bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthèse, à partir du (+) — camphre, d'hétérocycles dérives des tétrahydroxanthone, tétrahydroacridone, tétrahydroacridine et octahydroacridine
Authors: Sotiropoulos Jean , El Batouti Nagui , Lamazouère Anne‐Marie
Published: April 2009

Certaines arylidène‐3, arylméthyl‐3 et aroyl‐3 bornanones‐2, convenablement substitutés dans le noyau aromatique, et des dibornanonylarylméthanes peuvent subir une hétérocyclisation avec de bons rendements sous l'action de l'ammoniac ou des amines ou de la potasse, en présence ou non de catalyseurs, pour conduire à des dérivés de la tétrahydroxanthone, de la tétrahydro ou octahydroacridine et de la tétrahydroacridone. Dans certains cas, la cyclisation est accompagnée d'aromatisation.
Synthesis of phosphacoumarins and phosphonocoumarins. Two new classes of fluorescent dyes
Authors: Chen Chin H. , Fox John L. , Lippert Joseph L.
Published: April 2009

The synthesis of two new classes of phosphorous‐containing coumarin dyes is described and their fluorescent properties are compared with those of known coumarin dyes.
Improved syntheses of 6‐hydroxy‐5‐methoxy‐ and 5‐hydroxy‐6‐methoxyindoles and their O‐acetates, analogs of natural eumelanin precursors
Authors: Rogers C. Bradford , Blum Charles A. , Murphy Bryan P.
Published: April 2009

Improved routes for syntheses of gram quantities of the isomeric 5,6‐acetoxymethoxyindoles, and milligram amounts of the 5,6‐hydroxymethoxyindoles, have been developed. They depend on regiospecific nitration of the benzyl ethers of vanillin and isovanillin as the first steps. Improved condensations of 4,5‐acetoxymethoxy‐2‐nitrobenzaldehydes with nitromethane gave 4,5‐acetoxymethoxy‐2,β‐dinitrostyrenes as the key intermediates to all four indoles.
Polycyclic N‐hetero compounds. XXII Reaction of pyridine N‐oxides and Pyrazine di‐N‐oxides with formamide
Authors: Hirota Takashi , Namba Tetsuto , Sasaki Kenji
Published: April 2009

Reactions of pyridine N‐oxides, pyrazine di‐N‐oxides, and their benzologues with formamide are described. Carbamoylation mainly occurred at aromatic ring with loss of the N‐oxide oxygen atom, however, 2,4,6‐trimethylpyridine 1‐oxide gave 2‐ and 4‐pyrimidinyl derivatives.
Diazapolycyclic compounds. XXVII. On the selective hydrogenation of benzo[g]phthalazine‐1,4‐dione and 5‐methoxybenzo[g]phthalazine‐1,4‐dione adducts
Authors: Campayo L. , Navarro P. , Contreras F. Gómez
Published: April 2009

A number of diazapolycyclic structures obtained by cycloaddition reaction of benzo[g]phthalazine‐1,4‐dione with several 1,3‐dienes have been catalytically hydrogenated on palladium over charcoal. In a first step the double bond formed in the cycloaddition was reduced, except in the case of tetrasubstitution. The use of longer reaction times led to the selective reduction of the terminal aromatic rings, although the presence of the 5‐methoxy substituent favored tetrahydropyridazine ring opening and prevented aromatic ring reduction. The stereochemical features of new compounds obtained are commented on the basis of X‐ray and nmr data.
Synthesis of aminomethyl and amino analogs of 5‐benzylacyclouridine and 5‐benzyloxybenzylacyclouridine
Authors: Chu Shih Hsi , Chen Zhi Hao , Weng Zun Yao , Rowe Elizabeth C. , Chu Edward , Chu Ming‐Yu Wang
Published: April 2009

Amino analogs of BAU (5‐benzylacyclouridine) and BBAU (5‐benzyloxybenzylacyclouridine) and their 2′‐hydroxymethyl derivatives were synthesized for evaluation as inhibitors of uridine phosphorylase and hence potential cancer chemotherapeutic agents. Both aminomethyl analogs were found to be potent inhibitors of this enzyme and good potentiators of the anti‐tumor action of FUdR.
“One pot” synthesis of 2,9‐disubstituted 8‐azaadenines (3,5‐disubstituted 7‐amino‐3H‐1,2,3‐triazolo[4,5‐d]pyrimidines)
Authors: Barili Pier Luigi , Biagi Giuliana , Livi Oreste , Mucci Luciana , Scartoni Valerio
Published: April 2009

A new simple method for the synthesis of title compounds is described starting from malononitrile, benzyl‐azide and an aliphatic or aromatic nitrile.
Synthesis of antimicrobial agents. II. Syntheses and antibacterial activities of optically active 7‐(3‐hydroxypyrrolidin‐1‐yl)quinolones
Authors: Uno Toshio , Iuch Koji , Kawahata Yoshihiro , Tsukamoto Goro
Published: April 2009

Two optically active isomers of 1‐ethyl‐6,8‐difluoro‐1,4‐dihydro‐7‐(3‐hydroxypyrrolidin‐1‐yl)‐4‐oxoquinoline‐3‐carboxylic acid (10) were prepared. One of the isomer, 7‐[(3S)‐hydroxypyrrolidin‐1‐yl] derivative 8, was about 4 times more potent in vitro than the other, 7‐[(3R)‐hydroxypyrrolidin‐1‐yl] derivative 4, and approximately two times more active than the racemate, 7‐[(3RS)‐hydroxypyrrolidine‐1‐yl] derivative 10.

Optical active 8 was the most active in in vivo, followed by 10, and 4 was the least active compound. But, they were more potent than CI‐934 12 and norfloxacin.

From the results, (3S)‐hydroxypyrrolidinyl group was found to be one of the beneficial group for PCA‐anti‐bacterial agent.
A new synthesis of aryl hetaryl ketones via SRN1 reactions of halogenated heterocycles with potassiophenylacetonitrile followed by phase‐transfer catalyzed decyanation
Authors: Hermann Christine K. F. , Sachdeva Yesh P. , Wolfe James F.
Published: April 2009

Reaction of halogenated pyridines, quinolines, pyrimidines, and pyrazines with potassiophenylacetonitrile (5) in liquid ammonia under near‐uv irradiation affords secondary nitriles, which then undergo oxidative decyanation under phase‐transfer catalytic conditions to afford aryl hetaryl ketones in excellent yields.
The proton and carbon‐13 NMR spectra of thioxanthone sulfoxide, thioxanthone sulfone and related ylides ‐ chemical shift assignments
Authors: Ternay A. L. , Cushman J. A. , Harwood J. S. , Yu C. P.
Published: April 2009

