bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential causal prophylactic antimalarial agents. Synthesis of quinoxaline, benzimidazole, and alkoxybenzene derivatives containing a novoldiamine moiety
Authors: Yan S. J. , Burton William H. , Chien Ping‐Lu , Cheng C. C.
Published: April 2009

Several quinoxaline, benzimidazole, and alkoxybenzene derivatives containing the novoldiamine function, either as a side chain or incorporated as a ring constituent, were synthesized as potential causal prophylactic antimalarial agents. 1‐(5‐Dimethylamino‐2‐pentyl)‐5‐methoxy‐benzimidazole (2a) was shown to have the desired prophylactic activity in the preliminary sporozoitc‐indueedPlasmodium gallinaceumtest.
The synthesis of several para‐substituted tropanyl benzoates
Authors: Wallace J. L. , Kidd M. R. , Cauthen S. E. , Woodyard J. D.
Published: April 2009

The synthesis of the p‐methyl‐, p‐methoxy‐, p‐t‐butyl‐, p‐phenyl‐, p‐cyano‐, p‐bromo‐, p‐chloro‐and p‐nitrobenzoate esters of tropine are reported. These compounds were characterized by their hmr, ir, mass spectra and analytical data.
Synthesis of some 3‐acetyl‐5‐arylmethyl‐ or arylaminomethyltetronic acids from 4‐ethoxycarbonyl‐3‐(2H)furanone precursors
Authors: Chantegrel Bernard , Gelin Suzanne
Published: April 2009

The synthesis of a series of tetronic acids was accomplished by ring opening of new 4‐ethoxycarbonyl‐3(2H) furanones.
The pummerer rearrangement with 7‐(trifluoromethyl)dibenzo[b,e] [1,4]‐thiazepine‐5(11H)‐carboxaldehyde 10‐oxide. Formation of a novel 5,11‐bridged tetracycle
Authors: Yale Harry L.
Published: April 2009

13‐Ethoxy‐7‐(trifluoromethyl)‐11H‐11,5‐(epoxymethano)dibenzo[b,e][1,4]thiazepine (3) was formed following the Pummerer Rearrangement of 7‐(trifluoromethyl)dibenzo[b,e] [1,4]‐thiazepine‐5(11H)carboxaldehyde 10‐oxide (1), when the work‐up involved the use of diethyl ether that contained ethanol as a normal ingredient, i.e., the grade of that solvent employed in anesthesia.
Synthèse d'hétérocycles dérivés du (+)‐camphre
Authors: Seube Serge , Lamazouère Anne‐Marie , Sotiropoulos Jean
Published: April 2009

Les diamines agissent, suivant les conditions expérimentales, sur le dimercaptométhylène‐3 camphre avec formation, soit d'un bis‐oxothioamide, soit d'un hétérocycle par l'intérmediaire d'un oxoaminothioamide. De měme, les diamines réagissent sur les β‐oxothioamides pour conduire, par un mécanisme similaire où une transamination intervient, aux měmes hétérocycles dans lesquels le groupement carbonyle du camphre est conservé. Par contre, l'hydrazine avec les mémes dérivés du camphre donne des thioxo, alcoylamino ou arylamino indazoles. Cette hétérocyclisation se fait alors aux dépens du carbonyle du camphre.
Cyclization of 5‐amino‐1‐β‐d‐ribofuranosylimidazole‐4‐carboxamide (AICA‐riboside): A review
Authors: Yamazaki Akihiro , Okutsu Masaru
Published: April 2009

The synthesis of various purine nucleosides by cyclization of AICA‐riboside(5‐amino‐1‐β‐D‐ribofuranosylimidazole‐4‐carboxamide) is described. A variety of cyclization reactions provide new synthetic routes to inosine and guanosine. In this review, emphasis will be placed on the synthesis of the latter.
New, convenient synthesis of 2‐alkyl‐ and 2‐vinylpyrazolo[3,4‐d]‐pyrimidine derivatives
Authors: Senga Keitaro , Kanamori Yukako , Kanazawa Hashime , Nishigaki Sadao
Published: April 2009

Treatment of 1,3‐dimethyl‐6‐hydrazinouracil with the appropriate dimethylformamide dialkylacetal afforded the, corresponding 2‐alkyl‐5,7‐dimethylpyrazolo[3,4‐d]pyrimidine‐4,6‐(5H,7H)diones. The reaction of 1,3‐dimethyl‐6‐(α‐methylbenzylidenehydrazino)uracils with dimethylformamide dimethylacetal or triethyl orthoformate gave the corresponding 5,7‐dimethyl‐2‐vinylpyrazolo[3,4‐d]pyrimidine‐4,6(5H,7H)diones, respectively. Similarly, treatment of 1,3‐dimethyl‐6‐(α‐methylbenzylidenehydrazino)uraeils with triethyl orthopropionate yielded the corresponding 5,7‐dimethyl‐3‐ethyl‐2‐vinylpyrazolo[3,4‐d]pyrimidine‐4,6(5H,7H)diones.
Trimethine pyrylium dyes
Authors: Vanallan J. A. , Reynolds G. A. , Petropoulos C. C.
Published: April 2009

The synthesis and electronic absorption spectra of some pyranylidene trimethine pyrylium salts are described.
Selenium heterocycles XXV. Synthesis of thieno[3,4‐d][1,2,3]‐thiadiazole, selenolo[3,4‐d][1,2,3]thiadiazole and pyrrolo[3,4‐d][1,2,3]‐thiadiazole. Three novel ring systems
Authors: Shafiee Abbas
Published: April 2009

Starting from the readily available 4‐bromomethyl‐5‐benzoyl‐1,2,3‐thiadiazole and 5‐bromomethyl‐4‐benzoyl‐1,2,3‐thiadiazole; thieno[3,4‐d][1,2,3]thiadiazole, selenolo[3,4‐d][1,2,3]‐thiadiazole and pyrrolo[3,4‐d][1,2,3]thiadiazole were synthesized in good yield.
Reaction of sulfamides with diketene (III). Synthesis of N‐sulfamoyl‐2,6‐dimethyl‐4‐pyrone‐3‐carboxamides
Authors: Goya P. , Stud M.
Published: April 2009

Preparation of N‐(tetrahydropyran‐2‐yl)sulfamide, N‐(2,3,4,6‐tetra‐O‐aeetyl‐β‐D‐glucopyranosyl)sulfamide and N‐(2,3,5‐tri‐O‐benzoyl‐D‐ribosyl)sulfamide is described. Reactions with diketene, in the presence of pyridine, yielded N‐sulfamoyl‐2,6‐dimethyl‐4‐pyrone‐3‐carboxamide derivatives.
Ring transformations in reactions of heterocyclic compounds with nucleophiles (XX). Conversion of 5‐nitropyrimidine into 3,5‐dinitropyridine. A novel ring transformation
Authors: van der Plas H. C. , Jongejan H. , Koudijs A.
Published: April 2009

Heating of 5‐nitropyrimidine with acetic acid in water leads to the formation of 3,5‐dinitro‐pyridine. The mechanism proposed for this novel ring transformation involves a fragmentation of the pyrimidine ring, leading to the formation of a two‐atom and a four‐atom moiety, which on condensation gives the pyridine ring. With hydrazine hydrate, 5‐nitropyrimidine undergoes ring contraction into 4‐nitropyrazole.
Quaternary derivatives from 2‐aminobenzimidazole and 2‐phenylethyl‐ and phenyloxymethyl halides
Authors: Yale Harry L. , Bristol J. A.
Published: April 2009

