bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of halogenated hydrazone derivatives and their applicability in the preparation of 4‐chloropyrazoles
Authors: Barluenga José , Iglesias M. José , Muñiz Laudina , Gotor Vicente
Published: March 2009

Reaction of hydrazonic derivatives 1 with N‐chlorosuccinimide affords monohalogenated hydrazones 3 with nearly quantitative yields. When 3 is treated with mineral acids or trifluoroacetic acid 4‐chloropyrazoles are isolated.
Synthesis of lipophilic crown ethers with pendant carboxylic acid groups
Authors: Czech Bronislaw P. , Czech Anna , Son Byungki , Lee Han Koo , Bartsch Richard A.
Published: March 2009

Synthetic routes to thirteen highly lipophilic crown ether carboxylic acids are described. Seven contain 12–15‐membered crown ether units with four ring oxygens and are designed for lithium ion complexation. Three others possess large ring 24‐crown‐8, 27‐crown‐9, and 30‐crown‐10 units. Six new hydroxymethyl crown ethers are prepared as synthetic intermediates.
Amination of 3,6‐dinitro‐1,8‐naphthyridines
Authors: Wozniak M. , Plas C. Van Der
Published: March 2009

Treatment of 2‐amino‐3,6‐dinitro‐1,8‐naphthyridines with liquid ammonia/potassium permanganate gives 2,4‐diamino‐3,6‐dinitro‐1,8‐naphthyridine. From 2‐ethoxy‐3,6‐dinitro‐1,8‐naphthyridine a mixture of 4‐amino‐and 5‐amino‐3,6‐dinitro‐1,8‐naphthyridine was obtained. 2‐Chloro‐3,6‐dinitro‐1,8‐naphthyridine afforded a mixture of four compounds i. e. 2,4‐ and 2,5‐diamino‐3,6‐dinitro‐1,8‐naphthyridine and 2‐chloro‐5‐amino‐3,6‐dinitro‐1,8‐naphthyridine and 2‐amino‐3,6‐dinitro‐1,8‐naphthyridine. A study on covalent amination has shown that 4‐amino‐2‐ethoxy‐3,6‐dinitro‐1,8‐naphthyridine undergoes covalent amination at C‐5, whereupon in this adduct amino‐deethoxylation takes place. In a similar way, 2‐chloro‐ and 2‐ethoxy‐5‐amino‐3,6‐dinitro‐1,8‐naphthyridine give covalent amination at C‐4.
Furopyridines. V. A simple synthesis of furo[2,3‐c]pyridine and its 2‐and 3‐methyl derivatives
Authors: Morita Hiroyuki , Shiotani Shunsaku
Published: March 2009

A simple synthesis of furo[2,3‐c]pyridine and its 2‐ and 3‐methyl derivatives from ethyl 3‐hydroxyisonicotinate (2) is described. The hydroxy ester 2 was O‐alkylated with ethyl bromoacetate or ethyl 2‐bromopropionate to give the diester 3a or 3b. Cyclization of compound 3a afforded ethyl 3‐hydroxyfuro [2,3‐c]pyridine‐2‐carboxylate (4) which was hydrolyzed and decarboxylated to give furo[2,3‐c]pyridin‐3(2H)‐one (5a). Cyclization of 3b gave the 2‐methyl derivative 5b. Reduction of 5a and 5b with sodium borohydride yielded the corresponding hydroxy derivative 6a and 6b, respectively, which were dehydrated with phosphoric acid to give furo[2,3‐c]pyridine (7a) and its 2‐methyl derivative 7b. 4‐Acetylpyridin‐3‐ol (8) was O‐alkylated with ethyl bromoacetate to give ethyl 2‐(4‐acetyl‐3‐pyridyloxy) acetate (9). Saponification of compound 9, and the subsequent intramolecular Perkin reaction gave 3‐methylfuro[2,3‐c]pyridine (10). Cyclization of 9 with sodium ethoxide gave 3‐methylfuro[2,3‐c]pyridine‐2‐carboxylic acid, which in turn was decarboxylated to give compound 10.
The synthesis and proton nuclear magnetic resonance study of some nitro‐ and amino‐unsymmetrically meta‐substituted tetraphenylporphyrins
Authors: Sun Yizhen , Martell Arthur E. , Tsutsui Minoru
Published: March 2009

Procedures for the synthesis of new partially‐substituted mesotetraphenylporphyrins (TPP's) are described. The 5‐(3‐nitrophenyl)‐10,15,20‐triphenylporphyrin is the primary product from a 1:2:3 molar ratio of m‐nitrobenzaldehyde, benzaldehyde and pyrrole. The crude reaction product also contained TPP, 5,10‐bis‐(3‐nitrophenyl)‐15,20‐diphenylporphyrin, 5,15‐bis(3‐nitrophenyl)‐10,20‐diphenylporphyrin, and 5,10,15‐tris‐(3‐nitrophenyl)‐20‐phenylporphyrin. The crude mixture of m‐nitrophenylporphyrins was reduced to a mixture of the corresponding amino derivatives, which was separated into TPP, 5‐(3‐aminophenyl)‐10,15,20‐triphenylporphyrin, 5,10‐bis(3‐aminophenyl)‐15,20‐diphenylporphyrin, and 5,15‐bis(3‐aminophenyl)‐10,20‐diphenylporphyrin. The products were characterized by uv‐visible and ir spectrophotometry, and by high resolution nmr spectroscopy and mass spectroscopy.
A modified synthesis of 4‐chloromethylthiazoles
Authors: Marzoni Gifford
Published: March 2009