The proton and carbon‐13 nmr spectra of thioxanthone sulfoxide, thioxanthone sulfone, thioxanthonium bis(carbomethoxyl)methylide and thioxanthonium bis(carbomethoxyl)methylide S‐oxide are assigned using 2‐D nmr techniques and compared to those of thioxanthone. The pseudo‐equatorial methylide fragment shields C4a/5a by ˜ 11 ppm relative to the corresponding sulfoxide and by ˜ 4 ppm relative to thioxanthone. The pseudo‐axial methylide fragment in the oxysulfonium ylide has the same effect upon C4a/5a as does the pseudo‐axial oxygen of the corresponding sulfone. The sulfoxide and the sulfonium ylide have similar chemical shifts for C2/7 (˜ 131 ppm) as do the sulfone and oxysulfonium ylide (˜ 133 ppm).
Proton‐ionizable crown compounds. 10. Preparation and structural studies of macrocyclic ligands containing two sulfonamide units and with seventeen to twenty‐six ring members
Authors: Bradshaw Jerald S. , Koyama Hiroyuki , Dalley N. Kent , Izatt Reed M. , Biernat Jan F. , Bochenska Maria
Published: April 2009

Eight new macrocylic ligands each containing two sulfonamide groups have been prepared. Six of these compounds have both the sulfur and nitrogen atoms of the sulfonamide units substituted with aromatic rings. The nitrogen atoms of the other two compounds have alkyl ring connections. X‐ray crystal structure data were obtained for new macrocyclic compounds of 20 and 23 ring members. Each crystal structure showed two molecules in the asymmetric unit. Molecule A of 5 and both molecules of 7 exist in a compact conformation suggesting that they could wrap around a metal ion during complexation. Some of these compounds will be used as cation carriers in a bulk liquid membrane system.
Synthesis of 3‐alkyl‐6‐phenyl‐4(3H)‐pteridinones and their 8‐oxides. Potential substrates of xanthine oxidase
Authors: De Meester J. W. G. , Kraus W. , Van Der Plas H. C. , Brons H. J. , Middelhoven W. J.
Published: April 2009

Synthetic routes for the preparation of 3‐alkyl‐6‐phenyl‐4(3H)‐pteridinones 6 and their corresponding 8‐oxides 5 (R = CH3, C2H5, (CH2)2CH3, (CH2)3CH3, CH(CH3)C2H5, CH(CH3)2 and CH(C2H5)CH2OCH(OC2H5)2 are described and their reactivities towards xanthine oxidase from Arthrobacter M‐4 are determined. Only the 3‐methyl derivative of 6‐phenyl‐4(3H)‐pteridinone and its 8‐oxide i. e. 6a and 5a are found to be substrates although their reactivities are still very low. Oxidation takes place at C‐2 of the pteridinone nucleus. All the 3‐alkyl derivatives are less tightly bound to the enzyme than 6‐phenyl‐4(3H)‐pteridinone. Introduction of the N‐oxide at N‐8 considerably lowers the binding of the substrates. Inhibition studies have revealed that 3‐methyl‐6‐phenyl‐4(3H)‐pteridinone (6a) is a non‐competitive inhibitor with a Ki‐value of 47 μM and the 3‐ethyl derivative (6b) an uncompetitive one with a Ki‐value of 19.6 μM.
[2 + 2] Cycloaddition reactions of unsymmetrically substituted carbodiimides
Authors: Ulrich Henri , Richter Reinhard , Tucker Benjamin
Published: April 2009

N‐Alkyl‐N′‐arylcarbodiimides add alkyl and aryl isocyanates to the N‐alkyl substituted CN double bond to yield 4‐arylimino‐1,3‐diazetidine‐2‐ones 3. In the case of bulky alkyl substituents the reaction still proceeds across the sterically hindered CN double bond. N‐Aryl‐N′‐[(4‐dimethylamino)phenyl]carbodiimides form [2 + 2] cycloadducts with aryl isocyanates preferentially across the CN double bond not attached to the electron‐rich aryl groups. However, steric crowding on this CN double bond directs the reaction to the adjacent double bond of the heterocumulative system. The rate of the [2 + 2] cycloaddition reaction of N'‐methyl‐N′‐phenylcarbodiimide with 4‐nitrophenylisocyanate is about 2.5 times faster in acetonitrile than in benzene.
The synthesis of methyl 1‐aryl‐2‐pyrrolecarboxylates
Authors: Kiely John S. , Huang Suchin
Published: April 2009

A series of alkyl 1‐(aryl)‐2‐pyrrolecarboxylates were prepared by the condensation of the appropriate aniline with methyl tetrahydro‐2,5‐dimethoxy‐2‐furancarboxylate in refluxing acetic acid. It was found that condensation proceeds even in substituents possessing steric bulk are present in the ortho positions of the aniline. Strong electron withdrawing substituents if conjugated to the nitrogen diverts the reaction from product to unidentified tars.
Heterocycles. Part XII. Synthesis of new benzo[6,7]cyclohepta[1,2‐d]pyrimidine
Authors: El‐Rayyes N. R. , Ramadan H. M.
Published: April 2009

Selected 2‐arylidene‐1‐benzosuberones I were condensed with guanidine hydrochloride to give the corresponding substituted 2‐aminopyrimidines II and III respectively. Condensation of chalcones I with benz‐amidine hydrochloride revealed the formation of the corresponding substituted 2‐phenylpyrimidines IV. The structure of all products was substantiated by chemical and spectroscopic methods.
On triazoles. VIII The reaction of 5‐amino‐1,2,4‐triazoles with ethyl 2‐cyano‐3‐ethoxyacrylate and 2‐cyano‐3‐ethoxyacrylonitrile
Authors: Reiter József , Pongó László , Dvortsák Péter
Published: April 2009

The reaction of different 5‐amino‐3‐Q‐1H‐1,2,4‐triazoles 1 with ethyl 2‐cyano‐3‐ethoxyacrylate (5a) and 2‐cyano‐3‐ethoxyacrylonitrile (5b) to yield either the a type 5‐amino‐, or the b type 7‐amino‐1,2,4‐triazolo[1,5‐a]‐pyrimidine derivatives 6–10 was studied. The structure of compounds 6 and 9 was proved by their degradation to the corresponding derivatives 17a and 18a, respectively, through intermediates 11a, 12a, 13a, 14a, 15a and 16a, respectively. The structure of derivatives 7, 8 and 10 was proved on the basis of the analogy of their uv spectra with those of 6a and 9a, respectively. The isolation of the intermediates 19 and 20 helped to prove the mechanism of the reactions leading to the formation of 6a and 9a, respectively. In the reaction of the N‐substituted 5‐amino‐1,2,4‐triazoles with 5a the expected condensed ring products were not formed. Instead the aminoacrylates 22 and 24 were obtained. The “Z”‐“E” isomeric structure of derivatives 19, 20, 22 and 24 was proved with the help of their pmr spectra. The “Z” isomeric structure of the thermodynamically stabile 22 was corroborated with the help of its proton coupled cmr spectra, too.
Intramolecular cyclization of ethyl ω‐(5‐amino‐4‐aminocarbonylimidazol‐1‐yl)carboxylates
Authors: Bridson P. K. , McGowan A. , Wilson C. M. , Yeh Y. M.
Published: April 2009