2‐Aminobenzimidazole has been reacted with phenylethyl bromides and phenyloxymethyl chlorides to prepare a number of novel 1,3‐bis‐substituted quaternary derivatives.
Thermal rearrangement and fragmentation of 1a, 7b‐dihydro‐1H‐cyclopropa[c]cinnolines
Authors: Garanti Luisa , Zecchi Gaetano
Published: April 2009

Heating of 1a, b in boiling xylene resulted in the rearranged products 2a, b, probably through concerted ring cleavage and 1,5‐hydrogen shift. Under the same conditions, 1c reacted slowly to give a mixture from which the fragmentation products 4 and 5 were obtained.
The synthesis of l‐alkyl‐1,4‐dihydro‐4‐quinolone‐2‐carboxylic acids
Authors: Cairns H. , Payne A. R.
Published: April 2009

A general method tor the preparation of 1,4‐dihydro‐4‐quinolone‐2‐carboxylic acids, especially those which carry alkyl substituents on the ring N‐atom, is described.
Studies on furan derivatives. II. Preparation of α‐substituted β‐2‐(5‐nitrofuryl)vinylamines
Authors: Tanaka Akira , Usui Toshinao , Yoshina Shigetaka
Published: April 2009

α‐Subslituted β‐2‐(5‐nitrofuryl)viriylamines were synthesized from α‐ary]‐β‐2‐(5‐nitrofuryl)‐aeryloyl azides and N‐[α‐substituled β‐2‐(5‐nitrofuryl)vinyl] pyridinium bromides.
An improved synthesis of gliamilide®, a high‐potency sulfamylurea hypoglycemic agent
Authors: Kuhla Donald E. , Sarges Reinhard , Barth Wayne E.
Published: April 2009

An efficient synthesis of the sulfamylurea, Gliamilide®, is described, which involves as a key feature the selective reduction of the more basic alkyl‐substituted pyridine ring in the mono‐hydrochloride salt of dipyridyl compound 11 to form 12 without affecting the 2‐methoxy‐nicotinamide moiety.
Synthesis of 7‐methoxy‐2‐methyl‐3,5,8‐isoquinolinetrione
Authors: Fukumi Hiroshi , Kurihara Hideshi , Mishima Hiroshi
Published: April 2009

Synthesis of 7‐methoxy‐2‐methyl‐3,5,8‐isoquinolinetrione from either 7‐ or 8‐isoquinolinol is described. 3,5,8‐Isoquinolinetrione is a novel heteroeyelic quinune which constitutes the aromatic carbon skeleton of mimosamycin.
Quinazolines and 1,4‐benzodiazepines. LXXXV syntheses of 3‐substituted lmidazo[1,5‐a] [1,4]benzodiazepines
Authors: Walser Armin , Flynn Thomas , Fryer R. Ian
Published: April 2009

1,4‐Benzodiazepines having a leaving group in the 2‐position were condensed with carbanions of 1,3‐dicarbonyl compounds. The products obtained were converted to the title compounds by a sequence of steps involving hydrolytic decarboxylation, nitrosation, catalytic hydrogenation and condensation with an orthoester or an amide acetal.

Oxidative condensation of the enediamine 12 with a variety of aldehydes also led to imidazo‐benzodiazepines with various substituents in the 1‐position.
Assignment and solvent dependence of the carbon‐13 nuclear magnetic resonance spectrum of nicotine
Authors: Pitner T. Phil , Seeman Jeffrey I. , Whidby Jerry F.
Published: April 2009

The 13C nmr spectrum of nicotine is assigned in Acetone‐d6, DMSO‐d6, Pyridine‐d5, and deuterium oxide (pD 10.7, 5.4, < 1). Attention is focused on assignment of the closely‐spaced C(2) and C(6) resonances, using selective decoupling, population transfer, and long‐range coupling constant measurements. C(2) resonates at lower field in the organic solvents hut at higher field in deuterium oxide at all pD values investigated.
Selenium heterocycles XXVI. Synthesis of theino[3,4‐b]benzofuran and selenolo[3,4‐b] benzofuran. Two novel heterocycles
Authors: Shafiee A. , Behnam E.
Published: April 2009

Starting from the readily available aryl 3‐methyl‐2‐benzo[b] furyl ketones a series of 3‐sub‐stituted thieno[3,4‐b] benzofurans and 3‐substituted selenolo[3,4‐b] benzofurans were prepared in high yield. The parent compound, thieno[3,4‐b] benzofuran was prepared through the reaction of thioacetamide with 2‐chloromethyl‐3‐formylbenzo[b] furan in moderate yield.
A novel synthesis of 8‐arylaminotheophyllines
Authors: Senga Keitaro , Ichiba Misuzu , Kanazawa Hashime , Nishigaki Sadao , Higuchi Masatsugu , Yoneda Fumio
Published: April 2009

A novel synthesis of 8‐arylaminotheophyllines (8a‐e) by the reaction of 5‐arylazo‐6‐ethoxy‐methyleneamino‐1,3‐dimethyluracils (2a‐e) or 5‐arylazo‐1,3‐dimethyl‐6‐dimethylaminomethylene‐aminouracils (3a‐e) with sodium dithionite in formic acid is described.
Novel heterocycles. I. Synthesis and reactions of 6,7‐dihydro‐1H,3H,5H‐pyrido[3,2,l‐ij] [3,1]benzoxazine‐1,3‐dione
Authors: Coppola Gary M.
Published: April 2009

6,7‐Dihydro‐1H,3H,5H‐pyrido[3,2,l‐ij][3,1 ]benzoxazine‐1,3‐dione (1b) was synthesized by a new route and its reactions with various nueleophiles are described.
An unexpected and efficient synthesis of 3‐chloro‐4‐cyanopyridine
Authors: Rokach Joshua , Girard Yves
Published: April 2009

Reaction of 4‐cyanopyridine N‐oxide with phosphorus oxychloride/phosphorus pentachloride gave 3‐chloro‐4‐cyanopyridine in good yield in sharp contrast to the expected chlorination in the 2‐position. A mechanistic interpretation of the results is proposed involving a chloride attack at the 4‐position as the main feature.
Authenticity of 2,6‐Dichloro‐1,5‐naphthyridine
Authors: Newkome George R. , Garbis Sam J.
Published: April 2009

The structure of 2,6‐dichloro‐1,5‐naphthyridine (1) was established based on physical and spectral data; thus, correcting the numerous inaccurate literature reports.
Substituted‐γ‐lactones. XXIX. N‐heterocycles via photolysis or thermolysis of 3‐(2‐azidophenylmethylene)‐4,5‐dihydro‐2‐(3H)furanone
Authors: Zimmer Hans , Downs Bruce
Published: April 2009

The thermolysis and/or photolysis of 3‐(2‐azidophenylmethylene)‐4,5‐dihydro‐2‐(3H)furanone offers a preparatively useful way towards the synthesis of indoles and quinolines. This method is superior over previously published methods which afforded these heterocycles in poor yields by the deoxygenative cyclization of 3‐(2‐nitrophenyImethylene)‐4,5‐dihydro‐2‐(3H)furanones. J. Heterocyclic Chem., 15, 703 (1978)
The synthesis of macrocyclic polyether‐diester compounds with a pyridine subcyclic unit
Authors: Bradshaw J. S. , Asay R. E. , Maas G. E. , Izatt R. M. , Christensen J. J.
Published: April 2009

