bluuebunny/crossref_metadata_2025_split huggingface dataset:
Furopyridines. XXX. Synthesis and reaction of difuro[3,2‐c:‐ 3′,2′‐e]pyridine, a new tricyclic heterocycle
Authors: Shiotani Shunsaku , Yamaguchi Seiji , Kurosaki Masahide , Yokoyama Hajime , Hirai Yoshiro 
Published: March 2009

AbstractDifuro[3,2‐c:3′,2′‐e]pyridine 1, a new tricyclic heteroaromatic, has been prepared for the first time. Bromination of 1 with molecular bromine gave 3‐bromo 7, 8‐bromo 7′ and 3,8‐dibromo derivative 8; nitration with fuming nitric acid yielded 2‐nitro compound 9, while nitration with a mixture of fuming nitric acid and sulfuric acid gave 2,7‐dinitro derivative 10; formylation with n‐butyllithium and dimethylformamide gave 2‐formyl 11, 7‐formyl 11′, and 2,7‐diformyl compound 12. The N‐oxide 14 of 1 afforded 4‐cyano compound 15 by cyanation with trimethylsilyl cyanide, 4‐chloro compound 16 by chlorination with phosphorus oxychloride, and 4‐acetoxyl compound 17 by acetoxylation with acetic anhydride.
Synthesis and antiviral evaluation of several 6‐(Methylene‐carbomethoxy)pteridine‐4,7(3H,8H)‐diones
Authors: Molina S. , Cobo J. , Sánchez A. , Nogueras M. , De Clercq E. 
Published: March 2009

AbstractThe reactions of 5,6‐diaminopyrimidin‐4(3H)‐one derivatives 1a‐h, with dimethyl acetylenedicarboxylate are discussed in this paper. 6‐Amino‐5‐(E)(1′,2′‐dicarbomethoxyvinyl)aminopyrimidines, 2, and 6‐(methylenecarbomethoxy)pteridinones, 3, have been obtained as main the products, which can be explained on the basis of a Michael addition on pyrimidine derivatives, and cyclization. Those compounds were evaluated for their in vitro antiviral activity.
Synthesis of spiro[1,4‐benzothiazine‐2,2′‐pyrans] starting from methyl β‐D‐arabino‐2‐hexulopyranosonate
Authors: Andersch Jens , Sicker Dieter , Wilde Horst 
Published: March 2009

AbstractDedicated to Professor Klaus Burger on the occasion of his 60th birthday Methyl β‐D‐arabono‐2‐hexulopyranosonate 1 has via the novel glycosyl donor 3 been transformed into the thiophenyl glycosides 4 and 5. Catalytic hydrogenation of the nitro compound 4 in alkaline solution led to spontaneous cyclization and deprotection to form the cyclic hydroxamic acid 7. The related lactams 8 and 9 were obtained from amine 5. The spiro[1,4‐benzothiazine‐2,2′‐pyrans] 7–9 are the first representatives of a novel class of heterocycles structurally related to bioactive natural products. As shown by the values for J3′,4′ and J4′,5′ the glycosides 4, 5 and 6 adopt a 5C2 conformation of the pyranoid ring whereas the 1,4‐benzothiazine system in 7–9 forces a conformational change into the 2C5 conformation.
Synthesis of tetracyclic and pentacyclic phenothiazines via benzotriazole methodology
Authors: Katritzky Alan R. , Agamy Samia , Yang Baozhen , Qiu Guofang 
Published: March 2009

AbstractTreatment of 10‐(benzotriazol‐1‐yl)alkylphenothiazine with electron‐rich alkenes in the presence of zinc bromide gave tetracyclic phenothiazines 4 and 9 as well as pentacyclic phenothiazines 5, which have potential use in the pharmaceutical industry.
Amalgam (Na.Hg) reduction of some 4‐Substituted‐2‐amino‐3,5‐dicyano‐6‐methoxypyridines. New evidence regarding the oxidation step in their synthesis
Authors: Fuentes LuÍS , Lorenzo Ma Jesús , Márquez César , Galakhov Mikhail 
Published: March 2009

