bluuebunny/crossref_metadata_2025_split huggingface dataset:
The synthesis of benzofuroquinolines. V. Some benzofuro[3,2‐B]quinoline derivatives
Authors: Yamaguchi Seiji , Tsuzuki Kunihiro , Sannomiya Yoshie , Oh‐Hira Yutaka , Kawase Yoshiyuki 
Published: March 2009

AbstractSome benzofuro[3,2‐b]quinoline derivatives 1a‐d and 3a were synthesized by condensation of 2‐amino‐benzaldehyde, 2‐aminoacetophenone, 2‐aminobenzophenone, isatin, or 2‐aminobenzoic acid with 3(2H)‐benzofuranone. The benzofuroquinolinone 3a was also obtained from 2‐aminobenzoic acid and phenoxy‐acetyl chloride in two steps and converted to 10‐chloro derivative 1e. Similarly, some 8‐halobenzofuro[3,2‐b]‐quinoline derivatives 1d,e and 3a (X = F, Cl, Br, I) were synthesized from 5‐haloisatin or 2‐amino‐5‐halo‐benzoic acid. And benzofuro[3,2‐b]quinolines 1a‐e thus obtained were converted to corresponding N‐oxides 2.
Aminophenyl‐X‐azolopyridines as precursors of heterocyclic azo dyes
Authors: Savarino P. , Viscardi G. , Carpignano R. , Borda A. , Barni E. 
Published: March 2009

AbstractAminophenyl‐X‐azolopyridines (X = O, S, NH) are interesting intermediates for the synthesis of disperse azo dyes and, provided the pyridine nitrogen is quaternized, of their cationic counterparts. A set of novel amines and nitro derivatives is described, and their physical properties and spectral parameters are discussed in comparison with those of analogous compounds. Some dyes in the oxazole series function as probes of the reactivity of the pentatomic ring.
Enzymatic ADP‐ribosylation of benzotriazoles and related triazoles. Difference of glycosidation site between triazoles and indazoles
Authors: Tono‐Oka Shuichi , Azuma Ichiro 
Published: March 2009

AbstractSome benzotriazoles and related triazole were ADP‐ribosylated in the presence of NAD and NAD‐nucleo‐sidase to give corresponding dinucleotides. The site of ribosylation for these dinucleotides was found exclusively to be N‐1 on the basis of their uv and 15N‐nmr spectra, contrasting with N‐2 for indazole dinucleotides. The origin of this difference in regiochemical specificity between the triazole and diazole systems is discussed.
Furan derivatives. Part 10. Synthesis of cyclohepta[cd]benzofuran
Authors: Horaguchi Takaaki , Hasegawa Eietsu , Shimizu Takahachi , Tanemura Kiyoshi , Suzuki Tsuneo 
Published: March 2009

AbstractCyclohepta[cd]benzofuran 2 was synthesized by heating (5‐oxo‐5H‐benzocyclohepten‐4‐yloxy)acetic acid 16 with sodium acetate in acetic anhydride or by photocyclization of 16 in acetonitrile. Several reactions of cyclohepta[cd]benzofuran 2 were examined. Protonation of 2 with trifluoroacetic acid occurred at the 2‐position to give a tropylium ion 17. Catalytic hydrogenation of 2 with palladium on charcoal proceeded smoothly to give tetrahydrocyclohepta[cd]benzofuran 18. The Diels‐Alder reaction of 2 with tetracyano‐ethylene produced an adduct 19. Formylation of 2 with phosphorus oxychloride and dimethylformamide occurred easily at the 2‐position to afford compound 20. Cyclohepta[cd]benzofuran 2 has both properties of heptafulvene and benzofuran.
Synthesis and reactions of halo‐, nitro‐, and arylazo‐substituted 3‐cinnamoyltropolones. Formation of styryl‐substituted heterocycle‐fused troponoid compounds
Authors: Gao Wen‐Tao , Jin Zhong‐Tian , Yin Bing‐Zhu , Imafuku Kimiaki 
Published: March 2009

