bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical resolution of rotenoids
Authors: Abidi S. L. 
Published: April 2009

AbstractOptical resolution of selected rotenoids containing 1‐3 asymmetric centers in dihydrobenzopyranofuroben‐zopyranone and dihydrobisbenzopyranopyranone series has been achieved on two chiral high‐performance liquid chromatographic (hplc) stationary phases. In most cases, the absolute stereochemistry at the cis‐B/C ring junction of the rotenoidal antipodes can be related to their elution order. Generally, the 6aα,12aα‐enantiomers were more strongly retained by the chiral substrate than their corresponding optical antipodes. The elution‐configuration relationship provides potential utility for predicting the absolute configuration of related rotenoidal compounds. Chiral phase hplc on amino‐acid‐bonded‐silica yielded results explicable in terms of Pirkle's bonding schemes for chiral recognition. Resolution data for 12a‐hydroxy‐, 12a‐methoxy‐, and 12‐hydroxyiminorotenoids further corroborate the mechanistic rationale, and demonstrate that nonpolar π‐π interactions appeared to be important for enantiomeric separation on helic poly‐triphenylmethylacryl‐ate‐silica (CPOT). In the latter system, steric effects and conformational factors in association with the modification of E‐ring structures might play significant roles in the chiral separation process in view of the reversal to the elution order observed for all methoxylated rotenoids and elliptone derivatives including the parent deguelin. The unique separability (α = 1.44) of 12a‐hydroxyelliptone on CPOT was suggestive of structural effects of the 5′‐side chain on the resolution of the rotenoids having a five‐membered‐E‐ring. The results obtained with two different types of chiral phases are complementary and useful for optical resolution of a wide variety of natural and synthetic rotenoidal compounds.
Sulfur‐containing 2‐arylquinolinemethanols as potential antimalarials
Authors: Epling Gary A. , Lin Kuei‐Ying 
Published: April 2009

AbstractThe synthesis and antimalarial activity of six new 2‐arylquinoline‐4‐methanols is described. The compounds bearing a sulfur were prepared to determine if antimalarial activity can be retained while photo‐reactivity and phototoxicity is diminished by such substituents. The observed antimalarial activity of some of the new compounds show this to be possible.
Direct synthesis of pyrrole nucleosides by the stereospecific sodium salt glycosylation procedure
Authors: Ramasamy Kandasamy , Robins Roland K. , Revankar Ganapathi R. 
Published: April 2009

AbstractA stereospecific high‐yield glycosylation of preformed fully aromatic pyrroles has been accomplished for the first time. Reaction of the sodium salt of pyrrole‐2‐carbonitrile (1a) and pyrrole‐2,4‐dicarbonitrile (1b) with 1‐chloro‐2‐deoxy‐3,5‐di‐O‐p‐toluoyl‐α‐D‐erythro‐pentofuranose (2) gave exclusively the corresponding blocked nucleosides with β‐anomeric configuration 3a and 3b, which on deprotection gave 1‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl) derivatives of 1a (3c) and 1b (3d). Functional group transformation of 3c and 3d provided a number of 2‐monosubstituted 4a‐c and 2,4‐disubstituted 4d‐f derivatives of 1‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl)pyrrole. Similar glycosylation of the sodium salt of 1a and 1b with 1‐chloro‐2,3,5‐tri‐O‐benzyl‐α‐D‐arabinofuranose (5) and further functional group transformation of the intermediate blocked nucleosides 6a and 6b provided 1‐β‐D‐arabinofuranosyl derivatives of pyrrole‐2‐carboxamide (7b) and pyrrole‐2,4‐dicarboxamide (7d). The synthetic utility of this glycosylation procedure for the preparation of 1‐β‐D‐ribofuranosylpyrrole‐2‐carbonitrile (12) has also been demonstrated by reacting the sodium salt of 1a with 1‐chloro‐2,3‐O‐isopropylidene‐5‐O‐(t‐butyl)dimethylsilyl‐α‐D‐ribofuranose (10) and subsequent deprotection of the blocked intermediate 11. This study provided a convenient route to the preparation of aromatic pyrrole nucleosides.
Acetylenchemie. 4 mitt. Synthese von haplophyllin und N‐methylflindersin, zwei wege zu N‐funktio‐nalisierten pyrano[3,2‐c]chinolin‐alkaloiden
Authors: Reisch Johannes , Bathe Andreas , Rosenthal Bernd H. W. , Salehi‐Artimani Reza A. 
Published: April 2009