AbstractThe amalgam (Na.Hg) reduction of some 4‐substituted‐2‐amino‐3,5‐dicyano‐6‐methoxypyridines 3 results in the formation, in high yields of 3,4‐dihydropyridines 2. Highfield 1H and 13C nmr studies provide unambiguous support for the structures proposed. The synthesis of C‐4 deuterium labeled dihydropyridine 2c‐D, by this procedure, let us understand the role played by this dihydropyridines as intermediates in the necessary oxidation path into the synthesis of pyridines 3 from malononitrile and benzylidenemalononitriles 1 in methanol/sodium methoxide.
Behavior of 5,6‐dihydrobenzo[h]cinnolinones towards hydrazine. Synthesis of benzo[h]cinnolinones and of 4‐Aminobenzo[h]cinnolinones
Authors: Villa Stefania , Evoli Giacomo Luca , Cignarella Giorgio , Curzu Michela M. , Pinna Gérard A. 
Published: March 2009

AbstractDehydrogenation and amination of 4,4a,5,6‐tetrahydro and 5,6‐dihydrobenzocinnolinones in refluxing hydrazine hydrate to give new benzo[h]cinnolinones and 4‐aminobenzo[h]cinnolinones are reported, and reaction mechanisms proposed. Experiments were also extended to 4,4a‐dihydro‐5H‐indenopyridazinone which underwent hydrazine induced dehydrogenation to 5H‐indenopyridazin‐3‐one but not subsequent amination.
Synthesis of new 6‐Aroylpyrido[2,3‐d]pyrimidines
Authors: Quiroga Jairo , Viveros GermÁN , Insuasty Braulio , Nogueras Manuel , Sánchez Adolfo , Cobo Justo 
Published: March 2009

AbstractThe synthesis of 6‐dimethylaminomethylenaminopyrimidin‐4(3H)‐ones 2 and its reaction with β‐dimethyl‐aminopropiophenone hydrochloride 3 is discussed in this work. The reaction of 6‐aminopyrimidin‐4(3H)‐ones 1 with an excess of dimethylformamide dimethyl acetal gives rise to the formation of 6‐dimethylaminomethyleneaminopyrimidines 2. The heating of equimolecular quantities of 2 and 3 in dimethylformamide leads to the 6‐aroylpyrido[2,3‐d]pyrimidines derivatives 4. The structures of compounds 2 and 4 were determined on the basis of nmr measurements.
Reactivity of p‐phenyl substituted β‐Enamino compounds using K‐10/ultrasound. II. Synthesis of isoxazoles and 5‐Isoxazolones
Authors: Valduga Claudete J. , Santis Denise B. , Braibante Hugo S. , Braibante Mara E. F. 
Published: March 2009

AbstractThe condensation of 4‐phenyl substituted β‐enamino ketones 1a‐d and β‐enamino esters 5a‐d with hydroxylamine hydrochloride using K‐10 as the solid support under sonication was studied to evaluate the formation of isoxazole and 5‐isoxazolone rings from β‐enamino compounds with a substituted aromatic ring. Isoxazoles 2a‐c, 3c‐d and 5‐isoxazolones 6a‐c and 7a‐d were obtained. The use of K‐10/ultrasound in this reaction furnished novel results in some cases.
Phenylsulfonyl‐methylenation of aldonolactones
Authors: Alzérreca Arnaldo , Hernández Eliud , Mangual Edgar , Prieto José A. 
Published: March 2009

AbstractThe low temperature addition of dilithiomethylphenyl sulfone to 2,3‐O‐isopropylidene‐D‐erythronolactone, and to 5‐O‐(tert‐butyldimethylsilyl)‐2,3‐O‐isopropylidene‐D‐ribofuranolactone gives the lactols 2 and 3a, respectively. Dehydration of lactol 2 in the presence of boron trifluoride etherate produces tetrahydrofuranylidene sulfones 5 and 6 in good yields. The reaction of lactol 3a under the same reaction conditions proceeds with formation of the 1′,5′‐anhydro derivative 7 via competing intramolecular substitution.
The chemistry of 4H‐3,1‐benzoxazin‐4‐ones
Authors: Coppola Gary M. 
Published: March 2009

