bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ring nitrogen functionalization of 2‐aminothiazol‐4‐acetic acid derivatives. I. Synthesis and properties of novel 2‐aminothiazole N‐oxides
Authors: Perrone Ettore , Alpegiani Marco , Giudici Franco , Bedeschi Angelo , Pellizzato Renato , Nannini Giuliano 
Published: April 2009

AbstractCyclization of thiocyanomethylketone oximes with hydroxylamine hydrochloride and oxidation of 2‐aminothiazole derivatives with peracids are shown to afford the same products, which can be formulated either as 2‐imino‐3‐hydroxy‐2,3‐dihydrothiazolines or 2‐aminothiazole N‐oxides. Compounds of this type bearing at position 4 an acetic or α‐oxyiminoacetic residue are useful synthons for highly active β‐lactam antibiotics; the problems connected with their preparation in a suitably protected form are examined. Scope and limitations of this previously unreported oxidation of the thiazole nucleus are discussed. All the products show limited stability in alkaline media: the 4‐acetic derivatives, in addition, undergo a transposition to afford 4‐methylidenethiazolidines. Possible types of isomerism and tautomerism are discussed in the light of the acquired spectral data. The uv and ir spectra of the compounds synthesized lend support to their formulation as 2‐aminothiazole N‐oxides.
Pyrimidines. 7. A study of the chlorination of pyrimidines with phosphorus oxychloride in the presence of N,N‐dimethylaniline
Authors: Gershon Herman , Grefig Anthony T. 
Published: April 2009

AbstractThe chlorination of 6‐trifluoromethyluracils by phosphorus oxychloride in the presence of N,N‐dimethylaniline was studied and compared with results obtained with 6‐methyluracils. 6‐Trifluoromethyluracil and its 5‐chloro analog afforded moderate yields of the di‐ and trichloropyrimidines, accompanied by good yields of the 2‐N‐methylanilino by‐products, after a 3‐hour reaction time. After 24 hours, the 2‐N‐methylanilinopyrimidines were the primary or sole products. A small yield of 2,4‐bis(N‐methylanilino)‐6‐trifluoromethylpyrimidine was also obtained. The 6‐methyluracils afforded high yields of the di‐ and trichloropyrimidines, after 3 and 24 hours, along with minor amounts of the 2‐N‐methylanilino by‐products. After 48 hours, the proportion of 2,4‐dichloro‐6‐methylpyrimidine decreased, and the 2‐N‐methylanilino product increased. 2‐Chloro‐4‐methylanilino‐6‐methylpyrimidine and bis(2‐N‐methylanilino)‐6‐methylpyrimidine were also formed in small amounts. The chlorination products from 5‐chloro‐6‐methyluracil remained constant over 188 hours of reaction time.It appears that the π electron distribution around the ring, as influenced by the substituents, controls the course of the chlorination and by‐product formation. Since the amination by a tertiary amine is a type of Hofmann reaction, the presence of the chlorine in the 5 position of the ring adds steric hindrance and thus enhances the regiospecificity of the formation of by‐products.
Non‐steroidal antiinflammatory agents. 1. Synthesis of 4‐hydroxy‐2‐oxo‐1,2‐dihydroquinolin‐3‐yl alkanoic acids by the wittig reaction of quinisatines
Authors: Faber Kurt , StÚckler Hubert , Kappe Thomas 
Published: April 2009

AbstractThe Wittig reaction of quinisatines (1a,b) with 1‐ethoxycarbonylethyliden‐ (2a) and ethoxycarbonylmeth‐ylenetriphenylphosphorane (2b) has been investigated. In both cases unusual reaction products (3a,b and 12a,b respectively) were isolated in high yields and converted to potential antiinflammatory acids 6, 8, 15 and lactones 4, 7.
Synthesis of 2‐aroylpiperazinyl‐4‐alkoxyquinazolines by phase‐transfer‐catalysed heteroaromatic nucleophilic substitution
Authors: GÓmez‐Gil M. C. , GÓmez‐Parra V. , SÁnchez F. , Torres T. 
Published: April 2009

