bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel heterocycles. 9. Synthesis of the benzofuro[2,3‐c][1,2]thiazine ring system
Authors: Coppola Gary M. 
Published: March 2009

AbstractThe treatment of 2‐coumaranone with the Vilsmeier reagent affords three products: 2‐chloro‐3‐benzofurancarboxaldehyde (3), 3‐dimethylaminomethylene‐2‐(3H)benzofuranone (4), and 3‐dimethylaminomethylene‐2,3‐dihydro‐2‐oxo‐6‐benzofurancarboxaldehyde (5). Both 4 and 5 are isolated as a mixture of E and Z isomers. The reaction of 3 with the anion of N‐methylmethanesulfonamide affords the title compound 1‐methyl‐1H‐benzofuro[2,3‐c][1,2]‐thiazine 2,2‐dioxide (6). Spectral data is also discussed.
1‐Azidoisochromenes. A new route to 3,1‐benzoxazepines
Authors: Le Roux Jean‐Pierre , Desbene Paul‐Louis , Cherton Jean‐Claude 
Published: March 2009

AbstractNucleophilic attack of sodium azide on isochromylium salts leads to the preparation of 1‐azidoisochromenes which when heated lose molecular nitrogen and give 3–1‐benzoxazepines.
Synthesis of nitrooxazoles
Authors: Hammar W. James , Rustad Mark A. 
Published: March 2009

AbstractA reaction sequence involving halogenation and replacement of the halo substituent by a nitro group using dinitrogen tetraoxide has led to a general, convenient route to 5‐nitrooxazoles. Reaction schemes employing both bromine and iodine as the halo substituent have been investigated; however, the method using iodine preceded by a mercuration step affords a better overall yield in the range of 20–50%. Both 2‐ and 4‐nitro‐oxazoles can be prepared by this latter sequence, though in lower overall yields (4–12%).
The synthesis of 2‐chloromethylpyridine from 2‐picoline‐N‐oxide
Authors: Ash Mary Lynne , Pews R. Garth 
Published: March 2009

AbstractPhosphoryl chloride reacts with 2‐picoline‐N‐oxide in the presence of triethylamine to give 2‐chloromethylpyridine in 90% conversion with 98% selectivity. Diethylchlorophosphate, ethyl chloroformate, chloroacetyl chloride and phosgene also react with 2‐picoline‐N‐oxide to give 2‐chloromethylpyridine in moderate yields. Other potential chlorinating agents, titanium tetrachloride, zinc chloride, magnesium chloride and sulfuryl chloride, did not convert 2‐picoline N‐oxide into 2‐chloromethylpyridine.
Synthesis of naphthyridinone derivatives as potential antimalarials
Authors: Carroll F. Ivy , Berrang Bertold D. , Linn C. Preston 
Published: March 2009

AbstractIn this paper we present the synthesis of 8‐(4′‐amino‐1′methyl‐butylamino)‐5‐(β,β,β‐trifluoroethoxy)‐1,6‐naphthyridine (4), 8‐(4′‐amino‐1′methylbutylamino)‐6‐methyl‐1,6‐naphthyricline‐5‐one (5), two 1‐alkyl‐3‐(4′‐amino‐1′‐methylbutylamino)‐7‐methyl‐1,8‐naphthyridin‐4‐ones (20a) and 20b), 3‐(1′‐amino‐4′‐methylbutyl‐amino)‐l‐ethyl‐7‐methyl‐l,8‐naphthyridin‐4‐one (20c), and 4‐(4′‐diethylamino‐1′‐methylbutylamino)‐7‐methyl‐1,7‐naphthyridin‐8‐one (28). The compounds were evaluated for antimalarial activity in the Plasmodium berghei screen and found to be inactive.
Synthesis of pyreno[b]thiophenes
Authors: Pratap Ram , Tominaga Yoshinori , Lee Milton L. , Castle Raymond N. 
Published: March 2009

AbstractThe synthesis of all the isomers of pyreno[b]thiophene namely, pyreno[1,2‐b]thiophene, pyreno[2,1‐b]thiophene and pyreno[4,5‐b]thiophene is described. Their spectral characteristics are also discussed.
Synthesis of phenaleno[1,9‐bc]thiophene
Authors: Tominaga Yoshinori , Lee Milton L. , Castle Raymond N. 
Published: March 2009