A two‐reaction synthesis of 2‐substituted‐4‐chloromethylthiazoles from thioamides and 1,3‐dichloroacetone is reported. The first step, cyclization to a 2‐substituted‐4‐chloromethyl‐4‐hydroxythiazoline is carried out in the presence of bicarbonate in an aprotic solvent. Dehydration of this intermediate to a 2‐substituted‐4‐chloromethylthiazole is accomplished by reaction with thionyl chloride, sulfuryl chloride, phosphoryl chloride, phosphorus trichloride or phosphorus pentachloride. Substituents on the thioamide, such as amino, alkyl, or aryl, are shown not to affect the success of the reaction. As a trend, alkylthioamides give slightly better yields of 4‐chloromethylthiazoles than do arylthioamides. The yields of 4‐chloromethylthiazoles prepared using this procedure are comparable to the yields obtained using acid catalyzed procedures.
Synthesis of hydroxymethyl‐functionalized diazacrowns and cryptands
Authors: Babb David A. , Czech Bronislaw P. , Bartsch Richard A.
Published: March 2009

Synthetic routes are established for the preparation of hydroxymethyl‐substituted diazacrowns and cryptands with systematically varied cavity sizes.
Some novel halogenated phenazine derivatives
Authors: Twomey Dermot
Published: March 2009

3‐Amino‐10‐aryl‐2‐arylimino‐2,10‐dihydrophenazines 1 undergo iodination in the 4‐position of the phenazine nucleus yielding compounds which are identical with those obtained by oxidation of appropriate N‐aryl‐o‐phenylenediamines with sodium iodate in the presence of acid. Bromination also takes place in this position but a second bromine atom enters the para‐position of the arylimino moiety. The isomeric 10‐aryl‐3‐aryl‐amino‐2,10‐dihydro‐2‐iminophenazines 2 yield unstable iodo‐derivatives but undergo bromination in the 1‐and 4‐position of the phenazine nucléus and in the ortho‐ and para‐positions of the arylamino substituent. Preliminary chlorination experiments indicate that the substitution pattern is analogous to that established for the brominated products. The removal of bromine and iodine from the phenazine ring by reaction with a primary or secondary amine and their replacement by hydrogen rather than by the amine residue is also recorded.
A galactoside derivative of a nitrosoisocytosine inhibitor of dihydropteroate synthase: Synthesis and biological evaluation
Authors: Lever O. William , Hyman Clifton , Ray Paul H. , Ferone Robert , Kelsey John E.
Published: March 2009

The synthesis of the O‐β‐D‐galactosyl derivative 3 of the dihydropteroate synthase inhibitor 6‐(3‐(4‐hydroxyphenoxy)propylamino)‐5‐nitrosoisocytosine (2) was accomplished through coupling of N‐(3‐(4‐hydroxyphenoxy)propyl)phthalimide (4) with 2,3,4,6‐tetra‐O‐acetyl‐α‐D‐galactopyranosyl bromide followed by complete deblocking of the resulting β‐glycoside 9 with hydrazine and then methanolic ammonia to provide amine 10, and subsequent condensation of 10 with 6‐methylthio‐5‐nitrosoisocytosine (11). Glycoside 3 inhibited the synthase with moderate potency (I50 = 11 μM) but did not exhibit antibacterial activity.
Reaction of 3‐amino‐5,6‐dimethyl‐1,2,4‐triazine with electrophiles
Authors: Suzuki Toshinobu , Okazaki Masahiko , Mitsuhashi Keiryo
Published: March 2009

The title compound was reacted with four types of electrophiles and the respective reaction sites were investigated. The reaction with aryl isocyanates in the conventional way yielded the corresponding ureas. In the presence of triethylamine, the 3‐amino group was diacylated with acyl chlorides. On the other hand, in the cases with arylsulfonyl chlorides and p‐nitrobenzaldehyde under similar conditions, the methyl group at 5‐position was preferentially attacked to give arylsulfonylmethyl and p‐nitrostyryl derivatives, respectively.
Preparation of benzo[c][2,7]naphthyridin‐5(1H)‐ones as analogs of benzopyrano[3,4‐c]pyridin‐5‐one bronchodilators
Authors: Unangst Paul C. , Connor David T. , Carethers Mary E. , Schwender Charles S. , Brown Richard E. , Puchalski Chester
Published: March 2009

A series of 2,3,4,6‐tetrahydro‐8,9‐dimethoxybenzo[c][2,7]naphthyridin‐5(1H)‐ones was prepared as potential anticholinergic bronchodilators. The naphthyridine ring system was constructed by cyclization of a 3‐amido‐4‐piperidone. Alkylation with alkylaminoethyl chlorides or reductive amination of an intermediate methyl ketone yielded the final target compounds.
Synthesis of 2‐aminomethyl‐1,10‐phenanthroline. A new chelating agent and versatile synthon for other chelating compounds
Authors: Engbersen J. F. J. , Koudijs A. , Joosten M. H. A. , van der Plas H. C.
Published: March 2009

The synthesis of 2‐aminomethyl‐1,10‐phenanthroline (4) from 1,10‐phenanthroline (1) is described. The reduction of 2‐cyano‐1,10‐phenanthroline (3) to 4 in the presence of 10% palladium on carbon in acetic acid under mild reaction conditions also proved to be a very efficient method for conversion of cyanopyridines to methylaminopyridines.
The photochemistry of α,β‐acetylenic ketones. II. Formation of furan derivatives
Authors: Nishio Takehiko , Nakata Hiroyuki , Omote Yoshimori
Published: March 2009

The photochemical reactions of α,β‐acetylenic ketones have been examined. Irradiation of 1‐p‐substituted phenyl‐2‐propyn‐1‐ones 2–4 in primary alcohols gave 2,5‐disubstituted furans 2a–4c. The formation of furans can be explained in terms of cyclization, followed by dehydration of the 1:1‐adduct of acetylenic ketone and alcohol, which was formed initially by hydrogen atom abstraction from alcohol by the excited acetylenic ketone. Irradiation of 1‐p‐tolyl‐2‐propyn‐1‐one (2) in ethanol‐d1 yielded 2‐methyl‐5‐p‐tolylfuran (2b) containing no deuterium. This result was consistent with a mechanism that involves hydrogen atom abstraction from alcohol by the carbon of triple bond rather than abstraction by carbonyl oxygen.
Structural effects on the rates of the ion molecule reactions of organic heterocycles
Authors: Scala A. A. , Caputo M. G. , Billings D.
Published: March 2009