AbstractPyrano[3,2‐c]chinolin‐Alkaloide (3), geeignete Vorstufen für photobiomimetische Dimerisierungen, sind durch PTC‐Reaktion eines 4‐Hydroxychinolin‐2‐ons (1) mit 3‐Chlor‐3‐methylbut‐1‐in zugänglich, wobei als Nebenprodukt die Furo[3,2‐c]chinolin‐2‐on‐isomere (5) anfallen. Bei der Synthese von Flindersin (3a) wurde zusätzlich das Oxazolo[3,2‐a]chinolin‐5‐on (4) gewonnen; bei der vom N‐Methylflindersin (3b) das Bis‐(N‐methyl‐4′‐hydroxychinolin‐2′‐on‐3′‐yl)‐isopenten (7). Alkaloiddimere, deren Bildung aus Intermediaten formulierbar ist, traten nicht auf. Die Entstehung von 7 bestätigt bislang diskutierte Reaktionsabläufe. Halplophyllin (3c) wurde durch N‐Alkylierung von 3a mit 3‐Methylcrotonsäurechlormethylester erstmalig synthetisch dargestellt.
Photochemical intramolecular nitrene insertion of 6‐azidouridine derivatives
Authors: Miyasaka Tadashi , Tanaka Hiromichi , Satoh Kazue , Imahashi Mie , Yamaguchi Kentaro , Iitaka Yoichi 
Published: April 2009

AbstractA highly efficient intramolecular nitrene insertion was observed upon irradiation of 6‐azidouridine derivatives. The N6,2′‐cyclo structure of the product was determined unequivocally by X‐ray crystallography.
Establishing vicinal proton‐proton connectivities using two‐dimensional proton zero quantum coherence NMR
Authors: Zektzer Andrew S. , Martin Gary E. , Castle Raymond N. 
Published: April 2009

AbstractPhenanthro[3,4:3′,4′]phenanthro[2,1‐b]thiophene (1) served as the model system to evaluate two‐dimensional proton zero quantum coherence nmr in order to establish the vicinal proton‐proton connectivities. The utility of the two‐dimensional proton zero quantum nmr experiment has been compared with the utility of the traditional autocorrelated proton‐proton (COSY) experiment. In the case of a molecule such as 1, where the proton chemical shifts are so highly congested, the zero quantum coherence experiment provides data not obtainable from the COSY experiment.
A convenient and one‐pot synthesis of 9‐substituted carbazoles from primary amine hydrochlorides and 2,5‐dimethoxytetrahydrofuran
Authors: Kashima Choji , Hibi Shigeki , Maruyama Tatsuya , Harada Kazuo , Omote Yoshimori 
Published: April 2009

AbstractCarbazoles are the very important compounds in material science, nevertheless conventional syntheses required severe and complicated reaction conditions. In the process of preparation of pyrrole derivatives, we found that a primary amine hydrochloride 1 and 2,5‐dimethoxytetrahydrofuran 2 were refluxed in a benzenewater (100:4 (v/v)) mixture to be obtained 9‐substituted carbazole 5 in a high yield. This method is the one‐pot synthesis of 9‐substituted carbazoles 5 under mild and convenient conditions.
On triazoles. VII Synthesis of novel tri‐ and tetracyclic ring systems
Authors: Reiter József , Pongó László , Krajcsi Péter , Esses‐Reiter Klára , Sohár Pál , Molnár Hilda , Dvortsák Péter 
Published: April 2009

