bluuebunny/crossref_metadata_2025 huggingface dataset:
Copolymeric cyclodextrin polysiloxane stationary phases prepared from 6A,6C‐ and 6A,6D‐dialkenyl‐substituted β‐cyclodextrin
Authors: Yi Guoliang , Bradshaw Jerald S. , Rossiter Bryant E. , Malik Abdul , Yun Hao , Lee Milton L.
Published: March 2009

The syntheses of four new β‐cyclodextrin‐hexasiloxane copolymers from heptakis(2,3‐di‐O‐methyl)‐β‐cyclodextrin (2) by multi‐step processes are described. 6A,6C‐Di‐O‐[p,p'‐methylenebis(benzenesulfonyl)]hetakis(2,3‐di‐O‐methyl)β‐cyclodextrin (3), which was prepared by the reaction of 2 with p,p'‐methylenebis‐(benzenesulfonyl chloride), is a key intermediate for the preparation of permethylated 6A,6C‐bisalkenyl‐β‐cyclodextrins 5, 6, and 9. Permethylated 6A,6C‐bissulfonate ester 4, which was obtained from 3 by a methylation reaction under mild conditions, was reacted with sodium allyloxide or sodium ω‐undecenyloxide to produce permethylated 6A,6C‐bisallyl‐ (or bis‐ω‐undecenyl)‐β‐cyclodextrin 5 or 6 or was hydrolyzed with 2% sodium amalgam in methanol to yield diol 7. Compound 7 was oxidized with periodinane, followed by Wittig's reaction with methyltriphenylphosphonium iodide to give permethylated 6A,6C‐dideoxy‐6A,6C‐dimethylene‐β‐cyclodextrin (9). Treatment of 2 with p,p'‐methylenebis(benzenesulfonyl chloride) or p,p'‐biphenyldisulfonyl chloride gave bissulfonate esters 10 or 11, respectively. Both of them were treated with sodium p‐allyloxy‐phenoxide in DMF, followed by methylation, to form permethylated 6A,6D‐di‐O‐(p‐allyloxyphenyl)‐β‐cyclo‐dextrin (16). Bisalkenes 5, 6, 9 and 16 were copolymerized with α,ω‐dioctyldecamethylhexasiloxane by a hydrosilylation process to give the cyclodextrin‐containing copolymers 17–20.
2‐carbaldoximes of pyridine‐4‐ and 5‐carboxylic acids
Authors: Reyes‐Rivera Hector Manuel , Hutehins Robert O. , Dalton David R.
Published: March 2009

A series of pyridine‐2‐carbaldoximes, all of which are substituted at the 4‐ or 5‐position with derivatives of the corresponding carboxylic acids, have been prepared via the corresponding pyridine‐2‐carbaldehydes.
Synthesis of artificial receptors as potential candidates for recognition and binding of pterin analogs
Authors: Papadopoulou Maria V. , Goswami Shyamaprosad , Hamilton Andrew D.
Published: March 2009

Open chain podands 2a‐c and macrocycles 2d‐e have been synthesized as potential candidates for 4‐aminopterin recognition and binding, featuring Hbonding characteristics and “stacking interaction” 2e. Preliminary binding studies between 6, 7, and 8 (simpler analogs of the above 2a‐e) as “bosts” and appropriate “guests”, showed that carbamates 2a and 2e are the most promising receptors for 4‐aminopterin binding.
Acetylenic amides. 2. The generation and reactions of dianions derived from 2‐propynamides
Authors: Coppola Gary M. , Damon Robert E.
Published: March 2009

The dianion of N‐benzyl‐2‐propynamide can be generated by the treatment of 4 with two equivalents of LDA at −65° or ethylmagnesium bromide at −20°. The trilithio species 6 is readily formed using 3 equivalents of LDA. Reaction of 5 with aldehydes or ketones produce hydroxypropynamides 9 in good yields. Silation of 5a with chlorotrimethylsilane produces N‐benzyl‐3‐trimethylsilyl‐2‐propynamide (13) in high yield. Reduction of 9 furnishes either fully saturated amides 15 or partially reduced cis‐olefins 16 or 18. Compounds 16, on heating, rearrange to 4‐ketoamides 17. Carboxylation of 5a with carbon dioxide produces 3‐benzyl‐2,4‐dioxo‐5‐oxazidinylacetic acid (11). Warming 11 in dimethyl sulfoxide results in the loss of carbon dioxide and the formation of N‐benzylpyruvamide (21).
Regioselectivity of the metalation of polymethoxylated pivaloyl‐aminobenzenes. Synthesis of methoxy‐2(1H)‐quinolones precursors of 2‐substituted‐5,8‐quinolinediones
Authors: Fourquez J. M. , Godard A. , Marsais F. , Quéguiner G.
Published: March 2009

Synthesis of methoxy‐2(1H)‐quinolones precursors of 2‐substituted‐5,8‐quinolinediones is described. A metalation, Heck coupling reaction and cyclisation sequence is used. Regioselectivity of the metalation of methoxypivaloylaminobenzenes is studied.
Reaction of 4,5‐diamino‐1,6‐dihydropyrimidin‐6‐ones with two equivalents of chalcones
Authors: Insuasty Braulio , Ramos Monica , Moreno Rodolfo , Quiroga Jairo , Sánchez Adolfo , Nogueras Manuel , Hanold Norbert , Meier Herbert
Published: March 2009

The reaction of 4,5‐diamino‐1,6‐dihydropyrimidin‐6‐ones 1 with two equivalents of the chalcones 2 leads in an acidic medium to the formation of the 2,3,6,7‐tetrahydro‐1H‐pyrimido[4,5‐b][1,4]diazepin‐6‐one derivatives 3a‐d. The structure elucidation of the products is based on nmr measurements and an X‐ray diffraction.
Reaction of 2,2′‐bis(N‐methylindolyl) with dimethyl acetylenedicarboxylate and thermally‐ and photochemically‐induced cyclizations of the product
Authors: Pindur U. , Kim Y. S. , Schollmeyer D.
Published: March 2009

2,2′‐Bis(N‐methylindolyl) 1 reacts with dimethyl acetylenedicarboxylate to furnish the 3‐dimethyl maleoyl‐substituted 2,2′‐bisindolyl 2. Compound 2 cyclizes under aluminum trichloride catalysis according to a polar process to give a cyclopenta[2,1‐b:3,4‐b′]diindole derivative 4. Reaction of compound 4 with benzyl‐amine yields the spiro derivative 5. Photochemically‐induced 1,6‐electrocyclization of compound 2 gives rise to the indolo[2,3‐a]carbazole 6 directly, which is readily transformed to the pyrrolo‐annelated carbazole 7 by treatment with benzylamine.
Reactions of carbethoxycarbene with enaminones. Formation of unexpected pyrroles
Authors: Augusti Rodinei , Eberlin Marcos N. , Kascheres Concetta
Published: March 2009