Attempted elaboration of the title compounds to purines by reaction with ethyl formate leads instead to some novel fused imidazoles by intramolecular cyclization.
Nitrogen‐15 studies of the mechanisms of acetolyses of hexamethylenetetramine and 3,7‐diacetyl‐1,3,5,7‐tetraazabicyclo[3.3.1]nonane (DAPT)
Authors: Cooney Aidan P. , Crampton Michael R. , Jones Michael , Golding Peter
Published: April 2009

[15N4]‐Hexamethylenetetramine (Hexamine), and [15N4]‐3,7‐diacetyl‐1,3,5,7‐tetraazabicyclo[3.3.1]nonane(DAPT) have been prepared starting from 15NH3. Synthetic acetolysis reactions were performed using mixtures of pure [15N4]‐ and [14N4]‐compounds and the destination of the nitrogen isotopes in the products was determined mass spectrometrically. The results show that relatively little isotopic mixing occurs in the acetolysis of hexamine to DAPT though the formation of some products with isotopic composition [14N315N1] and [14N115N3] indicates limited ring cleavage. However the more severe conditions used in the formation of 1,3,5‐triacetyl‐1,3,5‐triazacyclohexane (TRAT) give rise to considerable isotopic scrambling. The acetolysis of DAPT to give 1,3,5,7‐tetraacetyl‐1,3,5,7‐tetraazacyclooctane occurs by selective cleavage of the methylene bridge.
Synthesis of heterocycles. Part VII Synthesis and antimicrobial activity of some 7H‐s‐triazolo[3,4‐b][1,3,4]thiadiazine and s‐triazolo[3,4‐b][1,3,4]thiadiazole derivatives
Authors: Eweiss N. F. , Bahajaj A. A.
Published: April 2009

The cyclization of 4‐amino‐5‐aryl‐3‐cyanomethylthio‐1,2,4‐triazoles II in the presence of concentrated sulfuric acid yields 7H‐6‐amino‐s‐triazolo[3,4‐b][1,3,4]thiadiazines III. Cyclization of 4‐amino‐5‐aryl‐1,2,4‐tria‐zole‐3‐thiones I with phenacyl chloride yields 7H‐3‐aryl‐6‐phenyl‐s‐triazolo[3,4‐b][1,3,4]thiadiazines IV. Similarly, compounds I condensed with cyanogen bromide, phenyl isothiocyanate and carbon disulfide to give the corresponding cyclized products 6‐amino‐3‐aryl‐s‐triazolo[3,4‐b][1,3,4]thiadiazoles V, 3‐aryl‐6‐phenyl‐amino‐s‐triazolo[3,4‐b][1,3,4]thiadiazoles VI and 3‐aryl‐striazolo[3,4‐b][1,3,4]thiadiazol‐6(5H)thiones VII, respectively. Also in the presence of phosphoryl chloride, compounds I underwent cyclization with monocarbo‐xylic acids and oxalic acid to 3,6‐diaryl‐s‐triazolo[3,4‐b][1,3,4]thiadiazole VIII and 6,6′‐bis(3‐aryl‐s‐triazolo‐[3,4‐b][1,3,4]thiadiazoles) IX. The above compounds were screened for their antimicrobial activity.
Heterocyclic systems. VII Synthesis of 1H‐pyrazolo[3,4‐e]indolizine derivatives
Authors: Stefancich Giorgio , Corelli Federico , Massa Silvio , Silvestri Romano , Di Santo Roberto
Published: April 2009

Suitable 1‐phenyl‐5‐(1‐pyrryl)pyrazole intermediates underwent Knoevenagel or Wittig intramolecular olefination to give derivatives of 1H‐pyrazolo[3,4‐e]indolizine, a hitertho unknown tricyclic heteroaromatic system.
Reaction of hydrazonyl chlorides and carboalkoxymethylene triphenylphosphoranes to give 5‐alkoxy substituted pyrazoles
Authors: Padwa Albert , MacDonald J. Gavin
Published: April 2009

The reaction of ethyl chloroglyoxylate phenyl hydrazone and diphenyl hydrazonyl chloride with several carboalkoxymethylene triphenylphosphoranes has been examined. The products isolated correspond to N‐phenyl‐3‐carboalkoxy‐5‐alkoxy substituted pyrazoles. The mechanism advanced to account for the formation of the products involves the stepwise addition of a nitrile imine intermediate with the Wittig reagent.
Thermal ring transformation of 5‐aryl‐2‐carbazoyl‐1,2,3,4‐tetrazole derivatives
Authors: Milcent René , Barbier Géo
Published: April 2009

Unstable 5‐aryl‐2‐(3‐benzylidene‐2‐phenylcarbazoyl)‐1,2,3,4‐tetrazoles 8 have been prepared. By thermal ring transformation, they gave 5‐aryl‐2‐(2‐benzylidene‐1‐phenylhydrazino)‐1,3,4‐oxadiazoles 9., Hydrazinolysis of 9 afforded 5‐aryl‐2‐(1‐phenylhydrazino)‐1,3,4‐oxadiazoles 10. Elimination of a molecule of benzonitrile from 9 on heating converted them into 2‐anilino‐5‐aryl‐1,3,4‐oxadiazoles 11.
Reaction of 5‐(substituted‐amino)oxazoles with N‐phenylmaleimide
Authors: Shimada Sadakatsu
Published: April 2009

Reaction of 5‐aminooxazoles with N‐phenylmaleimide gave 7‐hydroxy‐2‐phenylpyrrolo[3,4‐c]pyridine‐1,3‐diones and 7‐amino‐2‐phenylpyrrolo[3,4‐c]pyridine‐1,3‐diones via tricyclic adducts. The ratio of the 7‐hydroxy compound and 7‐amino compound depended on the basicity of the leaving group of the adducts. The reaction of 5‐acetaminooxazole with dienophiles is described.
Pyrimidines. 9. Chlorination of 6‐trifluoromethyluracil with phosphorus oxychloride in the presence of trialkylamines
Authors: Gershon Herman , Grefig Anthony T. , Clarke Donald D.
Published: April 2009

Ring‐chlorination of 6‐trifluoromethyluracil in phosphorus oxychloride in the presence of triethyl, tri‐n‐propyl, and tri‐n‐butylamines was studied with respect to by‐product formation. Comparisons were made with the results obtained by treating the preformed chlorinated pyrimidine with triethyl amine in boiling toluene.

Amination of chloropyrimidines by tertiary amines takes place by a Hofmann type reaction with substituent orientation generally in the 2 position of the ring. Yields of products depended on the base and reaction time. The rate of substitution in the 2 position is significantly enhanced by the presence of the trifluoromethyl group in the 6 position as compared with a methyl group.