AbstractThe ring‐closure of the 5‐amino‐1‐(2‐aminophenyl)‐3‐methylthio‐1H‐1,2,4‐triazole derivatives 3 and 4 with different simple and cyclic C1 components lead to the formation of 1,2,4‐triazolo[1,5‐α]‐1,3,5‐benzotriazepines 5–6, their 4,5‐dihydro‐ 7, different 5‐spiro‐homocyclic‐ 8–13, and 5‐spiro‐heterocyclic‐ 14‐15 analogues. The structure of the compounds obtained was proved with the use of their ir, uv, 1H‐nmr and 13C‐nmr spectra.
Methylation of 3‐methyl‐ and 3‐phenyl‐4‐arylhydrazonoisoxazol‐5‐ones with diazomethane
Authors: Singh Shyam K. , Summers Lindsay A. 
Published: April 2009

Abstract3‐Methyl(or phenyl)‐4‐arylhydrazonoisoxazol‐5‐ones on methylation with diazomethane afford 3‐methyl(or phenyl)‐4‐(N‐methylarylhydrazono)isoxazol‐5‐ones and 3‐methyl(or phenyl)‐5‐methoxy‐4‐arylazoisoxazoles. The latter compounds readily rearrange to 4‐methoxycarbonyl‐5‐methyl(or phenyl)‐2‐aryl‐2H‐1,2,3‐triazoles.
Synthesis of N‐(chloromethyl)‐2,6‐diethylcarbaniloyl chloride (1) and derivatives
Authors: D'amico John J. , Bollinger Frederic G. , Tung Ching C. , Dahl William E. 
Published: April 2009

AbstractThe reaction of N‐methylene‐2,6‐diethylbenzenamine with phosgene furnished the titled compound 1. The reaction of 1 with the potassium salts of various thiazolethiols in an acetone medium afforded the expected N‐substituted 2,6‐diethylthiolcarbanilates 2–6. Substituting the above thiazolethiols with the potassium salt of 2‐mercaptobenzimidazole furnished a novel heterocyclic compound 7 in 98% yield. The rection of 1 with the triethylamine salt of disubstituted‐dithiocarbamic acids afforded an alternate method for the synthesis of bis(N‐substituted‐thiocarbonyl)sulfides 8 and 9.
Synthesis of 2‐(β‐D‐ribofuranosyl)pyrimidines, A new class of C‐nucleosides
Authors: Riley Timothy A. , Hennen William J. , Dalley N. Kent , Wilson Bruce E. , Robins Roland K. , Larson Steven B. 
Published: April 2009

AbstractA new C‐glycosyl precursor for C‐nucleoside synthesis, 2,5‐anhydroallonamidine hydrochloride (4) was prepared and utilized in a Traube type synthesis to prepare 2‐(β‐D‐ribofuranosyl)pyrimidines, a new class of C‐nucleosides. The anomeric configuration of 4 was confirmed by single‐crystal X‐ray analysis. Reaction of 4 with ethyl acetoacetate gave 6‐methyl‐2‐(β‐D‐ribofuranosyl)pyrimidin‐4‐(1H)‐one (5). Reaction of 4 with diethyl sodio oxaloacetate gave 2‐(β‐D‐ribofuranosyl)pyrimidin‐6(1H)‐oxo‐4‐carboxylic acid (6). Esterification of 6 with ethanolic hydrogen‐chloride gave the corresponding ester 7 which when treated with ethanolic ammonia gave 2‐(β‐D‐ribofuranosyl)pyrimidin‐6(1H)‐oxo‐4‐carboxamide (8). Condensation of 2,5‐anhydroallonamidine hydrochloride (4) with ethyl 4‐(dimethylamino)‐2‐oxo‐3‐butenoate (9), gave ethyl 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxylate (10). Treatment of 10 with ethanolic ammonia gave 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxamide (11). Single‐crystal X‐ray analysis confirmed the β‐anomeric configuration of 11. Acetylation of 11 followed by treatment with phosphorus pentasulfide and subsequent deprotection with sodium methoxide gave 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐thiocarboxamide (14). Dehydration of the acetylated amide 12 with phosphorous oxychloride provided 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carbonitrile (15). Treatment of 15 with sodium ethoxide gave ethyl 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboximidate (16), which was converted to 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxamidine hydrochloride (17) by treatment with ethanolic ammonia and ammonium chloride. Treatment of 16 with hydroxylamine yielded 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐N‐hydroxycarboxamidine (18). Treatment of 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxamide (11) with phosphorus oxychloride gave the corresponding 5′‐phosphate, 19, Coupling of 19 with AMP using the carbonyldiimidazole activation procedure gave the corresponding NAD analog, 2‐(β‐D‐ribofuranosyl)pyrimidine‐4‐carboxamide‐(5′ ⇋ 5′)‐adenosine pyrophosphate (20).
Benzofuran derivatives. Part 3 On the reactivities of the intermediates in benzofuran synthesis
Authors: Horaguchi Takaaki , Matsuda Shinichi , Tanemura Kiyoshi , Suzuki Tsuneo 
Published: April 2009