AbstractThe cyclization of 2‐acetonylthionaphthalene, prepared from 2‐mercaptonaphthalene (1) and chloro‐acetone in the presence of sodium hydroxide, with polyphosphoric acid gave 1‐methylnaphtho[2,1‐b]thiophene (4) in 64% overall yield from 1. By bromination with N‐bromosuccinimide, 4 was converted in 40% yield into l‐bromomethylnaphtho[2,1‐b]thiophene (8). Treatment of 8 with potassium cyanide in a phase‐transfer medium gave l‐cyanomethylnaphtho[2,1‐b]thiophene (10) in good yield. Compound 10 was reduced to the corresponding aldehyde 11 and then cyclized with polyphosphoric acid to phenaleno[l,9‐bc]thiophene (12) in 24% overall yield from 10.
Some anomalous reactions of 4‐quinolone‐5‐diazonium salts
Authors: Frank Judit , Rákóczy Piroska , Radics Lajos , Gács‐Baitz Eszter 
Published: March 2009

AbstractDiazotisation of the 5‐amino function in 6,7‐alkoxy‐l‐ethyl‐l,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acids led to various products. Dediazoniation was always accompanied by fission of the 6‐alkoxy substituent; 6,7‐methylenedioxy groups gave formaldehyde which could form a m‐dioxino ring. Hydrolysis of the diazonium chlorides resulted in halo‐dediazoniation.
Some heterocyclic sulfonyl chlorides and derivatives
Authors: Cremlyn Richard J. , Swinbourne Fred J. , Yung Kin‐Man 
Published: March 2009

AbstractThe syntheses of 4‐ and 5‐chlorosulfonylfuran‐2‐carboxylic acid (Ia,IIa), 4‐chlorosulfonylfuran‐2‐carboxamide (Ib), 3,5‐dimethylpyrazole and isoxazole‐4‐sulfonyl chlorides (IIIa,IVa) and 2,4‐dimethylthiazole‐5‐sulfonyl chloride (Va) are described. The sulfonyl chlorides were converted into a range of amides, hydrazides and azides. Condensation of the sulfonohydrazides with β‐dicarbonyl compounds, gave the corresponding β‐ketohydrazones (VII), which, with the exception of the derivatives (VIIe,f,g,i), were converted to the sulfonylpyrazoles (VIII). The structures and spectral data of these compounds are briefly discussed. The reaction of the sodio derivative of acetylacetone with thiophene‐2‐sulfonyl chloride (VIc) gave 3‐(thiophene‐2‐sulfonyl)pentane‐2,4‐dione (XII), which with hydrazine gave 4‐(thiophene‐2‐sulfonyl)‐3,5‐dimethylpyrazole (XIII). However, the analogous reaction with thiophene‐2‐sulfonohydrazide (VIa) failed to give the expected 1,4‐bisthiophenesulfonylpyrazole.
Synthesis of some 3‐substituted [1,8]naphthyrido[3,2‐c][1,8]naphthyridines. A new heterocyclic ring system
Authors: Ferrarini Pier Luigi , Biagi Giuliana , Livi Oreste , Primofiore Giampaolo , Carpenè Marino 
Published: March 2009

AbstractSome 3‐substituted‐5,6‐dihydro[1,8]naphthyrido[3,2‐c][1,8]naphthyridines (V) were obtained by the condensation of 7‐substituted‐2,3‐dihydro‐1,8‐naphthyridin‐4‐(1H)ones (IV) with 2‐aminonicotinaldehyde. All of the 5,6‐dihydro derivatives V were transformed into the fully aromatic compounds VI by refluxing with nitrobenzene.
Synthesis of pyridinium heterocyclic ylides. Degradation of the pyridinium group
Authors: Esteve Marta E. , Gaozza Carlos H. 
Published: March 2009

AbstractThe synthesis of pyridinium‐quinolone chlorides and ylides, a pyridinium‐methylquinazolone ylide, 9‐pyridinium acridine chloride, and their behaviour by treatment with boiling aniline are described.
Reaction of sulfene with heterocyclic N,N‐disubstituted α‐aminomethyleneketones. VII. Synthesis of 1,2‐oxathiino‐[5,6‐g]benzothiazole derivatives
Authors: Mosti Luisa , Menozzi Giulia , Schenone Pietro 
Published: March 2009