Rate constants for proton transfer reactions of seven heterocyclic amines, eight heterocyclic ethers and propylene sulfide have been measured by photoionization mass specrometry. Rate constants for dimerization of four sulfides have also been measured. The measured rate constants have also been compared to the theoretical (ADO) rate constants. In all cases the ADO rate constants show only small variations with structure. In fact for the mono‐heterocycles all but one of the ADO rate constants are between 2.0 and 1.5 × 10−9 cc molec−1 sec−1. The observed rate constants show considerable dependence on chemical structure. The amines react faster than the oxides which in turn react faster than the sulfides. N‐Methyl substitution on pyrrolidine and piperidine lowers their rate constants by about a factor of two while, propylene oxide reacts eighteen percent faster than ethylene oxide. Examination of the variation in the observed rate constants as a function of ring size for each group of heterocycles indicates a distinct structure‐reactivity correlation although we have not attempted to rationalize this correlation. There is also a structure‐reactivity dependence observed in the six‐membered oxygen heterocycles having a second heteroatom O, NH, or S in the 4‐position. The rate constants increase with the electronegativity of the second heteroatom.
Base‐induced ring cleavage of 4‐functionalized‐3‐unsubstituted isoxazoles. Synthesis of 5‐aminoazoles and 4‐cyanoazoles
Authors: Alberola A. , Antolin L. F. , Gonzalez A. M. , Laguna M. A. , Pulido F. J.
Published: March 2009

The base‐induced ring cleavage of 4‐nitro‐(Ia), 4‐ethoxycarbonyl‐ (Ib) and 4‐acetyl‐5‐methylisoxazole (Ic) and the conversion of the resulting β‐cyanoenolates and β‐enaminonitriles into 5‐aminoazoles and 4‐cyanoazoles was studied.
Hétérocycles à fonction quinone. 7. Benzo[f]quinazolinediones‐7,10 à action antitumorale potentielle
Authors: Parrot‐Lopez Hélène , Delacotte Jean‐Michel , Renault Jean , Cros Suzanne
Published: March 2009

Les benzo[f]quinazolinediones‐7,10 4a‐c sont obtenues par oxydation par le nitrosodisulfonate de potassium (réactif de Frémy) des benzo[f]quinazolinamines correspondantes, préparées par réduction du dérivé nitré lui‐même obtenu à partir de la méthoxy‐8 2H‐benzo[f]quinazolinone‐1 (8). Le dérivé 4a présente une cytotoxicité non négligeable.
A reinvestigation of the synthesis of 3H‐[1,2]diazepino[5,6‐b]indoles. The synthesis of pyrido[4,3‐b]indoles
Authors: Karrick Gregory L. , Peet Norton P.
Published: March 2009

Recently reported [1] syntheses of 6‐methyl‐1,2,4,5‐tetrahydro‐1,4‐dioxo‐3H[1,2]diazepino[5,6‐b]indole (5) and 4‐hydroxy‐6‐methyl‐3H[1,2]diazepino[5,6‐b]indole (12) were reinvestigated and shown to be in error. The correct assignments for these respective structures are 3‐amino‐1,9‐dihydro‐9‐methyl‐2H‐pyrido[4,3‐b]indol‐2,4(3H)‐dione (6) and 3‐amino‐3,9‐dihydro‐9‐methyl‐2H‐pyrido[4,3‐b]indol‐2‐one (13). Condensation of 6 and 13 with p‐nitrobenzaldehyde produced benzylidene derivatives, which confirmed the presence of the amino groups.
Alkaloids asymmetric synthesis from (S)‐pyroglutamic acid. II. Attempted asymmetric total synthesis of trans‐5‐ethyl‐2‐n‐heptylpyrrolidine
Authors: Marco José L.
Published: March 2009

From the readily available (S)‐pyroglutamic acid 1 the asymmetric synthesis of trans and cis 5‐n‐heptyl‐2‐(S)‐hydroxymethylpyrrolidines 7, some derivatives and transformations are described.
Reaction of ketenes with N,N‐disubstituted α‐aminomethyleneketones. XVIII. Synthesis of N,N‐disubstituted 4‐amino‐3‐phenyl‐2H‐naphtho[1,2‐b]pyran‐2‐ones
Authors: Bargagna Alberto , Schenone Pietro , Longobardi Mario
Published: March 2009

1,4‐Cycloaddition of phenylchloroketene to N,N‐disubstituted 2‐aminomethylene‐3,4‐dihydro‐1(2H)naphthalenones gave the corresponding adducts, namely N,N‐disubstituted 4‐amino‐3‐chloro‐3,4,5,6‐tetrahydro‐3‐phenyl‐2H‐naphtho[1,2‐b]pyran‐2‐ones II, in the case of aliphatic N,N‐disubstitution or aromatic N‐monosubstitution. Apart from IIf (NR2 = NMePh), adducts II were unstable and were dehydrochlorinated in situ with DBN to give N,N‐disubstituted 4‐amino‐5,6‐dihydro‐3‐phenyl‐2H‐naphtho[1,2‐b]pyran‐2‐ones III in fair overall yields. Compounds III were dehydrogenated with Pd/C in boiling p‐cymene to afford the title compounds generally in high yields.
Darstellung und eigenschaften trifluormethylmercapto‐substituierter pyrimidine
Authors: Haas A. , Lieb M.
Published: March 2009