AbstractA series of quinazolines, with cardiovascular activity, having 2,3‐dihydroxypropoxy or 2‐hydroxy‐3‐t‐ butylaminopropoxy groups substituted at the 4‐position and chlorine or 2‐aroylpiperazinyl groups at the 2‐position have been synthesized. The introduction of the alkoxy substituent at C‐4 was carried out under phase‐transfer catalysis conditions.
Quenching of the fluorescence of quinoline derivatives by exciplex formation with heteroatom‐containing compounds
Authors: Epling Gary A. , Lin Kuei‐Ying 
Published: April 2009

AbstractThe efficient fluorescence of 2‐phenylquinoline compounds is readily quenched by heteroatom‐containing compounds such as amines and sulfides. The mechanism of quenching involves the formation of an exciplex between the quencher and the quinoline; in a few cases a new, red‐shifted emission from the exciplex was observed. The efficiency of quenching depends on the ionization potential of the quencher ‐ the compounds having low ionization potentials quench the fluorescence at a diffusion‐controlled rate.
Studies in organic mass spectrometry. IV. Electron impact induced fragmentation of 2‐substituted 3‐(5‐isoxazolyl)‐4(3H)‐quinazolinones of pharmaceutical interest
Authors: Ceraulo̊ Leopoldo , Plescia Salvatore , Daidone Giuseppe , Bajardi Maria Luisa 
Published: April 2009

AbstractThe fragmentation under electron impact of thirteen 2‐substituted‐3‐(5‐isoxazolyl)‐4(3H)‐quinazolinones has been investigated with the aid of metastable ion detection and high resolution measurements. Molecular ions are always abundant and the main primary fragmentation route involves acetonitrile elimination through isoxazole ring opening. The other common processes, particularly those leading to the abundant [R‐C8H4N2]+ ion (b or b'), as well as those due to the nature of the 2‐substituent are reported and discussed.
The synthesis of naphtho[1,2‐b]thiophene and all of the eight isomers of monomethylnaphtho[1,2‐b]thiophene
Authors: Tedjamulia Marvin L. , Stuart John G. , Tominaga Yoshinori , Castle Raymond N. , Lee Milton L. 
Published: April 2009

AbstractThe synthesis of naphtho[1,2‐b]thiophene and all of the eight monomethylnaphtho[1,2‐b]thiophene isomers is described.
Synthesis of 8‐methyl‐2‐azainosine and related nucleosides
Authors: Andrés J. Ignacio , Herranz Rosario , López M. Teresa García 
Published: April 2009

AbstractThe synthesis of 6‐methyl‐7‐(β‐D‐ribofuranosyl)imidazo[4,5‐d]‐v‐triazin‐4‐one (8‐methyl‐2‐azainosine (2)) and 6‐methyl‐7‐(β‐D‐glucopyranosyl)imidazo[4,5‐d]‐v‐triazin‐4‐one (5) by diazotization of 5‐amino‐1‐(β‐D‐ribofuranosyl)‐2‐methylimidazole‐4‐carboxamide (1) and diazotization of 5‐amino‐1‐(2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosyl)‐2‐methylimidazole‐4‐carboxamide (3), followed by deacetylation of the resulting compound 4, is described. The preparation of 6‐methyl‐5‐(β‐D‐ribofuranosyl)imidazo[4,5‐d]‐v‐triazin‐4‐one (10) and 6‐methyl‐5‐(β‐D‐glucopyranosyl)imidazo[4,5‐d]‐v‐triazin‐4‐one (11) by glycosylation of 6‐methylimidazo[4,5‐d]‐v‐triazin‐4‐one (8‐methyl‐2‐azahypoxanthine, (7)) is also described. Structural assignments were made on basis of analytical and 1H‐nmr and uv spectral data.
Synthesis of 5H‐5‐oxobenzimidazo[2,1‐b]pyrido[3,2‐e][1,3]thiazine, A novel ring system
Authors: Belgodere Elena , Bossio Ricardo , Cencioni Roberto , Marcaccini Stefano , Pepino Roberto 
Published: April 2009

