bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and nitrosation of 3,4‐dimethyl‐3‐penten‐2‐one (e)‐ and (z)‐oximes. Formation of 3,3,4,5‐tetramethyl‐3H‐pyrazole 1,2‐dioxide and of 2‐isoxazoline derivatives
Authors: Hansen John F. , Novak Bennett H. 
Published: March 2009

AbstractThe stereoisomeric (E)‐ and (Z)‐oximes of 3,4‐dimethyl‐3‐penten‐2‐one were prepared and nitrosated with butyl nitrite in methanol. The (E)‐oxime gave 3,3,4,5‐tetramethyl‐3H‐pyrazole 1,2‐dioxide in nearly quantitative yield, while the (Z)‐oxime reacted less readily, giving a lower yield of the same product, with five other products identified as isoxazoline derivatives. Three of these were 4‐hydroxy‐, 4‐methoxy‐, and 4‐nitro‐3,4,5,5‐tetramethyl‐2‐isoxazoline. The fourth was the O‐(3,4,5,5‐tetramethyl‐2‐isoxazolin‐4‐yl) derivative of the starting (Z)‐oxime, and the fifth was 4‐methylene‐3,5,5‐trimethyl‐2‐isoxazoline.
Synthesis of some novel fused tetracyclic quinolonecarboxylic acids via 7‐methyl‐6,7,8,9‐tetrahydro‐3H‐imidazo[4,5‐f]quinoline and 6‐methyl‐5,6,7,8‐tetrahydro‐1H‐imidazo[4,5‐g]quinoline
Authors: Le Goff Corinne , Bouyssou Pascal , Chenault Jacques 
Published: March 2009

AbstractA series of fused tetracyclic quinolonecarboxylic acids was prepared for biological evaluation. These compounds were synthesized by a route involving a regiospecific functionalization of 5‐fluoro‐2‐methyl‐1,2,3,4‐tetrahydroquinoline to obtain a series of new substituted 7‐methyl‐6,7,8,9‐tetrahydro‐3H‐imidazo[4,5‐f]quinolines and 6‐methyl‐5,6,7,8‐tetrahydro‐1H‐imidazo[4,5‐g]quinolines as convenient precursors of quinolones.
On the syntheses of 1,3‐disubstituted dithieno[3,4‐b:3′,2′‐d]pyridines via halogen‐metal exchange of 1,3‐dibromodithieno[3,4‐b:3′,2′‐d]pyridine
Authors: Gronowitz Salo , Temciuc Ecaterina , Hörnfeldt Anna‐Britta 
Published: March 2009

AbstractHalogen‐metal exchange of 1,3‐dibromodithieno[3,4‐b:3′,2′‐d]pyridine with butyllithium under different conditions has been studied. Upon reaction with iodine, N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethyl carbonate, dimethyl disulfide and thiuram disulfide, the 1,3‐diiodo‐, 1,3‐diacetyl‐, 1,3‐diformyl‐, 1,3‐dicarbomethoxy, 1,3‐di(thiomethyl)‐ and 1,3‐di(N,N‐dimethyldithiocarbamoyl)dithieno[3,4‐b:3′,2′‐d]‐pyridines, respectively, were obtained in varying yields. 3‐Monosubstituted derivatives were obtained in some cases. The formation of 3,7‐disubstituted derivatives was sometimes also observed.
Synthesis and transformations of some (heteroaryl)acetylazides, (heteroaryl)methyl isocyanates and alkyl (heteroaryl)methyl carbamates
Authors: Koĉaevar Marijan 
Published: March 2009

AbstractThe synthesis of two complex acetyl azides 6 and 10 having an heteroaryl residue bound to the acetyl group through the ring nitrogen, and their further transformations into the corresponding carbamates 7a‐b and 11a‐b and isocyanates 16 and 14 are described. Hydrolysis of these products results in the elimination of the substituted methyl group from the heterocyclic residue and formation of 1‐unsubstituled heterocycles. A similar transformation was also observed under mass measurement conditions.
Preparation of 4‐bromo‐1‐hydroxypyrazole 2‐oxides by nitrosation of α‐bromo‐α,β‐unsaturated ketoximes
Authors: Hansen John F. , Easter John A. , Eckert David A. , Hunt Karen J. , Little David A. 
Published: March 2009