Abstract3‐Methyl‐5‐nitrobenzofuran (2) and 3‐methyl‐5‐nitrobenzofuran‐2‐carboxylic acid (3) were obtained by heating 2‐acetyl‐4‐nitrophenoxyacetic acid (1) with various bases in acetic anhydride. It appeared that 3‐hydroxy‐3‐methyl‐5‐nitro‐2,3‐dihydrobenzofuran‐2‐carboxylic acid (4) was the intermediate in the benzofuran synthesis. The properties of 4 were examined under various conditions. Using strong bases such as triethyl‐amine in place of sodium acetate, 3‐methyl‐5‐nitrobenzofuran‐2‐carboxylic acid (3) was obtained exclusively. However, in the presence of acetic acid in the reaction mixture 3‐methyl‐5‐nitrobenzofuran (2) was obtained in good yield. The reaction pathways for the formation of 2 and 3 are discussed.
Synthesis of 2H‐indazole‐4,7‐dione derivatives from 3‐phenylsydnone and p‐toluquinone. The crystal and molecular structure of 6‐bromo‐5‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐dione
Authors: Nan'ya Seiko , Katsuraya Kaname , Maekawa Eturǒ , Kondo Kazumoto , Eguchi Shoji 
Published: April 2009

AbstractThe 1,3‐dipolar cycloaddition of 3‐phenylsydnone with p‐toluquinone afforded 5‐methyl‐ and 6‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐diones 3a and 3b. No regioselectivity was observed in this cycloaddition yielding an equimolar amount of the regioisomers. Reactions of 3a and 3b with bromine gave the corresponding mono‐4a and 4b and dibromo derivatives 5a and 5b, respectively. The crystal structure of 6‐bromo‐5‐methyl‐2‐phenyl‐2H‐indazole‐4,7‐dione (4a) has been determined by the single crystal X‐ray method. The crystals are monoclinic, space group PI with two molecules in a unit cell of dimensions a = 8.029(1), b = 14.309(1), c = 5.895(1)Å, β = 90.24(1)° and V = 621 Å3. The structure has been solved by the direct method using 1827 reflections and refined by full‐matrix least‐squares calculations to R = 0.0739.
Syntheses of 1‐, 2‐, 3‐ and 4‐acridinecarbaldehydes
Authors: Takahashi Kazufumi , Castle Raymond N. , Lee Milton L. 
Published: April 2009

AbstractThe four acridinecarbaldehydes, namely, acridine‐1‐carbaldehyde, acridine‐2‐carbaldehyde, acridine‐3‐carbaldehyde, and acridine‐4‐carbaldehyde have been synthesized for the first time.
Synthesis of nitro and amino N‐heterocycles via ring transformation of 2‐methyl‐3‐nitrochromone
Authors: Takagi Kaname , Tanaka Masaaki , Murakami Yukitoshi , Ogura Kuniyoshi , Ishii Katsuyuki , Morita Hikari , Aotsuka Tomoji 
Published: April 2009

Abstract2‐Methyl‐3‐nitrochromone (1) reacted with acid hydrazides, S‐methylisothiourea, hydroxylamine and ethyl aminoethanoate to give the nitro derivatives of pyrazole 2, pyrimidine 6, isoxazole 11 and pyrrole 13, respectively. These nitro compounds were reduced by catalytic hydrogenation to the corresponding amino derivatives. In the case of 2, a rearrangement of the acyl group took place during the reduction. Substitution reactions of the 2‐methylthio group in 6 were also described.
Synthesis of [1]benzothienonaphthyridines
Authors: Kudo Hirotaka , Takahashi Kazufumi , Castle Raymond N. , Lee Milton L. 
Published: April 2009