Two new series of macrocyclic polyether‐diester ligands (4‐15) containing a pyridine subcyclic unit have been prepared by treating various oligoethylene glycols and sulfur‐containing oligo‐ethylene glycols with 2,6‐ and 3,5‐pyridine dicarbonyl chlorides. The compounds prepared from 2,6‐pyridine dicarbonyl chloride were: 3,6,9,12‐tetraoxa‐18‐azabicyclo[12.3.1 ]oetadeca‐1(18), 14,16‐triene‐2,13‐dione (4); 3,6,9,12,15‐pentaoxa‐21‐azabieyclo[15.3.1]heneicosa‐1(21),17,19‐triene‐2,16‐dione (5); 3,6,12,15‐tetraoxa‐9‐thia‐21‐azabicyclo[15.3.1 ]heneicosa‐1(21),17,19‐tri‐ene‐2,16‐dione(6); 3,9,15‐trioxa‐6,12‐dithia‐21‐azabicyclo[15.3.1]heneicosa‐1(21),17,19‐triene‐2,16‐dione (7); 3,6,9,12,15,18‐hexaoxa‐24‐azabicyclo[18.3.1 ]tetracosa‐1(24),20,22‐triene‐2,19‐dione (8); 3,6,9,12,15,18,21‐heptaoxa‐27‐azabicyclo[21.3.1]heptacosa‐1(27),23,25‐triene‐2,22‐dione (9); and the corresponding analogues from 3,5‐pyridine dicarbonyl chloride (10‐15). The solid potassium thiocyanate complex of compound 5 was also prepared.
Quinazolines and 1,4‐benzodiazepines. LXXXVII. Synthesis of 1‐ and 3‐phenylimidazo[1,5‐a] [1,4]benzodiazepines
Authors: Walser A. , Lauer R. F. , Fryer R. Ian
Published: April 2009

The synthesis of the 1‐phenylimidazobenzodiazepine 5 from 1 and the anion of the nitrone 2 is described. The 3‐phenyl‐derivative 14 was prepared via the ammo alcohol 11 which was obtained by condensation of the nitrosamine 9 with benzaldehyde followed by catalytic hydro‐genolysis of the nitroso group.
Un nouvel hétérocycle telluré: le benzisotellurazole‐1,2. I. Synthèse et propriétés
Authors: Weber Roland , Piette Jean‐Louis , Renson Marcel
Published: April 2009

Nous décrivons la synthèse, par deux méthodes différentes, d'un nouvel hétérocycle telluré de base, le benzisotellurazole‐1,2, et nous en comparons les propriétés avec celles des analogues sulfuré et sélénié correspondants.
New polyheterocyclic series based on 4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine
Authors: Lalezari I. , Jabari‐Sahbari M. H.
Published: April 2009

4,8‐Dimethyl‐6,7,8,9‐tetrahydropyrido[4′,3′:4,5]thieno[2,3‐e][1,2,4]triazolo[3,4‐a]‐4H‐pyrimidin‐5‐ones, 7‐methyl‐2,3,6,7,8,9‐hexahydropyrido[4′,3′:4,5]thieno[2,3‐d]pyrrolo[1,2‐a]‐1H, 10H‐pyrimidin‐10‐one, 8‐methyl‐1,2,3,4,7,8,9,10‐octahydropyrido[4′,3′:4,5]thieno[2,3‐d]‐11H‐pyrimidin‐11‐one, and 9‐methyl‐2,3,4,5,8,9,10,11‐octahydro[4′,3′:4,5]thieno[2,3‐d]azepino‐[1,2‐a]‐1H, 12H‐pyrimidin‐12‐one which consist four new heterocyclic ring systems were synthesized from 2‐amino‐3‐carbethoxy‐5‐methyl‐4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine.
Synthesis of internal standards for analytical determinations of primidone, and its metabolite, phenylethylmalonamide (PEMA)
Authors: Dudley Kenneth H. , Bius Daniel L. , Maguire James H.
Published: April 2009

Synthetic routes are described tor the preparation of internal standards for analytical determinations of the antiepileptic agent primidone (1) and one of its primary in vivo metabolites, phenylethylmalonamide (PEMA, 3). The internal standards synthesized in the present study are p‐methylprimidone (9) and p‐methylPEMA (8). The internal standards differ in structure from the parent drug and metabolite in that the phenyl substituents of the drug and metabolite have been replaced by p‐tolyl substituents. The synthetic route for the preparation of p‐methylPEMA (8) entailed conversion of an appropriately substituted malonate to a 4,4‐disubstituted pyrazoli‐dine‐3,5‐dione, and Raney nickel reduction of the latter substance to a malonamide. This same sequence of reactions was useful for the preparation of PEMA (3) itself. A fusion of p‐methylPEMA (8) with formic acid and formamidine acetate resulted in the formation of p‐methyl‐primidone (9).
Nucleosides de synthèse XVI: Sur une synthèse sélective de divers ribofuranosyl‐1‐purines
Authors: Montero J. L. , Dhainaut A. , Imbach J. L.
Published: April 2009

Ce travail décrit une approche générale de synthèse permettant de parvenir aux D‐ribo‐furanosyl‐1‐purines anomères par cyclisation de précurseurs imidazoliques correspondents. En particulier, les dérivés oxo‐6 et mercapto‐6 ont été décrits et leur structure confirmée par les méthodes physico‐chimiques usuelles d'analyse.
Formycin analogs. I. Model studies in the preparation of an isomer of formyein and related derivatives (s‐triazolo[4,3‐a] pyrazines)
Authors: Schneller S. W. , May J. L.
Published: April 2009

The synthesis of a number of 8‐substituted‐ and 3‐methyl‐8‐substituted‐.s‐triazolo[4,3‐a]‐pyrazines as model molecules for an isomer of formyein (i.e., 8‐amino‐3‐(β‐D‐ribofuranosyl)‐s‐triazolo[4,3‐a ]pyrazine (2)) and some of its derivatives (including aglycone) is reported. The C‐8 subslituents include amino (3a and 4a), chloro (3b and 4b), hydroxy (as the 8‐ones 8a and 9a), mercapto (as the 8‐thiones 8c and 9c), hydroxylamino (3e and 4e), selenoxy (as the 8‐selenones 8d and 9d), metlioxy (3g and 4g), and thiomethoxy (3h and 4h). Also described are 7‐methyl‐s‐triazolo[4,3‐a]pyrazin‐8(7H) one (8b) and its 3‐methyl derivative (9b) together with imidazo[1,2‐g]‐s‐triazolo[4,3‐a]pyrazine (10a) and its 3‐methyl derivative (10b). Complete spectral data for all of these molecules is presented.
Synthesis of 3‐aryl‐4‐isothiazolecarboxylates
Authors: Howe Robert K. , Cruner Terry A. , Carter Linda G. , Franz John E.
Published: April 2009

A short, convenient route to 3‐aryl‐4‐isothiazolecarboxylates is described in which aryl Grig‐nard reagents are added to the magnesium etiolate of ethyl cyanoacetete, and the resultant β‐aminocinnamates are converted via a Vilsmeier‐Haack reaction, thiation, and oxidation to the isothiazolecarboxylates.
Derivatives of phenyl‐2,3‐dihydroimidazo[1,2‐a]pyridinone
Authors: Magatti Charles V. , Villani Frank J.
Published: April 2009