5‐Trifluoromethylthio‐substituted pyrimidines have been synthezised by halogenation of 5‐trifluoromethylthiouracile or barbituric acid with phosphorus halogenides POX3. The new compounds themselves are excellent starting materials for further nucleophilic exchange reactions. Thus fluoro‐, iodo‐, alkoxy‐ and aminoligands were introduced and further used for new synthesis. A new method for introducing trifluoromethylthio (SCF3)‐groups is presented.
Synthesis of thiophenedicarbonyldiazides and Di‐t‐butyl thiophendicarbamates
Authors: Galvez Carmen , Garcia Francisco , Garcia Juan , Soldevila Joan
Published: March 2009

Dicarbamates 1b and 1c, and dicarbonyldiazides 2b and 2c are obtained in good yields starting from thiophenedicarboxylic acids 3b and 3c, but the vicinal diacids 3a and 3d are not suitable for the synthesis of dicarbamates 1a and 1d and dicarbonyldiazides 2a and 2d; 1a is prepared by a stepway procedure previously described, and 1d by t‐butoxycarbonylation of the recently known 3,4‐thiophenediamine.
Acylation des β‐énaminoesters: Regio et stéréoformation des β‐énaminoesters N‐ ou C‐acylés
Authors: Brunerie Pascal , Célérier Jean‐Pierre , Petit Huguette , Lhommet Gérard
Published: March 2009

La taille du cycle des β‐énaminoesters cycliques oriente leur réaction avec les chlorures d'acides vers la formation sélective des dérivés N‐acylés pour les cycles à cinq chainons, et C‐acylés avec les cycles à sept chaînons; avec le cycle à six chainons on observe la formation d'un mélange de dérivés N et C‐acylés.
A novel and practical synthetic method of 3(2H)‐furanone derivatives
Authors: Sakai Takashi , Yamawaki Akitoshi , Ito Hiroshi , Utaka Masanori , Takeda Akira
Published: March 2009

A novel, convenient synthetic method of 5‐atyl‐2,2‐dimethyl‐3(2H)‐furanones (aryl = C6H5, 2‐CH3C6H4, 3‐CH3C6H4, 4‐CH3C6H4, 2‐CIC6H4, 4‐CIC6H4, 2,4‐Cl2C6H3) is described. It involves the Claisen‐Schmidt condensation (potassium hydroxide/ethanol) of aromatic aldehydes with 3‐hydroxy‐3‐methyl‐2‐butanone to give enones, whose bromination followed by alkaline hydrolysis (sodium hydroxide/ethanol) affords 3(2H)‐furanone derivatives in 54–64% overall yields. The procedure is also applicable to nicotinaldehyde and furfural, although the yields are not satisfactory.
Benzannelated analogs of phenanthro[1,2‐b]‐ and [2,1‐b]thiophene: Synthesis and structural characterization by two‐dimensional NMR and X‐ray techniques
Authors: Stuart John G. , Quast Michael J. , Martin Gary E. , Lynch Vincent M. , Simonsen Stanley H. , Lee Milton L. , Castle Raymond N. , Dallas Jerry L. , John Boban K. , Johnson LeRoy F.
Published: March 2009

Syntheses of benzo[3,4]phenanthro[1,2‐b]thiophene, benzo[3,4]phenanthro[2,1‐b]thiophene and their 1‐methyl analogs are reported as potential constituents of solvent refined coal liquids and for mutagenicity testing. The attempted synthesis of the 13‐methyl analogs which gave the 11‐methyl isomers is also described. Total assignments of the 1H‐ and 13C‐nmr spectra based on long range optimized heteronuclear protoncarbon two‐dimensional chemical shift correlation are reported. Carbon assignments obtained for benzo[3,4]‐phenanthro[1,2‐b]thiophene using this approach were confirmed with a 125 MHz 13C–13C INADEQUATE spectrum. X‐Ray crystal structures were determined for benzo[3,4]phenanthro[1,2‐b]thiophene and 1‐methyl‐benzo[3,4]phenanthro[2,1‐b]thiophene. Both molecules were helically distorted from planarity. Close intramolecular contacts between the bay region H1–H13 and ClMe‐H13 of 2.03 and 2.28 Å, respectively, were responsible for the distortions. There were no close intermolecular contacts of <3.5Å. both molecules refined to an R value of <0.05.
The chemistry of 4‐pyrimidinones: Acetylation and ring‐opening reactions
Authors: Sodum Rama S. , Klein Robert S. , Otter Brian A.
Published: March 2009

4(3H)‐Pyrimidinone, as well as its 5‐acetoxy and 5‐methoxy derivatives, undergoes selective acetylation at N‐1 when treated with acetic anhydride. In the presence of water, these 1‐acetylpyrimidines undergo spontaneous covalent hydration at C‐2 and cleavage of the 1,2‐bond to give crystalline cis‐3‐acetylamino‐N‐formyl‐acrylamides, generally in good yield. In contrast, the 6‐methyl derivative of 4(3H)‐pyrimidinone forms an equilibrium mixture of acetylated products that undergo the ring opening process to only a very limited extent, the major product (11%) being the 3‐formylamino‐N‐acetylacrylamide derivative formed via N‐3 acetylation and cleavage of the 2,3‐bond.
Thermolyzed products of naphth[1,2‐d]imidazo[2,1‐b]‐thiazole‐2,3‐dione
Authors: Liu Kang‐Chien , Shih Bi‐Jane
Published: March 2009

Themolysis of naphth[1,2‐d]imidazo[2,1‐b]thiazole‐2,3‐dione (1) in dimethylformamide gave an intermediate 2‐isocyanatonaphtho[1,2‐d]thiazole (2), which underwent [4 + 4] cyclodimerization to yield dinaphtho‐[1″,2″:4,5;1′″,2′″:4′,5′]dithiazolo[3,2‐a:3′,2′‐e]‐1,3,5,7‐tetrazocine‐9,19‐dione (3). The possible [4 + 2] cycloadduct, 3‐(2‐naphtho‐[1,2‐d]‐thiazolyl)naphtho[1′,2′:4,5]thiazolo[3,2‐a]‐1,3,5‐triazine‐2,4‐dione (4), an usual dimer type of heterocyclic isocyanates was not produced. Discrimination between the two isomers was established on the basis of spectral analyses.
Polycondensed nitrogen heterocycles. Part 21. Complete 13C NMR assignment of annelated phenanthridines
Authors: Cirrincione Girolamo , Dattolo Gaetano , Almerico Anna Maria , Aiello And Enrico , Cusmano Giuseppe , Macaluso Gabriella , Ruccia And Michele , Hinz Werner
Published: March 2009