Abstract3‐Chlorobenzo[b]thiophene‐2‐carbonyl chloride reacted readily with 2‐amino‐, 3‐amino‐, or 4‐aminopyridine to give the corresponding amides. Photocyclization of the amides afforded the following lactams: [1]ben‐zothieno[2,3‐c][1,5]naphthyridin‐6(5H)‐one (14), [1]benzothieno[2,3‐c][1,6]naphthyridin‐6(5H)‐one (7), [1]benzo‐thieno[2,3‐c][1,7]naphthyridin‐6(5H)‐one (11), and [1]benzothieno[2,3‐c][1,8]naphthyridin‐6(5H)‐one (3). These lactams have been converted to other derivatives including in two instances the unsubstituted ring system.
A comparison of nucleophilic reactions of 3‐benzenesulfonyloxyalloxazine and its 1‐methyl analog
Authors: Hamby James M. , Bauer Ludwig 
Published: April 2009

AbstractReactions of 3‐benzenesulfonyloxyalloxazine (1a) and its 1‐methyl analog1bwith a number of nucleophilic reagents are reported. Relatively small nucleophiles, such as hydroxide ion, methanol, ethanol, methylamine, hydrazine and hydroxylamine converted1ato 4‐carboxy‐s‐triazolo[4,3‐a]quinoxalin‐1(2H)‐ones and the corresponding esters or amides. As the size of the amine increased from methylamine to ethylamine, dimethylamine, propylamine and isopropylamine, there were obtained 4‐(carboxamido)‐s‐triazolo[4,3‐a]quin‐oxalin‐1(2H)‐ones, (1‐carboxamido)imidazolo[4,5‐b]quinoxalines and 2,3‐bis(ureido)quinoxalines. Sodium hydride or potassium cyanide in hot DMF degraded1ato imidazolo[4,5‐b]quinoxaline. However, methylmer‐captide and benzylmercaptide ions attacked the sulfonate group of1ato form 3‐hydroxyalloxazine.1‐Methyl‐3‐benzenesulfonyloxyalloxazine (1b) reacted with methanol, ethanol, 1‐propanol, and to some degree 2‐propanol, in the presence of triethylamine to furnish anhydro‐1‐hydroxy‐3‐methyl‐4‐(alkoxycarbonyl)‐s‐triazolo[4,3‐a]quinoxalinium hydroxides. However, sodium methoxide in methanol converted this starting material to a mixture of anhydro‐1‐hydroxy‐3‐methyl‐s‐triazolo[4,3‐a]quinoxalinium hydroxide and 1‐methyl‐3‐hydroxyflavazole. A saturated aqueous solution of triethylamine transformed1bto anhydro‐1‐hydroxy‐3‐methyl‐s‐triazolo[4,3‐a]quinoxalinium hydroxide, apparentlyviathe corresponding unstable 4‐carboxylic acid. The reactions of1bwith a number of aliphatic amines yielded either amides based on the above mesoionic system or on the 3‐carboxamido‐2‐quinoxalyl semicarbazide structure. The reaction of1bwith potassium cyanide furnished 1‐methylimidazolo[4,5‐b]quinoxaline. Mechanisms to explain all of the degradations are advanced.
Mass spectral fragmentation pattern of 4‐carboxy‐and 4‐methoxycarbonyl‐5‐methyl(or phenyl)‐2‐aryl‐2H‐1,2,3‐triazoles
Authors: Keats Neil G. , Singh Shyam K. , Summers Lindsay A. 
Published: April 2009

Abstract4‐Carboxy‐5‐methyl‐2‐aryl‐2H‐1,2,3‐triazoles undergo considerable fragmentation on electron impact including loss of OH and H2O from the molecular ions and rupture of the triazole ring. 4‐Carboxy‐5‐phenyl‐2‐aryl‐2H‐1,2,3‐triazoles, on the other hand, show no loss of H2O from the molecular ions.
Pyrrolocoumarin derivatives as potential photoreagents toward DNA
Authors: Rodighiero P. , Chilin A. , Pastorini G. , Guiotto A. 
Published: April 2009