Abstract3‐Cinnamoyltropolone (1) reacted with bromine to afford 7‐bromo‐ (2), 5,7‐dibromo‐3‐cinnamoyltropolone (3), and 6,8‐dibromo‐4,9‐dihydrocyclohepta[b]pyrane‐4,9‐dione (4) according to amount of the reagent. Iodination and nitration of 1 gave respectively 7‐iodo‐ (5) and 5‐nitro‐3‐cinnamoyltropolone (6). Azo‐coupling reactions gave 5‐arylazo‐3‐cinnamoyltropolones 7a‐f. Compounds 1, 2, 3 and 5 reacted with hydroxylamine to give 3‐styryl‐8H‐cyclohept[d]isoxazol‐8‐ones 10‐13, while 6 and 7a gave 5‐nitro‐3‐styryl‐8H‐cyclohept[d]‐isoxazol‐8‐one oxime (14) and 2‐cinnamoyl‐7‐methoxy‐4‐phenylazotropone (15), respectively. The reactions of 1,3, and 5 with phenylhydrazine gave 3‐styryl‐1,8‐dihydrocycloheptapyrazol‐8‐ones 16‐19.
Chemotherapeutic agents. IX. Synthesis and pesticidal activities of bis[4‐aryl/alkyl‐1, 2, 4‐triazoline‐5‐thione‐3‐yl]alkanes and 1 ‐Aryl/alkyl‐3‐[4‐(4‐aryl/alkyl‐1, 2, 4‐triazoline‐5‐thione‐3‐yl)phenyl]thiourea and related compounds
Authors: Ram Vishnu J. , Dube Vidyottama , Pieters Luc A. C. , Vlietinck Arnold J. 
Published: March 2009

AbstractVarious bis[4‐aryl/alkyl‐1, 2, 4‐triazoline‐5‐thione‐3‐yl]alkanes (3) were prepared from base cyclization of bis thiosemicarbazide 2 and transformed into sulphides by reaction with different alkyl halides in alkaline medium. These compounds were further oxidised to sulphones 5 with acidic potassium permanganate. 1‐Aryl‐3‐[4‐(4‐aryl/alkyl‐1, 2, 4‐triazoline‐3‐thione‐5‐yl)phenyl]thioureas (8) were prepared in two steps from p‐aminophenylhydrazide (6) and aryl/alkylisothiocyanates. Alkylation of 8 with different alkyl halides yielded exclusively sulphides 9. Some sulphides 12 and Mannich bases 13 from 5‐(p‐fluorophenyl)‐1, 3, 4‐oxadiazol‐2‐thione (11) were also prepared to evaluate their pesticidal activities. All the prepared compounds were screened for pesticidal activities but none of them exhibited any significant activity.
Synthesis of 1, 5‐ and 1, 7‐dichloro‐9H‐thioxanthen‐9‐ones
Authors: Okabayashi Ichizo , Murakami (Née Iwata) Noriko , Sekiya Kaoru 
Published: March 2009

Abstract1, 5‐Dichloro‐9H‐thioxanthen‐9‐one (2) was prepared by cyclization of 2‐chloro‐6‐[(2‐chlorophenyl)thio]‐benzoic acid (10) obtained from 2‐chloro‐6‐iodobenzoic acid (9) and 2‐chlorobenzenethiol. Similarly, 1, 7‐di‐chloro‐9H‐thioxanthen‐9‐one (6) was prepared from 9 via 2‐chloro‐6‐[(4‐chlorophenyl)thio]benzoic acid (11). Compound 6 was also obtained by condensation of 2‐chloro‐6‐mercaptobenzoic acid (12) with chlorobenzene in the presence of sulfuric acid.
Synthèse et étude structurale d'alcoxy‐8 et hydroxy‐8 [1, 2, 4]triazolo[4, 3‐c] et [1, 5‐c]pyrimidines
Authors: Sliwa H. , Blondeau D. , Rousseaux O. 
Published: March 2009

AbstractLes alcoxy‐8 [1, 2, 4]triazolo[4, 3‐c] et [1, 5‐c]pyrimidines ont été obtenues par condensation d'une alcoxy‐5 hy‐drazino‐4 pyrimidine avec l'orthoformiate d'éthyle. L'utilisation d'orthoacétate d'éthyle conduit aux dérivés correspondants méthylés au niveau du cycle triazole. Les nouveaux phénols hétérocycliques hydroxy‐8 [1, 2, 4]triazolo[4, 3‐c] et [1, 5‐c]pyrimidines ont été préparés par hydrogénolyse des éthers benzyliques correspondants.
Synthesis of substituted tetrahydropyrimido‐[4, 5‐b][1, 7]naphthyridines as potential antitumor agents
Authors: Gangjee Aleem , Donkor Isaac O. 
Published: March 2009