The reactions of carbethoxycarbene (:CH2‐CO2Et, 2) with several acyclic enaminones (RCOCH=CR1NHR2, 3) lead to the unexpected formation of 2‐Me, 3‐CO2Et, 4‐H, 5‐R1‐pyrroles 4. Structural variations of the enaminones show that the structural fragments C(3)‐CO2Et and C(2)‐Me are provided by 2 and that the fragment C(5)‐R1NHR2 originates from the enaminones 3, while the RCO group from 3 is eliminated during the course of reaction. Reactions with cyclic and nitrogen‐hindered enaminones do not lead to pyrrole formation but occur by simple insertion of 2 to the Cα‐H bond.
4‐Alkoxycarbonyl, 4‐alkylthiocarbonyl and 5‐alkoxycarbonyloxy derivatives of 1‐substituted‐3‐methylpyrazol‐5‐ones
Authors: López Rodolfo , León Gerardo , Oliva Alfonso
Published: March 2009

The reaction of 1‐substituted‐3‐methylpyrazol‐5‐ones 1 with alkyl chloroformates and calcium hydroxide in dioxane have been studied. With 1‐phenyl‐3‐methylpyrazol‐5‐one, the isolated product was alkyl 3‐methyl‐5‐oxo‐1‐phenylpyrazole‐4‐carboxylate 2 but with 1‐alkyl‐3‐methylpyrazol‐5‐one formation of 1‐alkyl‐5‐alkoxycarbonyloxy‐3‐methylpyrazole 3 was observed. Replacement of alkyl chloroformate by bis(alkoxythiocarbonyl) sulfide results in the formation of 4‐alkoxythiocarbonyl derivatives 4 in low yield with both 1‐substituted‐3‐methylpyrazol‐5‐ones.
Nucleophilic aromatic substitution with the anion of 3,5‐disubstituted isoxazole‐4‐carboxylic acids
Authors: Mosher Michael D. , Natale Nicholas R.
Published: March 2009

The preparation of the anion of a series of protected 3,5‐disubstituted 4‐isoxazolecarboxylic acids and the resulting addition of the anion to 9‐chloroacridine is described. The addition‐elimination reaction proceeds to give the expected acridinylmethylisoxazoles and has been justified based on calculated molecular mechanics energies and solvent effects.
A convenient synthesis of diaminoglyoxime and diaminofurazan: Useful precursors for the synthesis of high density energetic materials
Authors: Gunasekaran Ananthakrishnan , Jayachandran Thiruvalam , Boyer Joseph H. , Trudell Mark L.
Published: March 2009

The reaction of glyoxime (4) and hydroxylamine hydrochloride in aqueous sodium hydroxide was found to be a safe and inexpensive method for the preparation of multigram quantities of diaminoglyoxime (5). Potassium hydroxide mediated dehydration of 5 furnished diaminofurazan (1) in good yield of exceptional purity. The ready availability of 1 and 5 has facilitated the synthesis of new energetic furazan derivative 8.
Synthesis of new oxazolidine, oxazolidin‐2‐one and perhydro‐1,4‐oxazine derivatives of arylethanolamine as potential beta3‐adrenoceptor agonists
Authors: Monge Antonio , Aldana Ignacio , Cerecetto Hugo , Rivero Argimiro
Published: March 2009

The synthesis of new cyclic compounds, arylethanolamine derivatives, with potential beta3‐adrenoceptor agonist selectivity, which are associated with thermogenesis and regulation of insulin release, are described. Oxazolidine, oxazolidin‐2‐one, and perhydro‐1,4‐oxazine derivatives were obtained. The preliminary evaluation of the pharmacological effects of some of the synthesized compounds showed an activation of lypolysis in rat adipocytes with potency and efficiency similar to that observed for other accredited beta3‐adrenergic agonists.
Intramolecular sulfoxide electrophilic sulfenylation in 1‐ and 3‐acylindoles
Authors: Bates Dallas K. , Habib Qazi A.
Published: March 2009

Heating 1‐(2‐ethylsulfinyl)benzoylindole (1) in refluxing p‐xylene [thermal Sulfoxide Electrophilic Sulfenylation (SES)] produces indolo[2,1‐b][1,3]benzothiazin‐12‐one (2) in 66% yield. Similar treatment of 1‐methyl‐3‐(2‐ethylsulfinyl)benzoylindole (8) provides three products: sulfide 7 and cyclized products 9 and 10 in 10, 19 and 15% yield, respectively. Conversion of 10 to 9 under the reaction conditions is demonstrated and a spirocyclic intermediate 12, which may form from both 9 and 10 but undergoes only preferential S‐migration, is postulated to account for the rearrangement.
Synthesis and characterization of a novel octaphenyl substituted solvent soluble phthalocyanine
Authors: Yang Jiang , Van De Mark Michael R.
Published: March 2009

Novel metal free, zine 1,2,3,4,15,16,17,18‐octaphenyl‐9,10,23,24‐tetradodecyloxyphthalocyanines were synthesized by condensation of excess 1,3‐diimino‐4,5,6,7‐tetraphenylisoindoline with 1,3‐diimino‐5,6‐bis(dodecyloxy)isoindoline. The compound was separated by gel permeation chromatography. The structure was confirmed by elemental analysis, 1H nmr, 13C nmr, uv‐vis and ir spectroscopy.
Conformational analysis of c3′‐c8 connected biflavones
Authors: Konda Yaeko , Sasaki Tomomitsu , Kagawa Hitoshi , Takayanagi Hiroaki , Harigaya Yoshihiro , Sun Xue‐Long , Li Xian , Onda Masayuki
Published: March 2009

Two biflavones isolated from Taxus cuspidata were identified with ginkgetin (1) and sciadopitysin (2) which belong to C3′‐C8 connected biflavones. The conformation of 2 in the solid state was determined by X‐ray analysis and the conformations of 1 and 2 in the liquid state were discussed using nmr techniques. Complete assignments of 1H and 13C nmr spectra about 1 were made on the basis of COSY, HMQC, HMBC and nOe experiments.
Tetrazole compounds. 10. Novel tetrazolylindoles by fischer indolization of substituted tetrazolylacetaldehyde phenylhydrazones
Authors: Fischer Gerhard W.
Published: March 2009

The acid‐catalyzed reaction of substituted phenylhydrazines 1 with 1‐aryl‐5‐(2‐dimethylaminovinyl)‐1H‐tetrazoles 2 afforded (1‐aryl‐1H‐tetrazol‐5‐yl)acetaldehyde phenylhydrazones 3 which on heating in acetic acid/perchloric acid underwent a Fischer indolization to give substituted 3‐(1‐aryl‐1H‐tetrazol‐5‐yl)‐indoles 4a‐k. Indoles of this type are also formed on subjecting 1 and 2 directly to indolization conditions; thus, starting from phenylhydrazine the tetrazolylindoles 41‐s were obtained by a one‐pot procedure. Indolization of corresponding Nα‐methylphenylhydrazones 5 resulted in 1‐methyl‐3‐(1‐aryl‐1H‐tetrazol‐5‐yl)indoles 6.
Synthesis of new thiazolium betaines and the ring expansion reaction via 1,4‐dipolar cycloaddition
Authors: Kim Dong Chan , Kim Dong Jin , Park Sang Woo , Ho Yoo Kyung
Published: March 2009