AbstractReaction between 2‐chloronicotinic acid chloride and 2‐mercaptobenzimidazole afforded 5H‐5‐oxobenzimidazo[2,1‐b]pyrido[3,2‐e][1,3]thiazine, a novel heterocyclic ring system. The assigned structure was confirmed by means of mass spectrometry.
Etude spectroscopique du phosphate d'isaxonine sites de protonation
Authors: Monti Jean‐Pierre , Braguer Diane , Crevat Aimé , Murisasco Antoine 
Published: April 2009

AbstractNous avons étudié par rmn du proton et du carbone 13 et par spectrométrie de masse le phosphate d'isaxonine. Les résultats ont montré que cette molécule possède deux sites de protonation sur l'hétérocycle. De plus, la fragilité de la liaison isopropyl‐amine est mise en évidence par spectrométrie de masse.
Synthesis of 1‐hydrazinopyridazino[4,5‐b]quinoxaline and related compounds
Authors: Vega A. Onge , Gil M. J. , Fernández‐Alvarez E. 
Published: April 2009

AbstractThis paper describes the synthesis of 1‐hydrazinopyridazino[4,5‐b]quinoxaline (10), tetrazolo[4,3‐b]pyridazino[4,5‐b]quinoxaline (11) and some 1,2,4‐triazolo[4,3‐b]pyridazino[4,5‐b]quinoxalines 13. Starting with 2‐ethoxycarbonyl‐3‐methylquinoxaline 1,4‐dioxide (1), 1,2‐dihydro‐1‐oxopyridazino[4,5‐b]quinoxaline (5) was prepared by three different ways: (a) chlorination of 1 in acetic acid gave 2‐ethoxycarbonyl‐3‐dichloromethylquinoxaline 1,4‐dioxide, which reacts with an excess of hydrazine to give about 60% of 5; (b) oxidation of 1 with selenium dioxide gave 90% of 2‐ethoxycarbonyl‐3‐formylquinoxaline 1,4‐dioxide (3), which reacts with hydrazine to give 5 (63%); (c) compound 3 was treated with hydrazine to give 1,2‐dihydro‐1‐oxopyridazino‐[4,5‐b]quinoxaline 1,4‐dioxide (4) (70%), which by reduction with sodium dithionite gave 5 (80%). Compound 5 reacts with phosphorus pentasulfide or the Lawesson reagent to give 1,2‐dihydro‐1‐thiocarbonylpyridazino[4,5‐b]quinoxaline (9), which treated with hydrazine gave 5 (80%). This last compound reacts with nitrous acid to give 11. Some hydrazones 12 from 10 are described. Heating the aldehyde hydrazones 12a,c,d with dimethylsulfoxide some 1,2,4‐triazolo[4,3‐b]pyridazino[4,5‐b]quinoxalines 13 were obtained. Compound 13a was also obtained in the reaction of 10 with benzoyl chloride. Reaction of 3 with phenylhydrazine gave 1,2‐dihydro‐1‐oxo‐2‐phenylpyridazino[4,5‐b]quinoxaline (6). Reactions of 5 with acetic anhydride and dimethylsulfate gave, respectively, 1‐acetoxypyridazino[4,5‐b]quinoxaline (8) and 1,2‐dihydro‐1‐oxo‐2‐methylpyridazino‐[4,5‐b]quinoxaline (7). All the compounds were characterized by elemental analysis and 1H‐nmr spectra. Compounds 5 and 10 showed antihypertensive activity in rats.
The photo‐initiated substitution reactions of 4‐chloropyridine and the related 1‐(4′‐pyridyl)‐4‐pyridone with benzophenone in aqueous 2‐propanol
Authors: Cosgrove John P. , Vittimberga Bruno M. 
Published: April 2009

Abstract4‐Chloropyridine (1) converts to 1‐(4′‐pyridyl)‐4‐pyridone (4) in aqueous 2‐propanol. The photo‐initiated reaction of both of these compounds in acidic and non‐acidic 4:1 2‐propanol/water with and without benzophenone is reported.
The carbon‐13 and proton NMR spectra of nicotine in aqueous media
Authors: Slaven Robert W. 
Published: April 2009

