bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of 1,3,4‐oxadiazol‐2‐ones with aliphatic groups at N‐3
Authors: Huang Jamin , Bushey Dean F. , Graves Michael D. , Johnson Brenda F. , Singleton Dianne D. 
Published: April 2009

AbstractA series of 3‐substituted‐5‐methoxy‐1,3,4‐oxadiazol‐2‐ones were prepared from aldehydes, ketones, phenylacetic acids, and 1,2‐ and 1,3‐diketones. Conditions for the formation of these oxadiazolones from the precursor N‐carbamoyl chlorides depended on the structure, and varied from spontaneous ring closure to those requiring bases. Variation in the N‐3 substituents sometimes produced mixtures of isomers which were separated and identified. These molecules were prepared in order to study the effect of the N‐3 substituent variation on the biological properties of oxadiazolones.
Some novel heterocyclic systems derived from 7‐amino‐2,3‐dihydro‐8‐nitro‐1H‐pyrrolo[1,2‐α]benzimidazole and the corresponding diamine
Authors: Groves Clive L. , Ralph James T. , Temple Arthur F. 
Published: April 2009

AbstractThe preparation of 7‐amino‐2,3‐dihydro‐8‐nitro‐1H‐pyrrolo[1,2‐a]benzimidazole from 1,4‐diacetamido‐2,3‐dinitrobenzene is described. Reaction of this compound with 2,5‐dimethoxytetrahydrofuran produces 2,3‐dihydro‐8‐nitro‐7‐N‐pyrrolo‐1H‐pyrrolo[1,2‐a]benzimidazole, which can be cyclised to produce two new heterocyclic ring systems, 9,10‐dihydro‐8H‐pyrrolo[1,2‐a]pyrrolo(1′,2′:1,2]imidazo[5,4‐f]quinoxaline and 9,10‐dihydro‐8H‐pyrrolo[2,1‐c]pyrrolo[1′,2′:1,2]imidazo[4,5‐h][1,2,4]benzotriazine. The corresponding diamine, 7,8‐diamino‐2,3‐dihydro‐1H‐pyrrolo[1,2‐a]benzimidazole undergoes a variety of condensation reactions to produce several new heterocyclic systems, for example, with formic acid, 1,7,8,9‐tetrahydroimidazo‐[4,5‐e]pyrrolo[2,1‐6]benzimidazole is formed and with diacetyl, 9,10‐dihydro‐2,3‐dimethyl‐8H‐pyrrolo‐[1′,2′:1,2]imidazo[5,4‐y]quinoxaline is obtained.
Correlation of dihedral angles with 13C chemical shifts of quaternary carbon atoms of some phenothiazine derivatives
Authors: Jovanovic Misa V. , Biehl Edward R. 
Published: April 2009

AbstractA direct relationship between the 13C nmr chemical shifts of the quaternary carbon atoms of the central ring of phenothiazine and the dihedral angle of the respective derivatives has been observed. This correlation allows for the useful and quick estimation of the dihedral angles of novel phenothiazines from readily obtainable 13C nmr solution measurements. In addition, the change in the dihedral angle appears to be directly related to the S‐C4a‐C10a bond angle; however, the C4a‐S‐C5a bond angle is not affected by changes in the dihedral angle. This indicates that the “flattening” of the phenothiazine tricyclic ring system is compensated for by the vertical displacement of the sulfur atom, by changes in hybridization of N10, and by other angular distortions of the middle ring.
The synthesis of a pyrido[2,3‐c]pyridazine: A cinnoline related to 6‐fluoronalidixic acid
Authors: Sanchez Joseph P. , Trehan Ashok K. , Nichols Jeffry B. 
Published: April 2009