The 1,4‐dipolar cycloaddition of 3‐phenyl‐7‐[N‐pheny(carbamoyl)]‐5,6‐dihydroimidazo[2,1‐b]thia‐zolium betaine (7d) with a series of aliphatic alkylating agents such as ethyl bromoacetate, α‐chloroacetone, and ethyl 4‐chloroacetoacetate gave a variety of new ring‐expanded cycloadducts 10a‐c instead of ring transformation compounds 9. This result was derived from the difference of reactivity between N‐ and S‐alkylations of thiazolium betaines 7a,d. The advantage of our method is to prepare the triheterocyclic compounds 10a‐c of complicated structure using reactive thiazolium betaine 7d in a one‐pot without isolation of intermediates. Treatment of N‐bridged thiazolo compounds 1a‐c with benzoyl isothiocyanate led to new thiazolium betaines 2a‐c, which were reacted with methyl iodide to afford the S‐alkylated quarternary ammonium salts 3a‐c. Synthesis of new 2‐iminothiazolinium betaines 5a,b also was carried out.
Synthesis of α‐2′‐deoxynucleosides
Authors: Larsen Erik , Abdel Aleem Abdel Aleem H. , Pedersen Erik B.
Published: March 2009

α‐Thymidine (4) was synthesized from thymidine (1) in 3 steps in 36% overall yield without using chro‐matography and with the possibility of increasing the yield to 85% by reusing the remaining α,β‐mixture. 1‐(2‐Deoxy‐3,5‐di‐O‐p‐toluoyl‐α‐D‐erythro‐pentofuranosyl)thymine (3) was further converted to 1‐(2‐deoxy‐α‐D‐erythro‐pentofuranosyl)‐5‐methylcytosine (5).
An approach to substituted 4‐hydroxypyran‐2‐ones
Authors: Ramirez Mai‐Ly , Garey Donna , Peña Michael R.
Published: March 2009

We examined a method for the preparation of 4‐hydroxypyran‐2‐ones in two steps from aryl ketones and ethyl malonyl chloride (or ethyl 2‐methylmalonyl chloride). These 4‐hydroxypyran‐2‐ones are useful precursors as they may be transformed in two steps to the 2‐methoxypyran‐4‐ones, which is found in phenoxan—a naturally occurring compound discovered to have anti‐HIV activity.
A convenient synthesis of a permethyl‐substituted β‐cyclodextrin‐containing polysiloxane stationary phase using an amide linking group
Authors: Yi Guoliang , Li Wenbao , Bradshaw Jerald S. , Malik Abdul , Lee Milton L.
Published: March 2009

A novel amide‐linked permethyl‐substituted β‐cyclodextrin‐bound polysiloxane stationary phase was prepared in only four steps. First, mono(6‐O‐toluenesulfonyl)‐β‐cyclodextrin was treated with sodium azide. Second, the resulting azide derivative was treated with methyl iodide and base followed by reduction with hydrogen to give amine‐substituted permethylcyclodextrin 3. Third, cyclodextrin 3 was treated with p‐(allyloxy)benzoyl chloride to form 6A‐(p‐allyloxybenzamido)‐substituted permethyl‐β‐cyclodextrin 4. Lastly, β‐cyclodextrin 4 was hydrosilylated onto a polysiloxane backbone containing hydrogen, methyl, and p‐tolyl substituents. This new phase separated the enantiomers of certain chiral lactones and alcohols in capillary supercritical fluid chromatography.
Synthesis of pyrido[2,1‐b]‐ and thiazolo[2,3‐b]purines
Authors: Giudice Maria Rosaria Del , Borioni Anna , Mustazza Carlo , Gatta Franco
Published: March 2009

Some pyrido[2,1‐b]‐ and thiazolo[2,3‐b]purines, tricyclic compounds structurally related to [1,2,4]triazolo[1,5‐c]quinazolines 1 have been synthesized with a view to study their possible adenosine and benzodiazepine receptors affinity.
Synthesis of a new pyrrolo[1,3]diazepine: 4H‐pyrrolo[1,2‐a]thieno[2,3‐e][1,3]diazepine
Authors: Daïch Abdelali , Ohier Philippe , Decroix Bernard
Published: March 2009

The 4H‐pyrrolo[1,2‐a]thieno[2,3‐e][1,3]diazepine (20) was synthesized by the one‐pot intramolecular cyclization of the appropriate nitroaldehyde 13. This key intermediate 13 was obtained by two pathways from methyl 3‐bromomethylthiophene‐2‐carboxylate (6).
The synthesis of novel polycyclic heterocyclic ring systems.. Benzo[e][1]benzothieno[3,2‐g][1]benzothiophenes
Authors: Sasaki Kenji , Tokuda Osamu , Hirota Takashi , Luo Jiann‐Kuan , Casüe Raymond N.
Published: March 2009

The novel polycyclic heterocyclic ring system compound, methyl 3‐chlorobenzo[e][1]benzothieno‐[3,2‐g][1]benzothiophene‐2‐carboxylate was synthesized. The assignment of its 1H and 13C nmr spectra was also accomplished by utilizing two‐dimensional nmr methods.
Reactions of 2,2′,5′,2′‐terfuran
Authors: Mcfarland J. W. , Howe B. M. , Lehmkuhler J. D. , Myers D. C.
Published: March 2009

Formylation of 2,2′,5′,2′‐terfuran (1) with N‐methylformanilide and phosphorus oxychloride gave 5‐formyl‐2,2′,5′,2′‐terfuran (2) and 5,5′‐diformyl‐2,2′5′,2′‐terfuran (3). Reduction of 2 and 3 afforded 5‐hydroxymethyl‐2,2′,5′,2′‐terfuran (4) and 5,5′ dihydroxymethyl‐2,2′,5′,2′‐terfuran (5), respectively. Terfuran 1 reacted with phenylmagnesium bromide to give 5‐(phenylhydroxymethyl)‐2,2′,5′,2′‐terfuran (6), and was carbonated to 5‐carboxy 2,2′,5′,2′‐terfuran (7) and 5,5′‐dicarboxy‐2,2′,5′,2′‐terfuran (8). Bromination of 1 with N‐bromosuccinimide gave 5,5′‐dibromo 2,2′,5′,2′‐terfuran (9).
Synthesis and 1H, 19F NMR spectroscopic characterization of (pentafluorophenyl)3‐n (pyrazol‐1‐yl‐tetrafluorophenyl)n=1,2 porphyrins
Authors: Jagerovic Nadine , Fruchier Alain , Elguero JosÉ
Published: March 2009

Three new porphyrins bearing in the meso positions 4‐(pyrazol‐1‐yl)‐2,3,5,6‐tetrafluorophenyl substituents have been prepared and characterized by nmr spectroscopy.
A convenient synthesis of functionalized 8‐ and 9‐aza‐1‐oxaspiro[5.5]undecanes
Authors: Apostolopoulos Costas D. , Haroutounian Serkos A.
Published: March 2009

2‐Hydroxy‐8‐(or 9‐)aza‐1‐oxaspiro[5.5]undec‐3‐en‐5‐ones derived from their corresponding 2‐furfuryl alcohols were used as key intermediates for the convenient synthesis of several novel 8‐ and 9‐aza‐1‐oxaspiro[5.5]undecane derivatives.
Photocyclization reactions. Part 3. Synthesis of naphtho[1,8‐bc]‐furans and Cyclohepta[cd]benzofurans using photocyclization of 8‐alkoxy‐1,2,3,4‐tetrahydro‐1‐naphthalenones and 4‐alkoxy‐6,7,8,9‐tetrahydro‐5H‐benzocyclohepten‐5‐ones
Authors: Sharshira Essam Mohamed , Iwanami Haruki , Okamura Mutsuo , Hasegawa Eietsu , Horaguchi Takaaki
Published: March 2009

