mechanism proceeding by the rate‐determining formation of a charged tetrahedral transition state.
A facile synthesis and structure determination from 13c‐nmr spectroscopy of a novel heterocycle 1,1′‐ethylenebis[2,3,8,8a‐tetrahydro‐5,8a‐dimethyl‐1H‐imidazo[2,1‐c][1,4]thiazine], a case of transannular stabilization
Authors: Tandon Santokh S. , Larkworthy Leslie F.
Published: April 2009

The condensation of 4‐thiaheptane‐2,6‐dione with triethylenetetramine does not produce the macrocycle 1‐thia‐3,14‐dimethyl‐4,7,10‐13‐tetrazacyclopentadeca‐3,13‐diene; instead two molecules of the dione condense with one of the amine to give the title compound.
New synthesis of 1,2,3‐thiadiazole‐5‐thiol derivatives
Authors: Curran William V. , Sassiver Martin L. , Boothe James H. , Jacob Linda
Published: April 2009

New syntheses of 1,2,3‐thiadiazole‐5‐thiol derivatives utilizing the thionyl chloride ring‐closure of the aldehyde derivatives 5a, b, and c are reported.
Electronic structure of 4H‐pyrido[1,2‐a]pyrimidin‐4‐ones
Authors: Horváth Gábor , Hermecz István , Horváth Ágnes , Pongor‐Csákvári Marianna , Pusztay Levente , Kiss Árpád István , Czakó László , Abdirizak Osman Hassan
Published: April 2009

The characteristic features of ir and uv spectra of 43 4H‐pyrido[1,2‐a]pyrimidin‐4‐one derivatives with electron donor or acceptor groups in position 3, and positions 6, 7, 8, or 9, respectively, have been systematically studied. On the basis of the spectra some conclusions have been drawn for the molecular structure. The negative solvent effect of the lowest‐energy π → π* transition is investigated by the PPP method.
Facile synthesis of furans from 2‐ene‐1,4‐diones by diphosphorus tetraiodide
Authors: Demirdji S. H. , Haddadin M. J. , Issidorides C. H.
Published: April 2009

Diphosphorus tetraiodide effects reductive ring‐closure of a variety of 2‐ene‐1,4‐diones into furans within a few minutes at room temperature.
Heterodiene synthesis. Synthesis of fused thiopyrano [2,3‐d]thiazole, Benzopyrano[3′,4′:4,5]thiopyrano[2,3‐d]thiazole and thiazolo[3,4‐c]triazine derivative
Authors: Allah Sanaa O. Abd , Hammouda Hamdy A. , Ali Fatma A.
Published: April 2009

5‐Salicylidenethiazolidine‐2,4‐dithione (1) reacts with acrylonitrile,N‐phenylmaleimide and dimethyl acet‐ylenedicarboxylate to afford the fused thiopyrano[2,3‐d]thiazolidinethione derivatives2, 4and6, respectively. The salicylidene derivative1reacts with ethyl acrylate and malononitrile to afford the fused [1]benzopyrano[3′,4′:4,5]thiopyrano[2,3‐d]thiazoles3and9, respectively. 4‐Phenylhydrazono‐2‐thiazolidinethione (11) reacts with ethyl bromoacetate and/or phenacyl bromide to yield the fused thiazolo[3,4‐c]triazines13and14.
Preparation of 2‐iodotryptamine and 2‐iodo‐5‐methoxytryptamine
Authors: Kline Toni
Published: April 2009

The regiospecific iodination of indole and 5‐methoxyindole, and the elaboration of these 2‐iodoindoles to the corresponding tryptamines, are described.
Synthetic approaches to unsaturated five‐membered heterocycles containing both ring and side‐chain phosphorus atoms
Authors: Amin Md. , Holah David G. , Hughes Alan N. , Rukachaisirikul Thitima
Published: April 2009

The syntheses of several structurally interesting 2‐diphenylphosphinyl‐substituted 2‐phospholenes and phospholanes are reported together with a discussion of the 31P and 13° C nmr spectral properties of these compounds. Several of these syntheses were found to be highly stereoselective and the potential of some of the products of these reactions as precursors to phosphole derivatives bearing phosphorus‐containing side‐chains has also been explored. A new, and possibly general, route to 4‐oxo‐2‐phospholene oxides or sulfides from the corresponding 4‐methylene compounds is also reported. This route involves an unusual free‐radical catalyzed oxidative cleavage of the 4‐methylene group by molecular oxygen and a probable mechanism for this reaction is proposed.
A convenient route for the synthesis of s,s‐and R,R‐warfarin alcohols
Authors: Jeyaraj G. L. , Porter W. R.
Published: April 2009