The title compounds were prepared by the condensation of a series of β‐keto esters with 2‐benzylimidazoline. A mechanism is proposed wherein the dienamine 4 undergoes an intramolecular acylation with the elimination of ethoxide and subsequent hydride shift.
Composés hétérocycliques à partir (testers cyaniques. 4. Synthèse de nouvelles aroxy‐2 quinazolinones‐4
Authors: Hedayatullah Mir , Pailler Jacques
Published: April 2009

La réaction de cyclisation entre les cyanates d'aryle et l'anthranilate d'éthyle et le N‐méthyl‐anthranilate d'éthyle, en présence d'acide benzoique comme catalyseur, constitue une méthode símple eégenérale de synthèse d'aroxy‐2 quinazolinones‐4 et d'aroxy‐2 méthyl‐I quinazolinones‐4 avec des rendements élevés pour des temps de contact de quelques minutes.
Kinetic study on the conversion of pyridine‐ and quinolinecarboxylic acids to the corresponding trichloromethyl compounds
Authors: Takahashi Kazuyuki , Takeda Koichi , Mitsuhashi Keiryo
Published: April 2009

The reaction rates of the conversion of various substituted picolinic and quinaldinic acids to the corresponding trichloromethylpyridines and quinolines by treatment with phosphorus pentachloride in refluxing thionyl chloride have been measured, and the apparent second‐order kinetic constants determined. The logarithmic rate constants (log k) were found to be linear with the basicities (pKa) of the unsaturated ring nitrogens in the substrates. The reaction constant, p, of the conversion was estimated.
Fourier transform 13C NMR analysis of benzodiazepines
Authors: Singh Shiva P. , Parmar Surendra S. , Farnum Sylvia A. , Stenberg Virgil I.
Published: April 2009

The natural abundance carbon‐13 nuclear magnetic resonance spectra of diazepam, clonazepam, flurazepam and chlordiazepoxide were recorded in suitable solvent using the Fourier transform technique on a JEOL FX‐60 spectrometer. The relaxation time (T1) of these compounds were also measured. The chemical shift of the various carbon resonances have been assigned on the basis of chemical shift theory, multiplicity generated in single‐frequency off‐resonance decoupled spectra, relaxation time and the chemical shifts of the model compounds.
Synthesis of 5‐(1 ‐naphthylmethyl)‐4‐aryl‐s‐triazole‐3‐thiol/yl‐thioglycolic acids as possible anti‐inflammatory agents
Authors: Kothari P. J. , Kishore V. , Stenberg V. I. , Parmar S. S.
Published: April 2009

Several 5‐(1‐naphthylmethyl)‐4‐aryl‐S‐triazoIe‐3‐thiol/yl‐thioglycolic acids were prepared as possible anti‐inflammatory agents. The infrared, nuclear magnetic resonance and mass spectra of these compounds are reported.
Heterocycles. CLXIX. Barriers to rotation in some N,N‐Dimethyl‐N′‐heteroaryl, N,N‐Diethyl‐N′‐heteroaryl‐substituted formamidines and N,N‐Dimethyl‐N′‐heteroaryl‐substituted acetamidines
Authors: Drobnič‐Košorok M. , Polanc S. , Stanovnik B. , Tišler M. , Verček B.
Published: April 2009

The free energies of the rotational barriers, ΔG*, about CHNMe2 bond in N′‐heteroaryl N,N‐dimethylformamidines (A), about CHNEt2 bond in N‐heteroaryl N,N‐diethylformamidines (B), and about C(Me)NMe2 bond in N′‐heteroaryl N,N‐dimethylacetamidines (C) have been found to be in the range 17.5–20.1 kcal/mole for type A, 18.8–21.6 kcal/mole for type B and 13–14 kcal/mole or below for type C of compounds, respectively. The compounds of the types A and B exist in the forms IIa, IIIa, IV, V, and VI, while the compounds of the type C exist in the forms IIb and IIIb.
Synthesis of 10‐aminophenothiazines and derivatives
Authors: Corral Carlos , Lissavetzky Jaime , Quintanilla Gloria
Published: April 2009

In this paper it is shown that 2‐nitro‐2′‐(β‐acetyl) hydrazinodiphenyl sulfides cyclize, via a Smiles rearrangement, to 10‐acetylaminophenothiazines, which are inert to alkalis and suffer a strong decomposition by acids. 10‐Aminophenothiazine has been obtained by ring closure of 2‐bromo‐2′‐hydrazinodiphenyl sulfide via an assumed benzyne intermediate.
Synthesis of imidazo[1,2‐a] pyridinium salts from 2‐alkylaminopyridines. A reexamination
Authors: Kuhla Donald E. , Watson H. A.
Published: April 2009

1‐Alkyl‐2‐hydroxy‐2,3‐dihydroimidazo [1,2‐a] pyridinium salts (III) have been identified as isolatable intermediates in the synthesis of 1‐alkylimidazo[1,2‐a] pyridinium salts (II) from 2‐alkylaminopyridines and α‐haloketones. Spectral data suggest that these intermediates exist exclusively as the cyclic ring tautomers III rather than chain tautomers VI.
Etude des conditions d'accès au triazino‐1,2,4‐[4,5‐b] indazole
Authors: Robba Max , Lancelot Jean‐Charles , Maume Daniel , Rabaron Alain
Published: April 2009

Le dihydro‐1,2 oxo‐1 triazino‐1,2,4‐[4,5‐b] indazole et ses dérivés sont accessibles par transposition de l'[(oxadiazolyl‐1,3,4)‐2]‐3 indazole ou par cyclisation d'éthoxyméthylidène hydrazides indazoliques. La synthèse du dioxo‐1,4 tétrahydro‐1,2,3,4 triazino‐1,2,4‐[4,5‐b] indazole est realisable par cyclisation du N‐carbéthoxyhydrazide du carboxy‐3 indazole et celle du dihydro‐3,4 oxo‐4 triazino‐1,2,4‐[4,5‐b] indazole par cyclisation de la N‐carbéthoxy hydrazone du formyl‐3 indazole. Le triazino‐1,2,4‐ [4,5‐b] indazole est accessible par l'intermédiaire du dihydro‐1,2 thioxo‐1 triazino‐1,2,4‐[4,5‐b] indazole. Les spectres de rmn 1H sont étudiés.
Substituent effects on the mass spectrometric fragmentations of 4‐aryl‐3,3‐dichlorooxetan‐2‐ones
Authors: Krabbenhoft Herman O.
Published: April 2009

The electron impact mass spectrometric fragmentation pathways for a series of 4‐aryl‐3,3‐di‐chlorooxetan‐2‐ones were investigated. It was found that cleavage to radical cations of dichloroketene and/or the substituted benzaldehyde is preferred by a large measure to cleavage to radical cations of carbon dioxide and/or the substituted β,β‐dichlorostrene. Furthermore, it was demonstrated that the nature of the substituent has a significant influence on the localization of charge in the preferred direction of cleavage.
Novel heterocycles. 2. Synthesis of the 1,3,2‐benzodiazaphosphorin ring system
Authors: Coppola Gary M. , Mansukhani Ruth I.
Published: April 2009

A series of 1,3‐disubstituted‐2,3‐dihydro‐1,3,2‐benzodiazaphosphorin‐4(1H)one 2‐oxides was prepared by a method involving the treatment of an appropriate anthranilamide with phosphorus trichloride. Tricyclic diazaphosphorins 24 and 28 were also prepared. Some spectral data of the products are also discussed.
Carbocyclisations et hétérocyclisation de dérivés orthodibenzylés, par action du soufre
Authors: Lepage Lucette , Lepage Yves
Published: April 2009

Le diphényl‐1,4 dibenzyl‐2,3 butadiène est un bon précurseur de composes o‐dibenzylés grǎce à des réactions de cycloaddition. II permet aussi, par cyclisation, une synthèse d'un dérivé du naphtacène en trois étapes à partir de l'oxalate d'éthyle.