AbstractNitrosation of the oximes of 3‐bromo‐3‐penten‐2‐one, 3‐bromo‐4‐phenyl‐3‐buten‐2‐one, and 2‐bromo‐1,3‐diphenyl‐2‐propen‐1‐one using sodium nitrite in acetic acid gave low yields of 4‐pyrazolone 1,2‐dioxides. Nitrosation using butyl nitrite in the presence of copper(II) sulfate and pyridine in aqueous ethanol produced insoluble copper complexes from which 3,5‐dimethyl‐, 3‐methyl‐5‐phenyl‐, and 3,5‐diphenyl‐4‐bromo‐1‐hydroxypyrazole 2‐oxides could be liberated by treatment with dilute potassium hydroxide, filtration, and acidification of the filtrate. High yields were obtained with the first two oximes, but, presumably due to unfavorable stereochemistry of the oxime, the diphenyl derivative gave a lower yield of the complex, accompanied by 4‐bromo‐ and 4‐nitro‐3,5‐diphenylisoxazole and 4‐oximino‐3,5‐diphenyl‐4,5‐dihydroisoxazole.
γ‐Radiolysis of 5‐fluorouracil and 5‐fluorouridine derivatives having sulfur‐containing substituents
Authors: Kuroda Tokuyuki , Hisamura Koji , Nishikawa Hiroshi , Nakamizo Nobuhiro , Otsuji Yoshio 
Published: March 2009

Abstractγ‐Radiolysis reactions of eight 5‐fluorouracil (5‐FU) derivatives having sulfonyl group‐containing substituents at the 1‐position and five 5‐fluorouridine (5‐FUR) derivatives having thioureido group‐containing substituents were studied under the conditions where hydrated electron (eaq−) and hydroxyl radical (HO·) become the principal reactive species. The 5‐FU and 5‐FUR derivatives were radiolyzed to give 5‐FU and 5‐FUR, respectively. The efficiency of the reactions depended upon the nature of reactive species and also upon the nature of substituents. The reactivity features of the γ‐radiolysis reactions are discussed.
Addition of diamines to methylthiopyridones
Authors: Hehemann David G. , Winnik Witold 
Published: March 2009

AbstractThiopyridone derivatives react with diamines: ethylenediamine, 1,3‐propylenediamine and 1,4‐butylenediamine to produce bicyclic addition compounds. Ethanolamine reacts with thiopyridone derivatives to afford only open chain adducts. Diethylenetriamine and 2‐(2‐aminoethylamino)ethanol in reaction with thiopyridones yielded seven membered ring tricyclic derivatives. The procedures described here constitute a relatively simple method to prepare these novel heterocycles.
The counter anion effect of (16‐ethyl‐5,6,7,8‐tetrahydro‐9H‐dibenzo‐[b, i][1,4,8,11]tetraazacyclotetradecinato)nickel(II) complexes
Authors: Hashimoto Mamoru , Sakata Kazunori 
Published: March 2009

AbstractThe eight nickel(II) complexes with 16‐ethyl‐5,6,7,8,9,14‐hexahydrodibenzo[b, i][1,4,8,11]tetraazacyclotetradecine and a counter anion have been synthesized and their spectroscopic properties were studied. The δ N‐H values of NiLCl and NiLBr are observed in a more downfield range than those of NiLPF6, NiLBF4 and NiLClO4 in acetonitrile and nitromethane solutions. The plot of δ N‐H against molar conductance is found to be approximately linear. The N‐H stretching modes of NiLBF4, NiLPF6 and NiLClO4 shift to lower frequency and those of NiLCl, NiLBr and NiLI shift to higher frequency upon metal‐coordination.
Thienopyrrolizines: New condensed triheterocyclic systems
Authors: Lancelot Jean‐Charles , Letois Bertrand , Rault Sylvain , Robba Max , Rogosca Maria 
Published: March 2009