AbstractAn analog of the pyrido[2,3‐c]pyridazine ring system, 1‐ethyl‐6‐fluoro‐1,4‐dihydro‐7‐methyl‐4‐oxopyrido‐[2,3‐c]pyridazine‐3‐carboxylic acid (13), related to both Cinoxacin (1) and nalidixic acid (2), has been synthesized. The reductive ring closure of 2‐chloro‐α‐diazo‐6‐methyl‐5‐nitro‐β‐oxo‐3‐pyridinepropanoic acid, ethyl ester (7), proved to be the key reaction providing entry into the ring system.
Access to the 2,3‐dihydropyridazin‐3‐one and as‐triazino[3,4‐a]phthalazine ring systems from 4‐aryl‐2‐oxo‐butanoic acids
Authors: El‐Ashry El‐Sayed H. , Amer Adel , Labib George H. , Abdel Rahman Mohamed M. , El‐Massry Abdel Monem 
Published: April 2009

AbstractA novel series of 2,3‐dihydropyridazin‐3‐ones 15 were synthesized via condensation between hydrazines and 4‐(p‐chlorophenyl)‐2‐hydroxy‐2‐(2‐oxo‐2‐substituted ethyl)butanoic acids 8 which in turn were prepared by the reaction of substituted benzylpyruvic acids 6 with methyl alkyl(aryl) ketones 7. Dehydration of 8b‐d by a mixture of glacial acetic acid and hydrochloric acid afforded 4‐(p‐chorophenyl)‐2‐(substituted phenacyl)‐2‐butenoic acids 10. Condensation reaction of 10 with hydrazines gave type 15 compounds in good yields. Also, a new series of as‐triazino[3,4‐a]phthalazines 20 was obtained from the reaction of substituted benzylpyruvic acids 6 with hydralazine to give the hydralazones 19 which underwent dehydrative cyclization reaction with PPA to afford 20. Structure assignments are based on 1H, 13C nmr and ir spectra.
Synthesis of 4H‐3,3a‐dihydrothiazolo[4,3‐b]quinazolines
Authors: Adegoke Emmanuel A. , Alo Babajide I. , Familoni Oluwole B. 
Published: April 2009

AbstractRegiospecific synthesis of 4H‐3,3a‐dihydrothiazolo[4,3‐b]quinazolines and 7‐methyl‐4H‐3,3a‐dihydrothiazolo[4,3‐b]quinazolines IVa and IVb is described. The N‐substituted thiazolidinecarboxylic acids Ia and Ib were converted to the corresponding acid chlorides, IIa and IIb but neither reacted with silver trifluoromethanesulphonate. The carboxylic acids Ic and Id were however, decarboxylated to the corresponding iminium ions using phosphorus oxychloride and these afforded the nitroamines IIIa and IIIb. Reductive cyclisation led to the quinazolines IVa and IVb.
Crystal structures of 2,4‐dimethylthioxanthene 10,10‐dioxide, 2,4,9‐trimethylthioxanthene 10,10‐dioxide, and 2,4‐dimethyl‐9‐isopropylthioxanthene 10,10‐dioxide
Authors: Chu Shirley S. C. , Napoleone Vera , Chu Ting L. 
Published: April 2009

AbstractThe structures of 2,4‐dimethylthioxanthene 10,10‐dioxide, 1, 2,4,9‐trimethylthioxanthene 10,10‐dioxide, 2, and 2,4‐dimethyl‐9‐isopropylthioxanthene 10,10‐dioxide, 3, have been determined by x‐ray diffraction. The central ring of the thioxanthene ring system is in a boat conformation. The 9‐methyl substituent in 2 and the 9‐isopropyl substituent in 3 are both in the boat‐axial conformation with respect to the central ring. The folding angles between the planes of the two benzo rings are 136.6°, 142.9°, and 134.3° for 1, 2, and 3, respectively.
Synthesis and reactions of 4‐isopropylidene‐1‐aryl‐3‐methyl‐2‐pyrazolin‐5‐ones
Authors: Deruiter Jack , Carter Deborah Ann , Arledge Wilmer Scott , Sullivan Patrick J. 
Published: April 2009