Photocyclization reactions were carried out on 8‐alkoxy‐1,2,3,4‐tetrahydro‐1‐naphthalenones (six‐membered ring ketones) 4a‐g and 4‐alkoxy‐6,7,8,9‐tetrahydro‐5H‐benzocyclohepten‐5‐ones (seven‐membered ring ketones) 5a‐e in acetonitrile. Irradiation of 4a‐f gave rearranged naphthyl alcohols 8a‐f as major products. In the case of 4g, 2a,3,4,5‐tetrahydronaphtho[1,8‐bc]furan‐2a‐ol 6g was obtained. In contrast, irradiation of 5a‐e afforded 2,2a,3,4,5,6‐hexahydrocyclohepta[cd]benzofuran‐2a‐ols 9a‐e in good yields. The difference in reactivities between 4a‐g and 5a‐e is attributed to the conformation of six‐ and seven‐membered rings. Conformational and substituent effects in cyclization step of 1,5‐biradicals are discussed along with reaction pathways.
Synthesis and theoretical calculations of novel 5‐aryl substituted 2,4,7‐trioxo and 4,7‐dioxo‐2‐thioxopyrido[2,3‐d]pyrimidines
Authors: Rodríguez René , Suárez Margarita , Ochoa Estael , Morales Alhmed , González Leandro , Martín Nazario , Quinteiro Margarita , Seoane Carlos , Soto José L.
Published: March 2009

New substituted pyrido[2,3‐d]pyrimidines 5 and 6 have been prepared in one‐step from the readily available 6‐amino‐2,4‐dioxotetrahydropyrimidine (1) or 6‐amino‐4‐oxo‐2‐thioxotetrahydropyrimidine (2) and the arylidene substituted Meldrum's acid. The substitution pattern of the ethylene moiety in compounds 5 and 6 results in a strong push‐pull electronic effect. The semiempirical calculations using the AM1 method reveal two equally favoured conformations showing a distorted geometry. The calculated charge density values confirm the observed 13C nmr chemical shifts.
Ketalizations of aryl ω‐(2‐imidazolyl)alkyl ketones by glycerol and 3‐mercapto‐1,2‐propanediol. synthesis and characterization of cis‐ and trans‐{2‐aryl‐2‐[ω‐(2‐imidazolyl)alkyl](1,3‐dioxolan‐4‐yl and 1,3‐oxathiolan‐5‐yl)}methanols
Authors: Kim Jang‐Woo , Davis Frank S. , Huang Liang‐Fu , Abdelaal Salma M. , Upadhyaya Subhash P. , Lee Jae Jeong , Bauer Ludwig
Published: March 2009

Aryl 2‐[(2‐imidazolyl)ethyl or 3‐(2‐imidazolyl)propyl]ketones were ketalized by glycerol or 3‐mercapto‐1,2‐propanediol in boiling benzene in the presence of 4‐toluenesulfonic acid to provide the title compounds. The aryl substituents are 4‐chloro‐, 4‐bromo‐, 4‐fluoro‐, or 2,4‐dichlorophenyl. While aryl (2‐imidazolyl)methyl ketones condensed with glycerol to form cis‐ and trans‐{2‐aryl‐2‐[(2‐imidazolyl)methyl]‐4‐(hydroxymethyl)}‐1,3‐dioxolanes, related condensations with 3‐mercapto‐1,2‐propanediol, under similar, or even more stringent reaction conditions, produced no 1,3‐oxathiolane analogs, with the starting ketones being recovered. Separation and structure determination of these racemic cis and trans isomeric products are described. The structure of these stereoisomers was established by means of 1H and 13C nmr correlation and nOe experiments. Selective methylation of the N‐unsubstituted 2‐imidazolyl alcohols with one equivalent sodium hydride and methyl iodide provided the corresponding N‐methyl alcohols in excellent yields. With excess benzoyl chloride, N‐unsubstituted 2‐imidazolyl alcohols were initially converted to O, N‐dibenzoates from which the N‐benzoyl group was easily cleaved by ammonium hydroxide in ethanol to provide benzoate esters.
Nitrogen configuration determined by X‐ray analysis on an homogeneous series of 3‐Indolinones
Authors: Carloni Patricia , Greci Lucedio , Stipa Pierluigi , Cauzzi Daniele , Rizzoli Corrado , Sgarabotto Paolo
Published: March 2009

The X‐ray diffraction analyses of 2‐methyl‐2‐phenylindolin‐3‐one 1, 1,2‐dimethyl‐2‐phenylindolin‐3‐one 2, 1‐hydroxy‐2‐methyl‐2‐phenylindolin‐3‐one 3 and 1‐methoxy‐2‐methyl‐2‐phenylindolin‐3‐one 4 have been carried out and the structural data were compared with those of 1‐oxyl‐2‐methyl‐2‐phenylindolin‐3‐one 5. The results demonstrate that only compounds 2 and 5 show planar trigonal geometry which is coplanar with the conjugated benzene ring of the indolinic nucleus, whereas compounds 3 and 4 show a marked pyramidality of the nitrogen. Even if compound 1 shows a certain pyramidality of the nitrogen, it has been considered similar to compound 2. The reactivity of all studied compounds fit the structural data.
Ring‐opening reactions of 3‐substituted 1‐azabicyclo[1.1.0]butane with dichlorocarbene
Authors: Mlostoń Grzegorz , Galindo Alberto , Bartnik Romuald , Marchand Alan R. , Rajagopal D.
Published: March 2009

Reaction of 3‐ethyl‐1‐azabicyclo[1.1.0]butane (1a) with chloroform‐potassium tert‐butoxide afforded a ring‐opened product, 1,1‐dichloro‐2‐aza‐4‐ethylpenta‐1,4‐diene (4a), which was characterized via conversion to the corresponding N‐substituted 5‐chloro‐1,2,3,4‐tetrazole, Sa. Reaction of 3‐phenyl‐1‐azabicyclo‐[1.1.0]butane (1b) with “Seyferth's reagent” (PhHgCCl2Br) afforded 1,1‐dichloro‐2‐aza‐4‐phenylpenta‐1,4‐diene (4b), which also was characterized via conversion to a tetrazole derivative, i.e., 5b. Finally, the reaction of 1b with dichlorocarbene generated under phase transfer conditions (chloroform‐sodium hydroxide‐TEBA) was studied. At short reaction times (0.5 hour), the major reaction product was 4b. However, at longer reaction times (20–30 hours), two secondary products, 8 and 9, were formed which resulted via subsequent dichlorocyclopropanation of 4b.
The synthesis of 3,4‐dihydro‐2‐methyl‐3‐oxo‐2H‐benzo‐1,4‐thiazine‐2‐carboxylic acids
Authors: Leskovšek Cizej V. , Urleb U.
Published: March 2009