L'action du soufre sur divers composés aromatiques o‐dibenzylés permet d'accéder à des benzo [c] thiophènes et měme à des naphto [2,3‐c] thiophènes; des réactions concurrentes de carbocyclisation avec formation de benzo[a]acéanthrylène et de dihydro indéno [2,1‐a] fluorène sont observées.
as‐Triazino[4,5‐α] indoles. III. Etude des substitutions électrophiles des triazinoindolones
Authors: Robba Max , Maume Daniel , Lancelot Jean‐Charles
Published: April 2009

Les triazinoindolones‐1 et −4 1,2,3 se prětent a des réactions de substitution électrophile d'une part au niveau de l'azote lactamique au moyen d'agents électrophiles tels que le sulfate diméthylique ou le chlorure de benzyle et d'autre part au niveau de l'homocycle au moyen du brome ou de l'acide nitrique. Les réactions de bromation et de nitration aboutissent soit à des monosubstitutions en position 10, soit a des disubstitutions en position 7 et 10 ou 9 et 10 ou encore à des polysubstitutions conduisant à des melanges d'isomères tri ou tétrasubstitués. Les structures des dérivés obtenus ont été déterminées grǎce à plusieurs méthodes: rmn, étude de l'effet Overhauser et par synthèse univoque.
The coordination chemistry of simple phospholes. Complexes of rhenium, ruthenium, cobalt, rhodium and iridium chlorides and of some chlorocarbonyls of ruthenium and rhodium
Authors: Holah David G. , Hughes Alan N. , Hui Benjamin C. , Tse Pui‐Kwan
Published: April 2009

The reactions of 1‐phenylphosphole (PP), 3‐methyl‐1‐phenylphosphole (mPP), 3,4‐dimethyl‐1‐phenylphosphole (dPP) and, in certain instances, 1‐n‐butyl‐3,4‐dimethylphosphole (dBP) with some transition metal chlorides and some metal‐Cl‐CO systems are reported. These reactions show that simple phospholes in general unexpectedly behave much like ordinary tertiary phosphines and that, unlike the reactions with Ni(II), Pd(II) and Pt(II), the complexes formed are conventional in most respects. However, a few unusual reactions were observed. For example, mPP partially reduces Ru(III) to give a mixed‐valent Ru(III)‐Ru(II) complex while PP reduces Ir(III) to Ir(I). From infrared spectroscopic studies of the square‐planar Rh(I) complexes L2Rh(CO) Cl (L = phosphole), it appears that donor character decreases with decreasing substitution on the phosphole ring carbon atoms. Phosphorus‐phenyl cleavage has been observed in reactions of 1‐phenylphosphole with Rh‐CO systems. The results are briefly discussed in relation to the behaviour of other phospholes in similar reactions and in the context of the electronic structure of phospholes.
Thermal [1, 3] benzoyl migration in 1‐(α‐benzoyloxyarylideneamino)‐1,2,3‐triazoles. Part II
Authors: Kehrbach W. , Alexandrou N. E.
Published: April 2009

1‐(α‐Benzoyloxyarylideneamino)‐4, 5‐dirnethyl‐1,2,3‐triazoles (V) were prepared by reacting the sodium salt of substituted 1‐benzoylamino‐4, 5‐dimethyl‐1,2,3‐triazoles (IV) with benzoyl chloride at −50°. The uncatalyzed thermal isomerization of isoimides V to the corresponding imides VI was studied kinetically and the reaction mechanism is discussed.
γ‐Lactones from malonic acid derivatives
Authors: Campaigne E. , Raval P. , Beckman J. C.
Published: April 2009

The acid catalyzed cyclization of isopropylidene malonate derivatives of ketones to form α‐earboxy‐γ‐lactones has been shown to occur with boron trifluoride etherate or p‐toluenesulfonic acid, as well as with concentrated sulfuric or polyphosphoric acids. A similar cyclization of a diethyl ylidenemalonate to a lactone ester, in relatively poor yield, has also been accomplished. Acid catalyzed cyclization of the ylidenemalononitrile derived from pinacolone to form an α‐carbamoyl‐γ‐lactone has been shown to occur with rearrangement. However, that derived from 2,2‐dimethyleyclohexanone cyclized to the secondary carbon of the ring without rearrangement. The isopropylidene malonate derivatives of several ring‐substituted and bridged ketones have been converted to α‐earboxy‐γ‐laetones without rearrangement.
Reissert compound studies. XXXI. Emetine analogs based on the reaction of the reissert anion with 1,3,4,6,7,11b‐hexahydro‐9, 10‐dimethoxybenzo[a] quinolizin‐2‐ones
Authors: Watts Raymond F. , Popp Frank D.
Published: April 2009

Reaction of the Reissert anion with the carbonyl group of 1,3,4,6,7,11b‐hexahydro‐9,10‐dimethoxybenzo[a]quinolizin‐2‐one and with 3‐ethyl‐1,2,3,4,6,7‐hexahydro‐9,10‐dimethoxy‐11bH‐benzo[a]quinolizin‐2‐carboxaldehyde give emetine analogs. This anion does not react with the carbonyl group of 3‐aIkyl‐1,3,4,6,7,11b‐hexahydro‐9,10‐dimethoxybenzo[a]quinolizin‐2‐one but instead gives a rearrangement product and the benzoquinolizinone cyanohydrin.
Reactions with heterocyclic amidines 1. Cyanoethylation of cyclic amidines
Authors: Fahmy Sherif Mahmoud , Kandeel Ezzat Mohamed , Elsayed El‐Farouk Rabia , Elnagdi Mohamed Hilmy
Published: April 2009

2‐Amino‐5‐phenyl‐1,3,4‐oxadiazole (1a) and 2‐amino‐1,3,4‐thiadiazole (1b) reacted with acrylonitrile to yield β‐cyanoethylamino derivatives. On the other hand, 2‐amino‐4‐phenylthiazole (2) reacted with acrylonitrile under the same experimental conditions to yield a di‐β‐cyanoethylaminothiazole derivative. 3‐Phenyl‐Δ2‐1,2,4‐triazoline‐5‐thione reacted with acrylonitrile to yield the corresponding adduct. The structure of the adduct was established by its conversion into the acid 13 which could be synthesised via another independent route.
1,3‐Dipolar cycloadditions of anhydro‐5‐hydroxyoxazolium hydroxide generated from 2‐piperidinecarboxylic acid. Isolation of the primary adduct and synthesis of tetrahydroindolizines
Authors: Uchida Takane , Tsubokawa Shigeharu , Harihara Kiyoko , Matsumoto Kiyoshi
Published: April 2009