AbstractThe polar 1,4‐cycloaddition of sulfene to N,N‐disubstituted 6‐aminomethylene‐5,6‐dihydro‐2‐phenylbenzothiazol‐7‐(4H)ones gave, generally in good yield, N,N‐disubstituted 3,4,5,6‐tetrahydro‐8‐phenyl‐1,2‐oxathiino‐[5,6‐g]benzothiazol‐4‐amine 2,2‐dioxides, which are derivatives of the new heterocyclic system 1,2‐oxathiino‐[5,6‐g]benzothiazole. This reaction did not occur only with the N,N‐diphenylenaminone.
Condensation reaction of 3,4‐dibenzoyl‐1‐methyl‐2,5‐diphenylpyrrole and ‐1‐phenylpyrazole with methylamine derivatives affording pyrrolo [3,4‐c]pyridine and 2H‐pyrazolo[3,4‐c]‐ and [4,3‐c]pyridines
Authors: Mataka Shuntaro , Takahashi Kazufumi , Tashiro Masashi 
Published: March 2009

AbstractThe reaction of 3,4‐dibenzoyl‐1‐methyl‐2,5‐diphenylpyrrole (1) and ‐1‐phenylpyrazole (2) with methylamines (3a‐c) afforded pyrrolo[3,4‐c]pyridine (4), and isomeric 2H‐pyrazolo[3,4‐c]pyridines (5a‐c) and [4,3‐c]pyridines (6a‐c), respectively.
Cyclic isothioureido compounds. II. Reaction of trans‐3a,4,5,9b‐tetrahydronaphth[1,2‐d]‐imidazoline‐2‐thiones with α‐bromoketones
Authors: Hara Takeshi , Kayama Yasutaka , Fukushima Hisashi 
Published: March 2009

AbstractThe reaction of trans‐3a,4,5,9b‐tetrahydronaphth[1,2‐d]imidazoline‐2‐thiones (8) with α‐bromoketones gave, depending upon the structure of the α‐bromoketones, reaction solvent and reaction temperature, the hydrobromides of tetrahydronaphth[1,2‐d]imidazolin‐2‐ylthiomethyl ketone (10), hexahydro‐8‐hydroxynaphth[1′,2′:4,5]imidazo[2,1‐b]thiazoles (5, 11, 19 and 20) or tetrahydronaphth[1′,2′:4,5]imidazo[2,1‐b]‐thiazoles (12 and 16). Structural determinations based on ir and nmr spectroscopies are discussed.
On the reactivity of 1‐(p‐bromophenyl)‐2‐methyl‐5‐bromopyridazine‐3,6‐dione with aliphatic amines
Authors: Baloniak Sylwester , Van Der Plas Henk C. 
Published: March 2009

AbstractReaction of 5‐bromo‐1‐(p‐bromophenyl)‐2‐methylpyridazine‐3,6‐dione with morpholine leads to formation of 1‐(p‐bromophenyl)‐2‐methyl‐5‐morpholinopyridazine‐3,6‐dione. The structure of the morpholino compound was established by the chemical methods and an X‐ray crystal structure determination.
Synthesis of a rotenone‐like benzopyranobenzopyranone
Authors: Peet Norton P. , Sunder Shyam 
Published: March 2009

AbstractThe synthesis of a novel rotenone‐like molecule, 9‐methoxy‐8‐methyl‐6,6a,12,12a‐tetrahydro[1]benzopyrano‐[3,4‐b][1]benzopyran‐12‐one (2) is described. Efficient syntheses of 3,4‐dihydro‐2H‐[1]benzopyran‐3‐one (9) from ethyl 3‐hydroxy‐2H‐[1]benzopyran‐4‐carboxylate (6), an intermediate in the synthesis of2, were developed. Thermolysis of6and9in decalin yielded 6,8‐dihydro‐14H‐bis[1]benzopyrano[3,4‐b:4′,3′‐e]pyran‐14‐one (8), which has previously been described. Also produced in the thermolysis was the isomeric 1H‐bis[1]‐benzopyrano[3,4‐b:3′,4′‐á]pyran‐7‐(9H)one (10), the first member of a novel, pentacyclic ring system.
Approaches to phenazine‐derivedN‐isosteres of anthracyclinones
Authors: Acton Edward M. , Tong George L. 
Published: March 2009