Heating preformed chloropyrimidines with tertiary amines in toluene, offers a satisfactory approach for the preparation of 2‐N,N‐disubstituted aminopyrimidines. For the formation of ring‐chlorinated pyrimidines in phosphorus oxychloride with a minimum of by‐products, tri‐n‐propylamine, after a short reflux period is most useful.
Streptonigrin and lavendamycin partial structures. Preparation of 7‐amino‐2‐(2′‐pyridyl)quinoline‐5,8‐quinone‐6′‐carboxylic acid: A probe for the minimum, potent pharmacophore of the naturally occurring antitumor‐antibiotics
Authors: Yasuda Masami , Boger Dale L.
Published: April 2009

The preparation of 7‐amino‐2‐(2′‐pyridyl)quinoline‐5,8‐quinone‐6′‐carboxylic acid(4)constituting a potential minimum, potent pharmacophore of streptonigrin(1)and lavendamycin(2), two structurally‐related naturally‐occurring antitumor‐antibiotic, is detailed. In contrast to observations associated with streptonigrin and lavendamycin in which the C‐6′ acidpotentiatesthe antitumor, antimicrobial, and cytotoxic activity of the naturally‐occurring, substituted 7‐aminoquinoline‐5,8‐quinone AB ring systems, the C‐6′ carboxylic acid of 4diminishesthe observed antimicrobial and cytotoxic properties of 7‐amino‐2‐(2′‐pyridyl)quinoline‐5,8‐quinone.
Ring closures with α‐chloroazines
Authors: Pilgram Kurt H. , Skiles Richard D.
Published: April 2009

Two series of unsymmetrical 3,6‐disubstituted 1,2,3,4‐tetrahydro‐1,2,4,5‐tetrazines and 3,5‐disubstituted 4‐amino‐2,3‐dihydro‐1,2,4‐triazoles were synthesized from unsymmetrical 1,4‐disubstituted 1‐chloroazines with hydrazine, 1‐methylhydrazine, and 1,2‐dimethylhydrazine. These partially reduced heterocycles belong to little known and less accessible classes of heterocycles.
Oxamic acid derivaties in heterocyclic synthesis: Preparation of 1,2,4‐triazolo[1,5‐a]pyrazine derivatives
Authors: Molina P. , Vilaplana Ma. J. , Andreu P. L. , Møller J.
Published: April 2009

N‐Aryl‐N‐(α‐phenylphenacyl)oxamoyl chlorides react with N3‐arylsubstituted amidrazones to give functionalized 1,2,4‐triazoles which undergo ring‐closure by the action of thionyl chloride to give 1,2,4‐triazolo[1,5‐a]‐pyrazinium chlorides in excellent yields.
New syntheses of polyaza derivatives. Crystal structure of pyridazine‐3,6‐dicarboxylic acid
Authors: Sueur Stéphane , Lagrenee Michel , Abraham Francis , Bremard Claude
Published: April 2009

A new route allowing the synthesis of pyridazine‐3,6‐dicarboxylic acid in preparative quantities is described. The crystal structure of this compound is reported. Several polyaza derivatives were prepared and their structures determined by specroscopic methods (ir, 1H and 13C nmr).
Synthesis of the 1,2,3,4‐tetrahydrobenzofuro[2,3‐c]pyridine ring system
Authors: Jaen Juan C. , Wise Lawrence D.
Published: April 2009

As part of an on‐going research project, we required an efficient method for the preparation of compounds containing the 1,2,3,4‐tetrahydrobenzofuro[2,3‐c]pyridine ring nucleus. The parent compound 1 has not been described in the literature, and there is only one reference to the N‐methyl analog 2 [1]. A series of structurally related compounds, the 2‐substituted‐4‐hydroxy‐1,2,3,4‐tetrahydrobenzofuro[2,3‐c]pyridines, has been described [2].
Synthesis of 4‐methylthio‐2(1H)‐pyridone derivatives using ketene dithioacetals
Authors: Tominaga Yoshinori , Kawabe Masanori , Hosomi Akira
Published: April 2009

Reaction of various active methylene compounds with ketene dithioacetals, bis(methylthio)methylenemalononitrile (1a) and bis(methylthio)methylenecyanoacetamide (1b) gave the corresponding 3‐cyano‐4‐methylthio‐2(1H)‐pyridone derivatives. The transformation of 4‐methylthio‐2‐oxo‐2H‐pyran‐3‐carbonitrile in‐to 4‐methylthio‐2(1H)‐pyridone derivatives was also described.
Novel heterocyclic systems. Part 27. The synthesis of various diazathianthrenes and the discrimination of isomeric structures using 13C‐NMR and lanthanide induced shift data
Authors: Lindsay Charles M. , Smith Keith , Martin Gary E.
Published: April 2009

Syntheses of the previously unknown 1,7‐1,8‐ and 1,9‐diazathianthrenes are reported. The former two systems were prepared via the condensation of the dianion of 2,3‐dimercaptopyridine with 3‐chloro‐4‐nitropyridine 1‐oxide while the latter employed 2‐chloro‐3‐nitropyridine. The preparation of the 1,9‐diazathianthrene also led to the formation of the previously reported 1,6‐diazathianthrene as a by‐product in a 22% yield. The new ring systems were characterized by a combination of 13C nmr and 1H lanthanide‐induced shifts using Eu(fod)3.
On the chichibabin amination of pyrimidine and N‐alkylpyrimidinium salts using liquid ammonia/potassium permanganate
Authors: Buurman Dick J. , Van Der Plas Henk C.
Published: April 2009

Treatment of the 2‐R‐pyrimidines (1, R = methyl, ethyl, i‐propyl and t‐butyl) with potassium amide/liquid ammonia/potassium permanganate leads to amination at C‐4(6). The yields of the 4(6)‐amino compounds 3 in‐crease in the order 2‐methyl (10%), 2‐ethyl (30%), 2‐i‐propyl (45%) and 2‐t‐butyl (60%). Treatment of the 2‐R‐N‐methylpyrimidinium salts (4, R = hydrogen, methyl) with liquid ammonia/potassium permanganate leads to a regiospecific imination at C‐6, the corresponding 2‐R‐1,6‐dihydro‐6‐imino‐1‐methylpyrimidines 6 being obtained in 80‐85% yield. It is proved by 15N‐labelling that no ring opening is involved in these imination reactions. Treatment of the imino compounds with base leads to the corresponding 2.R‐6‐methylamino‐pyrimidines 8, involving, as proved by 15N‐labelling, an ANRORC‐mechanism. 2‐t‐Butyl‐1‐ethylpyrimidinium tetrafluoroborate (9b) when treated with liquid ammonia/potassium permanganate undergoes N‐deethylation, 2‐t‐butylpyrimidine being exclusively formed.
Intramolecular cyclization of 4‐aryl‐1,4‐dihydropyridine acetals
Authors: Hartman George D. , Phillips Brian T. , Springer James P. , Hirshfield Jordan
Published: April 2009

The synthesis of 4‐aryl‐1,4‐dihydropyridines possessing a protected aldehyde functionality at the ortho position is described. These compounds undergo iminium ion mediated cyclization when treated with titanium tetrachloride or gaseous hydrogen chloride. Mechanistically, cyclization utilizes attack of C‐3 of the dihydropyridine on the electrophilic species generated from complexation of the acetal. This methodology highlights opportunities for the construction of novel conformationally constrained dihydropyridine analogs.
Some reactions of 1‐methyl‐(2‐phenylethyl)‐1,2,3,4‐tetrahydropyridines with organic azides. Synthesis of 1‐methyl‐(2‐phenylethyl)piperidylidene‐2‐sulfonamides
Authors: Warren Brent K. , Knaus Edward E.
Published: April 2009

