bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on nitrogen containing heterocyclic compounds.XVII. Synthesis of 8H‐diimidazo[1,5‐a:2′,1′‐c][1,4]benzodiazepine, a novel tetracyclic ring of pharmaceutical interest
Authors: Stefancich Giorgio , Artico Marino , Silvestri Romano 
Published: March 2009

AbstractThe synthesis of 8H‐diimidazo[1,5‐a:2′,1′‐c][1,4]benzodiazepine6, a novel nitrogen‐containing tetracyclic ring, is reported starting from 5H‐imidazo[2,1‐c][1,4]benzodiazepine7.Reaction of this compound with nitromethane and subsequent reduction of the obtained nitromethyl derivative8afforded 11‐aminomethyl‐10,11‐dihydro‐5H‐imidazo[2,1‐c][1,4]benzodiazepine9.Treatment of the latter compound with formaldehyde led to 1,2,3,3a‐tetrahydro‐8H‐diimidazo[1,5‐a:2′,1′‐c][1,4]benzodiazepine10, which was then oxidized to the title compound.
Oxidation of (7,16‐diethyl‐5,6,7,8,9,14,15,16,17,18‐decahydrodibenzo[b,i][1,4,8,11]tetraazacyclotetradecine)nickel(II) complexes
Authors: Hashimoto Mamoru , Sakata Kazunori 
Published: March 2009

AbstractThe oxidation reaction of two isomers of (7,16‐diethyl‐5,6,7,8,9,14,15,16,17,18‐decahydrodibenzo[b,i]‐[1,4,8,11]tetraazacyclotetradecine)nickel(II) diperchlorate and/or dichloride (NiL1X2 (X = ClO4, Cl)) in methanol in air under atmospheric pressure leads to the production of (7,16‐diethyl‐5,6,7,8,9‐pentahydrodibenzo‐[b,i][1,4,8,11]tetraazacyclotetradecinato)nickel(II) complexes (NiL2X). Proton and 13C nmr spectra suggest that NiL2X is formed by partial oxidation from a macrocyclic skeleton of NiL1X2. The dehydrogenation of NiL1X2 does not occur at symmetric positions such as d‐ and k‐positions of the macrocyclic skeleton but at unsymmetrical positions such as d‐ and f‐positions. Treatment of NiL1X2 and/or NiL2X in a methanol solution with an excess of bases in air gives (7,16‐diethyldibenzo[b,t][1,4,8,11]tetraazacyclotetradecinato)nickel(II) (NiL3).
Mass spectrometry of 3,4‐dihydroquinazolin‐4‐ones of pharmaceutical interest. Part 3. Electron ionization mass spectra of 2‐substituted‐3‐(5′‐pyrazolyl)‐4(3H)‐quinazolinones
Authors: Ferrugia Mirella , Bajardi Maria Luisa , Ceraulo Leopoldo , Plescia Salvatore 
Published: March 2009

AbstractThe fragmentation reactions induced by electron impact of eighteen title compounds has been investigated with the aid of low beam energy spectra (14 eV, nom. value), metastable ion detection, high resolution measurements and labelling experiments. The loss of the 4‐carbonyl oxygen together with the 3‐substituent, which constitutes a characteristic fragmentation route of 3‐aryl and 3‐heteroaromatic substituted‐4(3H)‐quinazolinones, is again observed, but the presence of a carboxyethyl group at the 4′‐position of the pyrazole ring is responsible of an anomalous loss of 47 daltons from the molecular ion. Lastly, a comparison with the previously described behaviour of 3‐(5′‐isoxazolyl) derivatives was carried out.
Study of the diazoimine/triazole equilibria for substituted thiazoles and thiadiazoles
Authors: L'Abbé Gerrit , Luyten Ingrid , Toppet Suzanne 
Published: March 2009