Abstract1‐Hydroxyphenazine 5,10‐dioxide showed antitumor properties against mouse leukemia P388. It also participated in biochemical mechanisms of quinoid antitumor agents, as indicated by inhibition of radiolabeled DNA‐RNA precursors in cultured leukemia L1210 cells and by stimulation of oxygen consumption in mammalian microsomes. This suggests that the isosteric di‐N‐oxide system may be a biologically active substitute for 1,4‐quinone, and that di‐N‐oxides of tetrahydrobenzo[b]phenazines can be explored as anthracyclinoneN‐isosteres. As potential synthetic intermediates, 7,8,9,10‐tetrahydro‐6,11‐dihydroxybenzo[b]‐phenazines have been prepared by 1) Diels‐Alder addition of phenazine‐1,4‐quinone and 1‐methoxy‐3‐(trimethylsilyloxy)‐1,3‐butadiene to give isolable but labile adducts and 2) condensation of 6,7‐diamino‐1,2,3,4‐tetrahydro‐2‐hydroxy‐5,8‐dimethoxy‐2‐naphthoic acid with 3‐methoxy‐1,2‐quinone. Attempts atN‐oxidation gave instead oxidation of the 6,11‐hydroquinone ring to quinone, regardless of hydroxyl protection. Despite previous literature indications, we have been unable to synthesize the 1,4‐dihydroxyphenazine 5,10‐dioxide system. We conclude that this hydroxyl substitution pattern (1,4) in an adjacent ring must be avoided in the redesign of anthracyclinone isosteres that have diN‐oxide in place of quinone.
1,3‐dipolar addition of pyridine N‐imine to acetylenes and the use of C‐13 NMR in several structural assignments
Authors: Anderson Paul L. , Hasak James P. , Kahle Alicia D. , Paolella Nicholas A. , Shapiro Michael J. 
Published: March 2009

AbstractAddition of pyridine‐N‐imine to a variety of acetylenic mono‐ (Scheme I) and di‐ (Scheme II) carboxylic ester dipolarophiles was carried out. Several of the 3‐azapyrrocoline esters obtained were further converted into acids, amides and hydrazides as shown in Schemes I and II.
Polycondensed nitrogen heterocycles. X. 5,6,7,8‐Tetrahydropyrrolo[1,2‐e][1,5]benzodiazocin‐7‐ones. A new ring system
Authors: Aiello Enrico , Dattolo Gaetano , Cirrincione Girolamo , Almerico Anna Maria , D'Asdia Isabella 
Published: March 2009

AbstractThe synthesis of a new heterocyclic ring system is described. Condensation of 1,4‐diketones 1a,b with β‐alanine gave the substituted propionic acids 2a,b which upon reduction with palladium on charcoal afforded compounds 3a,b. Title compounds 4a,b were obtained by refluxing 3a,b in toluene with p‐toluenesulphonic acid as catalyst.
Studies on quinones. VII. Synthesis of some benzo[b]thiophene‐4,7‐diones
Authors: Ruiz V. M. , Tapia R. , Valderrama J. , Vega J. C. 
Published: March 2009

AbstractThe synthesis of methyl 4,7‐dihydro‐4,7‐dioxobenzo[b]thiophene‐2‐carboxylate (20) based on the reaction of methyl mercaptoacetate with activated 1,4‐benzoquinones is described. Methyl 4,7‐dihydro‐4,7‐dioxo‐5‐hydroxybenzo[b]thiophene‐2‐carboxylate (24) and its corresponding methyl ether 26 were obtained through a Thiele‐Winter acetoxylation on 20. On the basis of the properties of methyl 4,7‐dihydro‐4,7‐dioxo‐6‐methoxy‐benzo[b]thiophene‐2‐carboxylate (21) obtained from 2,4,5‐trimethoxybenzaldehyde (32), the structures of the products 24 and 26 are proposed.
Chemistry of the phenoxathiins and isosterically related heterocycles. XVII. First synthesis of a benzoxathiinopyridazine and the determination of structure by 13C‐NMR: 1‐Methoxy‐3,4‐diazaphenoxathiin
Authors: Womack Charles H. , Martin Gary E. 
Published: March 2009