AbstractThe synthesis of two linear trisubstituted 6, 7, 8, 9‐tetrahydropyrimido[4, 5‐b][1, 7]naphthyridines 1 and 3 were accomplished by the regiospecific cyclocondensation of two disubstituted 6‐aminopyrimidines 10 and 11 with the ketoaldehyde 1‐benzyl‐4‐hydroxymethylene‐3‐piperidone. Catalytic debenzylation of 1 afforded the disubstituted compound 2. The linear structures of 1–3 were established by 1H nmr and 13C nmr.
Selenium heterocycles. XXXIX. Synthesis of thieno[3, 4‐d]thiazole, thieno[3, 4‐d]selenazole, selenolo[3, 4‐d]thiazole and selenolo[3, 4‐d]selenazole
Authors: Shafiee A. , Shafaati A. , Habibi‐Khameneh B. 
Published: March 2009

AbstractStarting from readily available methyl 2‐substituted4‐methyl‐5‐thiazolyl ketone and methyl 4‐methyl‐2‐phenyl‐5‐selenazolyl ketone, thieno[3, 4‐d]thiazole, thieno[3, 4‐d]selenazole, selenolo[3, 4‐d]thiazole and selenolo[3, 4‐d]selenazole were prepared. The structures of all compounds were confirmed by analytical and spectroscopic methods.
Research on nitrogen containing heterocyclic compounds. XVI. Synthesis of 1, 3, 4, 14b‐tetrahydro‐2, 10‐dimethyl‐2H,10H‐pyrazino[2, 1‐d]pyrrolo[1, 2‐b][1, 2, 5]benzotriazepine (1:1) maleate (10‐methyl‐10‐azaaptazepine)
Authors: Stefancich Giorgio , Silvestri Romano 
Published: March 2009

AbstractA synthesis of the potential antidepressant 1, 3, 4, 14b‐tetrahydro‐2, 10‐ditnethyl‐2H,10H‐pyrazino[2, 1‐d]‐pyrrolo[1, 2‐b][1, 2, 5]benzotriazepine 4, structurally related to aptazepine, is reported in four steps. The key steps of the synthesis were the formation of the tricyclic compound ethyl 10, 11‐dihydro‐5‐methyl‐5H‐pyrrolo[1, 2‐6‐b][1, 2, 5]benzotriazepine‐11‐carboxylate 6 via a Pictet‐Spengler type condensation and the formation of the diketopiperazine 8 by cyclization of the chloroester 7 with methylamine.
Substitutions by nucleophilic free radicals: A new general reaction of heteroaromatic bases
Authors: Minisci Francesco , Fontana Francesca , Vismara Elena 
Published: March 2009

AbstractThe substitution of protonated heteroaromatic bases by nucleophilic carbon‐centered radicals has been developed as one of the most general reactions in the heterocyclic series; its great interest results from the fact that it reproduces most of the numerous aspects of the Friedel‐Crafts aromatic substitution, but with opposite reactivity and selectivity. The most recent developments, concerning the generation of free radicals by iodine and hydrogen abstraction and decarboxylation of carboxylic acids are particularly discussed. Some processes of high synthetic value were designed on the basis of the kinetic and thermodynamic features of all the elementary steps involved in complex but selective chain processes. New general procedures for the monosubstitution in the homolytic alkylation and acylation are reported and discussed.
A facile synthesis of methyl 2‐substituted‐4‐benzoxazolecarboxylates
Authors: Goldstein Steven W. , Dambek Paul J. 
Published: March 2009

AbstractMethyl 2‐substituted‐4‐benzoxazolecarboxylates were synthesized from methyl 2‐amino‐3‐hydroxybenzoate and the corresponding acid chloride or ortho acetal with pyridinium p‐toluenesulfonate as an acid catalyst. Decomposition due to hydration at the 2‐position was seen for some compounds during purification.
Reaction of N‐(4‐Pyridylrnethyl)benzamide N‐oxides and N‐[(α‐acetoxy)‐4‐pyridylmethyl]benzamides with 1,3‐diphenyl‐1,3‐propanedione
Authors: Braña Miguel F. , López Rodríguez María L. , Castellano José M. , Fernández Purificación , Garrido‐Pertierra Amando 
Published: March 2009