AbstractSeveral diazomethyl and diazoester substituted thiazoles and thiadiazoles were prepared and their ring/chain equilibria studied by nmr spectroscopy. The diazomethyl derivatives 17a,b,d and 19a exist predominantly or exclusively in the triazole form. Ring‐opening is promoted by introducing an ester group at the diazo function (17c,e, 19b, 21) or by changing thiazoles for thiadiazoles in the following order: thiazole < 1,3,4‐thiadiazole < 1,2,4‐thiadiazole. The diazoimine/triazole equilibria are also shifted towards the diazo form by raising the temperature and by using less polar solvents in the order: dimethyl sulfoxide < acetonitrile < chloroform < benzene. The ir spectra (potassium bromide discs) of the compounds indicate that they all, except 21, exist in the crystalline state in the triazole form.
NMR studies of bond orders in heteroaromatic systems
Authors: Gready Jill E. , Hatton Paul M. , Sternhell Sever 
Published: March 2009

AbstractFifty‐seven values for the ortho‐benzylic coupling constant 4JMeCCH (henceforth denoted as 4JOB) were obtained for a variety of heteroaromatic systems. It was shown that a good correlation exists between 4JOB when the methyl group is not α to the heteroatom and the SCF‐MO bond order. This method can therefore be used as an experimental means of determining bond orders in heteroaromatic systems. An examination of bond alternation in thirteen heteroaromatic systems has given a measure of relative “degree of aromaticity” for a larger number of systems than previously reported by any single method.
Synthesis and crystal structure analysis of a 6aλ4‐thia‐1,2,3,4,6‐pentaazapentalene
Authors: L'abbé Gerrit , Albrecht Ernestine , Feneau‐Dupont J. , Declercq J.‐P. 
Published: March 2009

Abstract6aλ4‐Thia‐1,2,3,4,6‐pentaazapentalenes 3 are conveniently prepared by reacting 5‐imino‐Δ3‐1,2,4‐thiadi‐azolines 2 with aromatic diazonium tetrafluoroborates in the presence of pyridine. The first crystal structure analysis of this class of compounds 3g is described and shows properties characteristic of a thiapentalene structure; i.e. long N‐S‐N bonds (1.85 and 1.975 Å) in a nearly linear arrangement (164°) and comprising a heterobicycle which is strictly planar.
Acetylenic chemistry. Part 24. N‐vinylation of N‐H acid heterocycles
Authors: Reisch Johannes , Dittmann Stefan 
Published: March 2009

AbstractThe vinylation of 9H‐carbazole (1), 1H‐indole (3a), and 1H‐pyrrolo[2,3‐b]pyridine (3b) with propiolic acid ethyl ester resulting in N‐acrylic esters is reported here.
The reactivity of 3‐methyl‐5‐phenylisothiazole with carbonyl compounds
Authors: Alberola Angel , Calvo Luis , Rodríguez Rodríguez M. Teresa , Carmen Sañudo M. 
Published: March 2009

AbstractThe reactivity of 3‐methyl‐5‐phenylisothiazole with carbonyl compounds in the presence of n‐butyllithium and the system lithium isopropylcyclohexylamide‐N,N,N',N'‐tetramethylethylendiamine (LICA‐TMEDA) is studied. n‐Butyllithium is found to lead to higher yields of the hydroxy derivatives of the isothiazole compound than LICA‐TMEDA. Ring opening products are not detected under the reaction conditions used.
Electrophilic benzylation of the pyridine ring. Action of benzyl chlorides on 2‐amino and 2‐benzylaminopyridine
Authors: Kowalski Piotr 
Published: March 2009

AbstractThe reaction of 2‐aminopyridine as well as 2‐benzylaminopyridine hydrochloride with benzyl chlorides used in molar ratio of 1:2 and 1:1 respectively and carried out at 250° leads via 2‐benzylamino‐5‐benzylpyri‐dines to 2‐amino‐5‐benzylpyridines as the final products. The formation of 2‐benzylamino‐5‐benzylpyridines did not occur in the direct C‐benzylation reaction of the 2‐benzylaminopyridine ring with the use of benzyl chloride. Its formation takes place via the intermediate state of 2‐(N,N‐dibenzylamino)pyridinium and 1‐benzyl‐2‐benzylaminopyridinium chlorides for which the solvent separated ion‐molecule form is proposed. Interaction of the ingredients of the intermediate state i.e., benzyl cation and 2‐benzylaminopyridine, leads in an electrophilic mechanism to the formation of 2‐benzylamino‐5‐benzylpyridine hydrochlorides. Thermolysis of the aminomethylene bond in 2‐benzylamino‐5‐benzylpyridine hydrochlorides leads to the final 2‐amino‐5‐benzylpyridines.
Reaction of nitriles under acidic conditions. Part VII. Study on the reaction of o‐aminonitriles with cyanamides to synthesize 2,4‐diaminothieno[2,3‐d]pyrimidines
Authors: Shishoo C. J. , Jain K. S. 
Published: March 2009