The 1,3‐dipolar cycloaddition reaction of 1‐methyl‐ and 1‐(2‐phenylethyl)‐1,2,3,4‐tetrahydropyridines 7 with organic azides 8 afforded the respective 1‐substituted‐piperidylidene‐2‐sulfon(cyan)amides 9. Nitration of the 1‐(2‐phenylethyl) analogue 9o yielded the 1‐[2‐(4‐nitrophenyl)ethyl] derivative 9r which on reduction with palladium‐on‐charcoal and hydrazine gave the 1‐[2‐(4‐aminophenyl)ethyl] analogue 9s.
On the reaction of 2‐chloroethylisothiocyanate with aromatic amines
Authors: Outcalt Russell J.
Published: April 2009

The reaction of aromatic amines with 2‐chloroethylisothiocyanate 2 to give 2‐arylaminothiazolines 1 was investigated. The course of this reaction was found to depend on the electronic nature of the amine and the reaction conditions. With arylamines that are relatively electron‐rich, good yields of the thiazolines 1 were obtained. With electron‐poor amines, adducts 4, in which two equivalents of 2 reacted with the amine, accompanied 1. The relative amounts of 2:1 adducts increased as the arylamine became progressively more electron deficient. With 3,4‐dichloroaniline, the yields of the 2:1 adducts were promoted by the presence of triethylamine.
The synthesis of 6,6′‐cyclo‐6′‐deoxyhexofuranosyluracils via a diazomethane‐promoted ring‐enlargement reaction
Authors: Sasson Isaac M. , Otter Brian A.
Published: April 2009

The protected 5′‐oxo‐6,5′‐cyclouridine 13 reacts with diazomethane to afford mostly the spiro‐epoxide 18 (79%), but it also undergoes ring‐expansion to give the corresponding 5′‐oxo‐6,6′‐cyclonucleoside 16. Under the conditions of the reaction, ketone 16 reacts further with diazomethane to give the enol ether 20 (12% overall), the isomeric 4‐methoxy nucleoside 15 (2%), and the spiro‐epoxide 19 (4.4%). Acid hydrolysis of the enol ether 20, followed by reduction of the resulting ketone with sodium borohydride, affords a separable mixture of the 5′S (L‐talo) and 5′R (D‐allo) methylene‐bridged cyclonucleosides 7 and 8, respectively. From proton nmr measurements, it appears that the 6′‐methylene groups of these cyclonucleosides project towards the 2′,3′‐edge of the furanose ring.
Heterocyclic systems. VIII. synthesis of 1H,4H‐pyrazolo[4,3‐f]pyrrolo[1,2‐a]azepine derivatives
Authors: Corelli Federico , Massa Silvio , Stefancich Giorgio , Silvestri Romano
Published: April 2009

The synthesis of the unknown title Compounds is described. The preparation involves intramolecular acylation of 3‐[1‐phenyl‐5‐(1‐pyrryl)pyrazol‐4‐yl]propanoic acid 9 to the tricyclic ketone 10, which was then transformed into 1H,4H‐pyrazolo[4,3‐f]pyrrolo[1,2‐a]azepine 12 and its dihydro derivative 13 by reductive procedures.
An improved synthesis of pyrido[2,3‐d]pyrimidines
Authors: Itoh Tsuneo , Fujii Ikuko , Tomii Yasuo , Ishikawa Ichiro , Ogura Hamo , Mizuno Yoshihisa , Kawahara Norio
Published: April 2009

An improved and efficient synthesis of 1,3‐dialkylpyrido[2,3‐d]pyrimidine‐2,4‐(1H,3H)‐diones from 6‐methylaminouracils and methyl propiolate or diethyl ethoxymethylenemalonate is described.
Studies on decarboxylation reactions. Part 6. Kinetic study of decarboxylation of 5‐amino‐1,3,4‐oxadiazole‐2‐carboxylic acid and its N‐phenyl derivatives at high hydrochloric acid concentrations
Authors: Noto Renato , Werber Giuseppe , Buccheri Francesco , Arnone Caterina
Published: April 2009

The dissociation constants (K1) of both acids 4a‐c and esters 5a‐c and the rate constants of the decarboxylation reaction of acids 4a‐c have been measured at various high concentrations of hydrochloric acid (0.5‐8.0 M range). The results obtained have enabled us to suggest the probable structure of the zwitterion which undergoes decarboxylation.
Saturated heterocycles. 136 . Synthesis of 2‐substituted 2‐azapyracridone derivatives
Authors: Huber Imre , Fülöp Ferenc , Bernáth Gábor , Hermecz István
Published: April 2009

By means of Substitution, addition and condensation on the secondary nitrogen of 9‐methyl‐1,2,3,4‐tetrahydro‐2‐azapyracridone (6), twenty new azapyracridones were prepared.
The rearrangement of 2‐amino‐5‐benzoyloxazoles with dimethylamine
Authors: Walker Frederick J. , Kraus Kenneth G.
Published: April 2009

The rearrangement of 2‐amino‐5‐phenacyloxazoles with dimethylamine is described. One such rearrangement provided an unexpected tricyclic product.
The effect of the steric requirements of trialkylsilyl ethers on ring closure of 1‐(benzylamino)‐3‐chloro‐2‐(trialkylsiloxy)propanesd
Authors: Higgins Robert H.
Published: April 2009

The ring closure of 1‐(benzylamino)‐3‐chloro‐2‐(trialkylsiloxy)propanes to 1‐benzyl‐3‐(trialkylsiloxy)azetidines was investigated. There appears to be little or no advantage in the use of trialkylsilyl substituents larger than trimethylsilyl.
New 7‐substituted quinolone antibacterial agents. The synthesis of 1‐ethyl‐1,4‐dihydro‐4‐oxo‐7‐(2‐thiazolyl and 4‐thiazolyl)‐3‐quinolinecarboxylic acids
Authors: Culbertson Townley P. , Domagala John M. , Peterson Phred , Bongers Shannon , Nichols Jeffrey B.
Published: April 2009

A series of 1‐ethyl‐1,4‐dihydro‐4‐oxo‐7‐(4‐thiazolyl)‐3‐quinolinecarboxylic acids and 1‐ethyl‐1,4‐dihydro‐4‐oxo‐7‐(2‐thiazolyl)‐3‐quinolinecarboxylic acids were prepared. Also prepared was 10‐[2‐(aminomethyl)‐4‐thiazolyl]‐9‐fluoro‐2,3‐dihydro‐3‐methyl‐7‐oxo‐7H‐pyrido[1,2,3‐de][1,4]benzoxazine‐6‐carboxylic acid. Analogs with basic amine substituents on the thiazole moiety were found to have antibacterial activity.
Reaction of acetone oxime with dialkylmalonyl chlorides. Synthesis of 2‐(2‐propenyl)isoxazolidine‐3,5‐diones and 2,2‐bis‐(2‐(4,4‐dialkylisoxazolidine‐3,5‐dione))propanes
Authors: Izydore Robert A. , Davis Ronda G. , Clements Nancy W.
Published: April 2009