AbstractThe reaction of 5‐methoxy‐3,4‐dichloropyridazine with the disodium salt of o‐mercaptophenol leads to the formation of 1‐methoxy‐3,4‐diazaphenoxathiin as the sole product of the reaction. The structure of the isolated product was confirmed by 13C‐nmr spectroscopy, with the development of arguments to discriminate the isolated compound from 4‐methoxy‐1,2‐diazaphenoxathiin, the other product possible in this reaction. Mechanistic considerations in the formation of the isolated product are discussed.
2′,3′,4′,9′‐Tetrahydrospiro[cyclohexane‐1,1′‐(1h)pyrido[3,4‐b]indol]‐2‐ones and their transformations into 2,3,4,4a,5,6,9,14‐octahydro‐4a‐hydroxy‐1h,8h‐pyrido[3,4‐b:2,1‐i']diindole‐5‐carbonitriles and 5‐substituted 2,3,4,4a,9,14‐hexahydro‐4a‐hydroxy‐1H,8H‐indolo[2′,3′:3,4]‐pyrido[1,2‐c]benzimidazol‐6‐(5H)ones
Authors: Bobowski George 
Published: March 2009

AbstractThe condensation of 1H‐indol‐3‐ethanamine derivatives 1 with 1,2‐cyclohexanedione (2) and subsequent transformation of the resulting 2‐[[2‐(1H‐indol‐3‐yl)ethyl]imino]cyclohexanones (3) into 2′,3′,4′,9′‐tetrahydrospiro[cyclohexane‐1,1′‐(1H)pyrido[3,4‐b]indol]‐2‐ones 4 using Pictet‐Spengler reaction conditions is described. The reaction of 4 with acrylonitrile gave a mixture of pentacyclic derivatives, 2,3,4,4a,5,6,9,14‐octahydro‐4a‐hydroxy‐1H,8H‐pyrido[3,4‐b:2,1‐i']diindole‐5‐carbonitriles 12. Treatment of 4 with alkyl and aryl isocyanates (14) at room temperature gave 5‐substituted‐2,3,4,4a,9,14‐hexahydro‐4a‐hydroxy‐1H,8H‐indolo[2′,3′:3,4]pyrido[1,2‐c]benzimidazol‐6‐(5H)ones 16. Dehydration of 16 gave 5‐substituted‐2,3,9,14‐tetra‐hydro‐1H,8H‐indolo[2′,3′‐3,4]pyrido[1,2‐c]benzimidazol‐6‐(5H)ones (17). Spectral and chemical evidence is presented to confirm structures 4, 12, 16, and 17.
Synthesis and biological activity of some new 3‐and 6‐substituted coumarin amino acid derivatives. Part I
Authors: El‐Naggar A. M. , Ahmed F. S. M. , El‐Salam A. M. Abd , Radi M. A. , Latif M. S. A. 
Published: March 2009

AbstractThe synthesis of 6‐nitrocouarrain‐3‐CO‐amino acids and their corresponding methyl esters (II‐XVII) and some dipeptide methyl esters (XVIII‐XXVI) are described. 6‐(N‐Tosyl‐ or N‐phthalylaminoacyl)aminocoumarin‐3‐carboxylic acid methyl esters (XXXIV‐XL) and 3‐(N‐phthalyl‐ or N‐tosylaminoacytyaminocoumarins (XLV‐LVI) have been prepared via the carbodiimide and acid chloride methods. Hydrazinolysis of 3‐ or 6‐(N‐phthalylaminoacyl)aminocoumarin derivatives in tetraline gave the corresponding 3‐ and 6‐(aminoacyl)aminocoumarins and the carboxylic acid hydrazides (XLI‐LVIII), respectively. 3‐(N‐Tosyl‐L‐Val‐L‐Leu‐)aminocoumarin (LIX) was synthesized via the azide method. Twenty four of various substituted 3‐ and 6‐aminoacylcoumarin derivatives were found to possess specific antimicrobial activities towards different microorganisms.
Some reactions of 4H‐pyrylium salts with tributylphosphine and with tertiary amines
Authors: Reynolds G. A. , Chen C. H. 
Published: March 2009