Two‐dimensional nmr techniques were used for the complete assignment of 13C nmr spectra of pyrrolo‐[1,2‐f]‐, pyrazolo[1,5‐f]‐, and 1,2,4‐triazolo[1,5‐f]phenanthridines.
Synthesis of substituted 5,6,7,8‐tetrahydroquinolines from conjugated ketoximes
Authors: Chelucci G. , Cossu S. , Soccolini F.
Published: March 2009

A number of 5,6,7,8‐tetrahydroquinolines have been prepared by heating conjugated ketoximes at 300° in a sealed tube.
Crystal and molecular structures of cis‐1‐phenyl‐3‐piperidinocyclohexan‐1‐ol hydrochloride
Authors: Kimura Michio , Okabayashi Ichizo
Published: March 2009

Mr = 295.84, triclinic, Pl, a = 6.786(1), b = 7.658(1), c = 8.561(1) Å, α = 108.17(1), β = 97.94(1), γ = 103.32(2)°, V = 400.6 Å3, Z = 1,Dm = 1.23, Dx = 1.226 Mgm−3, δ(Cu Kα) = 1.5418 Å, μ = 20.81 cm−1, F(000) = 160. The structure has been solved by direct and Fourier methods and refined by a least‐squares procedure to the final R = 0.043 for 1182 observed reflections (|Fo] >3σ(Fo)). cis‐1‐Phenyl‐3‐piperidinocyclohexan‐1‐ol possessing 1,3‐diaxial positions between the piperidine and hydroxyl groups is converted to the isomer with 1,3‐diequatorial positions in its hydrochloride. The hydrogen bond is formed between the chloride anion and the protonated nitrogen atom of piperidine instead of the intramolecular hydrogen bond in the free cis‐base between the oxygen and nitrogen atoms.
Nitrogen bridgehead compounds. Part 65. Vilsmeier‐haack formylation of 4H‐pyrido[1,2‐a]pyrimidin‐4‐ones. Part 6
Authors: Horváth ÁGnes , Hermecz István
Published: March 2009

2‐Substituted 3‐formyl‐4H‐pyrido[1,2‐a]pyrimidin‐4‐ones can be synthethized by Vilsmeier‐Haack formylation with the dimethylformamide‐phosphoryl chloride complex only from those 4H‐pyrido[1,2‐a]pyrimidin‐4‐ones which contain a substituent with electron‐releasing resonance effect in position 2. The products were characterized by uv, ir and 1H nmr spectroscopy.
Quinazolines and 1,4‐benzodiazepines. XCV. Synthesis of 1,4‐benzodiazepines by ring expansion of 2‐chloromethylquinazolines with carbanions
Authors: Walser A. , Flynn T. , Mason C. , Fryer R. Ian
Published: March 2009

1,4‐Benzodiazepines bearing a carbon substituent at the 2‐position were obtained by reaction of 2‐chloromethylquinazoline 3‐oxides with stabilized carbanions. The carbanions of alkyl acetates, N,N‐disubstituted acetamides, acetonitrile, dimethylsulfone, N,N‐dimethyl methanesulfonamide and 2‐methylpyridine were successfully applied. The conversion of some of the 2‐carbon substituted 1,4‐benzodiazepines to imidazo[1,5‐a][1,4]benzodiazepines and [1,2,5]oxadiazino[5,4‐a][1,4]benzodiazepines is described.
Macrocyclic polyether‐ and polythioether‐diesters and dithioesters from 1,10‐phenanthroline‐2,9‐dicarboxylic acid
Authors: Chandler Christopher J. , Deady Leslie W. , Reiss James A.
Published: March 2009

The synthesis of nine macrocyclic polyether‐ and polythioether‐diesters 9–13 and dithioesters 14–17 derived from 1,10‐phenanthroline‐2,9‐dicarboxylic acid are reported. The macrocycles were prepared under conditions of high dilution in the absence of metal templates in consistently good yields and their structures were confirmed by 1H and 13C nmr spectroscopy. A macrocyclic phenanthroline‐pyridine tetraester 18 is also recorded.
An approach to tetrahydrobenz[b,d]pyrans and hexahydrophenanthridines by reaction of dilithiated phenol and aniline with pulegone
Authors: Pedaja Peter , Westerlund Christer , Hallberg Anders
Published: March 2009

7,8,9,10‐Tetrahydro‐6,6,9‐trimethyldibenzo[b,d]pyran and 5,6,7,8,9,10‐hexahydro‐6,6,9‐trimethylphenanthridine have been prepared by reaction of pulegone with lithiumortho‐lithium phenolate and lithiumortho‐lithiumN‐trimethylsilylaniline. The cyclization into the annellated systems could be performed under essentially non‐acidic conditions.
Demethylation of crown ethers, aza crown ethers, and cryptands which have inward‐facing anisole units by lithium aluminum hydride in tetrahydrofuran
Authors: Czech Anna , Czech Bronislaw P. , Desai Dhimant H. , Hallman Johnny L. , Phillips John B. , Bartsch Richard A.
Published: March 2009

Lithium aluminum hydride in tetrahydrofuran is an efficient demethylating reagent combination for mono‐ and bicyclic polyether compounds which bear intra‐annular methoxyaryl groups.
2‐substituted 2,3‐dihydro‐5H‐thiazolo[2,3‐b]quinazoline derivatives
Authors: Georgiev Vassil St. , Bennett Grace A. , Radov Lesley A. , Kamp Dietgard K. , Trusso Laura A.
Published: March 2009