Reaction of acetone oxime with dialkylmalonyl chlorides in the presence of triethylamine gave as products 2‐(2‐propenyl)‐4,4‐dialkylisoxazolidine‐3,5‐diones 4 and 2,2‐bis‐(2‐(4,4‐dialkylisoxazolidine‐3,5‐dione))propanes 5. The 4,4‐dialkylisoxazolidine‐3,5‐diones 6 and dimethylketoximyl 4,4‐dialkylmalonates 7 were formed as minor products. Compounds 4 are stable in refluxing ethanol and in aqueous solution. Compounds 5 are stable when heated in refluxing toluene in the presence of either pyridine or monochloroacetic acid.
Sulfonylcarbamimidic azides from sulfonyl chlorides and 5‐aminotetrazole
Authors: Peet Norton P. , Sunder Shyam , Barbuch Robert J. , Huber Edward W. , Bargar Ester M.
Published: April 2009

Treatment of o‐nitrobenzenesulfonyl chloride (3) with 5‐aminotetrazole (5‐AT) gave [(2‐nitrophenyl)‐sulfonyl]carbamimidic azide (6), a ring‐opened isomer of the expected N‐(1H‐tetrazol‐5‐yl)‐2‐nitrobenzenesulfonamide (4). Sulfonylcarbamimidic azide 6 was converted to 2‐amino‐N‐(aminoiminomethyl)benzene‐sulfonamide (7) with ethanolic stannous chloride, and to 3‐amino‐1,2,4‐thiadiazine 1,1‐dioxide (8) with sodium dithionite. Methanesulfonyl chloride (9) and 5‐AT gave 2‐(methylsulfonyl)carbamimidic azide (10), which isomerized to 5‐[(methylsulfonyl)amino]‐1H‐tetrazole (11) in warm ethanol. Attempted cycloaddition of 2‐(phenylsulfonyl)carbamimidic azide (13) and ethyl vinyl ether led only to alkylated tetrazole products. In addition, other tetrazole‐alkylating reactions are described. Isomers produced from these alkylations were differentiated with 13C nmr spectroscopy.
Synthesis of indole derivatives from 2‐bromoanilines by a palladium‐assisted reaction
Authors: Kasahara Akira , Izumi Taeko , Kikuchi Tokio , Xiao‐Ping Lin
Published: April 2009

In the presence of palladium(II) acetate, 2‐bromoanilines readily react with enamines such as N‐vinyl‐pyrrolidone or α‐piperidinostyrene to produce indole derivatives.
The synthesis of dimethoxy‐ and trimethoxy[1]benzothieno[2,3‐c]quinolines
Authors: Stuart John G. , Khora Shinya , McKenney J. Dew , Castle Raymond N.
Published: April 2009

Three dimethoxy[1]benzothieno[2,3‐c]quinolines 24–26 were prepared by photocyclization of the appropriate 3‐chloro‐N‐phenylbenzo[b]thiophene‐2‐carboxamides 15–17 to [1]benzothieno[2,3‐c]quinolin‐6(5H)‐ones 18–20 followed by chlorination to 6‐chloro[1]benzothieno[2,3‐c]quinolines 21–23 and then dechlorination resulting in the title compounds. Reaction of 24–26 with methyl iodide furnished the corresponding N‐methyl quaternary salts 27–29. Sodium methoxide readily converted 21–23 to trimethoxy[1]benzothieno[2,3‐c]quinolines 30–32.
Tetracyclic benzodiazepines. 4. Synthesis of the novel benzo[c]pyrrolo[1,2,3‐ef][1,5]benzodiazepine ring system, and derivatives with potential antipsychotic activity
Authors: Glamkowski Edward J. , Chiang Yulin
Published: April 2009

The synthesis of the novel benzo[c]pyrrolo[1,2,3‐ef][1,5]benzodiazepine ring system is described. This was achieved by cyclization of an appropriately substituted (7‐aminoindolin‐1‐yl)benzamide or benzoic acid. The resulting tetracyclic lactams were reacted with N‐methylpiperazine in the presence of titanium tetrachloride to provide derivatives which were tested for potential antipsychotic activity.
Sels de N‐alcoxyquinoléinium et d'isoquinoléinium porteurs d'une fonction cétone dans leur chaîne alcoxyle: Synthèse et réactivité vis‐à‐vis d'amines secondaires
Authors: Sliwa Henri , Ouattara Lassina
Published: April 2009

Les sels d'α (quinoléine‐1 oxy) et α (isoquinoléine‐1 oxy) isobutyrophénone ont été préparés par action de l'α‐bromoisobutyrophénone sur les N‐oxydes hétérocycliques correspondants, en présence de perchlorate d'argent. L'action d'amines secondaires sur ces sels permet d'accéder, avec d'excellents rendements, respectivement à la benzoyl‐2 quinoléine et à la benzoyl‐1 isoquinoléine. Ces réactions s'interprétent par la formation d'un dérivé tricyclique isoxazolo[2,3‐a]quinoléinium ou isoquinoléinium subissant une décomposition alcoxylogue du mode A de la classification de Katritzky.
Unequivocal syntheses of 6‐methyl‐ and 6‐phenylisoxanthopterin
Authors: Neilsen J. Bryant , Broadbent H. Smith , Hennen William J.
Published: April 2009

Although 6‐methyl‐ (1) and 6‐phenylisoxanthopterin (2) have previously been synthesized, the requirement of high purity necessary for immunological testing has necessitated our development of the first reported synthesis of these compounds by unequivocal methods. In the process of so doing four new pyrazines, ethyl 3‐amino‐5‐chloro‐6‐methyl‐2‐pyrazinecarboxylate (11), N,N‐dimethyl‐N'‐(6‐chloro‐3‐cyano‐5‐phenylpyrazin‐2‐yl)methanimidamide (16), 2‐amino‐3‐ethoxycarbonyl‐5‐phenylpyrazine 1‐oxide (19), and ethyl 3‐amino‐5‐chloro‐6‐phenyl‐2‐pyrazinecarboxylate (20) were synthesized. Four new pteridines, 7‐methoxy‐6‐methyl‐2,4‐pteridinediamine (7), 7‐methoxy‐6‐phenyl‐2,4‐pteridinediamine (17), 2‐amino‐7‐ethoxy‐6‐methyl‐4(3H)‐pteridinone (12), and 2‐amino‐7‐ethoxy‐6‐phenyl‐4(3H)‐pteridinone (21) have also been synthesized enroute to these isoxanthopterins.
Synthesis and antileukemic activity of spiro[indoline‐3,2′‐thiazolidine]‐2,4′‐diones
Authors: Rajopadhye Milind , Popp F. D.
Published: April 2009