AbstractCyclization of 3‐(1‐pyrrolyl)thiophene‐2‐carboxamide derivatives of methyl 3‐(1‐pyrrolyl)‐2‐thiophenecarboxylate afforded imminium salts and resulted in the formation of thieno[2,3‐b]pyrrolizine derivatives.
Synthetic strategies directed to the antitumour alkaloids sesbanimide A and manzamine A
Authors: Pandit Upendra K. 
Published: March 2009

AbstractSynthons derived from nature's chiral pool have been utilized in developing strategies aimed at the syntheses of the alkaloids sesbanimide A and manzamine A. The route designed for sesbanimide A has provided the naturally occurring alkaloid and a facile access to several analogues for structure‐activity relationship studies. The approach to the synthesis of manzamine A has led to a strategically functionalized chiral tricyclic intermediate possessing the absolute stereochemistry of the natural product. Recent results on the synthesis of sesbanimide analogues and the progress towards the total synthesis of manzamine A is described.
Synthesis of bioactive nitrogen heterocycles from marine organisms
Authors: Hino Tohru , Nakagawa Masako 
Published: March 2009

AbstractRecently many bioactive indole alkaloids have been isolated from marine organisms. Many of them have novel ring systems which are not found in the indole alkaloids isolated from higher plants and molds on the land. We have chosen β‐carboline alkaloids, eudistomins and manzamines, as targets for total synthesis.
Acylaminoacetyl derivatives of active methylene compounds. 3. C‐Acylation Reactions via the Hippuric Acid Azlactone
Authors: Hamilakis Stylianos , Kontonassios Demetrios , Sandris Constantine 
Published: March 2009

AbstractThe C‐acylation reactions of the active methylene compounds, methyl cyanoacetate and Meldrum's acid, with hippuric acid, using the DCC activation and the mixed anhydride conditions, are shown to proceed through initial formation of 2‐phenyl‐5(4H)‐oxazolone, the hippuric acid azlactone. The conditions of these reactions using the azlactone as the acylating agent were investigated and discussed.
A new entry to the imidazo[4,5‐d]pyrimidine system. The reaction of 1,3‐dimethyl‐6‐aminouracil with N,N‐dimethyldichloromethyleniminium chloride (phosgeniminium chloride) and trimethylsilyl azide, a novel and convenient “one pot” synthesis of 8‐N‐arylaminotheophyllines (2‐N‐arylamino‐4,6‐dimethylimidazo[4,5‐d]pyrimidine‐(4H,6H)‐5,7‐diones), starting from 1,3‐dimethyl‐6‐aminouracil
Authors: Kokel Bruno 
Published: March 2009

Abstract1,3‐Dimethyl‐6‐aminouracil 2 was converted into various 8‐N‐arylaminotheophyllines (2‐N‐arylamino‐4,6‐dimethylimidazo[4,5‐d]pyrimidine‐(4H,6H)‐5,7‐diones) 17 through reaction successively, with phosgeniminium chloride (N,N‐dimethyldichloromethyleniminium chloride) (1a), trimethylsilyl azide (4) and arylamines. Starting with the synthesis of the N,N‐dimethyl(1,3‐dimethyl‐4‐aminouracil‐5‐yl)chloromethyleniminium chloride (amide chloride) 3 this new route to the imidazo[4,5‐d]pyrimidine skeleton was shown to proceed via the formation of a very unstable N,N‐dimethyl‐(1,3‐dimethyl‐4‐aminouracil‐5‐yl)azidomethyleniminium chloride (amide azide) (8) which would undergo an in situ rearrangement into very likely, a 4‐amino‐5‐(chloroformamidin‐1′‐yl)uracil and/or related compounds of types 10. Depending on reaction conditions, the latter was proved to be a very good precursor of the 8‐dimethylaminotheophylline 11 as well.
Synthesis of 1‐arylacenaphtho[1,2‐d]pyrazoles and 5,7‐Dehydro‐5H,7H‐benzo[b]acenaphtho[1,2‐e]‐1,3a,6a‐triazapentalenes
Authors: Tsuge Otohiko , Hatta Taizo , Kojima Hisashi , Miyahara Nobutaka , Sugaya Masafumi 
Published: March 2009