AbstractThe present review covers the synthesis and reactions of 4H‐3,1‐Benzoxazin‐4‐ones. Only those with carbon substituents at the 2‐position are included. Literature corverage includes publications primarily from the mid 1960's to May 1998.
Synthesis and spectral properties of 2,3‐dihydro‐2‐[(o‐ and p‐substituted)anilinylidene]‐1H‐4‐(p‐methylphenyl)‐7‐[(o‐ and p‐methyl)phenoxy]‐1,5‐benzodiazepines
Authors: Cortés Eduardo Cortés , Bravo Maria Paz Sánchez 
Published: March 2009

AbstractA series of twelve new 2,3‐dihydro‐2‐[(o‐ and p‐substituted)anilinylidene]‐1H‐4‐(p‐methylphenyl)‐7‐[(o‐ and p‐methyl)phenoxy]‐1,5‐benzodiazepines, which have potentially useful pharmacological properties, has been synthesized by condensing the 3,3‐dimercapto‐1‐(p‐methylphenyl)‐2‐propen‐1‐one with 3,4‐diaminophenyl‐R‐phenyl ethers. Subsequently the 1H‐1,5‐benzodiazepine‐2‐thiones obtained were treated with the (o‐ and p‐substituted)aniline. The structure of all products was corroborated by ir, 1H nmr, 13C nmr and ms.
Complete regioselective formation of 2‐(arylsulfinyl)diphenyl sulfides from 5‐arylthianthreniumyl perchlorates
Authors: Kim Jongyup , Kim Kab Sig , Kim Kyongtae 
Published: March 2009

AbstractTreatment of 5‐arylthianthreniurnyl perchlorates with potassium tert‐butoxide in dimethyl sulfoxide at room temperature gave 2‐(arylsulfinyl)diphenyl sulfides (29–79% yields), which are the first examples for complete regioselective formation of S‐monoxides from unsymmetrical arylthiodiphenyl sulfides.
N‐(2‐tetrahydrofuranyl)azole nucleoside analogs by reactions of azoles with dihalomethanes in tetrahydrofuran
Authors: Zadykowicz Jerzy , Potvin Pierre G. 
Published: March 2009

AbstractThe reactions of the mono‐N‐substituted bispyrazolylpyridine 2‐(1‐methyl‐4,5,6,7‐tetxahydroindazol‐3‐yl)‐6‐(2H‐4,5,6,7‐tetrahydroindazol‐3‐yl)pyridine, 3,5‐dimethylpyrazole and benzimidazole with sodium hydride and diiodomethane or dibromomethane in tetrahydrofuran produced the unexpectedN‐tetrahydrofuran‐2‐yl adducts as well as the expected diazolylmethanes. These side‐reactions are thought to involve the 2‐halo tetrahydrofuran derivative resulting from a free‐radical halogenation by the dihalomethane.
Synthesis of purinobenzodiazepine and purinobenzotriazocine derivatives, two new heterocyclic ring systems
Authors: Settimo Antonio Da , Primofiore Giampaolo , Marini Anna Maria , Settimo Federico Da , La Motta Concettina , Salerno Silvia 
Published: March 2009

AbstractThe preparation of two new heterocyclic ring systems, purinobenzodiazepine and purinobenzotriazocine derivatives by the condensation of 8‐aminotheophylline or 8‐hydrazinotheophylline with o‐carboxybenzaldehyde or o‐carboxyacetophenone is described.
Synthesis and NMR investigation of 3,4‐diazabicyclo[4.3.0]non‐2‐ene and N,N'‐azo‐3‐azabicyclo[3.3.0]octane. X‐ray crystal structure analysis of a new tetrazene derivative
Authors: Delalu H. , Elkhatib M. , Peyrot L. , Fenet B. , Mentzen B. F. 
Published: March 2009

Abstract3,4‐Diazabicyclo[4.3.0]non‐2‐ene and N,N'‐azo‐3‐azabicyclo[3.3.0]octane are the main products of the oxidation of N‐amino‐3‐azabicyclo[3.3.0]octane by chloramine. These new compounds have been isolated and characterized. A structural study has been performed with the goal of establishing the cis—trans configuration at the bicyclic junction. Multinuclear proton decoupling carried out on the endocyclic hydrazone has allowed the determination of the coupling constant of the bridgehead hydrogens. A low temperature conformational study shows splitting of the 13C signal of the carbon atom located α with respect to the ammonia nitrogen. This result, consistent with a cis structure, was confirmed by a nmr analysis conducted on the solid tetrazene derivative. The X‐ray data collection on a single cyrstal of the tetrazene has permitted us to determine the crystallographic properties of this compound. Data processing by direct methods reveals that the geometry of the molecule presents a cis configuration for the bicyclic bridge link and a trans one for the azo group, confirming thus the main results obtained by nmr studies.
Synthesis of some 2‐substituted‐thioxanthones
Authors: Moon Jung‐Kyen , Park Jung‐Won , Lee Woo Song , Kang Young‐Jin , Chung Hyun‐A , Shin Mi‐Seon , Yoon Yong‐Jin , Park Ki Hun 
Published: March 2009