AbstractThe reaction of N‐arylcyanamides with thiophene o‐aminonitriles under the influence of dry hydrogen chloride gas yields a mixture of two products. The major product has been identified as 2‐amino‐3‐aryl‐4‐iminothieno[2,3‐d]pyrimidine and the minor as 2‐amino‐3‐arylthieno[2,3‐H]pyrimidin‐4(3H)‐one.
Identification of a 4H‐benz[f]indole by‐product from the friedel‐crafts‐based synthesis of benzoylpyrrole calcium channel activators
Authors: Huber Edward W. , Barbuch Robert J. , Dalton Christopher R. , Kane John M. , Velayo Nelson L. 
Published: March 2009

Abstract9,9a‐Dihydro‐2,9a‐dimethyl‐4‐oxo‐4H‐benz[f]indole‐3‐carboxylic acid, methyl ester was formed in varying amounts from the Friedel‐Crafts‐based synthesis of benzoylpyrrole calcium channel activators. The structure of this by‐product was determined using two‐dimensional long‐range1H‐13C heteronuclear correlated and INADEQUATE nmr techniques.
Preparation of 4‐substituted 1,3‐oxathiolan‐5‐ones via the sulphenium ion intermediate generated by the pummerer rearrangement
Authors: Frechina J. V. , Palanca P. , Picher T. , Sanz V. , Ramirez J. A. 
Published: March 2009

Abstract4‐Substituted 1,3‐oxathiolan‐5‐ones have been synthesized via the Pummerer rearrangement from the S‐oxide of the parent molecule. The 4,5‐dione is obtained in the presence of pyridine N‐oxide.
Synthesis of methyl derivatives of new polycyclic systems of 4H‐furo[3,2‐g]pyrrolo[3,2,1‐ij]quinolin‐4‐one, of 1H,5H‐ and 3H,5H‐benzofuro[5,6,7‐ij]quinolizin‐5‐one
Authors: Rodighiero P. , Bandoli G. , Chilin A. , Manzini P. , Guiotto A. 
Published: March 2009

AbstractThe synthesis of new tetracyclic 4H‐furo[3,2‐g]pyrrolo[3,2,1‐ij]quinolin‐4‐ones, 15–17, 1H,5H‐benzofuro[5,6, 7‐ij]quinolizin‐5‐ones, 18–20, and 3H,5H‐benzofuro[5,6,7‐ij]quinolizin‐5‐ones, 21–23 is described. The planarity of the structure of benzofuroquinolizin‐5‐one 18 was determined by X‐ray single‐crystal analysis.
Structural elucidation of an oxazolo[5,4‐b]pyridine: An alternative cyclization product related to nevirapine
Authors: Norman Mark H. , Minick Douglas J. , Martin Gary E. 
Published: March 2009