AbstractReaction of N‐(4‐pyridylmethyl)benzamide N‐oxides 2 with 1,3‐diphenyl‐1,3‐propanedione in the presence of acetic anhydride afforded 1,1‐dibenzoyl‐2‐(4‐pyridyl)‐2‐(benzoylamino)ethanes 4 in low yield. Treatment of N‐[(α‐acetoxy)4‐pyridylmethyl]benzamides 3 with 1,3‐diphenyl‐1,3‐propanedione in the presence of triethylamine and chloroform as a solvent provided 4 in high yield. Reaction of 4 with nucleophiles as hydrazine, methyl and phenylhydrazine gave the corresponding pyrazoles 5.
The reaction of 2‐ethoxycarbonyl‐3‐isothiocyanatopyridine with α‐amino acids. The synthesis of 3‐substituted 2‐thiooxo‐2,3‐dihydropyrido[3,2‐d]pyrimidin‐4(3H)‐ones
Authors: Urleb UroŠ , Stanovnik Branko , Tišler Miha 
Published: March 2009

Abstract2‐Ethoxycarbonyl‐3‐isothiocyanatopyridine (1) reacts with α‐amino acids 2–11 and β‐alanine (12) to give pyrido[3,2‐d]pyrimidine derivatives 13–23 with the nitrogen of the amino acid component being incorporated into the fused pyrimidine ring at position 3. Methylation of 14 and 15 with DMFDMA produces S‐methylated products 24 and 25, while in the reaction of 14 with hydrazine the corresponding hydrazide 26 is formed. The reactions proceed under mild conditions, so that no racemization of chiral substituents was observed.
A convenient synthesis of 5‐acyl‐6‐substituted 3‐cyano‐2(1H)‐pyridinones
Authors: Jones Winton D. , Schnettler Richard A. , Huber Edward W. 
Published: March 2009

Abstract2‐Dimethylaminomethylidene‐1,3‐diketones are useful synthons for the construction of 5‐acyl‐6‐substituted‐3‐cyano‐2(1H)‐pyridinones. The reaction of these 1,3‐diketones and the anion of cyanoacetamide gave the title compounds. When the 1,3 diketone contained different alkyl or aryl groups, mixtures of regioisomers were formed. To circumvent this problem, dimethylaminomethylidene hydrazones, regioselectively prepared from dimethylhydrazino enones and dimethylformamide dimethyl acetal were reacted with cyanoacetamide anion followed by acid hydrolysis to give the title compounds.
Reactions of 3‐isopropenyltropolones with bromine and N‐bromosuccinimide: Formation of 8H‐cyclohepta[b]furan‐8‐one derivatives
Authors: Jin Ren‐Hao , Yin Bing‐Zhu , Jin Zhong‐Tian , Imafuku Kimiaki 
Published: March 2009

Abstract3‐Isopropenyltropolones 1a‐c were treated with bromine in carbon tetrachloride to give 3‐methyl‐8H‐cyclohepta[b]furan‐8‐ones 2a‐c and their corresponding 7‐bromo‐substituted compounds 3a‐c, while reactions in acetic acid gave the bromo‐substituted compounds 3a‐c. On the other hand, bromination of 1a‐c with N‐bromosuccinimide afforded 7‐bromo‐3‐(2‐bromo‐1‐methylethenyl)tropolones 5a‐c. The compound 2a was treated with bromine to give 2‐bromo‐3‐methyl‐8H‐cyclohepta[b]furan‐8‐one (4). The tropolones 5a‐c were heated in the presence of potassium carbonate to give the cyclized compounds 3a‐c.
Novel bicyclo[2.2.2]lactones from a facile condensation of dibenzoylethylene with arylacetonitriles
Authors: Atfah M. Adrian , Al‐Arab Mohammad M. 
Published: March 2009

AbstractSeveral novel bicyclo[2.2.2]lactones were synthesized from a facile one‐pot reaction by the condensation of dibenzoylethylene and an arylacetonitrile in basic medium. The reaction proved to be convenient and gives high yield. The structure of the reaction products was established on the basis of their proton and carbon‐13 nuclear magnetic resonance, and infrared spectral data as well as their elemental analysis.
Lithiation of 1‐benzylimidazole. A hypothesis on the regioselectivity of the electrophilic attacks on the lithiated species
Authors: Moreno‐Mañas M. , Bassa J. , Lladó N. , Pleixats R. 
Published: March 2009