AbstractThis paper presents the synthesis of 2‐amino‐, 2‐acetamido‐ and 2‐benzamidothioxanthones and their 10,10‐dioxides.
Synthesis, NMR spectroscopic and X‐ray crystallographic studies of functionalized 2‐aminopyrrolin‐4‐ones
Authors: Gola Anna , Samartzi Evangelia , Bardakos Vassilios , Petroliagi Margarita , Igglessi‐Markopoulou Olga , Markopoulos John , Barkley James V. 
Published: March 2009

AbstractAn efficient method for the preparation of novel cyano derivatives of 4‐amino‐3‐hydroxybutenoic acids 4–8 and N‐substituted‐2‐aminopyrrolin‐4‐ones 9–18 is described; the structure of compound 13 has been elucidated with X‐ray analysis.
Synthesis of 1,1‐bis(1,2,4‐triazol‐1‐yl)‐based potential aromatase inhibitors
Authors: Katritzky Alan R. , Pastor Alfredo , Voronkov Michael V. 
Published: March 2009

AbstractReactions of bis‐(1,2,4‐triazolyl) sulfoxide 2 with various carbonyl compounds 3 led to the formation of twelve corresponding 1,1 ‐bis‐(1,2,4‐triazolyl) compounds, with structures resembling closely some previously prepared aromatase inhibitors.
Pyrrolo[3,4‐e][1,2,3]triazolo[1,5‐a]pyrimidine and pyrrolo[3,4‐d] [1,2,3]triazolo[1,5‐a]pyrimidine. New tricyclic ring systems of biological interest
Authors: Lauria Antonino , Diana Patrizia , Barraja Paola , Almerico Anna Maria , Cirrincione Girolamo , Dattolo Gaetano 
Published: March 2009

AbstractDerivatives of the new ring system pyrrolo[3,4‐e][1,2,3] triazolo[1,5‐a]pyrimidine 6 were prepared in high yields in one step by reaction of 3‐azidopyrrole 3 and substituted acetonitriles. Compound 6b rearranged, upon heating in dimethyl sulfoxide in the presence of water, to pyrrolo[3,4‐d][1,2,3]triazolo‐[1,5‐a]pyrimidine 7.
Synthesis of N‐methyl‐4‐pyridyl‐1,2,3,4‐tetrahydroisoquinolines via a pictet‐spengler cyclisation
Authors: Prat Laurence , Levacher Vincent , Dupas Georges , Quéguiner Guy , Bourguignon Jean , Bureau Ronan , Daveu Cyril 
Published: March 2009

AbstractThe synthesis of N‐methyl‐4‐pyridyl‐1,2,3,4‐tetrahydroisoquinolines (6a,b,c) was achieved via a Pictet‐Spengler cyclization of an activated amino group derivatized in a carbamate form. The obtained compounds have been designed as potential serotonin analogs.
An improved procedure for the synthesis of 4,4‐disubstituted‐3‐oxo‐1,2,5‐thiadiazolidine 1,1 ‐dioxides
Authors: Xiao Zejun , Timberlake Jack W. 
Published: March 2009

AbstractAn improved synthesis for the preparation of 3‐oxo‐1,2,5‐thiadiazolidine 1,1‐dioxides has been developed. This facile two‐step procedure fromα‐amino acid esters and chlorosulfonyl isocyanate results in excellent yields of products.
Synthesis of bicyclic azacompounds (3‐dimethylcarbamoyloxyphenyl) substituted as acetylcholinesterase inhibitors
Authors: Borioni Anna , Giudice Maria Rosaria Del , Mustazza Carlo , Gatta Franco 
Published: March 2009