AbstractAn unexpected cyclization product was isolated in the final step of the synthesis of nevirapine, a non‐nucleoside inhibitor of HIV‐1 reverse transcriptase. Based on infrared spectrometry, mass spectrometry, and a number of two‐dimensional nmr experiments, the structure of this product was assigned to be 2‐((2′‐cyclopropylamino)‐3′‐pyridyl)‐7‐methyloxazolo[5,4‐b]pyridine, 9. Results of a single crystal X‐ray analysis confirmed this structural assignment. This product arises from cyclization of N‐(2‐chloro‐4‐methyl‐3‐pyridyl)‐2‐(cyclopropylamine)‐3‐pyridinecarboxamide, 8, by displacement of the chlorine with the amide carbonyl oxygen. A competitive reaction occurs when 8 is deprotonated prior to cyclization to form nevirapine, 11‐cyclopropyl‐5,11‐dihydro‐4‐methyl‐6H‐dipyrido[3,2‐b:2′,3′‐e][1,4]diazepin‐6‐one, 2.
Synthesis of 5,6‐ and 5,7‐dichloro‐3‐methyl‐4H‐1,4‐benzothiazines and their conversion into sulfones
Authors: Gupta R. R. , Saraswat Vandana , Gupta Vandana , Rajoria C. M. , Gupta Archana , Jain Mukesh 
Published: March 2009

AbstractA one pot synthesis of 5,6‐ and 5,7‐dichloro‐3‐methyl‐4H,4‐benzothiazines is reported by the condensation and oxidative cyclization of 2‐amino‐3,4‐ and 3,5‐dichlorobenzenethiols with β‐dicarbonyl compounds. The oxidation of 4H‐1,4‐benzothiazines by 30% hydrogen peroxide in glacial acetic acid has provided the corresponding sulfones. The effect of the conversion of the sulfide linkage to sulfone is discussed. The structure of all the newly synthesized compounds has been confirmed by elemental analysis and spectral studies.
Synthesis of imidazo[4,5‐b]quinoxaline 3‐oxides from reactions of furazano[3,4‐b]quinoxaline 1‐oxides with nitrones and diazo compounds
Authors: Gallos John K. , Malamidou‐Xenikaki Elizabeth , Lianis Pygmalion S. , Spyrou Labros I. 
Published: March 2009

AbstractThe title compounds are prepared in good yields by simple procedures from readily available starting materials. They can be easily O‐methylated by methyl iodide or deoxygenated by triphenylphosphine.
Methylation of 5‐Phenyl‐1,4‐benzodiazepin‐2‐one derivatives with N,N‐dimethylformamide‐dimethyl acetal
Authors: Pinto Julia C. , Fryer R. Ian 
Published: March 2009

AbstractA novel method for N‐methylation of the cyclic amide in the 1,4‐benzodiazepine ring system is presented. Methods traditionally used involve treatment of the 1,4‐benzodiazepinone anion with an alkyl halide. It has been demonstrated that these derivatives can be methylated on the amide nitrogen atom by use of dimethyl‐formamide dimethyl acetal which acts as both reagent and solvent for the reaction.
Novel oxidations of 1,3‐disubstituted indoles
Authors: Morales‐Ríos Martha S. , Bucio‐Vásquez Ma. Alvina , Joseph‐Nathan Pedro 
Published: March 2009

AbstractA study of oxidation versus nitration of 1,3‐disubstituted indole derivatives with nitric acid in acetic acid was carried out. Oxidation of methyl and ethyl 2‐cyano‐2‐(1‐alkoxycarbonyl‐1H‐indol‐3‐yl)acetates 1 and 2 under the above conditions gave rise to novel functionalized 2‐hydroxyindolenines as single products possessing the Z‐configuration, 8 and 10, respectively. The structure of 10 was determined by an X‐ray analysis. In contrast, 1‐methoxycarbonyl‐1H‐indol‐3‐acetonitrile (3) was nitrated to the corresponding 6‐nitroindole derivative 11, whereas the reaction of ethyl 2‐cyano‐2‐(1‐methyl‐1H‐indol‐3‐yl)acetate (4) with nitric acid effected an oxidative nitration to provide the corresponding ethyl Z‐5‐nitroisatyliene cyanoacetate (12), which in solution isomerized to the E isomer.
Synthesis and complexing properties of bis‐crown ethers incorporating benzo‐15‐crown‐5 and metallocene
Authors: Izumi Taeko , Oohashi Satoshi , Tate Yasuhiro 
Published: March 2009