AbstractA number of new methyl derivatives of linear and angular pyrrolocoumarins were synthesized by direct Fischer's indole synthesis. In the same way some linear 2H,10H‐pyrano[2,3‐b]carbazol‐2‐one and angular 2H,7H‐pyrano[3,2‐c]carbazol‐2‐one were prepared. The synthesis was performed starting from the 4‐methyl‐7‐aminocoumarin and methyl groups were introduced into positions which look most promising for the photoreactivity of the compounds toward DNA.
Nitrogen bridgehead compounds. Part 72 Straightforward synthesis of 1,2,3,4‐tetrahydrorutaecarpine and derivatives
Authors: Hermecz István , Horváth ágnes , Podányi Benjamin , Vasvári‐Debreczy Lelle , Mészáros Zoltán , Szász György , Kökösi József 
Published: April 2009

AbstractIn polyphosphoric acid, the Fischer indolization of 6‐arylhydrazono‐1,2,3,4,6,7,8,9‐octahydro‐11H‐pyrido‐[2,1‐b]quinazolin‐11‐ones, obtained from 1,2,3,4,6,7,8,9‐octahydro‐11H‐pyrido[2,1‐b]quinazolin‐11‐ones by three pathways, afforded substituted 1,2,3,4,7,8‐hexahydro‐5H‐13H‐indolo[2′,3′:3,4]pyrido[2,1‐b]quinazolin‐5‐ones in high yields. The structures of the 6‐substituted octahydropyridoquinazolinones and hexahydroindo‐lopyridoquinazolinones were characterized by uv, 1H and 13C nmr data.
Quaternary salts and polymethine dyes from 2‐(methylpyridyl)‐X‐azolo[4,5‐b]pyridine
Authors: Savarino Piero , Viscardi Guido , Barni Ermanno , Di Modica Gaetano 
Published: April 2009

AbstractIf picoline and X‐azolo[4,5‐b]pyridine are linked, an assembled system arises which has a particular behaviour towards various quaternizing agents. As soon as picolinium salts could be obtained, the corresponding styryl dyes were prepared. The structures of bases, salts and dyes were clarified and their physical and spectroscopic data were correlated and compared with those of similar systems previously studied.
Flash vacuum pyrolysis of 3‐t‐butylindeno[1,2‐c]isoxazol‐4‐one. Formation of 2‐carbonyl‐1,3‐indandione 2‐azine
Authors: Pérez Jorge D. , Wunderlin Daniel A. , Lemke Thomas L. , Sawhney Kailash N. 
Published: April 2009

AbstractFlash Vacuum Pyrolysis (FVP) of 3‐t‐Butylindeno[1,2‐c]isoxazol‐4‐one (1) and 3‐t‐Butylspiro[2H‐azirine‐2,2′‐(2H)indene]‐1′,3′‐dione (2) were carried out. Reaction of 1 from 300–400° afford 2 and 2‐carbonyl‐1,3‐indandione 2‐azine (3) as the major products, whereas 2‐t‐Butylindeno[1,3‐c]oxazol‐4‐one (4) was the main products in FVP of 2 together with minor amounts of 3.
Proton‐ionizable crown compounds. 13. Synthesis and structural studies of crown compounds containing the triazole subcyclic unit and lipophilic substituents
Authors: Bradshaw Jerald S. , Mcdaniel Christopher W. , Skidmore Brett D. , Nielsen Ralph B. , Wilson Bruce E. , Dalley N. Kent , Izatt Reed M. 
Published: April 2009

AbstractEight new macrocyclic polyether ligands containing the proton‐ionizable triazole subcyclic unit have been prepared. Most of these compounds contain octyl, benzo or cyclohexano lipophilic groups. The unsubstituted triazolo‐18‐crown‐6 (5) formed an unusual complex with silver ion. The crystal structure of this silver complex showed one crown complexed with one silver cation and two associated silver nitrate molecules. The new lipophilic triazolo‐crowns are being tested as cation carriers for alkali and other metal cations in a bulk liquid membrane system.
The synthesis of halogenated pyridines substituted at the carbon atom C‐3
Authors: Sutter Peter , Weis Claus D. 
Published: April 2009