AbstractSequential lithiations of 1‐benzylimidazole, 1, and of 1‐benzyl‐1,2,4‐triazole, 2, followed by treatment with electrophiles others than alkyl halides result in reactions at C‐2. However, benzyl halides and, to a certain extent, iodomethane react at the N‐benzyl carbon atom. An explanatory hypothesis based on steric ortho effects is advanced.
Synthesis of 1‐acyl‐5‐pyrazolones and pyrrolidino[2,3‐c]pyrazol‐3‐ones
Authors: Cocco Maria Teresa , Congiu Cenzo , Maccioni Antonio 
Published: March 2009

AbstractThe reactivity of acetamidrazones I in strong basicity conditions was examined. When compounds I are reacted with equivalent quantities of α‐haloketones in sodium alcoholate, the pyrrolidino[2,3‐c]pyrazol‐3‐ones IV were obtained by intermediate formation of 1‐acyl‐3‐amino‐5‐pyrazolones III.
Pyrimidines. 65. Synthesis of 6‐substituted thieno[2,3‐d]pyrimidine‐2,4(1H,3H)‐diones
Authors: Hirota Kosaku , Shirahashi Mitsuomi , Senda Shigeo , Yogo Motoi 
Published: March 2009

AbstractSeveral 6‐substituted thieno[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione derivatives were synthesized. 6‐Ethoxycarbonyl derivatives 3 and 7 were prepared by treatment of 6‐chloro‐5‐formyluracil 1 and 6‐chloro‐5‐cyanouracil 6 with ethyl 2‐mercaptoacetate in the presence of a base. Electrophilic substitution reactions (Vilsmeier‐Haack reaction, bromination, and nitration) of 5,6‐unsubstituted thieno[2,3‐d]pyrimidine 9, prepared by condensation of 6‐mercaptouracil 8 with chloroacetaldehyde, afforded the corresponding 6‐formyl‐, 6‐bromo‐, and 6‐nitrothieno[2,3‐d]pyrimidines 10, 15 and 16, respectively.
Syntheses of 6‐Amino‐1‐(β‐D‐ribofuranosyl)‐1H‐pyrazolo[3,4‐d]‐1,3‐oxazin‐4‐one, an isostere of oxanosine, and the guanosine analog 6‐amino‐1‐(β‐d‐ribofuranosyl)‐1H‐pyrazolo[3,4‐d]pyrimidin‐4(5H)‐one via ring closure of pyrazole‐5‐thioureido intermediates
Authors: Bhattacharya Birendra K. , Robins Roland K. , Revankar Ganapathi R. 
Published: March 2009

Abstract6‐Amino‐1‐(β‐D‐ribofuranosyl)‐1H‐pyrazolo[3,4‐d]‐1,3‐oxazin‐4‐one (4), an isostere of the nucleoside antibiotic oxanosine has been synthesized from ethyl 5‐amino‐1‐(2,3‐O‐isopropylidene‐β‐D‐ribofuranosyl)pyrazole‐4‐carboxylate (6). Treatment of 6 with ethoxycarbonyl isothiocyanate in acetone gave the 5‐thioureido derivative 7, which on methylation with methyl iodide afforded ethyl 1‐(2,3‐O‐isopropylidene‐β‐D‐ribofuranosyl)‐5‐[(N'‐ethoxycarbonyl‐S‐methylisothiocarbamoyl)amino]pyrazole‐4‐carboxylate (8). Ring closure of 8 under alkaline media furnished 6‐amino‐1‐(2,3‐O‐isopropylidene‐β‐D‐ribofuranosyl)‐1H‐pyrazolo[3,4‐d]‐1,3‐oxazin‐4‐one (10), which on deisopropylidenation afforded 4 in good yield. 6‐Amino‐1‐(β‐D‐ribofuranosyl)‐1H‐pyrazolo[3,4‐d]pyrimidin‐4(5H)‐one (5) has also been synthesized from the AICA riboside congener 5‐amino‐1‐(2,3‐O‐isopropylidene‐β‐D‐ribofuranosyl)pyrazole‐4‐carboxamide (12). Treatment of 12 with benzoyl isothiocyanate, and subsequent methylation of the reaction product with methyl iodide gave 1‐(2,3‐O‐isopropylidene‐β‐D‐ribofuranosyl)‐5‐[(N'‐benzoyl‐S‐methylisothiocarbamoyl)amino]pyrazole‐4‐carboxamide (15). Base mediated cyclization of 15 gave 6‐amino‐1‐(2,3‐O‐isopropylidene‐β‐D‐ribofuranosyl)‐1H‐pyrazolo[3,4‐d]pyrimidin‐4(5H)‐one (14). Deisopropylidenation of 14 with aqueous trifluoroacetic acid afforded 5 in good yield. Compound 4 was devoid of any significant antiviral or antitumor activity in culture.
Regioselective synthesis of trifluoromethylated pyrazoles by selective protection of trifluoromethyl‐β‐diketones
Authors: Lyga John W. , Patera Russell M. 
Published: March 2009