AbstractThis paper describes the synthesis of some bicyclic 2‐(3‐dimethylcarbamoyloxyphenyl) substituted azaderivatives, obtained from 1,4‐ and 1,5‐diketones, which were cyclized with ammonium acetate, methylamine and by reductive amination. Corresponding 3‐substituted derivatives were instead prepared by reaction of 1,5‐ketoesters with formamide. The carbamates were tested as in vitro acetylcholinesterase inhibitors.
1H and 13C spectral assignment of naphtho[2′,1′:5,6]‐naphtho[2′,1′:4,5]thieno[2,3‐c]quinoline using the IDR‐GHSQC‐TOCSY experiment
Authors: Hadden Chad E. , Martin Gary E. , Luo J.‐K. , Castle Raymond N. 
Published: March 2009

AbstractThe assignment of the NMR spectra of the polynuclear heteroaromatic naphtho[2′,1′:5,6]naphtho‐[2′,1′:4,5]thieno[2,3‐c]quinoline is reported. The analysis was based on the homonuclear ROESY, heteronuclear direct GHSQC, IDR‐GHSQC‐TOCSY, and long‐range GHMBC experiments. The complete 1H and 13C shift assignments are reported.
Ring‐ring interconversions. Part 3. On the effect of the substituents on the thiazole moiety in the ring‐opening/ring‐closing reactions of nitrosoimidazo[2,1‐b][1,3]thiazoles with hydrochloric acid
Authors: Billi Roberta , Cosimelli Barbara , Spinelli Domenico , Leoni Alberto 
Published: March 2009

AbstractThe reaction of 6‐(4‐chlorophenyl)‐5‐nitrosoimidazo[2,1‐b][1,3]thiazole 1b, 6‐(4‐chlorophenyl)‐2‐methyl‐5‐nitrosoimidazo[2,1‐b][1,3]thiazole 1c, 6‐(4‐chlorophenyl)‐2,3‐dimethyl‐5‐nitrosoimidazo‐[2,1‐b][1,3]thiazole 1d and 2‐(4‐chlorophenyl)‐3‐nitrosobenzo[d]imidazo[2,1‐b][1,3]thiazole 1e with hydrochloric acid has been carried out in order to investigate the effect of substituents on the thiazole ring in a recently reported ring‐ring interconversion reaction. In every case the corresponding [1,4]‐thiazino[3,4‐c][1,2,4]oxadiazol‐3‐ones 2b‐e have been obtained. In particular, the benzoderivative 1e furnished the 4‐(4‐chlorophenyl)‐4‐hydroxy‐4H‐benzo[5,6][1,4]thiazino[3,4‐c][1,2,4]oxadiazol‐1‐one 2e, containing a new tricyclic system with a quasi‐planar geometry whose pharmacological potentialities appear promising.
Synthesis of optically active hydroxyalkylbenzothiazepinones by ring transformation of 2‐alkylidenelactons with o‐aminothiophenol
Authors: Otto Andreas , Liebscher Jürgen 
Published: March 2009

AbstractA stereoselective synthesis of new optically active 3‐(hydroxyalkyl)‐2,3‐dihydro‐1,5‐benzothiazepin‐4‐ones 4 and 7 was achieved by Michael‐like addition of o‐aminothiophenol to chiral α‐alkylidenelactons 1 and 5 followed by ring chain transformation of the resulting adducts 3 and 6.
Synthesis of 2,4‐diaminopyrido[2,3‐d]pyrimidines and 2,4‐diamino‐quinazolines with bulky dibenz[b,f]azepine and dibenzo[a,d]‐cycloheptene substituents at the 6‐position as inhibitors of dihydrofolate reductases from pneumocystis carinii, toxoplasma gondii, and mycobacterium avium
Authors: Rosowsky Andre , Fu Hongning , Queener Sherry F. 
Published: March 2009