AbstractBis‐crown ethers in which the benzo‐15‐crown‐5 units were linked to 1,1′‐positions of metallocene (M = Fe or Ru) with amide, ester, or CC bonds were synthesized. Complexing ability of the compounds with alkali, alkali earth, and transition metal cations were measured by the solvent extraction method. The results showed that these crown ethers had high affinity toward alkali metal cations (Li+, Na+, K+, and Rb+) and heavy‐metal cations (Ag+ and Tl+). The difference of complexing ability for metal cations between ferrocene and ruthenocene derivatives could not be detected significantly. The extractability of metallocene‐bis‐crown ethers for metal cations was more larger than that of the corresponding mono‐crown ethers, and irregular increments of extractability were explained by assuming the existence of a mixture of 1:1 and 2:1 complexes.
Cyclic β‐enamino esters dialkylation: A new route to cyclic imines
Authors: Eugene Marina , Celerier Jean‐Pierre , Ronzani Nello , Lhommet Gérard 
Published: March 2009

AbstractThe bis‐alkylation of cyclic β‐enamino esters has been investigated, and exploited as a general method of synthesis of cyclic monosubstituted imines.
Synthesis of 5‐phenyl‐2,3,8,9‐tetramethoxy‐11H‐indeno[1,2‐c]isoquinoline
Authors: Ibañez Adriana F. , Martinez Andrea R. , Iglesias Graciela Y. Moltrasio 
Published: March 2009

AbstractA novel approach to the title compound 10 starting with a conveniently available cinnamic acid is proposed. It involves a Friedel‐Crafts reaction followed by the synthesis of the amide and subsequent cyclodehydration via a Bischler‐Napieralski reaction.
Acetylene chemistry. Part 27. Palladium catalysed CC bond formation between quinoline and mono‐substituted alkynes: Synthesis of 4‐alkynyl‐2‐bromoquinolines
Authors: Reisch Johannes , Gunaherath G. M. Kamal B. 
Published: March 2009

AbstractSix new 4‐alkynyl‐2‐bromoquinolines have been synthesised via palladium catalysed CC bond formation between 2,4‐dibromoquinoline and mono‐substituted alkynes. Position of the alkyne substituent was confirmed to be at C‐4 by an nOe experiment on some methoxy derivatives prepared by nucleophilic displacement of bromo substituent.
On the syntheses and some reactions of bis‐ and tris(methylthio)thiophenes
Authors: Gronowitz Salo , Temciuc Marcel , Hörnfeldt Anna‐Britta 
Published: March 2009

AbstractReaction between various thienyllithium derivatives and dimethyl disulfide has been used for the preparation of 2,5‐, 2,3‐, and 3,4‐bis(methylthio)thiophenes, as well as 2,3,4‐ and 2,3,5‐tris(methylthio)thiophenes. Bromination of (methylthio)thiophenes with N‐bromosuccinimide was found to be most convenient for the preparation of brominated (methylthio)thiophenes such as 3‐bromo‐2,5‐bis(methylthio)‐ and 5‐bromo‐2,3‐bis(methylthio)thiophene, 3,4‐dibromo‐2,5‐bis(methylthio)‐, 2,5‐dibromo‐3,4‐bis(methylthio)‐ and 2,3‐dibromo‐4,5‐bis(methylthio)thiophene as well as 3‐bromo‐2,4,5‐tris(methylthio)thiophene. The reaction of methylthio substituted thienyllithium derivatives with methyl chloroformate was used for the syntheses of methyl methylthio substituted thiophenecarboxylates and using 1/3 of an equivalent for the direct preparation of methylthio substituted 3‐thienylcarbinols as tris[2,4,5‐tris(methylthio)‐3‐thienyl]carbinol.
Manganese(III) acetate oxidation of 1‐acetylindole derivatives
Authors: Izumi Taeko , Kohei Kunihiro , Murakami Satoshi 
Published: March 2009