The synthesis of a series of 2‐substituted 2,3‐dihydro‐5H‐thiazolo[2,3‐b]quinazoline derivatives is described. Some of the title compounds exerted antiinflammatory and immunomodulating activities in laboratory animal models.
Preparation of 1,5‐disubstituted 4‐sulfonylpyrazoles, β‐cyano‐β‐sulfonylenamines and 5‐substituted 4‐sulfonylisoxazoles from β‐keto‐β‐sulfonylenamines
Authors: Takahashi Masahiko , Mamiya Tsutomu , Hasegawa Hisao , Nagai Takashi , Wakita Hideki
Published: March 2009

Reaction of β‐keto‐β‐sulfonylenamines 1a,b with N‐substituted hydrazines gave 1,5‐disubstituted 4‐sulfonylpyrazoles 2a‐h in moderate yields, which were ring‐opened on treatment with n‐butyllithium to afford β‐cyano‐β‐sulfonylenamines (3a,b,d‐f). 5‐Substitued 4‐sulfonylisoxazoles 6a‐d were also prepared from 1a‐d and hydroxylamine.
Polycondensed nitrogen heterocycles. Part 19. Pyrrolo[1,2‐f]phenanthridines by pschorr‐type cyclization brought about by hypophosphorous acid
Authors: Dattolo Gaetano , Cirrincione Girolamo , Almerico Anna Maria , Aiello Enrico , D'Asdia Isabella
Published: March 2009

Pyrrolo[1,2‐f]phenanthridines were prepared in good yields by the diazotization in acetic acid of the amines la,b and subsequent treatment with hypophosphorous acid. The necessity for hypophosphorous acid in the reaction was demonstrated.
Synthesis of 3‐(α‐chlorophenylhydrazono)heteroarylmethyl‐2‐oxo‐1,2‐dihydroquinoxalines with antimicrobial activity
Authors: Kurasawa Yoshihisa , Muramatsu Muneto , Yamazaki Kaoru , Okamoto Yoshihisa , Takada Atsushi
Published: March 2009

The reactions of 3‐(α‐chlorophenylhydrazono)hydrazinocarbonylmethyl‐2‐oxo‐1,2‐dihydroquinoxalines 4a,c with triethyl orthoesters resulted in the intramolecular cyclization to give the 3‐(α‐chlorophenylhydrazono‐1,3,4‐oxadiazol‐2‐ylmethyl)‐2‐oxo‐1,2‐dihydroquinoxalines 5a‐d, but not the 1,2,4,5‐tetrazepinylquinoxalines 6a‐d. The cyclization mode into the 1,3,4‐oxadiazole ring was confirmed by the alternate syntheses of 5a,c from the reactions of the 3‐(1,3,4‐oxadiazol‐2‐ylmethylene)‐2‐oxo‐1,2,3,4‐tetrahydroquinoxalines 7a,b with o‐chlorobenzenediazonium chloride. Moreover, the reactions of 3‐(benzimidazol‐2‐ylmethylene)‐2‐oxo‐1,2,3,4‐tetrahydroquinoxaline hydrochloride 8 with o‐, m‐ and p‐chlorobenzenediazonium chlorides afforded the 3‐(α‐chlorophenylhydrazonobenzimidazol‐2‐ylmethy])‐2‐oxo‐1,2‐dihydroquinoxa]ine hydrochlorides 9a‐c, respectively. Compounds 5a‐d and 9a‐c were found to exhibit antimicrobial activities.
Methylx derivatives of tetrahydrobenzo‐ and benzofurocoumarins, a new class of potential photoreagents toward dna
Authors: Rodighiero P. , Palumbo M. , Magno S. Marciani , Manzini P. , Gia O. , Piro R. , Guiotto A.
Published: March 2009

A number of new tetracyclic furocoumarin derivatives with a linear structure or with various angular arrangements, were synthetized. The new compounds are characterized for having an additional cyclohexene or phenyl ring condensed at the 4′,5′ double bond of the furan ring of the furocoumarin nucleus. The syntheses were performed starting from the appropriate hydroxycoumarins on which the tetrahydrobenzofuran or benzofuran moiety was built. Methyl groups have been introduced into positions which look most promising for enhancement of the photoreactivity of the compounds toward DNA.
The crystal structure of 3a,4,5,6‐tetrahydro‐3a,5,5‐trimethyl‐1,3‐diphenyl‐3H‐1,2,4‐triazolo[4,3‐a][1,5]benzodiazepine
Authors: Aversa M. C. , Ferlazzo A. , Giannetto P. , Kohnke F. H. , Slawin A. M. Z. , Williams D. J.
Published: March 2009

The crystal structure of the title compound is described.
Synthesis and biological activity of bridgehead nitrogen heterocycles
Authors: Goswami B. N. , Kataky J. C. S. , Baruah J. N.
Published: March 2009

The reaction of 3‐(2,4‐dichlorophenyl)‐5‐mercapto 1,2,4–1H‐triazole with α‐haloketones and with 1,2‐dibromoethane leading to the formation of fused heterocycles were carried out and the orientation of cyclization was studied. The reaction of 3‐(2,4‐dichlorophenyl)‐5‐mercapto‐4‐amino‐1,2,4‐s‐triazole with α‐haloketones
Applications of 1‐alkoxycarbonyl‐ and 1‐acyl‐v‐triazolo[4,5‐b]pyridines as acylating reagents
Authors: Torrini Ines , Zecchini Giampiero Pagani , Agrosì Francesco , Paradisi Mario Paglialunga
Published: March 2009