AbstractThe phosphonium salt from tributylphosphine and 2,6‐di(4‐methoxyphenyl)pyrylium perchlorate (3) reacted with diisopropylethylamine in acetonitrile to give 2,2′,6,6′‐tetra(4‐methoxyphenyl)‐Δ4.4′‐bi‐4H‐pyran in quantitative yield. The reaction of 3 and other 4H‐pyrylium salts with tertiary amines gave 4H‐pyrans.
Reaction of ketenes with N,N‐disubstituted α‐aminomethyleneketones. XI. Synthesis of 2H‐pyrano[3,2‐g]benzothiazole derivatives
Authors: Mosti Luisa , Menozzi Giulia , Schenone Pietro 
Published: March 2009

AbstractCycloaddition of dichloroketene to N,N‐disubstituted 6‐aminomethylene‐5,6‐dihydro‐2‐phenylbenzothiazol‐7‐(4H)ones gave in good yield N,N‐disubstituted 4‐amino‐3,3‐dichloro‐3,4,5,6‐tetrahydro‐8‐phenyl‐2H‐pyrano[3,2‐g]benzothiazol‐2‐ones II, which are derivatives of the new heterocyclic system 2H‐pyrano[3,2‐g]benzothiazole.Dehydrochlorination with triethylamine of II afforded N,N‐disubstituted 4‐amino‐3‐chloro‐5,6‐dihydro‐8‐phenyl‐2H‐pyrano[3,2‐g]benzothiazol‐2‐ones III in good to moderate yield. The dimethylamino adduct was dehydrochlorinated in high yield by refluxing in toluene, whereas the diisopropylamino adduct gave in low yield 6‐(2,2‐dichloroethylidene)‐5,6‐dihydro‐2‐phenylbenzothiazol‐7‐(4H)one with the triethylamine treatment. The dehydrochlorinated product IIId (NR2 = pyrrolidino) was obtained directly in low yield by cycloaddition of dichloroketene to the corresponding enaminone. Full aromatisation of IIIa,g [NR2 = N(CH3)2 and N(CH3)C6H5, respectively] to the corresponding N,N‐disubstituted 4‐amino‐3‐chloro‐8‐phenyl‐2H‐pyrano‐[3,2‐g]benzothiazol‐2‐ones was accomplished with DDQ in refluxing benzene.
Synthesis and biological activity of 2‐substituted‐3‐ethyl‐N‐alkyl/arylindoles
Authors: Kumar Ashok , Agarwal J. C. , Nath C. , Gurtu S. , Sinha J. N. , Bhargava K. P. , Shanker K. 
Published: March 2009

AbstractSome new2‐substituted‐N‐(aminomethylaryl/aminoethylaryl)indole‐3ylglyoxylamides3a‐hand their corresponding 2‐substituted‐3‐ethyl‐N‐alkyl/aryl indoles4a‐d,f,gwere synthesized. These compounds were evaluated for their cardiovascular as well as antiparkinsonian activities.
Heterocyclic β‐Enamino esters. 28. The reaction of heterocyclic β‐Enamino esters and nitriles with cyclic amidines. A simple route to azolopyrimidines
Authors: Elnagdi Mohamed H. , Wamhoff Heinrich 
Published: March 2009

AbstractWhereas 2‐amino‐3‐ethoxycarbonyl‐4,5‐dihydrofurans Ia‐c condense with 5‐membered amidine derivatives, via elimination of ethanol to afford the azolopyrimidines IIIa,b, XI, and XIVa,b, the 2‐amino‐3‐cyano‐4,5‐dihydrofurans Id,e give with the same reagents, under elimination of ammonia, the novel ring systems of furo‐azolopyrimidines XVIII and XXa,b. 2‐Amino‐3‐ethoxycarbonyl‐5,6‐dihydro‐4H‐thiopyrane (XXI) reacts with 5‐amino‐1,2,4‐triazole (II) to yield the triazolo[1,5‐a]pyrimidine XXII, and with 2‐aminobenzimidazole to XXIII. The mechanism of these reactions is discussed. XIVb and VIIb are cyclized in a secondary step to give the novel furo[2,3‐d]benzimidazo[1,2‐a]pyrimidine XXVI, and furo[2,3‐d]‐1,2,4‐triazolo[1,5‐a]pyrimidine XXVIII respectively, besides the acetoxy derivatives XVII and XXIX.
Neue 1,5‐benzodiazepinderivate
Authors: Capuano Lilly , Gärtner Klaus 
Published: March 2009