AbstractThe carbon‐13 and proton nmr spectra of nicotine in aqueous solution have been ivnestigated. The changes resulting from alteration of pD level are detailed. In the case of the carbon‐13 spectrum, these changes are essentially independent of the acid present. Changes in previously published assignments for carbons (2) and (6) and protons (2) and (6) are presented.
A simple synthesis of compounds with the benz[h]imidazo[1,2‐c]quinazoline ring system
Authors: Petridou‐Fischer Joanna , Papadopoulos Eleftherios Paul 
Published: April 2009

AbstractThe ureas obtained from 1‐amino‐3(or 4)‐methyl‐2‐naphthalenecarbonitrile and 2‐chloroethyl isocyanate, or ethyl isocyanatoacetate undergo a double cyclization upon thermal decomposition, or treatment with base to yield compounds with the benz[h]imidazo[1,2‐c]quinazoline ring system.
One step synthesis of 6,7‐dimethyl‐2‐oxo‐1,2,3,4‐tetrahydropyrrolo[1,2‐a][1,3]pyrimidines
Authors: Bayomi Said M. , Haddad Dahlia Y. , Sowell J. Walter 
Published: April 2009

AbstractA one‐step synthesis of substituted pyrrolo[1,2‐a][1,3]pyrimidines from acetyl methyl carbinol, 3‐aminopropionic acid, and substituted acetonitriles is reported.
The reactions of 4‐hydroxy‐2‐pyrones with 2‐hydroxybenzaldehydes. A note of warning
Authors: De March P. , Moreno‐Mañas M. , Roca J. L. 
Published: April 2009

AbstractThe reaction between 2‐hydroxybenzaldehyde and 4‐hydroxy‐6‐methyl‐2‐pyrone (triacetic acid lactone) affords 3‐acetoacetyl‐2‐chromenone, 7, instead of 3‐(2‐hydroxybenzylidene)‐6‐methyl‐3,4‐dihydro‐2H‐pyran‐2,4‐dione, 6. The structures previously reported in the literature for the products formed in the reactions of 4‐hydroxy‐2‐chromenone with 2‐hydroxybenzaldehydes in a molar ratio 1:1 are considered erroneous. Thus, the previously reported 3‐(2‐hydroxybenzylidene)chroman‐2,4‐dione, 10, should be formulated as 3‐(2‐hydroxybenzoyl)‐2‐chromenone, 11.
Etude dans la série des pyrrolidinones: Dérivés de l'acide N‐méthylol pyroglutamique; synthèse d'un nouveau système bicyclique, la dioxo‐(1,5) pyrrolidino[2,1‐c]oxazolidine
Authors: Rigo B. , De Quillacq J. , Fossaert E. , Kolocouris N. 
Published: April 2009

AbstractL'acide N‐méthylol pyroglutamique et son ester méthylique ont été synthétisés, et la réactivité de leur groupe N‐CH2‐O‐H a été étudiée: suivant les réactifs, ils réagissent par coupure des liaisons N‐C, C‐O ou O‐H. Un nouveau système bicyclique simple, une azlactone accolée à un cycle lactame, la dioxo‐(1,5) pyrrolidino‐[2,1‐c]oxazolidine, a été obtenu. Certains des nouveaux composés présentent des propriétés antifongiques.
Synthesis of 1,3‐oxazaspiro[4.4]nona‐3,6,8‐trienes via 1,3‐dipolar cycloadditions of benzonitrile‐4‐nitrobenzylide with substituted cyclopentadienones. Crystal and molecular structure of a cycloadduct. II
Authors: Tsatsaroni E. G. , Argyropoulos N. G. , Alexandrou N. E. , Houndas A. , Terzis A. 
Published: April 2009

Abstract1,3‐Dipolar cycloaddition of benzonitrile‐4‐nitrobenzylide with four substituted cyclopentadienones 1 afforded the title compounds 3 in good yields (20–50%), by addition of the 1,3‐dipole to the carbonyl double bond. The cycloaddition is examined on the basis of frontier molecular orbitals of the reacting species and an X‐ray crystallographic analysis of the cycloadduct 3c is made.
Application of isatoic anhydride chemistry to the synthesis of racemic paraensine
Authors: Coppola Gary M. , Schuster Herbert F. 
Published: April 2009