Abstract1,1,1‐Trifluoropentane‐2,4‐dione was selectively protected by treatment with pyrrolidine to give 6. The reaction of 6 with arylhydrazines gave 5 exclusively. The structural assignment for 5 was confirmed by quenching the dianion of 8 with ethyl trifluoroacetate.
Furan derivatives. part 11 [1]. on substituent effects in the synthesis of 3,4,5,6‐tetrahydrocyclohepta[cd]benzofurans
Authors: Horaguchi Takaaki , Kobayashi Hiroto , Miyazawa Kazuhiro , Hasegawa Eietsu , Shimizu Takahachi , Suzuki Tsuneo , Tanemura Kiyoshi 
Published: March 2009

AbstractTetrahydrocyclohepta[cd]benzofurans 7a‐e were synthesized by the treatment of (5‐oxo‐tetrahydro‐5H‐benzocyclohepten‐4‐yloxy)acetic acids 5a‐e with sodium acetate in acetic anhydride or by heating of their esters 6a‐e with sodium hydroxide or sodium hydride in dioxane. The yield of furans 7 decreased as a substituent R of acids 5 or esters 6 was changed from hydrogen to a methyl, ethyl, or isopropyl group. When R was a phenyl group furan 7e was always prepared in good yield. Sodium hydride was a useful base for synthesis of tetrahydrocyclohepta[cd]benzofurans.
Synthesis of novel pyrido[3,4‐f]pyrrolo[1,2‐b][1,2,5]triazepines. A Novel heterocyclic ring system
Authors: Effland Richard C. , Davis Larry , Kapples Kevin J. , Olsen Gordon E. 
Published: March 2009

AbstractThe synthesis of novel pyrido[3,4‐f]pyrrolo[1,2‐b][1,2,5]triazepines 6–17 is described. Subsequent reactions on the parent system include reduction, Grignard addition, alkylation, acylation and carbamoylation.
Synthesis of some N‐[pyridyl(phenyl)carbonylamino]‐alkyl‐1,2,3,6‐tetrahydropyridines
Authors: Redda Kinfe K. , Melles Hailemichael , Rao Kode Nageswara 
Published: March 2009

AbstractAlkyl substituted 2,4‐dinitrophenylpyridinium chlorides 3 are formed by the nucleophilic substitution of 1‐chloro‐2,4‐dinitrobenzene with alkyl pyridines. Reaction of pyridyl acid hydrazides or benzoyl hydrazides 4 with the pyridinium chlorides 3 furnish the isolable 2,4‐dinitroanilino derivatives 5 which undergo hydrolysis when refluxed in water:p‐dioxane mixture (1:4 v/v) to yield the pyridinium ylides 6. Sodium borohydride reduction of 6 in absolute ethanol at 0° for 4 hours result the formation of the title compounds 7 in moderate to excellent yields.
Synthesis of pyridines by heterocyclization of new dienamino esters
Authors: Cocco Maria Teresa , Congiu Cenzo , Maccioni Antonio 
Published: March 2009

AbstractThe synthesis of pyridine derivatives is reported starting from the new dienamino esters 2. Thermal cyclization of 2 afforded the ethyl 2‐amino‐3‐pyridinecarboxylate derivatives 3; from the reaction of 2 in sodium ethoxide the 2‐aminopyridines 3 and 4, and the 1,2‐dihydro‐2‐oxopyridines 5 and 6 were obtained.
A novel synthesis of the isoxazolo[5,4,3‐kl]acridine ring system
Authors: Shutske Gregory M. 
Published: March 2009