AbstractThe reactions of 4‐isopropylidene‐1‐aryl‐3‐methyl‐2‐pyrazolin‐5‐ones 4a‐d were investigated under a variety of conditions. In the presence of thiols or piperidine, 4a‐d failed to yield conjugate addition products, presumably due to the steric bulk provided by the two methyl substituents of the isopropylidene side chain. Reaction of 4a‐d with hydrazine derivatives gave the 1‐aryl‐3‐methyl‐2‐pyrazolin‐5‐ones 3a‐d and isopropyl‐hydrazones. Treatment of 4a with potassium cyanide yielded a stable conjugate addition product which exists as a mixture of tautomers in different solvents. Also, oxidation of 4a with hydrogen peroxide gave a spiroepoxide 22, while m‐chloroperbenzoic acid oxidation afforded both the spiroepoxide 22, and a small quantity of a hydroxyspiroepoxide 23.
Research on heterocyclic compounds. XXI. Synthesis of imidazo[2,1‐b]benzothiazole and imidazo[2,1‐b]thiazole derivatives
Authors: Abignente Enrico , De Caprariis Paolo , De Martino Giovanni , Patscot Rosaria 
Published: April 2009

AbstractThe reaction of some 2‐aminobenzothiazoles and 2‐aminothiazoles with ethyl 3‐bromo‐4‐oxopentanoate was investigated with the aim to obtain the corresponding imidazo[2,1‐b]benzothiazole and imidazo[2,1‐b]‐thiazole derivatives, respectively. In some cases, two unexpected side products were obtained together with the required compound and their structures were elucidated: e.g., 2‐aminobenzothiazole reacted with ethyl 3‐bromo‐4‐oxopentanoate to give ethyl 2‐methylimidazo[2,1‐b]benzothiazole‐3‐acetate together with ethyl imi‐dazo[2,1‐b]benzothiazole‐2‐propionate and ethyl 3‐(benzothiazol‐2‐yl)amino‐4‐oxopentanoate.
Reaktivitäut und reaktionswege von methylsubstituierten bisindolylcarbenium‐ionen
Authors: Pindur Ulf , Müller Johann 
Published: April 2009

AbstractMethyl substituted bisindolylcarbenium ions 1 react with some O‐ and C‐nucleophiles regioselectively. The cations 1b, 1c yield with hydroxide ions the tetraindolyldimethyl ether 4 and with methoxide ions the bisin‐dolylmethoxymethanes 5. Compounds 1a, 1b, 1c react with several methylindoles to isomeric bis‐ and trisin‐dolylmethanes. An electrophilic reactivity order of cations 1 can be derived supporting on the experimental results.
Synthesis and spectral properties of someN‐(2‐benzimidazoyl)‐α‐aminoesters and theirN‐oxides
Authors: Sabri Salim S. , El‐Abadelah Mustafa M. , Yasin Hani A. 
Published: April 2009

AbstractA series of newN‐(2‐benzimidazol)(S)‐α‐aminoesters and the respectiveN‐oxides have been prepared, and their spectral data discussed. The CD spectra of thealiphaticandaromaticamino ester derivatives of either series show sign reversal for the observed Cotton effect (CE) band. This chiroptical behaviour was rationalized as due to differences in conformational isomerism.
Reactions of 2‐aminobenzenethiols with 4‐hydroxycoumarin, maleic anhydride and p‐chlorobenzoylacetone: A single step synthesis of heterocycles containing the 1,4‐thiazine nucleus
Authors: Gupta R. R. , Gautam R. K. , Kumar Rakesh 
Published: April 2009

AbstractA single step and convenient synthesis of some heterocycles containing the 1,4‐thiazine nucleus are reported by the condensation and cyclization of substituted 2‐aminobenzenethiols with 4‐hydroxycoumarin, maleic anhydride and p‐chlorobenzoylacetone.
A new synthetic route to 7‐halo‐1‐cyclopropyl‐6‐fluoro‐1,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acid, an intermediate for the synthesis of quinolone antibacterial agents
Authors: Egawa Hiroshi , Kataoka Masahiro , Shibamori Koh‐Ichiro , Miyamoto Teruyuki , Nakano Junji , Matsumoto Jun‐Ichi 
Published: April 2009