S,S‐and R,R‐warfarin alcohols 3 are prepared in good yield and in 99% d.e. (diastereomeric excess) by the reaction of S‐ or R‐warfarin 1 with S or R‐Alpine‐Hidride 2.
2,4,4‐trisubstituted 5‐amino‐4h‐imidazoles. A new synthetic approach and reactivity
Authors: Avendaño C. , Ramos T. , Gómez‐Molinero E.
Published: April 2009

The scope and limitations of the reaction between imidates and α,α‐disubstituted α‐aminoacetonitriles to give 5‐amino‐4H‐imidazoles are studied. The reactivity of compounds 1a‐b has been explored.
1‐Methylphenanthro[3,4‐b]thiophene: Determination of the tertiary structure in solution and in the crystalline state by NMR spectroscopy and X‐ray diffraction
Authors: Musmar M. J. , Martin Gary E. , Gampe Robert T. , Lynch Vincent M. , Simonsen Stanley H. , Lee Milton L. , Tedjamulia Marvin L. , Castle Raymond N.
Published: April 2009

1‐Methylphenanthro[3,4‐b]thiophene was prepared by the photocyclization of 1‐(4′‐methyl‐2′‐thienyl)‐2‐(2″‐naphthyl)ethene. The 1H and 13C‐nmr spectra were assigned using two‐dimensional 1H/13C heteronuclear chemical shift correlation and relayed coherence transfer (RELAY) experiments. From nuclear Overhauser difference spectra, the H11‐C1 methyl‐H intramolecular distance was determined to be 2.10 Å. The molecule crystallized from chloroform in the monoclinic system, space group P21/c. A total of 3536 unique reflections were measured and the structure was solved by direct methods and refined to a final R = 0.049. The molecule is helical with both chiral forms observed in the crystal. The H11‐C1 methyl‐H distance in the crystal was 2.12(3)Å in excellent agreement with the distance measured in solution by NOE techniques.
Imino‐bridged heterocycles. III . Synthesis of mono‐bridgehead substituted 11H‐benzo[5,6]cyclohepta[1,2‐c]pyridin‐6,11‐imines by regiospecific amine to olefin cyclizations
Authors: Brenner Daniel G. , Halczenko Wasyl , Shepard Kenneth L.
Published: April 2009

Employing regiospecific amine to endocyclic olefin and hydroxylamine to exocyclic olefin cyclizations, we have developed pathways to two isomeric, bridgehead methyl‐substituted benzo[5,6]cyclohepta[1,2‐c]pyridin‐6,11‐imines. Acid catalyzed cyclization of 5 to 6 was accomplished under exceedingly mild conditions (silica gel/chloroform), whereas, thermal cyclization of 20 to generate 21 was performed analogously to the dibenzo[a,d]cyclohepten‐5,10‐imine system.
Heterocyclic‐fused benzopyrans as cannabinoid analogues
Authors: Press Jeffery B. , Birnberg Gary H.
Published: April 2009

A series of A‐ring heterocyclic analogues of tetrahydrocannabinol were investigated. Chromanones 1a and 1b were functionalized by formylation with base and ethyl formate to give 6a and 6b. These formylketones were reacted with hydrazine, and Phenylhydrazine to give pyrazoles 7a,b,e, and f, respectively. When 6a and 6b were reacted wtih methylhydrazine, mixtures of methyl isomers 7c and 8a and 7d and 8b formed in a ratio of 1:2.5. Isoxazoles 10a and 10b formed similarly when hydroxylamine was used as the condensing agent. Attempts to prepare the pyrimidine derivatives 11 were thwarted by the rearrangements of 6a and 6b to chromenones 12a and 12b.
4‐Hydroxy‐1(2H)‐isoquinolone‐3‐carboxamides synthesis and properties
Authors: Schapira Celia B. , Abasolo María I. , Perillo Isabel A.
Published: April 2009