AbstractThe 1,5‐benzodiazepines 1,6 add benzoylphenylketene (3) across the azomethine bond to produce the 1,3‐oxazino[3,2‐a]‐1,5‐benzodiazepines 4,5,7. In 6a azo coupling occurs at the exocyclic methyl group leading to the formation of 10, while diazo group transfer takes place at the cyclic methylene group to afford 11. The latter compounds react with 3 without loss of the diazo nitrogen, yielding the diazo‐oxazinobenzodiazepine 12; whereas, by interaction with phenyl isocyanate, the pyrazolo[4,3‐b]‐1,5‐benzodiazepine 14 is formed.
Synthesis and structure of heterocyclic compounds. 1‐Amino‐2,4‐Disubstituted imidazoles
Authors: Cerioni Giovanni , Cocco Maria Teresa , Congiu Cenzo , Maccioni Antonio 
Published: March 2009

AbstractA synthesis of 1‐aminoimidazoles by reaction between α‐halogenoketones and N‐acetylamidrazones is described. Structure and position of substituent groups in the synthesized aminoimidazoles were established by spectroscopical methods.
Chemistry of thienopyridines. XXVIII. Mass spectra of fourteen substituted thienopyridines and nmr spectra of four picrates
Authors: Klemm L. H. , Shabtai J. , Michaud Joan , Louris John N. 
Published: March 2009

AbstractElectron‐impact mass spectra are presented for various substituted thieno[2,3‐b]‐ and thieno[3,2‐b]‐pyridines. In particular, it is shown that chemical structures of alkylthienopyridines can be correlated (a) with their mass spectral fragmentation patterns and (b) with the proton magnetic resonance spectra of their picrate salts.
Utilization of deuterium labelling and 13C NMR spectroscopy in the investigation of the condensation of 1‐Methyl‐5‐nitroimidazole‐2‐aldehyde and 2‐Amino‐4‐methylpyrimidine
Authors: Bradamante Silvia , Colombo Silvana , Vittadini Giorgio 
Published: March 2009

AbstractThe product obtained condensing l‐methyl‐5‐nitroimidazole‐2‐aldehyde with 2‐amino‐4‐trideuteriomethyl‐pyrimidine and showing total deuterium incorporation at one of the olefinic carbons and partial deuterium incorporation para to the amino group, served to assign 13C and 1H resonances in the condensation products 3. The nature of the species undergoing condensation has been inferred from labelling experiments and from 1H and 13C nmr spectra of precursors and products in dimethylsulfoxide and trifluoroacetic acid.
Studies in the heterocyclic series. XX. 1,4‐Diazaphenoxazine and related compounds
Authors: Okafor Charles O. 
Published: March 2009

AbstractAs part of our program on the synthesis of new psychotropic agents, the parent rings of two diazaphenox‐azines are described. The reaction of 2‐aminophenol and 2,3‐dichloropyrazine in alkaline media gave good yields of 1,4‐diazaphenoxazine. Replacement of 2,3‐dichloropyrazine with 2,3‐dichloroquinoxaline gave on the other hand the heterocycle, 1,4‐diazabenzo[b]phenoxazine. Nitration and S‐oxide formation were achieved by reaction with mixed nitric and sulfuric acids. Mechanistic pathways to these compounds were also discussed.
The chemistry of polycyclic arene imines. I. Substitution at the nitrogen atom of 1a,9b‐dihydro‐1H‐phenanthro[9,10‐b]azirine
Authors: Weitzberg Moshe , Aizenshtat Zeev , Blum Jochanan 
Published: March 2009

AbstractChlorides of carboxylic, sulfonic and phosphoric acids proved to convert phenanthrene‐9,10‐imine into the corresponding rearranged acet‐ sulfon‐ and phosphonamidophenanthrene. Trimethylchlorosilane and N,O‐bis(trimethylsilyl)acetamide reacted with the imine without destruction of the aziridine ring. The silylated compound could be transferred into the respective N‐substituted phenanthrene‐9,10‐imines when treated with acetyl‐, methanesulfonyl‐, 4‐tosyl‐ and diethylphosphoryl chloride. A remarkably stable N‐chlorophenanthrene‐9,10‐imine was obtained from the unsubstituted compound and N‐chlorosuccinimide.