AbstractStarting from m‐fluorotoluene, 7‐chloro‐6‐fluoro‐ and 6,7‐difluoro‐1‐cyclopropyl‐1,4‐dihydro‐4‐oxoquino‐line‐3‐carboxylic acids, 3 and 16 were synthesized. Compounds 3 and 16 are useful intermediates for the synthesis of a class of quinolone antibacterial agents. The synthetic route involves two processes; i) construction of the quinoline ring by an intramolecular cyclization accompanied by the elimination of a nitro group and ii) introduction of fluorine atom by replacement of a nitro group with potassium fluoride. 7‐(3‐Amino‐1‐pyrroli‐dinyl)‐1‐cyclopropyl‐6‐fluoro‐1,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acid (18) was prepared from 3 or 16. The antibacterial activity of 18 compares favorably with that of ciprofloxacin (2).
3,6‐Dialkyl‐2‐hydroxypyrazine 1‐oxides as acyl carriers
Authors: Okuwaki Yukari , Inagawa Yukiko , Tamamura Hideo , Suzuki Taeko , Kuwana Hiroko , Tahara Mika , Yuasa Kayo , Ohta Akihiro 
Published: April 2009

Abstract3,6‐Dialkyl‐2‐hydroxypyrazine 1‐oxides were found to be useful as acyl carriers. Benzoyl derivatives were convenient reagents for benzoylation of amines and hydroxy compounds.
Pyrimidines. 8. chlorination of 6‐methyluracil with phosphorus oxychloride in the presence of trialkyamines
Authors: Gershon Herman , Grefig Anthony , Clarke Donald D. , Gershon Herman 
Published: April 2009

AbstractThe effect of the tertiary amines triethyl, tri‐n‐propyl, and tri‐n‐butylamines on the chlorination of 6‐methyluracil by phosphorus oxychloride was studied. A comparison with the reaction of preformed 2,4‐dichloro‐6‐methylpyrimidine and triethylamine in toluene was made. The reaction in phosphorus oxychloride in the presence of triethylamine afforded low yields of 2‐diethylamino derivative after short heating periods and high yields of the 2,4‐bis(diethylamino) derivative after 188 hours of boiling. Heating the preformed 2,4‐dichloro‐6‐methylpyrimidine in toluene in the presence of triethylamine yielded primarily the 2‐diethylaminopyrimidine along with a small amount of the 4‐diethylamino isomer. After 188 hours, the product mixture was composed of 87% 2‐diethylamino and 13% of 4‐diethylamino isomers. Although substituent orientation was essentially the same, the yields of products seem to have been influenced by the dielectric constants of the solvents.Tri‐n‐propylamine in phosphorus oxychloride yielded solely the dichloropyrimidine, even after 188 hours of boiling, and is recommended as the amine of choice in such chlorination reactions. Tri‐n‐butylamine was the same after 48 hours, but 4% of 4‐di‐n‐butylaminopyrimidine was found after 188 hours of heating.
A heterocyclic analog of leucine‐enkephalin
Authors: Carr Albert A. , Dudley Mark W. , Huber Edward W. , Kane John M. , Miller Francis P. 
Published: April 2009

AbstractA series of di‐, tri‐, tetra‐ and pentapeptide analogs of leucine‐enkephalin have been prepared in which the initial tyrosinylglycine fragment has been replaced by the 5,6‐dihydro‐5,5‐dimethyl‐2‐oxo‐3‐phenyl‐1(2H)‐pyrazineacetic acid moiety.
Nonaqueous diazotization of 4‐amino‐3‐arylisothiazole‐5‐carboxylate esters
Authors: Beck James R. , Gajewski Robert P. 
Published: April 2009

Abstract4‐Amino‐3‐arylisothiazole‐5‐carboxylate esters are converted to the corresponding desamino, chloro, bromo, and iodo esters by processes involving nonaqueous diazotization. These related procedures open up the possibility for the conversion of readily available heterocyclicortho‐amino esters and nitriles to related heterocyclic derivatives, which are not easily obtained by alternate routes.
Reactivity of aryl‐ and heteroarylmalonates against ortho‐dinucleophiles. Triaryl(heteroaryl)methane synthesis
Authors: Ramos Teresa , Avendaño Carmen , Elguero JosÉ 
Published: April 2009