1,3‐Dipolar cycloaddition reactions of anhydro‐5‐hydroxyoxazolium hydroxide 3 generated from 2‐piperidinecarboxylic acid and acetic anhydride, with dimethyl and diethyl acetylene‐dicarboxylates, dibenzoylacetylene, p‐benzoquinone, and 1,4‐naphthoquinone gave the corresponding tetrahydroindolizines. In the case of the reaction with p‐benzoquinone, the dihydroindolizine 12 was also formed. The primary N‐bridged lactone intermediate 4 was isolated from the reaction of 2 with dibenzoylacetylene. Several attempted conversions of these tetrahydroindolizines into the corresponding aromatic indolizines were fruitless.
Synthesis of 2,5‐disubstituted tetrazoles as possible antiinflammatory agents
Authors: Kishore Vimal , Parmar Surendra S. , Gildersleeve David L.
Published: April 2009

Several 2‐(1‐acetoxy‐3‐substituted carbamido)‐5‐phenyltetrazoles were synthesized as possible antiinflammatory agents. Nmr spectroscopy was used as a tool in assigning the structure of the. Positional isomers of these substituted phenyltelrazoles. Compounds possessing antiinflammatory activity (100 mg./kg., i.p.) provided 11–41% protection against carrageenin‐induced edema in rats. Seven of these substituted phenyltelrazoles possessed antiproteolytic activity and the in vitro inhibition of trypsin activity during hydrolysis of bovine serum albumin ranged from 9–66%.
Reaktionen von 5‐diazourazilen mit primären aminen zu 1,2,3‐triazolcarbonsäurederivaten
Authors: Romani Sigrun , Klötzer W.
Published: April 2009

The reaction of 5‐diazouracils with saturated primary amines affords [(1‐alkyl‐1,2,3‐triazol‐4‐yl) carbonyl]ureas. The primary formation of a non‐isolable 6‐amine‐adduct 2 is followed by 1,6‐ring opening of the pyrimidone and ring closure to the triazole derivative.
3,5‐Disubstituted‐1,2,4‐oxadiazoles and 4,5‐dihydro‐3,5‐disubstituted‐1,2,4‐oxadiazoles
Authors: Yale Harry L. , Spitzmiller E. R.
Published: April 2009

A series of 3,5‐disubstituted‐1,2,4‐oxadiazoles (2) were prepared from a mono‐ or dichlorophenyl‐substituted amidoxime and (i) an acid chloride, (ii) an isatoic anhydride, or (iii) a β‐keto ester. Although cyclizations of the same amidoximes with acetaldehyde gave 4,5‐dihydro‐5‐methyl‐substituted derivatives (5), that annulation procedure either failed or gave low yields with other aldehydes. A novel alternative method, the diborane reduction of 2, has been found to be a generally applicable procedure for preparing 5. The reduction is regioselective, i.e., only the 4,5‐(C=N) linkage is reduced even when a large excess of diborane is present.
Synthesis of benzofuro[3,2‐b] quinolin‐6(11H) one and derivatives
Authors: Sunder Shyam , Peet Norton P.
Published: April 2009

A new and efficient synthesis of benzof'uro[3,2‐b]quinolin‐6(11H) one (3) is reported, by treatment of 2‐ {[(phenoxy)acetyl]amino} benzoic acid (6a) with polyphosphoric acid. An intermediate in the conversion of 3 to 6a, namely, 2‐(3‐benzofuranylamino)benzoic acid (7), was defined. An improved method for the synthesis of 6a is also described, which was used to prepare analogs (6b‐n) of 6a. In addition, an 11‐alkoxy derivative (8) and 11‐dialkylamino derivatives (10 and 11) of benzofuro [3,2‐b]quinoline were prepared from 3.
Carbon‐13 Nmr spectra of 1,2,3‐thiadiazoles
Authors: Looker James H. , Khatri Nazir A. , Patterson Ronald B. , Kingsbury Charles A.
Published: April 2009

Natural abundance 13C nmr spectra are reported for 1,2,3‐thiadiazole and nine derivatives. The spectra are discussed in terms of α‐ and β‐effects of substituent groups and compared with corresponding spectra of alkene and benzene derivatives. 13C nmr spectra of four 1,3,4‐thiadiazoles are presented. Spectral data indicate that in dimethylsulfoxide solution 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazole exists predominantly as the thione tautomer.
Benzofuro[2,3‐d]pyridazines IV. Etude de la chloro‐4 benzofuropyridazine
Authors: Robba Max , de Sévricourt Michel Cugnon , Godard Anne‐Marie
Published: April 2009

La [1]benzofuro[2,3‐d]pyridazine est accessible par plusieurs méthodes: réduction catalytique de la chloro‐4 benzofuropyridazine, déshydrazination oxydative de l'hydrazino‐4 benzofuropyridazine et désulfuration de la 4 H‐benzofuropyridazinethione‐4. Ses dérivés de substitution en 4 sont obtenus par attaque nucléophile de la chloro‐4 benzofuropyridazine alors que la tétrazolo[1,5‐b]‐ et les s‐triazolo[1,2‐b]benzofuro[2,3‐d]pyridazines sont accessibles par cyclisation de l'hydrazino‐4 benzofuropyridazine. L'analyse du spectre de rmn de la benzofuropyridazine a été effectuée grǎce à l'étude de l'effet Overhauser.
Acylation of heteroaromatic amines . Perbenzoylation of diaminopyridazines
Authors: Suzuki Toshinobu , Katou Nobuhiro , Mitsuhashi Keiryo
Published: April 2009

Some diaminopyridazines such as 4,7‐diaminoimidazo[4,5‐d]pyridazine, 1‐methyl‐4,7‐diaminoimidazo[4,5‐d]pyridazine, 5,8‐diaminopyrazino[2,3‐d]pyridazine, 2,3‐dimethyl‐5,8‐diaminopyrazino[2,3‐d]pyridazine and 1,4‐diaminophthalazine, all of which were prepared by the reaction of hydrazine with the respective vic‐dicyanide as starting material, were reacted with benzoyl chloride in the presence of triethylamine, giving novel perbenzoylated derivatives in good yield. A dibenzoylation mechanism of the amino group has been proposed.
Compounds in the pyrrolo[3′,4′:4,5] pyrrolo[3,4‐b]indole series
Authors: Yevich Joseph P. , Murphy John R. , Dufresne Richard F. , Southwick Philip L.
Published: April 2009

Compounds in the new pyrrolo[3′,4′:4,5]pyrrolo[3,4‐b]indole series have been produced by an imide cyclization of appropriate derivatives of pyrrolo[3,4‐b]indole.
Ring transformation of 6‐methyl‐3,4‐dihydro‐2H‐1,3‐oxazine‐2,4‐diones
Authors: Kato Tetsuzo , Izumi Uichiro , Katagiri Nobuya
Published: April 2009