A number of spiro[indoline‐3,2′‐thiazolidine]‐2,4′‐diones have been prepared via the cyclocondensation of isatin‐3‐imines with α‐mercaptoacids. 1‐Benzyl‐5′,5′‐dimethylspiro[indoline‐3,2′‐thiazolidine]‐2,4′‐diones were prepared by simultaneously refluxing 1‐benzylisatin, α‐mercaptoisobutyric acid and various anilines in toluene. 3′‐(4‐Chlorophenyl)‐5,5′‐dimethylspiro[indoline‐3,2′‐thiazolidine]‐2,4′‐dione was active in the P388 and the L1210 leukemia screen tests. A number of analogs of the active spiro compound have been prepared and submitted for antileukemic screening. Anticonvulsant screening results of related compounds are also included.
The regiospecific synthesis of the A and B rings of phomazarin
Authors: Guay Vincent , Brassard Paul
Published: April 2009

Elaboration of the A ring of phomazarin by the Conrad‐Limpach approach has been shown to be possible in the case of a protected hydroquinone substrate. However similar condensations using a suitably substituted naphthoquinone gave a lactam instead of the expected benzoquinolone. Attempts to annulate simplified models of the A‐B rings with the appropriate diene have also been successful albeit in low yield.
On the amination of pyrimido[5,4‐e]1,2,4‐triazines in liquid ammonia
Authors: Brouwer A. C. , van der Plas H. C.
Published: April 2009

When dissolved in liquid ammonia 5‐chloro‐1,2‐dihydropyrimido[5,4‐e]‐1,2,4‐triazine (1) and 5‐methoxy‐pyrimido[5,4e]‐1,2,4‐triazine (4) quickly convert into 5‐aminopyrimido[5,4‐e]‐1,2,4‐triazine (2). When 2 is kept in liquid ammonia containing an excess of potassium permanganate, 3,5‐diaminopyrimido[5,4‐e]‐1,2,4‐triazine (5) is formed.
Synthesis of hydrazones derived from 2‐substituted‐10‐carboxyphenothiazine hydrazides
Authors: Tsitsa P. , Psarrea‐Sandris A. , Sandris C.
Published: April 2009

2‐Substituted‐10‐carboxyphenothiazine hydrazides 3 were found to yield hydrazones 5 on reaction with aromatic aldehydes. However, a similar reaction of hydrazides 3 with aliphatic ketones in refluxing ethanol failed to give the expected hydrazones 6. The corresponding phenothiazines 1 were isolated in this reaction, apparently through alcoholysis of the amide bond to the ring nitrogen atom in 3.
Reaction of 2‐dimethylaminomethylene‐1,3‐diones with dinucleophiles. VI. Synthesis of ethyl or methyl 1,5‐disubstituted 1H‐pyrazole‐4‐carboxylates
Authors: Menozzi Giulia , Mosti Luisa , Schenone Pietro
Published: April 2009

Reaction of ethyl or methyl 3‐oxoalkanoates with N,N‐dimethylformamide dimethyl acetal gave, generally in excellent yields, a series of ethyl or methyl 2‐dimethylaminomethylene‐3‐oxoalkanoates II which reacted with phenylhydrazine to afford the esters of 5‐substituted 1‐phenyl‐1H‐pyrazole‐4‐carboxylic acids III in high yields. Esters III were hydrolyzed to the relative 5‐substituted 1‐phenyl‐1H‐pyrazole‐4‐carboxylic acids which were converted by heating to 5‐substituted 1‐phenyl‐1H‐pyrazoles in excellent yields. Reaction of II with methylhydrazine afforded in general a mixture of 3‐ and 5‐substituted ethyl 1‐methyl‐1H‐pyrazole‐4‐carboxylates with the exception of IIg, which gave in high yield methyl 5‐benzyl‐1‐methyl‐1H‐pyrazole‐4‐carboxylate, which was hydrolyzed to the relative pyrazolecarboxylic acid. This afforded by heating 5‐benzyl‐1‐methyl‐1H‐pyrazole in quantitative yield.
Studies on heterocyclic enamines: New syntheses of 4H‐pyranes, pyranopyrazoles and pyranopyrimidines
Authors: Elnagdi Mohamed Hilmy , Abdel‐Motaleb Ramadan Maawad , Mustafa Mona , Zayed Mohamed Foad , Kamel Eman Moustafa
Published: April 2009

The behaviour of several 2‐amino‐3‐cyano‐4H‐pyran derivatives toward a variety of nucleophilic reagents is reported.
The reaction between 2‐aminobenzenethiol and diethyl oxalate. A structural reassegnement
Authors: Liso Gaetano , Trapani Giuseppe , Latrofa Andrea
Published: April 2009

It is proposed that the reported [2] condensation between 2‐aminobenzenethiol and diethyloxalate give rise to 2‐ethoxycarbonylbenzothiazole 3 rather than 3‐ethoxy‐2H‐1,4‐benzothiazin‐2‐one 2.
On triazoles. XII. The carbamoylation and thiocarbamoylation of 5‐amino‐1,2,4‐triazoles
Authors: Reiter József , Pongó László , Dvortsák Péter
Published: April 2009

The reaction of 5‐amino‐3‐R‐1H‐1,2,4‐triazoles 1 with isocyanates 2 (X = O) and isothiocyanates 2 (X = S) was studied. It was stated that with isocyanates 3a (X = O) type ring‐carbamoylated products were formed which did not rearrange to the corresponding exo‐carbamoylated derivatives 6a (X = O). On the other hand the thiocarbamoylation of derivatives 1 provided at mild conditions lead to derivatives 3a (X = S) which could be rearranged by heating to derivatives 6a (X = S). In one case the isomeric 4a (X = S) type derivative was also isolated. The comparison of the ir, uv, pmr and cmr spectra of the isomers isolated with the corresponding spectra of the carbamoylated and thiocarbamoylated 3,5‐diamino‐1,2,4‐triazole derivatives helped to prove unequivocally the isomeric and tautomeric structure of compounds obtained giving a possibility to correct many confusions in the literature.
Antikonvulsiva,II. Die cyanethylierung im system des butyroguanamins
Authors: Kreutzberger Alfred , Loch Michael
Published: April 2009

Die die Anlagerung von Acrylnitril (2) beinhaltende Cyanethylierung des Butyroguanamins (1) führt zu den cyanethylierten Propyl‐1,3,5‐triazinen3, 4und5. Spektroskopisch äußerst charakteristisch für diese Strukturen ist in den IR‐Spektren die scharfe Bande der C ≡ N‐Valenzschwingung bei 2260 cm−1. Kennzeichnend in den Massenspektren ist die Abspaltung eines Cyanethylradikals. Während4antikonvulsive und cytoprotektive Effekte auszulösen vermag, ist5Träger neuroleptischer und herbizider Wirksamkeit.
Tetrahydrocyclopenta[e]pyrido[3,2‐b][1,4]diazepine and ‐cyclopenta[e]pyrido[2,3‐b][1,4]diazepine derivatives
Authors: Savelli Francesco , Boido Alessandro , Vazzana Iana , Sparatore Fabio
Published: April 2009