AbstractThe alkaloid paraensine was obtained in racemic form in 84% overall yield by a two step reaction sequence which involves a hetero ring opening of N‐methylisatoic anhydride with the lithium enolate of 4,5‐di‐hydro‐4,5,5‐trimethyl‐2(3H)‐furanone followed by a thermal cyclization.
Synthesis and anticonvulsant properties of a novel series of 2‐substituted amino‐5‐aryl‐1,3,4‐oxadiazole derivatives
Authors: Omar A.‐Mohsen M. E. , Aboulwafa Omaima M. 
Published: April 2009

AbstractA novel series of 2‐substituted amino‐5‐aryl‐1,3,4‐oxadiazole derivatives were synthesized for their potential anticonvulsant activity. The synthesis involved the cyclodesulfurization of variously substituted salicylthiosemicarbazides with DCCD and mercuric oxide. Representative examples of the title compounds were also prepared by a one‐pot cyclodesulfurization of mixtures of salicylhydrazides and phenylisothiocyanate with DCCD.
Novel estradiol‐17α‐1,2,4‐triazoline derivatives. Synthesis and in vitro anabolic‐catabolic properties and binding affinity to steroid receptors
Authors: Omar A.‐Mohsen M. E. , Aboulwafa Omaima M. 
Published: April 2009

AbstractSeveral novel estradiol‐17α‐triazolines were synthesized and tested in vitro for anabolic‐catabolic acitivity and binding affinity to steroid receptors. While no binding affinity to steroid receptors was detected, due to the presence of a bulky triazoline ring in the 17α‐position of the steroidal nucleus, the products showed almost the same catabolic properties exhibited by estrone.
Synthesis and reactions of 2,3‐diamino‐4(3H)‐pyrimidinones and 3‐amino‐2‐hydrazino‐4(3H)‐pyrimidinones. I
Authors: Hlavka Joseph J. , Bitha Panayota , Lin Yang‐I , Strohmeyer Timothy 
Published: April 2009

AbstractA series of new 2,3‐diamino‐4‐pyrimidinones and 3‐amino‐2‐hydrazino‐4‐pyrimidinones were synthesized by the reactions of β‐ketoesters with amino or diaminoguanidines.
Synthesis of 1,2,3,4‐tetrahydro‐5H‐[1]benzopyrano[3,4‐c]pyridin‐5‐ones. II. Substitution at the 3‐position with 2‐aminoethyl and 2‐aminopropyl side chains
Authors: Connor David T. , Unangst Paul C. , Schwender Charles F. , Sorenson Roderick J. , Carethers Mary E. , Puchalski Chester , Brown Richard E. 
Published: April 2009

AbstractMethods for the synthesis of 3‐[2‐aminoethyl]‐1,2,3,4‐tetrahydro‐5H‐[1]benzopyrano[3,4‐c]pyridin‐5‐ones and 3‐[2‐aminopropyl]‐1,2,3,4‐tetrahydro‐5H‐[1]benzopyrano[3,4‐c]pyridin‐5‐ones are described. The scope and limitations of the various methods are discussed.
Chemistry of 2H‐3,1‐benzoxazine‐2,4(1H)‐dione (isatoic anhydride). 16. Facile construction of the furacridone ring system
Authors: Coppola Gary M. 
Published: April 2009

AbstractThe synthesis of the furacridone ring skeleton was accomplished in one step by the reaction of N‐methylisatoic anhydride (7) with the lithium enolate derived from 6,7‐dihydro‐4(5H)‐benzofuranone (10). Aromatization of the C ring with DDQ furnished 5‐dehydroxyfuracridone (6).
Synthesis and evaluation of radioiodinated terminal‐substituted 5‐iodo‐(2‐thienyl) fatty acids as new myocardial imaging agents
Authors: Goodman Mark M. , Kirsch Gilbert , Knapp Furn F. 
Published: April 2009