AbstractThe synthesis of four previously undescribed 2,4‐diaminopyrido[2,3‐d]pyrimidines (3,4) and 2,4‐diaminoquinazolines (5,6) with a bulky tricyclic aromatic group at the 6‐position is described. Condensation of dibenz[b,f]azepine with 2,4‐diamino‐6‐bromomethylpyrido[2,3‐d]pyrimidine (8) and 2,4‐diamino‐6‐bromomethylquinazoline (17) in the presence of sodium hydride afforded N‐[(2,4‐diaminopyrido[2,3‐d]‐pyrimidin‐6‐yl)methyl]dibenz[b,f]azepine (3) and N‐[(2,4‐diaminoquinazolin‐6‐yl)methyl]dibenz[b,f]‐azepine (4), respectively. Condensation of 5‐chlorodibenzo[a,d]cycloheptene (19) and 5‐chloro‐10,11‐dihydrodibenzo[a,d]cycloheptene (20) with 2,4,6‐triaminoquinazoline (13) afforded 5‐[(2,4‐diamino‐quinazolin‐6‐yl)amino]‐5H‐dibenzo[a,d]cycloheptene (5) and the corresponding 10,11‐dihydro derivative (6), respectively. The bromides 8 and 17, as hydrobromic acid salts, were obtained from the corresponding nitriles according to a standard three‐step sequence consisting of treatment with Raney nickel in formic acid followed by reduction with sodium borohydride and bromination with dry hydrogen bromide in glacial acetic acid. Compounds 3–6 were evaluated in vitro for the ability to inhibit dihydrofolate reductase from Pneumocystis carinii, Toxoplasma gondii, Mycobacterium avium, and rat liver. Compounds 3 and 4 were potent inhibitors of all four enzymes, with IC50 values in the 0.03–0.1 μM range, whereas 5 was less potent. However the selectivity of all four compounds for the parasite enzymes relative to the rat enzyme was<10‐fold, whereas the recently reported lead compound in this series, N‐[(2,4‐diaminopteridin‐6‐yl)methyl]dibenz[b,f]azepine (1) has > 100‐fold selectivity for the T. gondii and M. avium enzyme and 21‐fold selectivity for the P carinii enzyme.
Attempted synthesis of a tenidap isomer and formation of an unexpected stable water adduct
Authors: Esses‐Reiter Klára , Reiter József 
Published: March 2009

AbstractAn attempt to synthesize the Tenidap isomer 13 was performed starting from 2‐ethoxy‐5‐chloroindole (9). The acylation and carbamoylation reactions of 9 led to the expected intermediate 12, however the hydrolysis of 12 in acidic or alkaline media did not yielded the expected 13. Instead an unusually stable water adduct 18 or the cleavage product 16 was formed. The formation of the unexpectedly stable water adduct 18 was caused by the steric and electronic effect of the thienoyl group in position 1 as proved by the hydrolysis of 10 and 16.
Synthesis of a novel ring‐expanded nucleoside analogue containing the imidazo[4,5‐e][1,3]diazepine ring system with a guanidinocarbamoyl‐substituted cyclopropylidene group in place of a sugar moiety
Authors: Chen Huan‐Ming , Hosmane Ramachandra S. , Baldisseri Donna M. 
Published: March 2009

AbstractThe synthesis of a novel ring‐expanded nucleoside analogue, (Z)‐1‐((2‐Guanidinocarbamoyl‐cyclopropylidene)methyl)‐4,5,7,8‐tetrahydro‐6H‐6‐iminoimidazo[4,5‐e][1,3]diazepine‐4,8‐dione (1) has been reported. It was prepared starting from methyl imidazole‐4,5‐dicarboxylate by sequential condensations with 2‐bromo‐2‐bromomethylcyclopropane‐1‐carboxylate and guanidine. The overall yield for the two‐step synthesis is 46%.
Synthesis of 1,4,2‐benzodithiazine carboxylates via ring expansion reaction of 1,3‐benzodithioles
Authors: Stanetty Peter , Hattinger Gregor , Mihovilovic Marko D. , Mereiter Kurt 
Published: March 2009

AbstractA straight forward synthesis of the 1,4,2‐benzodithiazine system bearing an ester functionality as potential inducers of systemic acquired resistance in plants was developed utilizing the ring expansion reaction of 1,3‐benzodithioles. The structure of the isomers obtained was established using x‐ray diffraction. The reactivity of the products towards activated alkynes and ring contraction reactions in the presence of base is discussed.
Syntheses of thiopyrone and pyrone derivatives by photocyclization reaction of 3‐aryl‐2‐( Benzothien‐3‐yl)propenoic acids
Authors: Sasaki Kenji , Satoh Yasuyoshi , Hirota Takashi , Nakayama Taiji , Tominaga Yoshinori , Castle Raymond N. 
Published: March 2009