Reaction of some α‐phthalimidoacetamides 1a‐i with sodium ethoxide was carried out under drastic conditions. Compounds 1b‐g afforded 4‐hydroxy‐1(2H)‐isoquinolone‐3‐carboxamides 2b‐g, while 1h‐i afforded the acid 3a‐b together with the expected isoquinolones 2h‐i. Compound 1a gave phthalimide as the major product. Compounds 2 are acidic and unstable in basic media. The most acidic compounds presented the longest half‐life. An explanation of these results was given.
Use of hypervalent iodine oxidation for the C(3)‐hydroxylation of chromone, flavone and α‐naphthoflavone
Authors: Moriarty Robert M. , Prakash Om , Musallam H. A.
Published: April 2009

C(3)‐Hydroxylation of chromone (1a), flavone (1b) and α‐naphthoflavone (4) via acid‐catalysed hydrolysis of the corresponding β‐methoxy‐α‐hydroxydimethylacetals (2a, 2b, and 5) formed by iodobenzene diacetate‐potassium hydroxide methanol oxidation is described.
Chemische eigenschaften und synthese‐verfahren von 3‐vinylindolen
Authors: Akgün E. , Pindur U.
Published: April 2009

Selectively functionalized 3‐vinylindoles are mostly stable compounds, which may serve as potent building blocks for anellation of the indole nucleus, in particular for synthesis of carbazole alkaloides and to obtain pharmacologically active compounds. This review describes from a great number of the permanent increasing literature of vinylheterocycles the chemical properties, the most important principles of the synthetic methods and the synthetic applications of 3‐vinylindoles. Among the synthetic methods to obtain 3‐vinylindoles the classical condensation, the Wittig‐Horner‐/Wadsworth‐Emmons‐Olefination and the recently developed Pd‐catalyzed vinylation should be considered as reliable standard methods. Depending on the special functionalization in the desired product some others methodologies are developed, so the thermolysis or the acid catalyzed ipso‐cleavage of hetarylindolylethanes for deriving 1‐hetaryl‐1‐indolylethenes.
Nitrogen bridgehead compounds. Part 50. Vilsmeier‐haack acylation of 6,7,8,9‐tetrahydro‐4H‐pyrido[1,2‐a]pyrimidin‐4‐ones, Part 5
Authors: Horváth Ágnes , Hermecz István , Podányi Benjamin , Mészáros Zoltán
Published: April 2009

6‐Methyl‐6,7,8,9‐tetrahydro‐4H‐pyrido[1,2‐a]pyrimidin‐4‐ones 1‐5 were subjected to Vilsmeier‐Haack acylation with complexes of phosphoryl chloride and different amides. Acylation at position 9 of the pyridopyrim‐idines was successful with the iminium salt formed in situ from N‐formylpiperidine, N‐methylformanilide or N,N‐diethylbenzamide, but unsuccessful with the iminium salt formed from N,N‐diethylacetamide or N,N‐di‐ethylisobutyramide, respectively. The iminium salt formed from formanilide, N‐methylpyrrolidinone or formamide reacted only with those tetrahydropyridopyrimidinones which contain a strongly electronegative substituent (e.g. CN or CO2Et) in position 3. With the latter derivatives, the 9‐phenylaminomethylene group could be introduced using N,N‐diphenylformamide or in a “one‐pot” procedure with aniline and triethyl orthoformate. Ethanolysis of 9‐N‐methyl‐N‐phenylaminomethylene derivatives 15 and 19 afforded 9‐ethoxy‐methylene compounds 26 and 27 in the presence of hydrogen chloride. The structures of the 9‐substituted 6‐methyltetrahydropyridopyrimidin‐4‐ones 14‐25 were elucidated by means of uv, 1H and 13C nmr spectroscopy. 9‐Piperidinomethylene 14, 9‐(N‐methyl‐N‐phenylaminomethylene 15‐19 and 9‐(N‐methyl‐2‐pyrrolidinylidene) 21 derivatives exist as E geometric isomers. 9‐Phenylaminomethylene‐6‐methyl‐4‐oxo‐6,7,8,9‐tetra‐hydro‐4H‐pyrido[1,2‐a]pyrimidine‐3‐carbonitrile 20 displays a solvent‐dependent E‐Z isomerism. The bis‐compound 25 contains both E and Z geometric exo C  CH double bonds. 9‐Benzoyl derivatives 23 and 24 exist predominantly as the 1,6,7,8‐tetrahydropyridopyrimidin‐4‐one tautomer.
Synthesis of nitrogen heterocycles by condensation of the conjugate base of open‐chain reissert compound analogs with vinyltriphenylphosphonium bromide (schweizer's salt)
Authors: Cooney John V. , Beaver Bruce D. , Mcewen William E.
Published: April 2009