Selective N‐protection of hydroxyamino esters has been readily achieved using 1‐alkoxycarbonyl‐ or 1‐acyl‐v‐triazolo[4,5‐b]pyridines. The amide‐type triazolides reacted with alcohols in the presence of DBU at room temperature to afford in high yields the corresponding esters. The different reactivity of 1‐ and 3‐alkoxycarbonyl derivatives of the title bicyclic system toward primary amines has been further investigated.
Furopyridines. VI. Preparation and reactions of 2‐ and 3‐substituted furo[2,3‐b]pyridines
Authors: Morita Hiroyuki , Shiotani Shunsaku
Published: March 2009

This paper describes the synthesis and chemical properties of some 2‐ and 3‐substituted furo[2,3‐b]pyridines. Reaction of ethyl 2‐chloronicotinate 1 with sodium ethoxycarbonylmethoxide or 1‐ethoxycarbonyl‐1‐ethoxide gave β‐keto ester 2 or ketone 5, respectively. Ketonic hydrolysis of 2 afforded ketone 3, from which furo[2,3‐b]pyridine 4 was obtained by the method of Sliwa. While, 2‐methyl derivative 7 was prepared from 5 by reduction, O‐acetylation and the subsequent pyrolysis. Reaction of ketone 3 with methyllithium gave tertiary alcohol 8 which was O‐acetylated and pyrolyzed to give 3‐methyl derivative 9. Formylation of 4, via lithio intermediate, with DMF yielded 2‐formyl derivative 10, from which 7, was obtained by Wolff‐Kishner reduction. Dehydration of the oxime 11 of 10 gave 2‐cyano derivative 12, which was hydrolyzed to give 2‐carboxylic acid 13. Reaction of 3‐bromo compound 14 with copper(I) cyanide gave 3‐cyano derivative 15. Alkaline hydrolysis of 15 afforded compound 16 and 17, while acidic hydrolysis gave carboxamide 18. Reduction of 15 with DIBAL‐H afforded 3‐formyl derivative 19. Wolff‐Kishner reduction of 19 gave no reduction product 9 but hydrazone 20. Reduction of tosylhydrazone 21 with sodium borohydride in methanol afforded 3‐methoxymethylfuro[2,3‐b]pyridine 22.
Heteroannulated‐9,10‐anthracenediones. The synthesis of substituted 5‐ and 7‐chloroanthra[1,9‐cd]pyrazol‐6(2H)‐ones, precursors to anticancer anthrapyrazoles
Authors: Showalter H. D. Hollis , Johnson Judith L. , Hoftiezer Jeanne M.
Published: March 2009

Synthetic methodologies to a number of 5‐ and 7‐chloroanthra[1,9‐cd|pyrazol‐6(2H)‐ones, 4 and 37 respectively, optionally substituted with side chains at N‐2 and dioxy substituents in the A ring, are reported. Reported also are detailed uv, ir and 1H‐nmr spectroscopy for representative compounds.
Synthesis of furazano‐substituted 1,5‐diazepines
Authors: Fischer John W. , Atkins Ronald L. , Nissan Robin A. , Lowe‐Ma Charlotte K. , Decker David L.
Published: March 2009

A series of furazano‐substituted 1,5‐diazepines have been synthesized from the reaction of a methyl ketone and 3,4‐diaminofurazan in the presence of a mild Lewis acid. The reaction was found to be regiospecific. Other ketone substrates also yielded diazepines, however, these products were found to be unstable and decomposed upon contact with air.
Synthesis of 4‐Aryl‐1,4‐dihydro‐2,6‐bis(trifluoromethyl)‐3,5‐pyridinedicarboxylates
Authors: Kim Dong H.
Published: March 2009

Treatment of 4‐aryl‐2,6‐dihydroxy‐2,6‐bis(trifluoromethyl)‐3,5‐piperidinedicarboxylic acid esters with phosphorus oxychloride in pyridine afforded 4‐aryl‐1,4‐dihydro‐2,6‐bis(trifluoromethyl)‐3,5‐pyridine dicarboxylic acid esters which were reported originally by Balicki and Nantka‐Namirski, but were later proven to be 4‐aryl‐2,6‐dihydroxy‐2,6‐bis(trifluoromethyl)‐3,5‐piperidine dicarboxylic acid esters.
Synthesis of 6‐phenyl and 6‐styrylthiazolo[3,2‐b] [1,2,4]triazoles
Authors: Hénichart Jean‐Pierre , Houssin Raymond , Bernier Jean‐Luc
Published: March 2009

Thiazole rings have been often encountered in the structure of antibiotic or antitumor drugs. An easy synthesis of them has revealed itself necessary in order to elucidate the mechanism of action of these naturally occurring substances. A method of preparation of conjugated b‐ethylenic thiazole[3,2‐b] [1,2,4]triazoles by heating a 3‐thio substituted [1,2,4]triazole in the presence of polyphosphoric acid is reported here, giving the expected product in a 60% yield.
Synthesis and reaction of 5‐amino‐3‐trifluoromethylisoxazole and ‐pyrazole‐4‐carboxylic acids
Authors: Tanaka Kiyoshi , Suzuki Takashi , Maeno Seiji , Mitsuhashi Keiryo
Published: March 2009

5‐Amino‐3‐trifluoromethylisoxazole‐ and ‐pyrazole‐4‐carboxylic acids were prepared by the reactions ot trifluoroacetonitrile oxide or ‐imines with cyanoacetic acid derivatives, respectively. The behavior of thus obtained aminoazole‐4‐carboxylic acids toward some electrophiles was examined. In acylation with acyl chlorides, the aminoisoxazole‐4‐carboxylate 2a was diacylated to give the (diacylamino)isoxazole‐4‐carboxylate 7, whereas the analogous aminopyrazole 5a produced the cyclized pyrazolooxazinone 13. Moreover, carbamoylation of 2a with isocyanates gave the trifluoromethylisoxazolouracils 10.
3,3′‐diaryl‐5‐morpholino‐4,5,4′,5′‐tetrahydro‐4,5′‐spirobi[isoxazoles]. Synthesis by cycloaddition reactions and substituent effect on the cycloaddition kinetics
Authors: Beltrame Paolo , Gelli Gioanna
Published: March 2009