AbstractIn the presence of malonic acid, the reaction of 1‐acetylindole (2) with manganese(III) acetate resulted in the formation of 4‐acetyl‐3,3a,4,8b‐tetrahydro‐2H‐furo[3,2‐b]indol‐2‐one (5). The same reaction of 1‐acetyl‐2,3‐dimethylindole yielded a mixture of 2‐acetoxymethyl‐1‐acetyl‐3‐methylindole and 4‐acetyl‐3a,8b‐dimethyl‐3,3a,4,8b‐tetrahydro‐2H‐furo[3,2‐b]indol‐2‐one, furthermore, the oxidation of 1‐acetylindoline proceeded to the formation of 2, 5 and 1‐acetylindoline‐5‐carboxylic acid.
Haloacetylated enol ethers. 2. Synthesis of 5‐trifluoromethylpyrazoles
Authors: Braibante Mara E. F. , Clar Gunter , Martins Marcos A. P. 
Published: March 2009

Abstract1‐Methyl‐5‐(trifluoromethyl)‐1H‐pyrazoles 2, 3 and 4,5‐dihydro‐1‐phenyl‐5‐(trifluoromethyl)‐1H‐pyrazol‐5‐ol 4 were prepared by reaction of 4‐alkoxy‐1,1,1‐trifluoro‐3‐alken‐2‐ones 1 and hydrazine, methylhydrazine, and phenylhydrazine, respectively, in good yields. Compound 1 proved to be a versatile building block for the regiospecific construction of pyrazole rings having an 5‐trifluoromethyl substituent.
Natural product chemistry. Part 160. Synthesis of 8‐, 9‐, 10‐ and 11‐methylacronycines to improve the cytostatic activity of acronycine
Authors: Reisch Johannes , Dziemba Peter , Adam Thomas 
Published: March 2009

AbstractWith the help of drug design, 8‐, 9‐, 10‐ and 11‐methylacronycines 24, 25, 26 and 27 have been selected and synthesised to improve the cytostatic potency of acronycine (31). The condensation of phloroglucinol with 6‐methylanthranilic acid gave 7‐hydroxy‐1,9‐dimethyldibenzo[b,j][1,7]phenanthroline‐8,14(5H,13H)‐dione (32) as the main product.
Synthesis of [1,5]benzothiazepine derivatives
Authors: Letois Bertrand , Lancelot Jean‐Charles , Saturnino Carmela , Robba Max , De Caprariis Paolo 
Published: March 2009

AbstractVarious derivatives of 2,3‐dihydro[1,5]benzothiazepin‐4(5H)‐ones were synthesized. Alternative route for the synthesis of 5‐dimethylaminoethyl‐2,3‐dihydro[1,5]benzothiazepin‐4(5H)‐ones and 4‐dimethylaminopro‐poxy‐(2H,5H)‐[1,5]benzothiazepines are described.
Synthesis of 4‐(2‐chloroethyl)‐2,3‐dihydro[1,4]oxazino[2,3‐b]quinoline and 4‐(2‐chloroethyl)2,3‐dihydropyrido[2,3‐b][1,4]oxazine
Authors: Anderson Wayne K. , Dalvie Deepak K. 
Published: March 2009

AbstractThe title compounds were synthesized from 3‐[bis(2‐hydroxyethyl)amino]quinolin‐2(1H)‐one 11a and 3‐[bis(2‐hydroxyethyl)amino]pyridin‐2(1H)‐one 18 respectively. The preparation involved a tandem chlorination/cyclization reaction.
Regio‐ and stereoselective formation of tri‐ and tetrasubstituted tetrahydrofuranylidenes from hydroxy ketosulfones
Authors: Alzérreca Arnaldo , Martínez Judith , Velázquez Loyda , Prieto José A. , Arias LuÍS 
Published: March 2009

AbstractFour tri‐ and tetrasubstituted E‐1‐(benzenesulfonyl)‐1‐tetrahydrofuranylidenes 7‐10 were synthesized from their corresponding α′‐benzenesulfonyl‐γ‐hydroxyketones 1 in good yields. The examination of the regio‐and steroselectivity of these thermally induced reactions shows preference for both, the exocyclic nature of the double bond and the E‐geometry in all tetrahydrofuranylidenes described. Structural assignments are based on infrared, 1H nmr, 13C nmr, 2D 1H‐1H and 13C‐1H correlation spectra. In contrast to tetrahydrofuranylidenes 7‐10, hemiketal 6 shows no tendency towards dehydration under the thermal reaction conditions used. This paper discusses the extent and limitations of this method as a tool of synthetic utility for the regio‐and stereoselective preparation of the target compounds.
λ‐radiolysis of mitomycin c derivatives
Authors: Kuroda Tokuyuki , Hisamura Koji , Nakamizo Nobuhiro , Otsuji Yoshio 
Published: March 2009