Reaction of the conjugate base of several open‐chain Reissert compound analogs with vinyltriphenylphosphonium bromide is shown to afford a convenient route to substituted pyrroles. The condensation is a two‐step process involving an initial reversible addition to form an unstabilized Wittig reagent followed by an intramolecular Wittig reaction upon the carbonyl group of the tertiary amide functionality with concomitant elimination of HCN. Several applications to the synthesis of 1,2,5‐trisubstituted pyrroles are presented, together with attempts to expand this methodology to the synthesis of other heterocyclic systems.
Conformation and bonding in unsymmetrically 3,6‐disubstituted dihydro‐1,2,4,5‐tetrazine
Authors: Pilgram Kurt H. , Gale Laird H. , Skiles Richard D.
Published: April 2009

The molecular structure of the title compound, I, has been determined by single‐crystal X‐ray diffraction. The crystals are triclinic, space group PI. The analysis revealed that the dihydro‐s‐tetrazine molecule is in a slightly twisted boat conformation with the nitrogen atoms carrying the two hydrogens, N(2) and N(4), pointing upward. All substituents on the dihydro‐s‐tetrazine ring exist in pseudo‐equatorial configurations. Adjacent hydrogen and bulky groups (CF3 and p‐Cl‐C6H4) have cis‐relationships. The p‐chlorophenyl group is twisted with respect to the dihydro‐s‐tetrazine ring. The unit cell for I contains six molecules. Each dihydro‐s‐tetrazine ring participates in four intermolecular hydrogen bonds (N···H bond distance 2.23 to 2.41 A), two hydrogen bonds to each adjacent tetrazine ring in the same unit cell.
13C‐NMR spectra and carbon‐proton coupling constants of variously annulated furocoumarins
Authors: Guiotto A. , Manzini P. , Chilin A. , Pastorini G. , Rodighiero P.
Published: April 2009

The 13C‐nmr spectra of variously annulated methylfurocoumarins are reported. The assignments of chemical shifts for all the C resonances has been achieved by using carbon‐proton coupling constants, relaxation efficiency considerations and shift effects caused by the introduction of methyl groups at various positions of the furocoumarin nucleus. Substituent effects on 13C chemical shifts and carbon‐proton coupling constants are discussed.
Synthesis of 2‐deamino‐ and 2‐deamino‐2‐nitroactinomycin D
Authors: Sehgal Raj K. , Sengupta Sisir K. , Dieter R. Karl
Published: April 2009

A single step synthesis of 2‐deaminoactinomycin D (3a) and 2‐deamino‐2‐nitroactinomycin D (2a) arising from actinomycin D (1a, AMD) is reported. Structural confirmation was made by nmr, ir and chemical conversion to known materials.
Synthese von pyridylphenyl‐imidazo[2,1‐b]thiazolen
Authors: Klose Walter , Schwarz Katica
Published: April 2009

The synthesis of the isomeric 6(5)‐phenyl‐5(6)‐pyridyl‐2,3‐dihydroimidazo[2,1‐b]thiazoles are described. Only the synthesis of 5‐phenyl‐6‐(2‐pyridyl)‐2,3‐dihydroimidazo[2,1‐b]thiazole failed.
Crystal and molecular structure of 3,4,4,5‐tetramethyl‐1‐(p‐methoxybenzoyl)‐5‐(p‐methoxybenzoylazo)‐2‐pyrazoline
Authors: Stephanidou‐Stephanatou J. , Alexandrou N. E. , Salem G. , Terzis A.
Published: April 2009

The crystal and molecular structure of the title compound, derived by lead tetraacetate oxidation of the bis‐p‐methoxybenzoylhydrazone of 3,3‐dimethylpentane‐2,4‐dione, is studied by an X‐ray crystallographic analysis.
Synthesis of 6‐phenyl‐3‐azabicyclo[4.2.1]nonane
Authors: Mazzocchi P. H. , Kim C. H.
Published: April 2009

The synthesis of the title compound was achieved in five steps in 19% overall yield. The key step was an intramolecular Mannich reaction.
2‐Methylpyridinium salts as 1,4‐dinucleophiles. Quinolizinium salts from the westphal condensation
Authors: Alvarez‐Builla J. , Trigo G. Gonzalez , Ezquerra J. , Fombella M. E.
Published: April 2009