AbstractCondensations of several aryl(heteroaryl)malonates 1 and ortho‐dinucleophiles are studied as a possible synthetic approach to aryl(heteroaryl)bisheteroarylmethanes 2.
On mechanistic aspects of 5‐deazaflavin dependent dehydrogenation of alcohol
Authors: Tanaka Kiyoshi , Kimura Teiji , Yoneda Fumio , Ijuin Mineko , Sakuma Yoshiharu 
Published: April 2009

AbstractThe reaction of 5‐deazaflavins with alcoholates was investigated and the direct hydride equivalent transfer from C1 of alcoholates to C5 of 5‐deazaflavins was confirmed by chemical methods. 5‐Alkoxy‐10‐butyl‐3‐methyl‐5‐deazaflavins were synthesized by treatment of 10‐butyl‐5‐chloro‐3‐methyl‐5‐deazaflavin with the corresponding alcoholates. The 5‐alkoxy‐5‐deazaflavins were reduced by sodium borodeuteride or sodium hydro‐sulfite in deuterium oxide or monodeuteriomethanol to give 10‐butyl‐3‐methyl‐1,5‐dihydro‐5‐deazaflavin‐5,5‐D2 exclusively. 3,10‐Dimethyl‐5‐deazaflavin radical anion was detected by esr technique on treatment of 3,10‐dimethyl‐5‐deazaflavin with potassium in DMF. From the above reactions, a mechanism of 5‐deazaflavin dependent dehydrogenation of alcoholate was proposed.
Nonaqueous diazotization of 5‐amino‐1‐aryl‐1H‐pyrazole‐4‐carboxylate esters
Authors: Beck James R. , Gajewski Robert P. , Lynch Michael P. , Wright Fred L. 
Published: April 2009

Abstract5‐Amino‐1‐aryl‐1H‐pyrazole‐4‐carboxylate esters are converted to the corresponding desamino, chloro, bromo, iodo, and methylthio esters by processes involving nonaqueous diazotization. Diazotizing agents are alkyl nitrites except in the case of chlorine where nitrosyl chloride is used. Evidence is presented that the latter reagent leads to the formation of cationic rather than radical intermediates.
Diphenyl cyancarbonimidate and dichlorodiphenoxymethane as synthons for the construction of heterocyclic systems of medicinal interest
Authors: Lee Webb R. , Eggleston Drake S. , Labaw Clifford S. , Lewis Joseph J. , Wert K. 
Published: April 2009

AbstractSimple high yield methods for the preparation of heterocyclic N‐cyanoguanidines (including the anti‐ulcer drug cimetidine), substituted triazoles, benzimidazoles and oxadiazoles with anti‐histaminic (H2) activity from the title compounds are described.
Synthesis of 10‐propargylfolic acid from 2‐amino‐6‐(bromomethyl)‐4(1h)‐pteridinone
Authors: Piper James R. , Mccaleb George S. , Montgomery John A. 
Published: April 2009

Abstract6‐(Bromomethyl)‐2,4‐pteridinediamine hydrobromide (1) is readily converted to 2‐amino‐6‐(bromomethyl)‐4(1H)‐pteridinone hydrobromide (2) by treatment with 48% hydrobromic acid. Compound 2 is of interest for direct attachment of the (2‐amino‐3,4‐dihydro‐4‐oxo‐6‐pteridinyl)methyl group to appropriate side‐chain precursors of analogues of folic acid, particularly those bearing functional groups incompatible with conditions required for hydrolytic deamination of the corresponding 2,4‐diaminopteridine analogues. An example of the use of 2 in this connection is demonstrated through synthesis of 10‐propargylfolic acid.
Synthesis of some hydroxy and methoxymethyl derivations of 1H‐pyrazolo[5,1‐c]‐1,2,4‐triazoles
Authors: Goddard John D. 
Published: April 2009

AbstractElectrophilic hydroxylation of a pyrazolotriazole with a mixture of trifuoroacetic attack of methanolic hydroxide ion on a dichloropyrazolotriazole gave a 6‐methoxymethylpyrazolotriazole by a mechanism involveing a cyclopropane intermediate.
Reductive cyclization of ketoesters utilizing sodium cyanoborohydride: Synthesis of γ‐ and δ‐lactones
Authors: Podraza Kenneth F. 
Published: April 2009