AbstractThe λ‐Radiolysis reactions of mitomycin C (1) and its derivatives were studied in the hope of developing a radiation‐induced drug (RID). The λ‐radiolysis reactions were carried out in aqueous solutions under the condition where hydrated electron (e−aq) was generated as a principal reactive species. The competitive λ‐radiolysis studies revealed that the rate constants for the reactions of 1 with e−aq at room temperature was 3.6 × 1010 dm3 mol−1s−1. Among mitomycin C derivatives, the 5H‐6‐alkoxyimino derivatives 11 and 12, and compound 13 in which ring A of 1 has the 4‐hydroxy‐6‐hydroxyimino structure cleaved to give 1. The mechanic aspect of these λ‐radiolysis reactions is discussed.
New process for the synthesis of imidazo[4,5‐b]pyridine derivatives as potent orally active thromboxane a2 receptor antagonists
Authors: Nicolaï E. , Claude S. , Teulon J. M. 
Published: March 2009

AbstractA new synthetic route to prepare the 4‐[3‐(4‐chlorophenyl)methyl‐6‐chloroimidazo[4,5‐b]pyridin‐2‐yl]‐3,3‐dimethylbutanoic acid (UP 116‐77) is described. UP 116‐77 is a potent orally active TXA2/PGH2 receptor antagonist currently under pharmacological investigation. Its development needed a suitable synthesis for industrial processing. The cyclization of 3‐amino‐5‐chloro‐2‐(4‐chlorophenyl)methylaminopyridine 4 with 3,3‐dimethylglutaric anhydride in refluxing acetic acid affords a new efficient and simple way to UP 116‐77 and subsequently to various 2‐substituted imidazo[4,5‐b]pyridine derivatives.
Synthesis and structural determination of 5H‐benzocyclohepten‐5,8‐imines
Authors: Dicesare John C. , Burgess Jason P. , Mascarella S. Wayne , Carroll F. Ivy , Rothman Richard B. 
Published: March 2009

AbstractTreatment of 4‐hydroxy‐N‐methylisoquinolinium iodide with triethylamine in tetrahydrofuran or acetonitrile forms 2‐methyl‐4‐oxidoisoquinolinium (2)in situ.Once formed,2can be trapped with dipolarophiles possessing varying degrees of activation to form the 5H‐benzocyclohepten‐5,8‐imine ring system. Various 2‐D nmr experiments were used in the identification of the stereochemical and regiochemical assignments for the ring system.
Action of benzyl chloride on 2‐(N,N‐dimethylamino)pyridine and 2‐benzoylaminopyridine
Authors: Kowalski Piotr 
Published: March 2009

AbstractThe results of the reaction of 2‐(N,N‐dimethylamino)pyridine (1) and 2‐benzoylaminopyridine (2) with benzyl chloride (3) proved that 3 did not undergo direct reaction with the pyridine ring to form a C‐benzyl product.
Reaction of enaminonitriles with isocyanates. Synthesis of new 2‐oxo‐ and 6‐oxopyrimidines
Authors: Cocco Maria Teresa , Congiu Cenzo , Maccioni Antonio , Onnis Valentina 
Published: March 2009

AbstractThe reaction of enaminonitriles 1 with aryl or benzyl isocyanates afforded C‐ 3–5 or N‐adducts 6–8 or a mixture of both depending on the substitution pattern of the considered enaminonitrile. The one‐step synthesis of 6‐oxopyrimidines 9–11 and 2‐oxopyrimidines 12–14 by cyclization of compounds 3–5 and 6–8 respectively is also described.