The synthesis of 3,4‐dihydro‐2‐methyl‐3‐oxo‐2H‐benzo‐1,4‐thiazine‐2‐carboxylic acids 4a, b, 6a‐e is presented. After the condensation of o‐aminothiophenols with diethyl 2‐bromo‐2‐methylmalonate in the presence of KF as a catalyst the nitrogen in the fused derivatives 3a, b, was alkylated to provide 5a‐f, the corresponding esters 3a, b, 5a‐f were hydrolysed.
Photocyclization reactions. Part 4 . Synthesis of naphtho[1,8‐bc]‐furans and cyclohepta[cd]benzofurans using photocyclization of Ethyl 2‐(8‐Oxo‐5,6,7,8‐tetrahydro‐1‐naphthyloxy)acetates and ethyl 2‐(5‐Oxo‐6,7,8,9‐tetrahydro‐5H‐benzocyclohepten‐4‐yloxy)acetates
Authors: Sharshira Essam Mohamed , Iwanami Haruki , Okamura Mutsuo , Hasegawa Eietsu , Horaguchi Takaaki
Published: March 2009

Photocyclization reactions were carried out on ethyl 2‐(8‐oxo‐5,6,7,8‐tetrahydro‐1‐naphthyloxy)acetates 1a‐e and ethyl 2‐(5‐oxo‐6,7,8,9‐tetrahydro‐5H‐benzocyclohepten‐4‐yloxy)acetates 2a‐e in acetonitrile. Irradiation of 1a‐e gave naphtho[1,8‐bc]furanols 3a‐e and naphtho[1,8‐bc]furans 4a‐e in 33–83% yields and ethyl acrylates 5b‐d were produced in 3–25% yields during irradiation of 1b‐d. On the other hand, 2a‐e afforded cyclohepta[ad|benzofuranols 6a‐e and cyclohepta[ad]benzofurans 7a‐e in 44–87% yields. Ethyl acrylates 8b‐d were also produced in 7–43% yields from irradiation of 2b‐d. Substituent effects on photocyclization and reaction pathways are discussed.
Oligomers with four 3,4‐quinolinediyl units and α,ω‐bis (4‐chloro‐3‐quinolinylthio)alkanes
Authors: Boryczka Stanislaw , Rudnik Magdalena , Maślankiewicz Andrzej
Published: March 2009

Starting from the reaction of thioquinanthrene 1 with sodium methoxide followed by the reaction with α,ω‐dihalogenoalkanes, title bis‐methoxy oligomers 4a‐c with four 3,4‐quinolinediyl units were prepared (40–91%). Acid catalysed hydrolysis of methoxy groups in 4a‐c gave tetramers 5a‐c (46–94%) with two 4(1H)‐quinolinone functions. The reactions of bis‐quinolinones 5a‐c with phosphoryl chloride in DMF run as deoxo‐chlorination and afforded tide dichlorotetramers 6a‐c (51–66%) with 4‐chloroquinolinyl groups. The treatment of bis‐methoxy tetramers 4a‐c with boiling phosphoryl chloride led to title α,ω‐bis(4‐chloro‐3‐quinolinylthio)alkanes 7a‐c (52–56%) and thioquinanthrene (65–70%).
Synthesis of thiazoles from the reaction of phenyliodonium ylids of cyclic β‐dicarbonyl compounds with thioureas
Authors: Kamproudi Heleni , Spyroudis Spyros , Tarantili Petroula
Published: March 2009

Phenyliodonium ylids of cyclic β‐dicarbonyl compounds react with substituted thioureas to form the corresponding thiouronium ylids. The latter, when they have one free amino group, are converted upon heating to fused thiazoles. The reaction can be considered as a modification of the Hantzsch synthesis.
Phenyliodonium derivatives from 4‐aminocoumarin and their reactivity
Authors: Papoutsis Ioannis , Spyroudis Spyros , Varvoglis Anastasios
Published: March 2009

The reaction of 4‐aminocoumarin with [hydroxy(tosyloxy)iodo]benzene affords 4‐amino‐3‐phenyliodoniocoumarin tosylate which upon basification is converted to the corresponding stable iodine‐nitrogen 1,4‐dipole. The reactivity of the latter is briefly discussed.
Radical mediated synthesis of 6‐arylphenanthridines via benzotriazole ring‐opening
Authors: Katritzky Alan R. , Yang Baozhen
Published: March 2009

Lithiation of diarylbenzotriazol‐1‐ylmethanes followed by addition of copper(I) iodide gave 6‐arylphenanthridine derivatives in moderate yields. When the two aryl groups were the same or contained very different electron densities, only one product was obtained. However, when the two aryl groups exhibited electron densities of similar magnitude, two isomers were afforded. According to the substituent effect, we believe that the reactions proceed via radical intermediates formed by copper(I) iodide.
Synthesis and reactions of 3‐aroyl derivatives of 4‐hydroxy‐2‐quinolones and 4‐hydroxycoumarin
Authors: Kappe Thomas , Schnell Barbara
Published: March 2009

3‐Aroyl‐4‐hydroxy‐2‐quinolones 4 and 11 can be synthesized starting with 1 or 9 via Fries rearrangement of the corresponding esters 3 and 10, catalyzed by potassium cyanide and 18‐crown‐6. A one pot procedure is presented in which the esters do not need to be isolated. Reduction of the aryl ketones 4 and 11 with zinc dust leads to the benzyl derivatives 5 and 12. Reaction of the aryl ketones 4 and 11 with hydroxylamine and subsequent heating of the crude product leads via thermal Beckmann rearrangement and dehydration to oxazoloquinolones 7 and 14. 2‐Aroyloxypyrido[1,2‐a]pyrimidin‐4‐ones 17 and 20 could not be converted to the corresponding ketones by Fries rearrangement.
Diels‐alder adducts of a spirocyclopentenotriazoloazodienophile. Assignment of their 1H and 13C NMR spectra
Authors: Alexandrou N. E. , Mertzanos G. E. , Stephanidou‐Stephanatou J. , Tsoleridis C. A.
Published: March 2009

1‐Phenyl‐cyclopenteno[1,2‐d]‐1,2,3‐rriazolo‐5‐spiro‐4′‐[perhydropyrazolino‐3′,5′‐dione] (5) afforded in situ, by oxidation with lead tetraacetate, the corresponding cyclopentenotriazolo‐spiropyrazolodione 6, which was trapped with dienes giving the hetero‐Diels‐Alder adducts 10–12 in good yields. The Diels‐Alder reactions were examined on the basis of AM1 MO calculations. Total assignment of the 1H‐ and 13C‐nmr chemical shifts as well as the relative configuration of these adducts was accomplished with the help of 2D (1H‐1H COSY, 1H‐1H NOESY, 1H‐13C XHCORR, 1H‐13C COLOC) and NOE difference spectroscopy. The structures of compounds 11a and 11b were also examined by molecular modeling.
Azido/tetrazole equilibrium in the thiazoloacridinone series
Authors: Hanoun Jean‐Pierre , Faure Robert , Galy Jean‐Pierre , Elguero José
Published: March 2009

Compounds 2‐azido‐6H‐thiazolo[5,4‐a]acridin‐11‐one 3 and 2‐azido‐6‐butylthiazolo[5,4‐a]acridin‐11‐one 4 have been prepared for the first time. The azido/tetrazole equilibria of the most soluble compound 4 has been studied in six solvents. The resulting tautomeric equilibrium constants have been compared with those of 2‐azido‐4,5‐dimethylthiazole 1 and 2‐azidobenzothiazole 2. The rather insoluble NH derivative 3 when dissolved in DMSO contains 66% of tetrazole 3b while the corresponding anion (obtained by adding sodium hydride) is all in the tetrazole 13b form.
Synthesis of new imidazo[4,5‐d][1,3]diazepine derivatives from 5‐amino‐4‐(cyanoformimidoyl)imidazoles
Authors: Dias Alice M. , Fernanda M. , Proença J. R. P. , Booth Brian L.
Published: March 2009