AbstractThe Schmidt reaction of 6,7‐dihydro‐3‐phenyl‐1,2‐benzisoxazol‐4(5H)‐one (1) is described. In addition to the expected isomeric lactams, 3‐phenyl‐5,6,7,8‐tetrahydro‐4H‐isoxazolo[4,5‐c]azepin‐4‐one (3) and 7,8‐dihydro‐3‐phenyl‐4H‐isoxazolo[4,5‐b]azepin‐5(6H)‐one (4), 4‐amino‐3‐phenyl 1,2‐benzisoxazole (5) was isolated, along with 4,5‐dihydro‐3H‐isoxazolo[5,4,3‐kl]acridine (6). Possible mechanisms for the formation of these products are discussed and some chemistry of the little‐known ring system represented by 6 is also described.
Preparation and reactivity of polyfunctional phenazine derivatives
Authors: Lehn Jean‐Marie , Schmidt Frédéric , Vigneron Jean‐Pierre 
Published: March 2009

AbstractTreatment of 2,3,6,7‐tetramethylphenazine with N‐bromosuccinimide under light irradiation afforded in good yield the tetrakis(bromomethyl) derivative. Weakly basic nucleophilic reagents such as thiols, phenols, amines and the azide anion allow the preparation of a variety of functionalized derivatives. Some 2,7‐disubstituted phenazines have also been obtained.
Selective lateral metalation and electrophilic quenching of c‐4 functionalized isoxazoles. IX. Direct formation of the C‐N bond utilizing an electrophilic nitrogen source
Authors: Mirzaei Yousef R. , Balasubramaniam T. N. , Lefler Barbara J. , Natale N. R. 
Published: March 2009

AbstractC‐5 Lithio‐alkylisoxazoles were quenched with dialkyl azodicarboxylates to form the C‐5 alkylhydrazine derivatives in synthetically useful yields.
A new heterocyclic structure. The Benzopyrano[6,5,4‐def] Benzopyran. (1,6‐dioxapyrene)
Authors: Buisson Jean‐Pierre , Demerseman Pierre 
Published: March 2009

Abstract1,6‐Dioxapyrene, the first unsubstituted dioxa‐analogue of pyrene was synthesized in good yield from 2‐carbomethoxy‐6‐methoxynaphtho[1,8‐bc]pyran in a four‐step reaction involving a peri‐heterocyclisation. Its 1H nmr spectral characteristics were compared with those of native pyrene.
Synthesis of 3‐cyano‐2‐methylpyridines substituted with heteroaromatics
Authors: Shibata Katsuyoshi , Katsuyama Isamu , Matsui Masaki , Muramatsu Hiroshiga 
Published: March 2009

AbstractA series of title compounds were easily prepared by the sonication of α,β‐unsaturated carbonyl compound in acetonitrile in the presence of potassium t‐butoxide.
Electron ionization mass spectra of some 4β‐phenyl‐substituted cycloalkane‐cis‐fused 1,3‐oxazin‐2(3H)‐ones, ‐2(3H)‐thiones and 1,4‐oxazepin‐3(4H)‐ones
Authors: Vainiotalo Pirjo , Ronkanen Sari , Stájer Géza , Bernáth Gábor , Pihlaja Kalevi 
Published: March 2009

AbstractThe 70 eV mass spectra of 4β‐phenyl‐substituted cyclopentane‐ and cyclohexane cis‐fused 1,3‐oxazin‐2(3H)‐ones, the two related 2‐thiones, 6,7‐cis‐trimethylene‐5β‐phenyl‐1,4‐oxazepin‐3(4H)‐one and its 2β‐methyl derivative were recorded and their fragmentations examined by means of metastable ion analysis, collision induced dissociation technique and exact mass measurement. The fragmentation patterns of the 1,3‐oxazin‐2(3H)‐ones were relatively simple: the favored formation of cycloalkene ions implied that a considerable proportion of the molecular ions might possess an enol structure. Changes in the size of the fused cycloalkane ring had little or no effect on the fragmentations. Instead, small changes in the heterocyclic part of the molecule caused remarkable effects on the fragmentation behavior. Compared to 1,3‐oxazin‐2(3H)‐ones studied, both 1,3‐oxazine‐2(3H)‐thiones and 1,4‐oxazepin‐3(4H)‐ones showed much more complicated fragmentation patterns.