AbstractIn order to evaluate the stability of radioiodide attached to the 5 position of thiophenes substituted at the 2‐position with tissue‐specific groups as new radiopharmaceuticals, two [125I]iodothienyl‐substituted long‐chain fatty acids have been prepared and evaluated in rats. Radioiodide was introduced into the 5 position of 17‐(2‐thienyi)heptadecanoic acid and 13‐(2‐thienyl)tridecanoic acid by K‐125I treatment of their corresponding 5‐[bis‐(trifluoroacetoxy)]thallium derivatives. Tissue distribution studies in rats with 17‐[5‐[125I]iodo(2‐thienyl)]heptadecanoic acid shows significant heart uptake and prolonged retention accompanied by in vivo deiod‐ination and moderate blood levels. A comparison of the heart uptake of the 17 carbon fatty acid with a 13 carbon analogue, 13‐[5‐[135I]iodo(2‐thienyl)]tridecanoic acid, demonstrated a significantly greater myocardial uptake for the 17 carbon fatty acid than the 13 carbon analogue. These results suggest that the 5‐iodothienyl moiety substituted at the terminal position of long chain fatty acids does not interfere with myocardial uptake and that such compounds may be of value as a new class of myocardial imaging agents.
The chemistry of arene imines. IV. An unusual silver promoted transformation of N‐chlorophenanthrene 9,10‐imine into 9,10‐phenanthrenequinone dialkyl acetals
Authors: Shtelzer Sarah , Sheradsky Tuvia , Blum Jochanan , Zitrin Shmuel 
Published: April 2009

AbstractMethanolic silver nitrate and perchlorate convert N‐chlorophenanthrene 9,10‐imine (1) into 10,10‐dimethoxy‐9(10H)‐phenanthrone (2) in 60% yield. Substitution of the mthanol by ethanol, 1‐ and 2‐propanol gives phenanthrenequinone diethyl‐, di‐1‐propyl‐ and di‐2‐propylacetals (3‐5), respectively. Silver acetate promotes these transformations only in the presence of a protic acid. The reaction mechanism is assumed to involve the generation of a cyclic nitrenium ion, nucleophilic ring opening by methanol, hydrolysis of the imine function and silver ion promoted oxidation.
The chemistry of polycyclic arene imines. V. Reactions of phenanthrene 9,10‐imine with nucleophiles under phase transfer conditions
Authors: Weitzberg Moshe , Aizenshtat Zeev , Blum Jochanan 
Published: April 2009

AbstractReactions of phenanthrene 9,10‐imine (1) with alkyl halides, sodium azide and ammonium thiocyanate in two liquid phase systems were investigated. In the presence of aqueous sodium hydroxide and alkyl halides triethylbenzylammonium (TEBA) salts promote N‐alkylation of 1 with preservation of the aziridine ring. Tetrabutylammonium (TBA) salts catalyze nucleophilic substitutions in which the three membered ring is cleaved. Aqueous sodium azide reacts with 1 to give trans‐10‐azido‐9,10‐dihydro‐9‐phenanthrenamine (2). Ammonium and potassium thiocyanate cause expansion of the aziridine ring; while the unsubstituted imine 1 yields the 2‐thiazolamine derivative 4, N‐butylphenanthrene 9,10‐imine (8) froms trans‐3a,11b‐dihydro‐3‐butylphenanthro[9,10‐d]thiazol‐2‐imine (9) with an exocyclic CN bond. The structure of 9 was established by X‐ray crystal analysis.
Composés sulfurés hétérocycliques. CIII. Action de la phénylhydrazine sur les dihydro‐1,2 benzothiazine‐3,1 thiones‐4
Authors: Legrand Louis , Lozac'h Noël 
Published: April 2009