Abstract2‐Benzoyl‐ 5 and 2‐acetylacenaphthenone 6, prepared from the corresponding 1‐acyl‐2‐(1‐pyrrolidinyl)‐acenaphthylenes 2 and 3, reacted with arylhydrazines 8 under acidic conditions to give the corresponding 1‐arylacenaphtho[1,2‐d]pyrazoles 9 and 10. Novel heteropentalene mesomeric betaines, 5,7‐dehydro‐5H,7H‐benzo[b]acenaphtho[1,2‐e]‐1,3a,6a‐triazapentalenes 13 and 14 were prepared by reductive cyclization of 1‐(o‐nitrophenyl)acenaphtho[1,2‐d]pyrazoles 9d and 10d, respectively.
Synthesis and transformations of some quinolines and 1H‐pyrido[3,2‐c]azepines containing amino acid units
Authors: Anžič Borut , Kočevar Marijan , Polanc Slovenko 
Published: March 2009

AbstractThe synthesis of two complex acetyl azides 5 and 12 having quinoline or pyrido[3,2‐c]azepine ring bound to the acetyl group through the ring nitrogen, and their further transformations into the corresponding carbamates 6 and 13, isocyanates 7 and 14 and 1‐unsubstituted heterocyclic compounds 8 and 15 are described. The later compounds were debenzoylated on heating in concentrated sulfuric acid to give the corresponding products 9 and 16.
Demethylation reactions of 4‐amino‐N‐(2,6‐dimethoxy‐4‐pyrimidinyl)benzenesulfonamide (sulfadimethoxine) in strongly basic aqueous solution
Authors: Miura Tadayoshi , Ono Makoto , Yoshida Atomi , Kato Masahiro , Yoshioka Toshiyuki , Tachi Hiroshi , Eguchi Shoji 
Published: March 2009

AbstractHydrolysis of 1 in strongly basic aqueous solution afforded mono‐ and didemethylated products 2,3 and 4, that are postulated as the metabolites of 1 in some animals. This hydrolytic demethylation was shown to proceed stepwise via mono‐demethylation to give 2 and 3, followed by their further demethylation to 4. The hydrolytic reactivity of 1–3 was rationalized based on MO calculation results and 13C nmr data.
Synthesis of nitrogen‐containing heterocycles 6. Formation and structures of imidazolinones and related compounds through cyclization of diaminomethylenehydrazones with dimethyl acetylenedicarboxylate
Authors: Miyamoto Yoshiko , Yamazaki Chiji 
Published: March 2009

AbstractDiaminomethylenehydrazones 1 of aromatic and aliphatic carbonyl compounds react with dimethyl acetylenedicarboxylate (DMAD) at room temperature to give four types of heterocycles, (5‐oxoimidazolin‐4‐ylidene) acetates 2, 3 and 6, (2‐imino‐5‐oxoimidazolidin‐4‐ylidene) acetate 4 and 6‐oxo‐1,6‐dihydropyrimidine‐4‐carboxylates 5 according to the substitution patterns of 1 in moderate to high yields. Amino (N,N‐dimethylamino)methylenehydrazones of ketones give exclusively (5‐oxoimidazolin‐4‐yl‐idene) acetates, both (Z)‐ and (E)‐isomers 2 and 3 about the exocyclic alkenic linkage, with the (Z)‐isomer 2 generally being predominant, while those of aldehydes give 5. Diamino‐ and amino (N‐methylamino)methylenehydrazones produce 5 and/or 6 and di (N‐methylamino) methylenehydrazone gives (2‐imino‐5‐oxoimidazolidin‐4‐ylidene) acetate 4 as the sole cyclized product.
Approaches toward the synthesis of 2,5‐disubstituted‐1,3‐thiazolidines
Authors: Faury Philippe , Camplo Michel , Charvet Anne‐Sophie , Mourier Nicolas , Barthelemy Philippe , Graciet Jean‐Christophe , Kraus Jean‐Louis 
Published: March 2009