Condensation of 2‐methylpyridinium salts with 1,2‐dicarbonyls in the presence of base, yielded 2,3‐disubstituted quinolizinium compounds. Results obtained with different pyridinium substrates are discussed.
The electron‐impact mass spectra of 1,2‐benzisoxazole N‐oxides
Authors: Tsiamis C. , Tsoungas P. G.
Published: April 2009

The mass spectra of a new class of heterocyclic N‐oxides are reported. It is proposed that the fragmentation processes proceed either by an initial deoxygenation, and or an impact‐induced isomerisation, prior to fragmentation. Substituents on the carbocyclic ring normally confer stability on the m olecular ions, whereas those on the heterocyclic ring open up additional fragmentation modes. A phenyl group at the 3‐position allows an intramolecular oxygen transfer prior to fragmentation.
Rearrangement of 3‐methoxy substituted [2, 1]benzisoxazole‐ and naphth[2,3‐c]isoxazolequinones in dimethyl sulfoxide solution
Authors: Torres Tomás , Eswaran S. V. , Schäfer Wolfram
Published: April 2009

The reactions of the 3‐methoxy‐isoxazole quinones 1 and 9 in a highly polar solution of dimethyl sulfoxide have been studied. Quinones of type 2, 4/11, 5/12, 6 and 7/13 have been isolated; nmr measurements give a detailed insight into the reaction mechanism.
Synthesis of 1,4‐dihydro‐4‐oxopyrrolo[3,4‐b]pyridine‐3‐carboxylic acid derivatives as potential antimicrobial agents
Authors: Bayomi Said M. , Price Kenneth E. , Sowell J. Walter
Published: April 2009

A route for the synthesis of various derivatives of 1,4‐dihydro‐4‐oxopyrrolo[3,4‐b]pyridine‐3‐carboxylic acid from 2‐phenyl‐3‐amino‐4‐t‐butoxycarbonyl‐5‐methylpyrrole hydrochloride is reported.
One‐step synthesis of 3‐amino‐2,4‐imidazolinediones (3‐aminohydantoins) from α‐amino acids
Authors: Lalezari Iraj
Published: April 2009

α‐Amino acids melted with ethyl or t‐butyl carbazate or, preferably, refluxed with t‐butyl carbazate in quinoline gave high yields of 3‐amino‐2,4‐imidazolidinediones (3‐aminohydantoins).
Imination of N‐methylazinium salts by liquid ammonia/potassium permanganate
Authors: Woźniak M. , Buurman D. J. , Van Der Plas H. C.
Published: April 2009

Treatment of 1‐methylquinolinium‐, 1,4‐dimethylquinolinium‐ and 1‐methyl‐1,X‐naphthyridinium iodides (X = 5,8) with liquid ammonia/potassium permanganate leads to introduction of the imino group at C‐2 forming the 1,2‐dihydro‐2‐imino‐1‐methylquinolines and 1,2‐dihydro‐2‐imino‐1‐methyl‐1,X‐naphthyridines (X = 5,8) respectively. 1,2‐Dimethylquinolinium iodide, when subjected to treatment with liquid ammonia/potassium permanganate undergoes an oxo‐demethylation reaction, yielding 1‐methylquinol‐2‐one. The nmr‐measurements of solutions of the above‐mentioned salts in liquid ammonia clearly show the formation of a σ‐adduct, strongly suggesting that these σ‐adducts are intermediates in the imination reactions.
Molecular structure and 13C chemical shift assignments of 10‐(2′‐pyridyl)pyrido[3,2‐b][1,4]benzothiazine using 10‐phenylpyrido[3,2‐b][1,4]benzothiazine as the model compound
Authors: Jovanovic Misa V. , Biehl Edward R. , de Meester Patrice , Chu Shirley S. C.
Published: April 2009