AbstractLa réaction de la phénylhydrazine sur les alkyl‐1 dihydro‐1,2 benzothiazine‐3,1 thiones‐4 (1) donne des alkyl‐1 phénylamino‐3 dihydro‐2,3 1H‐quinazolinethiones‐4 (2) tandis qu'avec les aryl‐1 dihydro‐1,2 benzothiazine‐3,1 thiones‐4 (3) elle fournit des aryl‐1 phénylhydrazono‐4 dihydro‐1,4 2H‐benzothiazines‐3,1 (4). Par chauffage à 200°, ces dernières donnent en général l'aryl‐1 phénylamino‐3 dihydro‐2,3 1H‐quinazolinethione‐4 (5) isomère et un aryl‐1 phénylimino‐3 dihydro‐1,3 benzo[c]isothiazole (7), exceptionnellement accompagnés d'aryl‐1 amino‐3 dihydro‐2,3 1H‐quinazolinethione‐4 (8). La structure des thiones 2 et 5, ainsi que celle des phénylhydrazones 4, est établie sans amabiguïté par les spectres de rmn de leurs dérivés acylés respectifs. Les thiones 2 et 5 acylées ou non, donnent les composés carbonylés correspondants par action du N‐oxyde de benzonitrile.
Antidiabetische wirkstoffe. III. 4,5,6‐Trisubstituierte 2‐(4‐toluidino)pyrimidine
Authors: Kreutzberger Alfred , Gillessen Jutta 
Published: April 2009

AbstractAus der Kondensation von 4‐Tolylguanidin (1) mit den β‐Diketonen 2a‐b gehen die 2‐(4‐Toluidino)pyrimidine 3a‐b hervor.
Studies on pyrimidine derivatives. Michael addition of β‐nitrostyrenes to substituted 6‐aminouracils
Authors: Prasad A. Siva , Sandhu J. S. , Baruah J. N. 
Published: April 2009

AbstractA series of 5‐(2‐nitro‐l‐phenyl)ethyluracils were obtained when β‐nitrostyrenes were reacted with 1,3‐di‐methyl‐6‐substituted uracil derivatives, instead of cyclic compounds. The structures of the compounds 5, 6, and 7 were proved by spectroscopic methods and their mass fragmentation patterns are discussed.
Synthesis of 5H‐imidazo[2,1‐c]pyrrolo[1,2‐a][1,4]benzodiazepine
Authors: Duceppe Jean Simon , Gauthier Jean 
Published: April 2009

AbstractWe have synthesized 5H‐imidazo[2,1‐c]pyrrolo[1,2‐a][1,4]benzodiazepine 1 in five steps from 1‐(2‐amino‐methylphenyl) pyrrole 4. Amidino derivatives 11‐12 have also been prepared.
Synthesis of pyrazolo[4,3‐d]oxazoles
Authors: Youssef M. S. K. , Metwally S. A. M. , El‐Maghraby M. A. , Younes M. I. 
Published: April 2009

Abstract1‐Phenyl‐3‐methyl‐5‐pyrazolone‐4‐oxime reacted with benzylamine, methylamine, methyl‐ and ethyl ioides to give 3‐methyl‐1,5‐diphenyl‐1H‐, 3‐methyl‐1‐phenyl‐1H‐ and 3,5‐dimethyl‐1‐phenyl‐1H‐pyrazolo[4,3‐d]oxazoles I, II. The structure of I was elucidated authentically through other routes by interaction of 1‐phenyl‐3‐methyl‐4,5‐dioxopyrazolone with benzylamine and/or benzaldehyde and ammonium acetate. Various 3‐meth‐yl‐5‐aryl‐1‐phenyl‐1H‐pyrazolo[4,3‐d]oxazoles IV were synthesized by the reaction of 4,5‐dioxopyrazolone with aromatic aldehydes in the presence of ammonium acetate. Also, the structure of I was elucidated authentically via other routes by the reaction of 1‐phenyl‐3‐methyl‐4‐imino‐5‐pyrazolone with each of benzylcyanide, benzylamine, benzaldehyde and benzalaniline.
MNDO studies on five‐membered 1,3‐heterocyclic systems. Part II. Nucleophilicity and carbenic character of the conjugate bases of “Olium” cations
Authors: Geijo Fernando , López‐Calahorra Francisco , Olivella Santiago 
Published: April 2009

AbstractThe nucleophilic character of the conjugate bases of the “olium” cations has been analyzed by means of MNDO SCF‐MO calculations. It is predicted that only the conjugate bases of the thiazolium and dithiolium cations show a remarkable nucleophilicity that is attributed to a reversion in the usual ordering of the two highest occupied MO's. An analysis of the ylide‐carbene resonance shown by these species reveals a significant contribution of the carbenic structure.