AbstractSynthetic approaches for new 2,5‐disubstituted‐1,3‐thiazolidines are described. Steric and electronic effects of the N‐substituent of the thiazolidine ring represent the major parameter in the rearrangement process. The nmr studies demonstrate that N‐unsubstituted 2,5‐disubstituted‐1,3‐thiazolidines exist as epimeric mixture, while the corresponding N‐acetylated analogues exist as a conformer mixture.
Synthesis of N‐alkoxycarbonyl and N‐carboxamide derivatives of anti‐inflammatory oxindoles
Authors: Robinson Ralph P. , Donahue Kathleen M. 
Published: March 2009

AbstractThe synthesis of N‐alkoxycarbonyl and N‐carboxamide derivatives of anti‐inflammatory oxindoles is described. These compounds, sought as potential prodrugs of the parent anti‐inflammatory agents, were obtained by ring opening of the oxadiazine dione intermediates formed by the treatment of 1‐unsubstituted 3‐acyloxindoles with chlorocarbonyl isocyanate.
Synthesis of oxazolo[4,5‐c]quinolones by thermolytic degradation of 4‐azido‐2(1H)‐quinolones
Authors: Steinschifter Waltraud , Fiala Werner , Stadlbauer Wolfgang 
Published: March 2009

Abstract4‐Azido‐2(1H)‐quinolones 1 are thermolyzed in the presence of carboxylic acids and polyphosphoric acid to yield oxazolo[4,5‐c]quinolones 3. Formation of other possible isomeric ring closure products such as oxazolo[5,4‐c]quinolones 2 or isoxazolo[4,3‐c]quinolones 4 could be excluded by independent syntheses.
Reactivity of nucleophilic uracil derivatives
Authors: Grangier Géraldine , Aitken David J. , Guillaume Dominique , Husson Henri‐Philippe , Tomas Alain , Viossat Bernard 
Published: March 2009

AbstractThe reactivity of uracil derivatives bearing acidic methylene groups at N1 was investigated. On treatment with strong base, compounds with nitrile as the activating group underwent extensive dimerisation to give new tricyclic systems. Ester‐activated compounds also produced dimers in the absence of an external electrophile, but their monomeric carbanions could be trapped by prompt addition of benzyl bromide to give normally alkylated products.
Synthesis of 1,3‐dihydro‐3,3‐dimethyl‐2H‐indol‐2‐one derivatives as possible nonsteroidal cardiotonics
Authors: Lee An‐Rong , Huang Wen‐Hsin , Lin Tung‐Liang , Shih Kun‐Min , Lee Hsiao‐Feng , Lin Cheng‐I 
Published: March 2009

AbstractNew substituted 1,3‐dihydro‐3,3‐dimethyl‐2H‐indol‐2‐one derivatives19–29and34–43were synthesized and examined for their inotropic activity in isolated dog ventricular tissues. Among them, compound26(2‐(2,3‐dimethoxybenzylamino)‐N‐(3,3,7‐trimethyl‐2‐oxo‐2,3‐dihydro‐1H‐indol‐5‐yl)acetamide) showed very potent activity.
Reaction of ninhydrin with β‐dicarbonyl compounds
Authors: Peet Norton P. , Huber Edward W. , Huffman John C. 
Published: March 2009

AbstractThe reactions of ninhydrin (1) with β‐ketoesters and β‐diketones were studied. Two kinds of products were observed, which were either simple adducts of the dicarbonyl compounds to the center carbonyl group of ninhydrin, or tricyclic indeno[1,2‐b]furans. Treatment of methyl 3‐aminocrotonate (2) with ninhydrin led in analogous fashion to an indeno[1,2‐b]pyrrole (3) which was reduced to a complex tetracyclic dihydropyridine 12. A mechanism for the production of 12 is presented. Structures for the novel heterocycles are supported by high resolution nmr studies and X‐ray crystallography.
Facile aerial oxidation of a porphyrin. Part 18. N‐alkylation of the oxidised product derived from Meso‐tetrakis(3,5‐di‐t‐butyl‐4‐hydroxyphenyl)porphyrin
Authors: Milgrom Lionel R. , Hill Jonathan P. , Yahioglu Gokhan 
Published: March 2009