The crystal structure of 10‐(2′‐pyridyl)pyrido[3,2‐b][1,4]benzothiazine, 6, shows that orientation of the 10‐pyridyl ring is in the plane bisecting the pyridobenzothiazine ring. This orientation is in contrast to that of 10‐(2′‐pyridyl)phenothiazine, 11, in which the heterocyclic ring is perpendicular to the plane bisecting the phenothiazine nucleus. X‐ray data also indicate that the resonance interaction between the lone pair of electrons of NSUB10 in 6 with either the pyridine protons of the tricylcic ring or the 10‐(2′‐pyridyl) ring is not significant. The folding angle of 166.1° in 6 is the largest observed for the pyridobenzothiazine ring. The nmr spectral assignments of the titled compound, 6, was accomplished using the structurally similar, 10‐phenylpyrido[3,2‐b][1,4]benzothiazine, 9, as the model compound. 10‐(2′‐Pyridyl)phenothiazine, 11, was shown to be an inadequate model for such assigments.
Ring transformation of 6H‐cyclopropa[e]pyrazolo[1,5‐a]pyrimidine. VI. Substituent effect of 6‐substituted 5a‐acetyl‐6a‐ethoxycarbonyl‐5a,6a‐ dihydro‐6H‐cyclopropa[e]pyrazolo[1,5‐a]pyrimidine‐3‐carbonitriles
Authors: Kurihara Takushi , Kawasaki Eiji , Morita Takamasa , Nasu Keiko
Published: April 2009

Synthesis and reactivity of 6‐ethoxycarbonyl‐, 6‐phenyl‐ and 6‐methyl‐5a‐acetyl‐6a‐ethoxycarbonyl‐5a,6a‐di‐hydro‐6H‐cyclopropa[e]pyrazolo[1,5‐a]pyrimidine‐3‐carbonitriles 4, 5, and 7 are described.
The site‐selectivity of cycloadditions of nitrile oxides to β‐aminocinnamonitriles. A remarkable solvent dependence
Authors: Corsaro Antonino , Chiacchio Ugo , Perrini Giancarlo , Caramella Pierluigi , Purrello Giovanni
Published: April 2009

Cycloadditions of nitrile oxides to N‐mono and unsubstituted β‐aminocinnamonitriles are remarkably affected by the hydrogen acceptor ability of the solvent. Addition to C  N bond predominates in non and weak hydrogen bond acceptor solvents because of the assistance of favourable hydrogen bonding effects. In strong hydrogen bond acceptor solvents the assistance is fully relieved and the regular addition to C  C bond becomes prevalent.
Some cyclisation reactions of 2,2′‐disubstituted‐N‐arylpyrroles
Authors: Cheeseman G. W. H. , Eccleshall S. A. , Thornton T.
Published: April 2009

Tricyclic products were derived from N‐(2‐methoxycarbonylphenyl)pyrrole‐2‐carboxaldehyde (2) and N‐(2‐chloromethylphenyl)pyrrole‐2‐carboxaldehyde (8).
Convenient synthesis of 3‐arylazopyrazoles and 2‐arylazo‐1,3,4‐Δ2‐ thiadiazoline derivatives from 3‐nitroformazans
Authors: Abdelhamid Abdou O. , Abbas Ikhlass M. , Abdallah Magda A. , Fahmi Abdelgawad A. , Shawali Ahmad S.
Published: April 2009

Reactions of 3‐nitro‐1,5‐diarylformazans 1a‐c with carbanions of acetylacetone, dibenzoylmethane, aceto‐acetanilide, benzoylacetonitrile, ω‐benzenesulfonylacetophenone and malononitrile yielded the corresponding 3‐arylazopyrazole derivatives 4‐9 respectively. Reactions of 1 with nucleophiles result in displacement of the nitro group and the formation of the corresponding 3‐substituted formazans 10‐13. Treatment of 1 with potassium thiocyanate gave, however, 5‐imino‐2‐arylazo‐1,3,4‐Δ2‐thiadiazolines 14. Structural assignments have been made on the basis of spectral and elemental analyses, chemical behaviour and alternate synthesis wherever possible.
Studies on the synthesis of 2‐(2‐arylvinyl)thieno[2,3‐d]pyrimidines and 5‐(2‐arylvinyl)triazolothieno[3,2‐e]pyrimidines
Authors: Shishoo C. J. , Devani M. B. , Ullas G. V. , Ananthan S. , Bhadti V. S.
Published: April 2009