Ring transformation of 6‐methyl‐3,4‐dihydro‐2H‐1,3‐oxazine‐2,4‐dione (Ia) and its N‐sub‐stituted derivatives, such as 3‐methyl (Ib), 3‐ethyl (Ic), and 3‐benzyl (Id) derivatives is described. Reaction of Ia with hydrazine hydrate gave 1‐amino‐6‐methyluracil (II), while Id reacted with hydrazine hydrate to give 3‐hydroxy‐5‐methylpyrazole (III). Reaction of Ia,b,d with ethyl acetoacetate in ethanol in the presence of sodium ethoxide afforded ethyl 3‐acetyl‐6‐hydroxy‐4‐methyl‐2(1H) pyridone‐5‐carboxylate derivatives (IVa,b,d). On the other hand, reaction of Ib,c,d with ethyl acetoacetate in tetrahydrofuran in the presence of sodium hydride did not give IV, but gave 3‐acetyl‐1‐alkyl‐5‐(N‐alkylcarbamoyl)‐6‐hydroxy4‐methyl‐2(1H) pyridone (VIb,c,d). Mechanisms for the formation of compounds IV and VI are discussed.
Chemical investigations of citraconimide
Authors: Earl Robert A. , Clough Fred W. , Townsend Leroy B.
Published: April 2009

The chemical reactivity of citraconimide (3‐methylmaleimide, 2) has been investigated with special emphasis being placed on the use of mild and selective reaction conditions. Particular attention has been focused on the theiotropic reactivity of citraconimide. The results indicate that the reaction of various mercaptans with citraconimide is highly regioselective resulting predominately in the geminally substituted products with the percentage of vicinally substituted products increasing as a function of the steric bulk of the alkyl mercaptan. Additional studies on the double bond of citraconimide have furnished 4‐halogeno‐ and the 3,4‐dihydro derivatives of citraconimide. Several N‐substituted citraconimide derivatives have also been prepared.
Synthèse et tautoméric d'amino‐3 et d'hydroxy‐3 buténolide
Authors: Payard Marc , Paris Joelle , Tronche Pierre
Published: April 2009

La synthèse d'amino‐3 et d'hydroxy‐3 méthyl‐2 cyclohexane spiro‐4,4 butène‐2 olide‐4 est effectuée au depart d'isocyanate ou de précurseur d'isocyanate. Les structures tautomères étudiées à l'aide des spectres ir et de rmn et par la réactivité des groupements fonctionnels sont discutées.
An improved preparation of tetrahydropyridines from 1‐alkyl‐3‐acylpyridinium salts
Authors: Chevolot L. , Husson H.‐P.
Published: April 2009

The hydrogenation of 1‐alkyl‐3‐acylpyridinium salts in methanol in the presence of 10% palladium‐charcoal/disodium hydrogen phosphate‐sodium dihydrogenphosphate suspension leads to the corresponding tetrahydropyridines. This represents an improvement over the Wenkert method.
Direct sulfhydrolysis of cyclic AMP: A one‐step synthesis of the cyclic ribonucleotide of 6‐mercaptopurine
Authors: Meyer Rich B. , Stone Thomas E. , Heinzel Frederick P.
Published: April 2009

Treatment of adenosine cyclic 3′,5′‐phosphate with liquid H2S in aqueous pyridine provided a convenient, one‐step synthesis of 9‐β‐D‐ribofuranosylpurine‐6(1H) thione cyclic 3′,5′‐phosphate.
1,3,4‐Thiadiazoles. XI. Synthesis and behaviour of 4‐Alkyl‐5‐acyl‐1,3,4‐thiadiazolines
Authors: Alemagna Andreina , Bacchetti Tullio
Published: April 2009

The synthesis of the title compounds from thiadiazolium salts and aldehydes, and their behaviour towards some nucleophiles and aldehydes are described.
Reaction of diethyl acetonedicarboxylate with nitrosyl chloride
Authors: Silverman Richard B.
Published: April 2009

The reaction of diethyl acetonedicarboxylate with greater than two equivalents of nitrosyl chloride or the reaction of diethyl isonitrosoacetonedicarboxylate with one equivalent of nitrosyl chloride gave diethyl 4‐hydroxyisoxazole‐3,5‐dicarboxylate in quantitative yield. Mechanistic possibilities are discussed.
Direct oxidation of a heterocyclic nitroso dimer
Authors: Bozzi Edward G. , Clapp Leallyn B.
Published: April 2009

A cyclic cis‐nitroso dimer, 3,4‐dibromo‐3,5,5‐trimethylpyrazoline 1,2‐dioxide was oxidized directly to an open chain 1,3‐dinitro compound by a peroxyacid but nitrosyl chloride displaced bromine, added, and oxidized the same compound to 3‐chloro‐4‐nitro‐3,5,5‐trimethylpyrazoline 1,2‐dioxide.
Polymorphism in the 2‐(4‐morpholinothio) benzothiazole
Authors: Guzman J. , Largo‐Cabrerizo J.
Published: April 2009

The existence of two conformational isomers (A and B) with different crystal structures in 2‐(4‐morpholinothio) benzothiazole is shown. The melting temperatures of the two conformers are 345° and 357° K, respectively. The difference between the values of the melting enthalpies and entropies gives an indication of the two isomers flexibility whose proportion depends on the thermal history of the sample.
Reactivity of the A‐CH=N‐NR‐CX‐B system: 1,3,4‐Oxadiazoles
Authors: Werber Giuseppe , Buccheri Francesco , Noto Renato , Solazzo Vittorio
Published: April 2009

A number of 5‐alkyl(or aryl)‐amino‐1,3,4‐oxadiazole‐2‐carboxyalkylesters have been prepared.
A new method of synthesis of some 2‐aryl and 2‐heterocyclic benzimidazole, benzoxazole and benzothiazole derivatives
Authors: Cohen Victor Israel
Published: April 2009

A new one‐step facile method for the synthesis of some benzimidazole, benzoxazole and benzothiazole derivatives is described. The method involves the action of aromatic and heterocyclic selenoamides on some o‐phenylenediamine, o‐aminophenol and o‐aminothiophenol and their derivatives.
Reaction of ketenes with N,N‐disubstituted α‐aminomethyleneketones VIII. Synthesis of N,N‐disubstituted 4‐amino‐3‐chloro‐6‐phenyl‐2H‐pyran‐2‐ones
Authors: Bargagna Alberto , Schenone Pietro , Evangelisti Filippo
Published: April 2009

The dipolar 1,4‐cycloaddition of dichloroketene to N,N‐disubstituted 3‐amino‐1‐phenyl‐2‐propene‐1‐onesled directly to N,N‐disubstituted 4‐amino‐3‐chloro‐6‐phenyl‐2H‐pyran‐2‐ones only in the case of an usual aliphatic N,N‐disubstitution. In the case of partial or full aromatic N‐substitution, N,N‐disubstituted 4‐amino‐3,3‐dichloro‐3,4‐dihydro‐6‐phenyl‐2H‐pyran‐2‐ones were instead obtained, which were dehydrochlorinated with DBN to the corresponding 4‐amino‐3‐chloro‐6‐phenyl‐2H‐pyran‐2‐ones.
Azo coupling of benzenesulfonylhydrazones of heterocyclic aldehydes
Authors: Shawali A. S. , Fahmi A. A. , Eweiss N. F.
Published: April 2009

The reaction of aldehyde phenylsulfonylhydrazones (VII‐XI) with diazotized aromatic and heterocyclic primary amines gave the tetrazoles (XIV‐XIX). The yield of the tetrazoles was found to depend to some extent on the nature of the substituent present in the aldehyde moiety. The structures of the tetrazoles obtained was established on the basis of their analytical and spectral data. A tentative explanation for their formation is proposed. The acid dissociation constants of the tetrazoles (XIV) were also determined.
The synthesis of a pyrido[3,4‐d]pyrimidine analog of pteroic acid
Authors: Maguire James H. , Mckee Robert L.
Published: April 2009