In pursuing the study on compounds obtained by condensation of N‐monoalkylated aromatic and hetero‐aromatic diamines with α‐ and β‐ketoesters, 7,8,9,10‐tetrahydrocyclopenta[e]pyrido[3,2‐b][1,4]diazepin‐6(5H)‐ones 4a, 4b and 5,7,8,10‐tetrahydrocyclopenta[e]pyrido[2,3,‐b][l,4]diazepin‐9H)‐ones 5a, 5b were prepared starting from 2,3‐diaminopyridine or 2,3‐diamino‐5‐chloropyridine and ethyl 2‐oxo‐cyclopentanecarboxylate. Compounds 4a,b and 5a,b suffer thermally induced ring contraction to the imidazolone derivatives 8a,b and 7a,b respectively and are unsuitable for preparing diazepinone derivatives. Thus the methylated diazepinones 15, 17 and 18, stable on heating, were prepared. Compound 17 was transformed into the clozapine analogue 22, through the diazepinthione 20 and its S‐methyl derivative 21.
Cyclocondensation of 3‐amino‐2‐iminonaphtho[1,2‐d]thiazole with oxalic acid derivatives
Authors: Liu Kang‐Chien , Shih Bi‐Jane , Hu Ming‐Kuan
Published: April 2009

Refluxing 3‐amino‐2‐iminonaphtho[1,2‐d]thiazole (1) with diethyl oxalate (2a) in a 2:1 molar ratio in dry pyridine provided 2,2′‐binaphtho[1′,2′:4,5]thiazolo[3,2‐b][1,2,4]triazole (3). On the other hand, when 1 was treated with excess amount of 2a in dimethylformamide, it afforded ethyl naphtho[1′,2′:4,5]thiazolo[3,2‐b][1,2,4]triazole‐2‐carboxylate (4a) on heating and ethyl N‐(2‐iminonaphtho[1,2‐d]thiazol‐3‐yl)oxamate (5) by stirring at room temperature. Cyclization of 5 upon fusion led to the formation of 3‐hydroxy‐2H‐naphtho‐[1′,2′:4,5]thiazolo[3,2‐b][1,2,4]triazin‐2‐one (6). Compound 6 could also be prepared directly from 1 by refluxing either with 2a neatly, in glacial acetic acid or with oxalic acid (2b) in the same medium. The acid form of 4a might be obtained from 1 and 2b on heating in dimethylformamide, but it was decarboxylated to naphtho‐[1′,2′:4,5]thiazolo[3,2‐b][1,2,4]triazole (4b) during the reaction.
The preparation of quinolines and related fused‐ring heterocycles from the dianions of benzoylacetone, certain cyclic ketone oximes, or certain substituted hydrazones
Authors: Mack H. Michael , Davis Everette A. , Kadkhodayan Babak , Taylor Richard A. , Duncan Dean C. , Beam Charles F.
Published: April 2009

C(α),O‐Dilithiooximes, C(α),N‐dilithiobenzoylhydrazones, or C(α),N‐dilithiocarboalkoxyhydrazones were prepared in an excess of lithium diisopropylamide (LDA) and condensed with 2‐aminobenzophenones, or isatoic anhydrides to give intermediates that were treated with aqueous acid, which caused their hydrolysis, cyclodehydration and/or linear dehydration to give products which were substituted quinolines or related fused‐ring heterocycles (e.g., cycloheptaquinolines). Dilithiobenzoylacetone was condensed with 2‐aminobenzophenones, which was followed by acid cyclodehydration to substituted 2‐phenacylquinolines.
The insertion and extrusion of heterosulfur bridges. XIV. Synthesis of nitrotriphenyleno[1,12‐bcd]thiophenes
Authors: Klemm L. H. , Hall Eliot , Cousins Lisa , Klopfenstein C. E.
Published: April 2009

Sulfur bridging to form triphenyleno[1,12‐bcd]thiophene (2) in ca. 46% yield has been effected at 540° by direct addition of crystalline triphenylene (1) or dodecahydrotriphenylene (4) to a heterogeneous catalyst in a stream of hydrogen sulfide. Treatment of a reaction mixture of 1 and 2 with hydrogen peroxide‐glacial acetic acid gives 2 sulfone 2d and 1,4‐triphenylenoquinone (3). Reduction of 2d with lithium aluminum hydride in tetrahydrofuran leads back to 2 (80%), while reductive acetylation of 3 produces 1,4‐diacetoxytriphenylene. Treatment of 2 with nitric acid in acetic anhydride at 65° gives a mixture of 1‐nitro (30%), 3‐nitro (47%), and 1,7‐dinitro (11%) derivatives, separable by chromatography on alumina. Structures of these derivatives are assigned on the basis of ultraviolet‐visible absorption and proton magnetic resonance spectra, as well as the chemical conversion 1‐nitro‐2 → 1,7‐dinitro‐2. The substitution pattern in 2 is correlated with Hückel molecular orbital calculations on reactivity and with substitution in analogous polycyclic, condensed aromatic compounds.
Studies on nitroenamines. Part III. Synthesis and spectral properties of 4‐Acyl‐1‐arylimidazoles
Authors: Gómez‐Sánchez A. , Hidalgo F. J. , Chiara J. L.
Published: April 2009

The catalytic (C/Pd) hydrogenation of 3‐arylamino‐2‐nitro‐2‐enones (1) in the presence of carboxylic ortho esters (2) affords 4‐acyl‐1‐arylimidazoles (3) in yields (20–70%) which depend on the degree of substitution of the imidazole ring. The spectral properties of compounds 3, and particularly the 13C‐nmr spectra, reflect both the electronic and steric effects of the substituents on the π‐electron delocalization and planarity of the bicyclic system.
A new method for the synthesis of novel 3‐substituted 4‐amino‐8‐ethoxycarbonylpyrazolo[5,1‐c][1,2,4]triazines and pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzodiazepines
Authors: Kurasawa Yoshihisa , Okamoto Yoshihisa , Takada Atsushi
Published: April 2009

Novel 3‐substituted 4‐amino‐8‐ethoxycarbonylpyrazolo[5,1‐c][1,2,4]triazines 7,8 were synthesized by the reactions of malononitrile and ethyl cyanoacetate with the pyrazole‐5‐diazonium salt 3. Moreover, compounds 7,8 were converted into the pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzodiazepines 9, 10.
A convenient synthesis of novel spiro[benzoxazole‐2′,4(1H,3′H)‐pyrazolo[5,1‐c][1,2,4]triazines] by ring transformation of novel pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzoxazepines
Authors: Kurasawa Yoshihisa , Okiyama Mari , Kamigaki Yumiko , Kanoh Megumi , Okamoto Yoshihisa , Takada Atsushi
Published: April 2009

Novel pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐b][1,5]benzoxazepines 5, 6 and 8 were synthesized, and these compounds were converted into novel spiro[benzoxazole‐2′,4(1H,3′H)‐pyrazolo[5,1‐c][1,2,4]triazines] 7 and 9 by ring transformation.
Reactions of acetoacetanilides ‐ a century of
Authors: Hussain S. M. , El‐Reedy A. M. , El‐Sherabasy S. A.
Published: April 2009

The chemical reactions of acetoacetanilides are reported and the literature data are discussed.