N1‐[(Z)‐2‐Amino‐1,2‐dicyanovinyl]formamidines 1a‐d react readily with tosyl isocyanate to form novel 8‐amino‐3‐substituted‐5‐oxo‐7‐tosylaminoimidazo[4,5‐d][1,3]diazepines 6a‐d rather than the 6‐cyano‐2‐oxopurine derivatives 5a‐d expected. Compound 5a has been synthesized from 1a by reaction with ethyl chloroformate and base‐catalyzed cyclization of the resultant 5‐ethoxycarbonylamino‐4‐(cyanoformimidoyl)imidazole. Treatment of the 5‐amino‐4‐cyanoimidazoles 7a and b with tosyl isocyanate under similar conditions gives the 4‐cyano‐5‐(3′‐tosylureido)imidazoles 8a and b, which on treatment with ethanolic ammonia cyclizes to the corresponding isoguanines 10a and b.
Synthesis of C‐nor‐heterocyclic steroid analogues
Authors: Esses‐Reiter Klára , Reiter József
Published: March 2009

2‐Substituted‐amino‐10H‐thiazolo[5,4‐b]benz[e]indene derivatives 5 representing a novel ring system were synthesized. Their acylation led to exo‐acylated derivatives 9 that could be converted to the corresponding glycine analogues 12.
Synthesis and 13C, 15N NMR study of a new functionalized pyrido[2,3‐b]indole derivative
Authors: Buisson J.‐P. , Bisagni E. , Monneret C. , Demerseman P. , Leon C. , Platzer N.
Published: March 2009

New functionalized α‐carbolinones especially the 4‐hydroxy‐3‐nitro‐1H,9H‐pyrido[2,3‐b]indol‐2‐one were synthesized in a good yield, three‐step reaction. A complete 13C, 15N nmr study of this carbolinone and precursors is presented.
Synthetic studies to the octahydrobenzo[f]quinoline system
Authors: Tagmatarchis Nikos , Katerinopoulos Haralambos E.
Published: March 2009

An improved procedure to 1,2,3,4,4a,5,6,10b‐octahydrobenzo[f]quinolines is reported giving single intermediate products and higher total yields.
Alkylation and arylation at the C‐3′ side chain position of cephalosporins via a pummerer intermediate
Authors: Gourdoupis Christos G. , Stamos Ioannis K.
Published: March 2009

The Pummerer intermediate generated from a 3‐exomethylene‐1‐oxocephem with trifluoroacetic anhydride was trapped intermolecularly in the presence of a Lewis acid by some aromatic or olefinic nucleophiles.
Mechanistic studies in the reaction of 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione with 2,5‐dimethyl‐2,4‐hexadiene
Authors: Vassilikogiannakis Georgios , Stratakis Manolis , Karabatsos Gerasimos J. , Orfanopoulos Michael
Published: March 2009

Secondary isotope effect measurements of methanol adducts from the reaction of 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione with 2,5‐dimethyl‐2,4‐hexadiene, support the formation of an aziridinium imide intermediate rather than an open dipolar intermediate in the rate determining step.
A trilactone related to anemonin
Authors: Stamos Ioannis K. , Cassady John M.
Published: March 2009

Treatment of Anemonin sequentially with two equivalents of the anion 2 and iodine gave the monoalkylated monoiodinated iodolactone t‐butyl ester 3. Ester cleavage in anhydrous acedic media followed by treatment with sodium hydrogen carbonate transformed 3 to trilactone 4.
NMR analysis of restricted internal rotation in 2‐substituted‐2,3‐dihydro‐3‐o‐tolyl(chlorophenyl)‐4(1H)‐quinazolinones
Authors: Noto Renato , Gruttadauria Michelangelo , Meo Paolo Lo , Pace Andrea
Published: March 2009

Steric interactions between aryl and heterocyclic moieties in 2‐substituted‐2,3‐dihydro‐3‐o‐tolyl(chlorophenyl)‐4(1H)‐quinazolinones 1a‐j produce sufficient restriction to rotation about the aryl CN bond that the presence of torsional isomers may be detected at room temperature. Diastereomeric population and free energy of activation for rotation have been calculated by 1H nmr spectra. Probably due to a preferred axial position of R2 substituent no dramatic variation both in A/B ratio and in ΔG≠ value has been observed for 1a‐f. The comparison between 1a and 1j ΔG≠ values allows to formulate a hypothesis on the structure of the transition state.
Synthesis and stereochemical studies of 6‐substituted 1H,3H,6H,7aH‐3,3‐dimethylimidazo‐[1,5‐c]thiazol‐5‐one‐7‐thiones
Authors: Györgydeák Z. , Kövér K. E. , Miskolczi I. , Zékány A. , Rantal F. , Luger R , Strumpel M. Katona
Published: March 2009

The reaction of (4S)‐5,5‐dimethyl‐4‐thiazolidine‐carboxylic acid 1 with alkyl and aryl isothiocyanates 2 gave bicyclic thiohydantoins 3. The (2R,4S)‐ and (2S,4S)‐mixtures of 2‐substituted 5,5‐dimethyl‐4‐thiazolidine‐carboxylic acids 4 and 8 containing two centers of chirality in the analogous reaction afforded thiohydantoins 7 and 10, respectively, with (1R)‐configuration. In some cases we managed to isolate the thioureido acid intermediates 6 and 9 or their triethylamine salts which afforded the corresponding bicycles 7 and 10 under thermal cyclization or acidification. The stereochemistry has been elucidated by high resolution ram studies, optical rotation measurements and X‐ray crystallography.
Synthesis and spectral properties of substituted [1,2,4]oxadiazolo[4,5‐a] [1,5] benzodiazepines
Authors: Cortés Eduardo CortÉS , Ambrosio Ana MarÍA Mendoza
Published: March 2009

The preparation of twelve novel substituted [1,2,4]oxadiazolo[4,5‐a][1,5]benzodiazepines which have potentially useful pharmacological properties; by 1.3‐dipolar cycloaddition of benzonitrile oxides, generated in situ from benzohydroxamoyl chloride and triethylamine, to 1,5‐benzodiazepine derivatives, is described. The structure of all products was corroborated by ir, 1H‐nmr, 13C‐nmr and ms.
Studies on pyrrolidinones. On the carbamoylation of some pyroglutamic derivatives
Authors: Cauliez Pascal , Fasseur Dominique , Couturier Daniel , Rigo BenoǏT , Kolocouris Antonios
Published: March 2009

The carbamoylation of some lactams derivatived from pyroglutamic acid as been studied; better yields were obtained starting from the unsubstitued lactam (toluene, 80°) rather than starting with the N‐silyllactam (room temperature), although these latter reaction conditions could be interesting for heat sensitive compounds. Methyl and phenyl isothiocyanate react only with the sodium salt of methyl pyroglutamate, giving 1,5‐diaddition products.
Reactivity of α‐acylated β‐enamino ketones and esters: Synthesis of pyrazoles
Authors: Missio Lauri J. , Braibante Hugo S. , Braibante Mara E. F.
Published: March 2009