A multistep synthesis of ethyl 5‐amino‐2‐methyIpyridine‐4‐carboxylate (5a) starting from ethyl acetopyruvate and nitroacetamide is described. The condensation of 5a with benzoylcyanamide gave 2‐amino‐3‐benzoyl‐6‐methylpyrido[3,4‐d]pyrimidin‐4(3H) one (10), which could be hydrolyzed in alkali to give 2‐amino‐4‐hydroxy‐6‐methylpyrido[3,4‐d]pyrimidine (9). Free radical bromination of 10 in bromotrichloromethane gave a mixture of the bromo‐ and chloromethyl‐ derivatives (11). Fusion of 11 with ethyl p‐aminobenzoate, followed by alkaline hydrolysis gave the corresponding pteroic acid analog (12).
Reactivity of the A‐CH=N‐NR‐CX‐B system. 4‐Methyl‐5‐hydroxy‐5‐phenyl‐(or thienyl)‐2,3,4,5‐tetrahydro‐1,2,4‐triazin‐3‐ones and their ring contraction products
Authors: Werber Giuseppe , Buccheri Francesco , Vivona Nicolò , Bianchini Rosangela
Published: April 2009

The behaviour of some monosemicarbazones of phenyl‐ (1a‐c) and thienyl‐glyoxal (2a‐c) towards cyclizing agents has been investigated. Upon aqueous sodium hydroxide treatment, 4‐melhyl‐semicarbazones 1a and 2a gave the addition products 3 and 4, respectively, whereas the 2‐methyl‐ and 2,4‐dimethyl derivatives 1b,c and 2b,c gave demolition products only. On the other hand, compounds 1b,c gave the addition product 8 and the triazine 7, respectively, on treatment with aqueous hydrochloric acid.

Bromination of 1a,b gave the bromosemicarbazone 10a and a mixture of 10b and 9, respectively. Performing the same reaction on 3 and 4 at 115°, the 1,3,4‐oxadiazoles 13 and 14 have been obtained.

The behaviour of bromosemicarbazones [10a,b] and of the bromo‐tetrahydrotriazine 9 towards heating or treatment with base has also been investigated.
Réactions de substitution nucléophile de l'hydroxyurée. Synthèse et étude des oxa‐6 dihydrouraciles
Authors: Bennouna Chakib , Petrus Francpise , Verducci Jean
Published: April 2009

L'action de l'hydroxyurée, hydroxylamine N‐protégée, sur les α‐bromoesters conduit aux α‐ureidoxyésters isolables dans certains cas; leur cyclisation est une voie de synthèse des oxa‐6 dihydrouraciles dont la structure est prouvée par les méthodes physicochimiques: en particulier la rmn 13C met en évidence la présence de la seule forme tautomère dicarbonylée.
A Synthesis of 2‐Arylimidazo[1,2‐a]pyridin‐3‐ols
Authors: Deady Leslie W. , Slanborough Mark S.
Published: April 2009

Substituted 2‐aminopyridine 1‐oxides condense with phenacyl bromides to form the title compounds.
Synthesis of 2‐amino‐3‐methoxypyrazinc
Authors: Bolta M. , De Angelis F. , Nicoletti R.
Published: April 2009

A new synthesis of 2‐amiuo‐3‐methoxypyrazine, an intermediate in the synthesis of sulfalene, via 2‐carbamido‐3‐hydroxy pyrazine and subsequent Hofmann rearrangement of 2‐carhamido‐3‐methoxypyrazine, is described.
Polycondensed nitrogen heterocycles. VII. 5,6‐Dihydro‐7‐h‐pyrrolo[1,2‐D]‐[1,4] benzodiazepin‐6‐ones. A novel series of annelatcd 1,4‐benzodiazepines
Authors: Aiello Enrico , Dattolo Gaetano , Cirrincione Girolarno , Plescia Salvalor E. , Daidone Giuseppe
Published: April 2009

The synthesis of a novel class of annelated 1,4‐benzodiazepinen, the 2‐R‐3 methyl‐5,6‐dihydro‐7H‐pyrrolo[1,2‐d][1,4]benzodiazepin‐6‐ones (Ve‐e), is described. The reaction of 2‐(o‐aminophenyl)‐3‐R‐5‐methylpyrroles(IIIa,b) with bromoacetyl bromide in the presence of triethylamine produced the title compounds. An alternative synthetic route was achieved by means of the reactions of 1a,b with the appropriated α‐aminoacids. The catalytic reduction of IVe‐e over 10% palladium on charcoal led in good to excellent yields directly to the formation of pyrrolo[1,2‐d]‐[1,4]benzodiazepines (Ve‐e).
Synthesis of 1,2,4‐oxadiazines and their rearrangement to pyrimidines
Authors: Santilli Arthur A. , Scotese Anthony C.
Published: April 2009

Several amide oximes underwent condensation reactions with dimethyl acetylene dicarboxylate to afford 1:1 adducts. Under basic conditions, these adducts underwent ring closure to afford several methyl [3‐(substituted)‐4,5‐dihydro‐5‐oxo‐6H‐1,2,4‐oxadiazin‐6‐ylidene]acetates. The reactions of these compounds with a variety of amines resulted in addition‐rearrangement reactions with the formation of the corresponding methyl 2‐substituted‐5‐substituted amino‐1,6‐dihydro‐6‐oxo‐4‐pyrimidine carboxylates.
Reaction of sulfene with n,N‐disubstituted α‐aminomethyleneketones vi. Synthesis of n,n‐disubstituted 4‐amino‐3,4‐dihydro‐6‐phenyl‐1,2‐oxathiin 2,2‐dioxides and of 4‐methylphenylamino‐3,4‐dihydro‐5,6‐polymethylen‐1,2‐oxathiin 2,2‐dioxides
Authors: Evangelisti Filippo , Schenone Pietro , Bargagna Alberto
Published: April 2009

The title compounds were obtained by cycloaddition of sulfene to N,N‐disubstituted 3‐amino‐1‐phenyl‐2‐propen‐1‐ones and to 2‐metbylphenylaminomethylenecycloalkanones, respectively. Steric and electronic aspects of these reactions, as well as the failure of cycloaddition in the case of N,N‐disubstituted 4‐arnino‐3‐buten‐2‐ones, are also discussed.
Ethers of indoxylie acid
Authors: Calun Arjeh , Us Arie Mark , Kampf Arieh
Published: April 2009

O‐alkylations of indoxylie acid (2b) to produce 3‐indolyl‐alkyl ethers and a synthesis of 5‐melhoxy‐2‐earboxyindol‐3‐oxyaeetic acid (25) are described.
Synthesis and aikylation of CIS‐α‐hydroxyisopropylindanone‐2‐carboxylic acid lactone
Authors: Campaigne E. , Frierson Manton R.
Published: April 2009

The Meldrum's acid adduct of isobutyrophenone was cyclized directly and in high yield to the title compound, which could then be alkylated at the 2‐position with methyl iodide or ethyl 6‐bromohexanoate. In the latter case, acid hydrolysis of the resultant ester gave the analogous acid, but alkaline hydrolysis resulted in ring opening of the indanone portion of the molecule.