AbstractIn basic solutions, the oxidised porphyrin 2 readily undergoes macrocyclic N‐alkylation, with up to four bulky alkyl groups, including decyl and substituted benzyl moieties, being accomodated: an argument is presented to show that N‐di‐alkylation occurs on opposite nitrogen atoms, on the same side of the macrocycle.
Alkoxide‐induced reactions of N‐substituted saccharins. Synthesis of 1,2‐benzothiazocine 1,1‐dioxide and 2,3‐dihydropyrrolo[1,2‐b]‐[1,2]benzisothiazole 5,5‐dioxide derivatives
Authors: Blanco Mercedes , Perillo Isabel A. , Schapira Celia B. 
Published: March 2009

AbstractThe reactions of saccharin derivatives 1 with sodium alkoxides were studied. Under mild conditions, compounds 1a‐f gave the corresponding open sulfonamides 5a‐f. Under drastic conditions, β‐(saccharin‐2)propionic acid derivatives 1a,b reacted with sodium ethoxide affording saccharin and β‐ethoxypropionic acid derivatives 4a,b. γ‐(Saccharin‐2)butyric acid derivatives 1c,d and γ‐(saccharin‐2)‐butyrophenone 1f reacted with sodium t‐butoxide in dimethyl sulfoxide affording 5‐substituted 6‐hydroxy‐3,4‐dihydro‐2H‐1,2‐benzothiazocine 1,1‐dioxides 9. From mother liquors, 1‐substituted 2,3‐dihydro‐pyrrolo[1,2‐b][1,2]benzisothiazole 5,5‐dioxides 10 were isolated several hours later, though not detected immediately after completing the reaction. When the reactions were carried out in t‐butyl alcohol, the yields of 9 diminished and those of 10 increased with product ratio inversion. Different experimental observations on the possible pathway generating 9 and 10 are discussed.
Facile synthesis of (±)‐, (+)‐, and (‐)‐galanthamine
Authors: Szewczyk Jerzy , Wilson Joseph W. , Lewin Anita H. , Carroll F. Ivy 
Published: March 2009

AbstractThe Amarylidacea alkaloid galanthamine (1a) is an acetylcholinesterase inhibitor that has been evaluated as a potential agent for the treatment of Alzheimer's disease. We report a very efficent synthesis of (±)‐galanthamine [(±)‐1a] from readily available isovanillin and tyramine. We have separated racemic galanthamine into its diastereoisomeric (1S)‐camphanate esters and obtained both natural (‐)‐ and unnatural (+)‐galanthamine by lithium aluminum hydride removal of the acyl group.
Synthesis and conformational study of acridine derivatives related to 1,4‐dihydropyridines
Authors: Martín Nazario , Quinteiro Margarita , Seoane Carlos , Soto José L. , Mora Arturo , Suárez Margarita , Ochoa Estael , Morales Alhmed , Bosque Jose R. Del 
Published: March 2009

AbstractNovel acridine derivatives have been synthesized from dimedone and different aromatic aldehydes by following the classical Hantzsch's procedure. The particular substitution pattern of these compounds is responsible for the observed strong push‐pull effect. Quantum chemical calculations were carried out on these molecules by using the AM1 method with complete geometry optimization. The calculated heats of formation reveal two equally favoured conformations. The parameter of planarity and the charge density calculations are in agreement with the 13C nmr spectroscopic data.
Synthesis of nevirapine and its major metabolite
Authors: Grozinger K. G. , Fuchs V. , Hargrave K. D. , Mauldin S. , Vitous J. , Campbell S. , Adams J. 
Published: March 2009