Synthesis of 2‐(2‐arylvinyl)thienopyrimidines, by the acid catalyzed condensation of nitriles with thiophene o‐aminocarbonyl compounds, the condensation of aldehydes with thiophene o‐aminoamides, the base catalyzed condensation of aldehydes with 2‐methylthienopyrimidines and by the Wittig condensation of 2‐thieno‐pyrimidinylmethylphosphonium salts with aldehydes is described. Isomeric 5‐methyltriazolothienopyrimidines were found to react, under basic condition, with aldehydes yielding 5‐(2‐arylvinyl)triazolo[2,3‐c]thieno‐pyrimidines. While 5‐styryltriazolo[4,3‐c] isomers resisted acid catalysed isomerization, they were found to isomerize to triazolo[2,3‐c]pyrimidines under base catalysis.
Synthesis of (E)‐5‐oxo‐2‐(3‐α and 3β‐hydroxy‐1‐octenyl)‐1‐(4‐N‐pyrrolidine‐2‐butynyl)pyrrolidine
Authors: Zoretic P. A. , Khan R. H. , Caspar M. L. , Saltzman M. D. , Jardin J.
Published: April 2009

The synthesis of an oxotremorine analog, (E‐5‐oxo‐2‐(3α and 3β‐hydroxy‐1‐octenyl)‐1‐(4‐N‐pyrrolidino‐2‐butynyl)pyrrolidine, is reported.
Phosphorus pentoxide in organic synthesis. XIX. Mixtures of phosphorus pentoxide and ortho‐substituted arylamines as reagents in the synthesis of 9‐aryl‐9H‐purin‐6‐amines
Authors: El‐Bayouki Khairy A. M. , Nielsen Flemming E. , Pedersen Erik B.
Published: April 2009

9‐Aryl‐9H‐purin‐6‐amines 2 were readily obtained by heating 5‐acetamido‐4‐amino‐2‐methylpyrimidin‐6(1H)‐one 1 in mixtures of phosphorus pentoxide, triethylamine hydrochloride and sterically hindered arylamines. Nonsterically hindered arylamines resulted in formation of 6‐arylaminopurines 3. The mechanism for rearrangement of 2 into 3 is discussed.
Synthesis of selenium analogs of glycerol from 1,2,3‐selenadiazoles
Authors: Ganjian I. , Lalezari I.
Published: April 2009

A series of 1‐(2‐arylethynylselenomercapto)‐2,3‐epoxypropane and 1,3‐di(2‐arylethynylselenomercapto)‐2‐propanol were synthesized starting from 1,2,3‐selenadiazoles and epichlorohydrin.
Synthesis of indole derivatives from N‐alkenyl‐o‐chloroanilines with zero‐valent nickel complex
Authors: Rodriguez J. G. , Canoira L.
Published: April 2009

Reaction of N‐alkenyl‐o‐chloroanilines in toluene with tetrakis(triphenylphosphine)nickel (0) was carried out mainly to give indole and indoline derivatives in good yields. A detailed analysis of the reaction products has been done and it allows us to confirm the postulated mechanism of the cyclization reaction. Torsional hindrance around the NCCsp2 bond seems to prevent the cyclization reaction.
Reaction of 6‐phenyl‐2‐(p‐toluenesulfonyl)‐3(2H)pyridazinone with grignard reagents
Authors: Kashima Choji , Katoh Akira , Fukasawa Miyuki , Omote Yoshimori
Published: April 2009

6‐Phenyl‐2‐(p‐toluenesulfonyl)‐3(2H)pyridazinone (I) reacted with Grignard reagents to give 5‐substituted 4,5‐dihydro‐3(2H)pyridazinones II and two types of dihydropyridazines, III and IV. The ratio of II, III, and IV was sensitively dependent on the reaction conditions. Further, by quenching the reaction mixture with alcohol, the ring‐opened product VII was mainly isolated.
A new look into the rothemund meso‐tetraalkyl and tetraarylporphyrin synthesis
Authors: Gonsalves A. M. D'A. Rocha , Pereira Mariette M.
Published: April 2009

meso‐Tetraalkylporphyrinogens are easily formed and unexpectedely stable compounds. Only through forced oxidation can they efficiently be converted into porphyrins. meso‐Tetraphenylphlorin was trapped as an intermediate in the Rothemund meso‐tetraphenylporphyrin synthesis.
A new method for the synthesis of novel 1,2,4‐triazolo[3,4‐f][1,2,4]triazines
Authors: Kurasawa Yoshihisa , Okamoto Yoshihisa , Takada Atsushi
Published: April 2009

Novel compounds 8‐(quinoxalin‐2‐yl)‐1,2,4‐triazolo[3,4‐f][1,2,4]triazines 3a,b were obtained by a new annulation method in the 1,2,4‐triazine synthesis.