The reactivity of the enamino compounds 4‐amino‐3‐phenylamino(thio)carbonyl‐3‐penten‐2‐one 1 and 2 and ethyl 3‐amino‐2‐phenylamino(thio)carbonyl‐2‐butyrate 7 and 8 was studied using the reaction with hydrazine hydrate and hydrazine hydrochloride to evaluate the 1,3 electrophilic center of the compounds by the formation of the pyrazole rings. The pyrazoles 3, 4, 5, 9, 11 and 13 were obtained depending on the reaction conditions employed.
The synthesis of 3‐bromo‐2,4,5‐trifluorobenzoic acid and its conversion to 8‐bromoquinolonecarboxylic acids
Authors: Renau Thomas E. , Sanchez Joseph R. , Domagala John M.
Published: March 2009

A series of 8‐bromo‐4‐oxo‐3‐quinolinecarboxylic acids was prepared via the borate ester, 8. The key intermediate in the synthesis of the final products 10a‐10d was 3‐bromo‐2,4,5‐trifluorobenzoic acid (3), conveniently prepared in two steps from the known oxazoline, 1. The preparation of 10a‐10d is a significant improvement of the literature procedure currently available for the synthesis of these compounds.
Synthesis of heterocyclic bioregulators and semiochemicals
Authors: Mori Kenji
Published: March 2009

Chemistry and biology of oxygen heterocycles as insect pheromones are reviewed referring to exo‐brevicomin, disparlure, japonilure and olean. Synthesis of koninginin A, a microbial metabolite, is discussed. Two azetidine alkaloids, penaresidin A and penazetidine A, were synthesized.
Azadiene diels‐alder reactions: Scope and applications. Total synthesis of natural and Ent‐fredericamycin A
Authors: Boger Dale L.
Published: March 2009

A review of our studies of the inverse electron demand Diels‐Alder reactions of heteroaromatic and acyclic azadienes is presented and the application of a N‐sulfonyl‐1‐aza‐1,3‐butadiene [4+2] cycloaddition reaction in the total synthesis of natural and ent‐fredericamycin A is described in detail.
Rearrangement reactions of aziridinylbenzaldoximes
Authors: Johnson James E. , Nwoko Delphine , Hotema Martha , Sanchez Natalia , Alderman Reidun , Lynch Vincent
Published: March 2009

Reactions of 2,2‐dimethylaziridine with benzohydroximoyl chlorides [ArC(Cl)NOH] give aziridinylbenzaldoximes 1. It has been found that the aziridine ring in these compounds undergoes ring opening in hydrogen chloride‐dioxane solution to give (Z)‐N‐hydroxy‐N′‐(2‐chloro‐2‐methylpropyl)benzenecarboximidamides [ArC(NHCH2CR1R2Cl)NOH, 4]. Treatment of 1 with hydrochloric acid followed by neutralization with aqueous sodium hydroxide gave 6,6‐dimethyl‐3‐aryl‐1,2,4‐oxadiazines 2. Reaction of 4 with sodium hydride in dioxane gave 5‐isopropyl‐3‐aryl‐4,5‐dihydro‐1,2,4‐oxadiazoles 5. Reaction of the 4,5‐dihydro‐1,2,4‐oxadiazoles 5 with N‐chlorosuccinimide gave the heteroaromatic 1,2,4‐oxadiazoles 6. It is suggested that reactions of 4 with sodium hydride in dioxane solution involve the conjugate base of 4 which undergoes a 1,2‐hydride shift that is concerted with loss of chloride ion. In aqueous sodium hydroxide solution it is suggested that the conjugate base of 4 undergoes ionization of the chlorine atom followed by nucleophilic attack by the oximate anion.
Preparation and characterization of tetraaza[14]annulene and its nickel(ii) and copper(II) complexes with crown ether functionalities
Authors: Sakata Kazunori , Shimoda Manabu , Hashimoto Mamoru
Published: March 2009

Three new organic hosts are described that contain a tetraaza[14]annulene core to which two crown ether voids are attached. These hosts include a free base tetraaza[14]annulene and/or its complexes with benzo‐15‐crown‐5 rings. The crown tetraaza[14]annulene is synthesized from tetraaza[14]annulene and 4′‐chloroformylbenzo‐15‐crown‐5. Its nickel(II) and copper(II) complexes are prepared in a similar manner as above. In solution the compounds do not tend to form aggregates. However, aggregation is affected by the presence of alkali‐metal salts, which coordinate to the crowns. Li+ and Na+ cations with diameters that match the diameters of the crown ether rings form 1:2 host‐guest complexes. Complexes with 2:2 host‐guest stoichiometry are formed when the diameters of K+ and Cs+ cations exceed that of the crown ether rings. Nevertheless, it is weak for the present macrocycle and its complexes to be inclined to form dimers owing to the steric hindrance of the substituent groups and owing to restraining the rotation of the carbonyl bond connecting the crown ether group.
Synthesis of 2‐aryl‐4‐hydroxy‐5‐thio substituted 1,3‐thiazin‐6‐ones via sulfenylation of 2‐aryl‐4‐hydroxy‐[1,3]thiazin‐6‐ones with sulfenyl chlorides
Authors: Prasad J. V. N. Vara
Published: March 2009

A series of 2‐aryl‐4‐hydroxy‐5‐thio substituted 1,3‐thiazin‐6‐ones were synthesized for human immunodeficiency virus‐1 protease inhibition. These compounds were synthesized by the treatment of 4‐hydroxy‐5‐thio substituted‐1,3‐thiazin‐6‐ones with the corresponding sulfenyl chlorides. The products were obtained in good isolated yields, inspite of the presence of bulkyl substitutents at the ortho position of phenyl sulfenyl chloride portion.
Synthesis of novel 5‐hydroxy‐3‐alkoxy‐ and 5‐hydroxy‐3‐alkylthioindole‐2‐carboxamides
Authors: Unangst Paul C. , Connor David T. , Miller Steven R.
Published: March 2009

The preparation of several novel 5‐hydroxyindole‐2‐carboxamides is described. A 5‐benzyloxyindole ester was elaborated to the 3‐bromo, 3‐hydroxy, and 3‐alkoxy ester intermediates followed by conversion to the amide and debenzylation. A related 5‐acetyloxy indole ester was converted to 3‐sulfinyl and 3‐alkylthio intermediates before simultaneous amidation and removal of the 5‐hydroxy protecting group.
4‐Cyano‐2‐oxo‐1,2,4‐oxadiazolo[2,3‐a]quinoxaline 5‐N‐oxides. New synthetic method and reaction with alcohols. Potential cytotoxic activity
Authors: Martínez Crespo F. J. , Palop J. A. , Sainz Y. , Narro S. , Senador V. , González M. , De Ceráin A. López , Monge A. , Hamilton E. , Barker A. J.
Published: March 2009