AbstractNaphtho[1,2‐b][1]benzothiophene‐6‐carboxylic acids, 6H‐benzo[b]naphtho[2,3‐d]thiopyran‐6‐ones and 6H‐benzo[b]naphtho[2,3‐d]pyran‐6‐ones were synthesized in one step by the photocyclization reaction of 3‐aryl‐2‐([1]benzothien‐3‐yl)propenoic acids. The photocyclization reaction did not occur when the 3‐aryl group contained the electron‐withdrawing nitro group. The assignment of the 1H and 13C nmr spectra of 6H‐benzo[b]naphtho[2,3‐d]thiopyran‐6‐one and 6H‐benzo[b]naphtho[2,3‐d]pyran‐6‐one by two‐dimensional nmr methods is described. The difference between the chemical shift values of H12 for these two compounds is attributed to different molecular geometries.
Studies on the reactivity of new types of tetracyclic‐1,5‐benzoxazepines: Part V
Authors: Sekhar Batchu Chandra , Ramana Devalla Venkata , Ramadas Sukuru Raghu 
Published: March 2009

AbstractThe syntheses of tetracyclic 1,5‐benzoxazepines 3a‐e from heterocyclic (3‐chloroaldehydes 1a‐e and 2‐aminophenol are reported herein (Scheme I). Attempted lithium aluminium hydride (LiAlH4) reduction of the imine double bond in 3a‐e failed to furnish the corresponding saturated compounds 5a‐e. Attempted catalytic hydrogenation of 3a‐e in the presence of acetic acid and acetic anhydride gave surprisingly only the acetoxy derivatives 6a‐e in high yields (Scheme II). Base catalysed hydrolysis of acetoxy derivatives 6a‐e furnished, as expected, the corresponding phenolic derivatives 7a‐e, in moderate yields. Attempted cyclofunctionalization of 3a‐e either with mercaptoacetic acid or its methyl ester to obtain the new penta‐cyclic heterocycles 4a‐e was, however, not successful.
Synthesis of novel 5H‐Pyrimido[5,4‐b]mdole‐(1H,3H)2,4‐diones as potential ligands for the cloned α1‐adrenoceptor subtypes
Authors: Romeo G. , Russo F. , De Blasi A. 
Published: March 2009

AbstractA new series of 3‐[ω‐[4‐(4‐substituted phenyl)piperazin‐1‐yl]alkyl]‐5H‐pyrimido[5,4‐b]indole‐(1H,3H)‐2,4‐diones (3–10and12–13) were synthesized from theN‐(2‐chloroethyl)‐N'‐[3‐(2‐ethoxycarbonyl)indolyl] urea (1) or theN‐(3‐chloropropyl)‐N'‐[3‐(2‐ethoxycarbonyl)indolyl] urea (2) and a number of 1‐(4‐substi‐tuted‐phenyl)piperazines. 3‐[2‐[4‐(4‐Aminophenyl)piperazin‐1‐yl]ethyl]‐5H‐pyrimido[5,4‐b]indole‐(1H,3H)2,4‐dione (14) was obtained by reduction of the parent nitro compound8. The obtained 5H‐pyrimido[5,4‐b]indole‐(1H,3H)2,4‐dione derivatives were tested towards cloned α1A, α1Band α1Dadrenergic receptors subtypes in binding assays. Some compounds showed good affinity and selectivity for the α1D‐adrenoceptor subtype.
On triazoles XLIII. Synthesis of 1,2,4‐triazolyl isoquinolinium zwitter ions
Authors: Prauda Ibolya , Kövesdi István , Trinka PÉTer , Reiter JÓZsef 
Published: March 2009

AbstractType 8 isoquinolinium zwitter ions were synthesised by the reaction of type 1 diketones or type 2 pyrylium salts with different 5‐amino‐3‐Q‐1H‐1,2,4‐triazoles. Spectroscopic and X‐ray diffraction evidence was given for the zwitter ion structure of the products obtained. The position of the negative charge on the 1,2,4‐tiazolium ring was proved by comparison of the cmr and uv spectra of the products obtained with the three possible N‐benzyl derivatives 14–16 prepared for this purpose.