AbstractSeveral synthetic methods were developed during the process optimization for the large scale synthesis of nevirapine (1), a non‐nucleoside inhibitor of HIV‐1 Reverse Transcriptase. The synthesis of its putative major metabolite 11‐cyclopropyl‐5,11‐dihydro‐4‐hydroxymethyl‐6H‐[3,2‐b:2′,3′‐e][1,4]diazepin‐6‐one (2) and the oxidation of 2 to the corresponding aldehyde 3, are described.
Electron ionization mass spectra and crystal structures of some [1,2,4]triazolo[1,2‐b]‐ and [1,3,4]thiadiazolo[3,4‐b]phthalazines
Authors: Joutsiniemi Karoliina , Ahlgrén Markku , Vainiotalo Pirjo , Morgenstem Olaf , Meusel Mario 
Published: March 2009

AbstractThe mass spectra of ten 1,3‐dithioxo[1,2,4]triazolo[1,2,‐b]phthalazines, five 3‐iminosubstituted 1‐thioxo‐[1,3,4]thiadiazolo[3,4‐b]phthalazines, three 3‐iminosubstituted‐1‐thioxo[1,2,4]triazolo[1,2‐b]phthalazines, and 1,3‐dithioxo‐5,10‐dihydro[1,3,4]thiadiazolo[3,4‐b]phthalazine were recorded under electron ionization. The fragmentation pathways were elucidated by metastable ion analysis and exact mass measurements. The changes in the ring‐system had little effect on the fragmentation mechanism, but the effect on peak intensities was considerable. The most important fragmentations began with the opening of the triazole ring. Substituents at nitrogen atoms also had a marked effect on the mass spectral behavior. The aryl substituents prompted a whole new fragmentation. The X‐ray crystal structure was determined for a few compounds. Two of the three structures of the 1,3‐dithioxo[1,2,4]triazolo[1,2‐b]phthalazines that were studied proved to be relatively planar, whereas the structure of 1,3‐dithioxo‐5,10‐dihydro[1,3,4]thiadiazolo[3,4‐b]phthalazine was considerably bent similarly to the 2‐(4‐chlorophenyl)‐1,3‐dithioxo‐2,3,5,10‐tetrahydro[1,2,4]triazolo[1,2‐b]‐phthalazine. The triazole and the thiadiazole rings had a strong double bond nature.
The synthesis of cycloalkylpyrido[1,2‐a]benzimidazole carbonitrile analogs
Authors: Russell Ronald K. , Van Nievelt Caroline E. 
Published: March 2009

AbstractThe preparation of various sustituted cycloalkylpyrido[1,2‐a]benzimidazolecarbonitrile analogs is described as well as the X‐ray of the cycloheptyl analog 13a.
Synthesis of some N‐[pyridyl(phenyl)carbonylamino]hydroxyalkyl‐(benzyl)‐1,2,3,6‐tetrahydropyridines as potential anti‐inflammatory agents
Authors: Rao Kode Nageswara , Redda Kinfe K. , Onayemi Folakemi Y. , Melles Hailemichael , Choi Jongoh 
Published: March 2009

Abstract1,2,3,6‐Tetrahydropyridines are known to possess analgesic, anti‐inflammatory, hyperglycemic and hypoglycemic activities. Substituted 2,4‐dinitrophenylpyridinium chlorides 3 were formed by reacting 1‐chloro‐2,4‐dinitrobenzene with hydroxypropyl, hydroxymethyl and benzyl substituted pyridines 2. Attack of the pyridinium chlorides 3 with pyridylcarbonyl hydrazides or benzoyl hydrazides 4 gave the isolable 2,4‐dinitroanilino derivative 5 which underwent hydrolysis when refluxed in water:p‐dioxane mixture (1:4 v/v) to afford the pyridinium ylides 6. Sodium borohydride reduction of 6 in absolute ethanol at 0° for 4–6 hours resulted in the isolation of the 1,2,3,6‐tetrahydropyridines 7 in good yields.