AbstractA new one pot procedure to synthesize γ‐ and δ‐lactones, in a 76‐84% yield, is accomplished by the reductive cyclization of 1,4‐ and 1,5‐ketoesters, utilizing sodium cyanoborohydride. The procedure is generally applicable to a wide variety of ketoesters with the exception of the ethyl ester of alkyl 1,5‐ketoesters and α,β‐unsaturated 1,4‐ and 1,5‐ketoesters.
1,3‐Dipolar cycloaddition reactions of nitrilimines with 1‐aroyl‐4,5‐dihydro‐3,4,4‐trimethyl‐5‐methylene‐1H‐pyrazoles. Synthesis of 6‐aroyl‐8,9,9‐trimethyl‐1,2,6,7‐tetrazaspiro[4.4]nona‐2,7‐dienes
Authors: Papadopoulos Stelios , Stephanidou‐Stephanatou Julia 
Published: April 2009

AbstractFrom the 1,3‐dipolar cycloaddition reactions of 5‐methylene‐1H‐pyrazoles 3 with N‐arylnitrilimines the novel spiro‐cycloadducts 4 were isolated, in addition to the corresponding 5‐(2‐aroylhydrazono‐1,1‐dimethylpropyl)‐1H‐pyrazoles 5. These pyrazoles 5 were the only products from the reactions of 3 with N‐methylnitrilimine 2d. The chemical behaviour of the spiro‐cycloadducts 4 was also examined.
Fused s‐triazino heterocycles. XIV 8H‐1,3,7,8,9,10c‐hexaazacyclopenta[a]phenalene, 1,3,7,8,10,11c‐hexaazabenz[de]anthracene and 13H‐4,6,8,13a, 13c‐pentaazabenzo[de]naphthacene, three new ring systems
Authors: Shaw John T. , Fair Mark C. 
Published: April 2009

AbstractThe synthesis of the title compounds 3,4 and 5 is described, using 7,9‐dibromo‐5‐tribromomethyl‐2‐t‐butyl‐4‐cyano‐1,3,6,9b‐tetraazaphenalene 2a as starting material. The key intermediates are 7,9‐dibromo‐2‐t‐butyl‐4‐cyano‐5‐hydrazino‐1,3,6,9b‐tetraazaphenalene 2b, 5‐benzamidino‐7,9‐dibromo‐2‐t‐butyl‐4‐cyano‐1,3,6,9b‐tetraazaphenalene 2c, and 7,9‐dibromo‐2‐t‐butyl‐5‐(2‐carboxyanilino)‐4‐cyano‐1,3,6,9b‐tetraazaphenalene 2e.
Synthesis of 3‐(2‐chloro‐5‐nitroanilino and 4‐nitroanilino)‐1‐(2,4,6‐trichlorophenyl)‐2‐pyrazolin‐5‐ones
Authors: Kim Chang‐Kyu , Debellis Francesco , Maggiulli Cataldo A. 
Published: April 2009

AbstractA new synthesis of 3‐anilino‐1‐aryl‐2‐pyrazolin‐5‐ones in which the pyrazolinone ring is built via NN bond formation is described. 2‐Cyano‐2′,4′,6′‐trichloroacetanilide 1 was converted to imino ether hydrochloride 2 which was reacted with anilines in methanol to produce N‐arylimino ether 3a,b. Reaction of these N‐arylimino ethers with hydroxylamine gave N‐arylamidoximes 4a,b. An 1,2,4‐oxadiazol‐5‐one 6a was prepared from the N‐arylamidoxime 4a and subjected to base‐induced rearrangement. The desired 3‐anilino‐pyrazolinone 7a was obtained only in a very low yield. However, O‐acetylation of the N‐arylamidoximes 4a,b followed by acid‐catalyzed ring closure and rearrangement in the presence of excess acetic anhydride gave a mixture of N‐acetylanilinopyrazolinones (e.g. 10) and 4‐acetyloxy‐3‐N‐acetylanilinopyrazoles (e.g. 12) which upon acid hydrolysis afforded the 3‐anilinopyrazolinones 7a,b in better yield.
The insertion and extrusion of heterosulfur bridges. XIII. Syntheses and structural studies of nitrophenanthro[4,5‐bcd]thiophenes
Authors: Klemm L. H. , Tsuchiya Reiko , Wong Eric K. L. , Stevens Michael P. , Lu Jennifer J. , Klopfenstein C. E. 
Published: April 2009