Several quinoxaline 1,4‐di‐N‐oxides have been shown to be efficient and selective cytotoxins for hypoxic cells. We present now a series of 4‐cyano‐2‐oxo‐1,2,4‐oxadiazolo[2,3‐a]quinoxaline 5‐N‐oxides 2a‐2k. They were prepared starting from 3‐amino‐2‐quinoxalinecarbonitrile 1,4‐di‐N‐oxides 1a‐1k and 2‐chloroethyl isocyanate in dry dioxane at 100–110°. A reaction mechanism is proposed. The treatment of 1a with phenyl isocyanate afforded 2a. Reaction of 2c with silica gel yielded 1c. Compounds 2a‐2g were heated in the presence of ethanol and 2‐propanol giving the corresponding carbamates 3a‐3g and 4a‐4g. Compound 2d was already obtained by heating a mixture of 1d and ethyl chloroformiate. Compound 2b was prepared when the carbamate 3b was heated at 150°. Quinoxalines were tested as cytotoxic agents both in oxic and hypoxic cells. The most interesting compounds were 3g and 4g.
Further studies on heterocyclic arene imines. Preparation of 1a,9b‐dihydroazirino[f][1,7]phenanthroline, 3b,4a‐dihydroazirino‐[2,3]phenaleno[1,9‐g,h]quinoline and 1a,13b‐dihydrodibenzo[1,2:6,7]phenazino[1,2‐b]azirine
Authors: Bazanov‐Katz Nina , Zangi Ronen , Blum Jochanan
Published: March 2009

The syntheses of the K‐imine derivatives of 1,7‐phenanthroline, phenaleno[1,9‐g,h]quinoline, and dibenzo[a,h]phenazine are described. The parent heterocyclic compounds 4, 9 and 14 were oxidized to the corresponding K‐oxides, 5, 10 and 15, which in turn were reacted with sodium azide in aqueous acetone. The resulting trans‐azido alcohols were then cyclized with tributylphosphine to the title compounds 6, 11 and 16.
Pyirolothieno[1,4]diazepines. Part IV. First synthesis of pyrrolo‐[1,2‐a]thieno[2,3‐f][1,4]diazepine Derivatives
Authors: Boulouard Michel , Dallemagne Patrick , Alsaïdi Abdellah , Rault Sylvain
Published: March 2009

Treatment of 3‐(2‐formyl‐1H‐pyrrol‐1‐yl)‐2‐thiophenecarboxamide by various nucleophiles like methyl ketones, amines, alcohols, thiols or acetates led to new 5,6‐dihydro‐4H‐pyrrolo[1,2‐a]thieno‐[2,3‐f][1,4]diazepines.
Iminium carbonic acid derivative salts. X. Synthesis of N,S‐containing heterobicycles from N‐protected 2‐methylthio‐1,3‐thiazinium and 2‐methylthiothiazolium salts. Part 2. Reaction of N‐protected 2‐methylthio‐1,3‐thiazinium and 2‐methylthiothiazolium salts with vinylogous CH‐acidic compounds
Authors: Hanefeld Wolfgang , Naeeni Mahmoud , Schlitzer Martin
Published: March 2009

N‐Boc‐protected 2‐methylthio‐1,3‐thiazinium 3 and 2‐methylthiothiazolium salts 4,7 obtained from the corresponding 1,3‐thiazine‐2‐thiones and thiazolidine‐2‐thiones by the action of methyl iodide or trimethyloxonium tetrafluoroborate were reacted with vinylogous CH‐acidic compounds forming ketene N,S‐acetals 5,6,8,9. The protection group was removed with trifluoroacetic acid whereupon the desired cyclisation to pyrido[2,1‐b]‐1,3‐thiazines 10 and thiazolo[3,2‐b]pyridines 11,12 took place.
Photocyclization reactions. Part 5. Synthesis of dihydrobenzofuranols using photocyclization of 2‐alkoxybenzophenones and ethyl 2‐benzoylphenoxyacetates
Authors: Sharshira Essam Mohamed , Shimada Satoru , Okamura Mutsuo , Hasegawa Eietsu , Horaguchi Takaaki
Published: March 2009

Photocyclization reactions were carried out on 2‐alkoxybenzophenones 1a‐h and ethyl 2‐benzoylphenoxyacetates 2a‐e in acetonitrile. Irradiation of 1a‐h gave dihydrobenzofuranols 4a‐h in 68–84% yields. Similarly, irradiation of 2a‐e afforded dihydrobenzofuranols 8a‐e in 72–75% yields. Ethyl acrylates 9b‐c were also produced in 6–8% yields from photoreactions of 2b‐c. Substituent effects on cyclization of 1,5‐biradical intermediates and reaction pathways are discussed. Benzophenones are useful compounds to prepare dihydrobenzofuranols by photocyclization.
Synthesis of 10‐amino‐1,2,3,4‐tetrahydrobenzo[b][1,6]‐naphthyridines and related derivatives
Authors: Gatta Franco , Giudice Maria Rosaria Del , Mustazza Carlo
Published: March 2009

This paper describes the synthesis of some 10‐amino‐1,2,3,4‐tetrahydrobenzo[b][1,6]naphthyridines and of the new 13‐amino‐6,6a,7,8,9,10‐hexahydro‐12H‐benzo[b]pyrido[1,2‐g][1,6]naphthyridines starting from isatins and 4‐piperidones or quinolizidin‐2‐one.
Aroylation of 5‐amino‐2H‐1,2,4‐thiadiazolin‐3‐one
Authors: Cho Nam Sook , Ra Chan Soo , Ra Do Young , Song Jin Soo , Kang Sung Kwon
Published: March 2009

2‐Aroyl‐5‐aroylamino‐1,2,4‐thiadiazolin‐3‐ones 2 have been synthesized through aroylation of 5‐amino‐2H‐1,2,4‐thiadiazolin‐3‐one (1) as an analog of cytosine. The aroylation was carried out with a substituted aroyl chloride in pyridine at 56–58°. It has been established that the intermediates of the reactions are 2‐aroyl‐5‐amino‐1,2,4‐thiadiazolin‐3‐ones 3 on the basis of the spectral data, additional experimental information and ab initio molecular orbital calculations.
Proton, carbon‐13 and fluorine‐19 NMR studies of 9,10,11,12‐tetra‐fluoro‐5,6‐dihydrobenzo[b]naphth[2,1‐f]oxepin: ‘Through‐space’ carbon‐fluorine coupling was revealed
Authors: Jones Claude R. , Parlow John J. , Schnur Dora M.
Published: March 2009

The 1H, 13C and 19F nmr spectra of 9,10,11,12‐tetrafluoro‐5,6‐dihydrobenzo[b]naphth[2,1‐f]oxepin (1) were totally assigned using a combination of two‐dimensional nmr techniques. Unequivocal interpretation of the spectral data allowed the complete assignments of the resonances. In addition, the spectra of compound 1 revealed an unusual through‐space carbon‐fluorine coupling which was further supported by NOE and modeling experiments.
Synthesis of 9‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]guanine, 1‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]cytosine and 9‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl] adenine
Authors: Kim Dae‐Kee , Gam Jongsik , Kim Key H.
Published: March 2009

The acyclic nucleoside phosphonate analogues, 9‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]guanine 6, 1‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]cytosine 7 and 9‐[(2‐hydroxy‐1‐phosphonylethoxy)ethyl]adenine 8, have been prepared by the coupling of a tosylate of the phosphonate side chain 12 with a purine or pyrimidine base followed by deprotection of the blocking groups.
Synthesis of thiazole‐containing polyethers
Authors: Kwon Il‐Chun , Koh Young Kook , Choi Jun‐Hyeak , Kim Hong‐Seok
Published: March 2009

Thiazole‐containing polyether podands were prepared from the reactions of hydroxymethylthiazole derivatives with di‐p‐tosylates of corresponding tri, terra, pentaethylene glycols in the presence of potassium hydride.