AbstractArylation of α‐methyleneglutaronitrile (MGN) occurred when arylamines, aminopyridines and 3‐aminothiophene were treated with alkylnitrites and copper(I) chloride in dimethyl methylphosphonate (DMMP) solutions. Results from this study exemplified the synthetic advantage of DMMP as a solvent in Meerwein reactions with an olefin of low reactivity, yielding 1‐aryl‐2 chloro‐2,4‐dicyanobutanes, and its 3‐pyridyl‐ and thiophen‐3‐yl analogues. Partial hydrolysis, followed by subsequent ring closure of the substituted 2,4‐dicyanobutanes to 2,6‐piperidinediones (glutaric acid imides) was effected with a solution of sulfuric acid in acetic acid. The aromatization of the substituted 2,6‐piperidinediones with phosphorus oxychloride in the presence of hexamethylphosphoric acid triamide (HMPT) yielded the 2,6‐dichloropyridine moiety substituted at the carbon atom C‐3.
The synthesis of monomethoxy[1]benzothieno[2,3‐c]quinolines
Authors: Castle Steven L. , Buckhaults Phillip J. , Baldwin Larry J. , McKenney J. Dew , Castle Raymond N. 
Published: April 2009

AbstractA series of monomethoxy[1]benzothieno[2,3‐c]quinolines 24‐28 were prepared by photocylization of the appropriate 3‐chloro‐N‐phenylbenzo[b]thiophene‐2‐carboxamides 9–13 to [1]benzothieno[2,3‐c]quinolin‐6(5H)‐ones 14‐18 followed by chlorination to 6‐chloro[1]benzothieno[2,3‐c]quinolines 19‐23 then dechlorination resulting in the title compounds except for 25 which was achieved by direct reduction of 15. Reaction of 24‐28 with methyl iodide provided the corresponding N‐methyl quaternary salts 29‐33. Also, conversion of 4‐meth‐oxy[1]benzothieno[2,3‐c]quinolin‐6(5H)‐one 16 to 4‐methoxy‐6‐methylthio[1]benzothieno[2,3‐c]quinoline 35 and 4,6‐dimethoxy[1]benzothieno[2,3‐c]quinoline 36 is described.
Mass spectral fragmentation patterns of 2‐methyl‐, 2,3‐methyl‐, 2,3‐dimethyl‐, 2‐aryl‐ and 3‐phenylindole derivatives
Authors: Erra‐Balsells Rosa 
Published: April 2009

AbstractThe electron impact mass spectrometric fragmentation pathways for several 2‐methyl‐, 3‐methyl‐, 2,3‐dimethyl‐, 2‐aryl‐ and 3‐phenylindole derivatives were investigated. An interesting relationship between the substitution pattern in the framework of the indole derivatives and the fragmentation patterns was observed.
Studies on the synthesis and interconversion of isomeric triazolothienopyrimidines. Part III. Cyclization reactions of 2‐amino‐3‐(1H‐1,2,4‐triazol‐3‐yl)thiophenes
Authors: Shishoo C. J. , Devani M. B. , Ullas G. V. , Ananthan S. , Bhadti V. S. 
Published: April 2009

AbstractIsolation of 2‐amino‐3‐(1H‐1,2,4‐triazol‐3‐yl)thiophenes in the hydrolytic cleavage reactions of isomeric triazolothienopyrimidines is reported. The 2‐amino‐3‐triazolylthiophenes on reaction with one carbon donors were found to cyclize to 1,2,4‐triazolo[1,5‐c]thienopyrimidines, exclusively.
Synthesis of the new pyrido[1,2‐c]benzo‐v‐triazinium system via valence bond isomerization
Authors: Messmer A. , Hajós Gy. , Giber J. , Holly S. 
Published: April 2009

Abstractα‐Pyridylphenyl diazonium salts 2 were found to undergo valence bond isomerization and gave the new pyrido[1,2‐c]benzo‐v‐triazinium salts 3. The ir and nmr studies on the products showed that isomers 2 and 3 form an equilibrium, and the ring closure is favoured by electron withdrawing substituents.