AbstractA simplified procedure for sulfur bridging of phenanthrene (2a) with hydrogen sulfide and a catalyst, but without solvent, is described. The product, phenanthro[4,5‐bcd]thiophene (1a), undergoes nitration at 25° or 60° in acetic anhydride to give mixtures (56–79%) of 1‐nitro‐1a and 3‐nitro‐1a in varying ratios. Reductive acetylation of these nitro derivatives gives 1‐ and 3‐acetylamino‐1a (93% and 33%). Hydrodesulfurization of the former amide produces crude 1‐acetylamino‐2a. Positions of substitution are assigned primarily on the basis of nmr chemical shifts of protons ortho or peri to the nitro substituent, and are consistent with calculations of reactivity indices by simple Hückel molecular orbital theory.
Cycloaddition of oxetanes with heterocumulenes catalyzed by organotin iodide‐lewis base complex
Authors: Shibata Ikuya , Imoto Takafumi , Baba Akio , Matsuda Haruo 
Published: April 2009

AbstractA series of 2‐oxazinones 1‐8 were synthesized from the cycloaddition reactions of oxetanes with isocya‐nates by utilizing the complex of diphenyltin diiodide with hexamethylphosphoric triamide (HMPA) as a catalyst. Moreover, the reactions with carbodiimides proceeded under milder conditions with the same catalyst system, and gave 2‐iminooxazines, 9 and 10, in high yields.
Reactions of lithium tributyl heteroaryl borates with allylic bromides in the presence of copper(I) cyanide
Authors: Ishikura Minoru , Kamada Machiko , Oda Izumi , Ohta Tsukasa , Terashima Masanao 
Published: April 2009

AbstractThe reaction of various lithium tributylheteroarylborates with allylic bromides in the presence of copper(I) cyanide furnished the regioselective allylation at the heteroaryl ring.
Amidomethylation of indoles and cyclisations to spiro[pyrrolo[4,3,2‐de]isoquinoline‐3,4′‐piperidines]
Authors: Carter Christine , Freter Kurt R. , Kriwacki Richard W. , Leonard Scott F. , Phil Pitner T. 
Published: April 2009

Abstract4‐Aminomethylindoles react with aldehydes and ketones to form pyrrolo[4,3,2‐de]isoquinolines. The structures of starting materials and end products were determined using 1D and 2D 1H nmr techniques.
Nitrogen bridgehead compounds. Part 71. Chiroptical properties of 9‐halo derivatives of 6,7,8,9‐tetrahydro‐4H‐pyrido[1,2‐a]pyrimidin‐4‐one and its 3‐carboxy derivative
Authors: Kajtár Márton , Kajtár Judit , Hermecz István , Breining Tibor , Mészáros Zoltán 
Published: April 2009

AbstractEarlier assignments [2] relating to the CD bands of 6,7,8,9‐tetrahydro‐4H‐pyrido[1,2‐a]pyrimidin‐4‐ones were utilized to explain the chiroptical properties of their 9‐halogenated derivatives. The signs of the most characteristic CD bands proved to be determined by the axial substituents in the benzylic position to the inherently achiral pyrimidinone chromophore.
Synthesis, structure elucidation and chemotherapeutic activity of 6‐substituted 1‐ethyl‐1,4‐dihydro‐7‐[(1‐imidazolyl)phenylmethyl]‐ 4‐oxo‐3‐quinolinecarboxylic acids
Authors: Frigola Jordi , Colombo Augusto , Más Josep , Parés Juan 
Published: April 2009

AbstractThe synthesis, structure elucidation and chemotherapeutic activity of novel 3‐quinolinecarboxylic acid derivatives are reported. These derivatives are characterized by a group (1‐imidazolyl)phenylmethyl attached to the 7‐position and chloro 10a, fluoro 10b or methoxy 10c appended to the 6‐position.