3‐Aryl‐4‐methylene‐5‐morpholino‐4,5‐dihydroisoxazoles 1a‐e were synthesized; fifteen different 3,3′‐diaryl‐5‐morpholino‐4,5,4′,5′‐tetrahydro‐4,5′‐spirobi[isoxazoles] 3 were obtained by their reaction with some stable aryl nitrile oxides. The spiro‐derivatives were characterized by their nmr spectra. Kinetic measurements showed that substituents on the nitrile oxide have a weak effect on the cycloaddition rate (Hammett 'p = ca 0.3), while substituents on the dipolarophile have no effect at all.
The Synthesis of pyrimido[4,5‐b][1,4]diazocines and pyrido[2,3‐b][1,4]diazoeines
Authors: Thompson Michael D.
Published: March 2009

The reaction conditions for the preparation of 7H,8H‐1,3‐dimethyl‐2,4,6,9‐tetraoxopyrimidino[4,5‐b][1,4]‐diazocine (9), 1,3‐dimethy 1–2,4,6,11‐tetraoxobenzo[f]pyrimidino[4,5‐b][1,4]diazocine (10), 7H,8H‐1,3‐dimethyl‐2,4,6,10‐tetraoxopyrimidino[4,5‐b][1,4]diazonine (16), and 7H,8H‐6,9‐dioxopyridino[2,3‐b][1,4]diazocine (19) were determined. The mechanism of the formation of these compounds was established. The scope of these reactions was found to be general for eight and nine ring formation from 2,3‐diamino‐N‐heterocycles.
Pyrrolopyridine analogs of nalidixic acid. 1. Pyrrolo[2,3‐b]pyridines
Authors: Toja Emilio , Tarzia Giorgio , Ferrari Pietro , Tuan Giorgio
Published: March 2009

A series of 4,7‐dihydro‐4‐oxo‐1H‐pyrrolo[2,3‐b]pyridine‐5‐carboxylic acids was synthesized from ethyl 5‐methyl(or 5H)‐2‐aminopyrrole‐3‐carboxylate. The starting pyrroles were obtained by reaction of carbethoxyacetamidine with bromoacetone or chloroacetaldehyde. One compound (10) showed antibacterial activity in vitro.
Definitive assignment of 13C NMR signals in tryptophan and related molecules
Authors: Morales‐Ríos M. S. , Joseph‐Nathan P.
Published: March 2009

Selective photodeuteration of carboxyltryptamines at C‐4 allowed to settle the controversy about the 13C nmr assignment of C‐4, C‐5 and C‐6, which for tryptophan are definitively assigned at 118.4, 118.2 and 120.6 ppm, respectively.
Darstellung und reaktionen eines 2H‐pyrrolo[3,4‐b]pyridins und eines 2H‐pyrrolo[3,4‐b]pyrazins
Authors: Troll Theodor , Schmid Klaus
Published: March 2009

Die kathodische Reduktion von Pyridin‐2,3‐dicarbonsäure‐N‐phenylimid (1) unter aprotischen Bedingungen in Gegenwart von Trimethylchlorsilan führt zu 2‐Phenyl‐1,3‐bis[trimethylsilyloxy]‐pyrrolo‐[3,4‐b]pyridin (4), das mit elektronenarmen Olefinen über eine Cycloaddition in Chinolinderivate überführt werden kann.

Aus Pyrazin‐2,3‐dicarbonsäure‐N‐phenylimid (3) entsteht unter gleichen Bedingungen 2‐Phenyl‐1,3‐bis‐[trimethylsilyloxy]‐pyrrolo[3,4‐b]pyrazin (13), das nicht mehr ausreichend stabil ist. Darstellung von 13 in Gegenwart eines Dienophils führt jedoch zu Chinoxalinderivaten als Abfangprodukte.

Die orthochinoiden Heterocyclen 4 und 13 sind auf diesem Weg erstmals zugänglich.
Reaction of benzamide oxime with DCC
Authors: Kawashima Etsuko , Tabei Katsumi
Published: March 2009

Reaction of benzamide oxime (1) with N, N′‐dicyclohexylcarbodiimide (2) afforded 5‐cyclohexylamino‐3‐phenyl‐1,2,4‐oxadiazole (3), N, N′, N″‐tricyclohexylguanidine (4) and N, N′‐dicyclohexyl urea (5). When acetone (8a) or ethyl acetoacetate (8b) was added as a trap, the yield of 3 increased slightly and N‐(2‐propylidene)cyclohexylamine (9a) or ethyl 3‐cyclohexylamino‐2‐butenoate (9b) was obtained as well as products 4 and 5. Acetylacetone (8c) and diacetyl (8d) were also used as the trap for the cyclohexylamino group. When p‐toluenesulfonic acid was added as a catalyst, 1‐cyclohexyl‐5‐cyclohexylamino‐3‐phenyl‐1H‐1,2,4‐triazole (11) was obtained in low yield.
The alkylation of hantzsch 1,4‐dihydropyridines
Authors: Patterson John W.
Published: March 2009

The reaction of carbanions derived from Hantzsch 1,4‐dihydropyridines with alkyl halides was studied and methods for mono‐ and di‐alkylation were devised.
Synthesis of 2‐(β‐D‐ribofuranosyl)[1,3,5]triazines
Authors: Riley Timothy A. , Hennen William J. , Dalley N. Kent , Wilson Bruce E. , Robins Roland K.
Published: March 2009

The synthesis of the first [1,3,5]triazine carbon linked nucleosides are reported. 4‐Amino‐6‐(β‐D‐ribofuranosyl)[1,3,5]triazin‐2(1H)‐one (8), an analog of 5‐azacytidine and pseudoisocytidine was prepared. 2,5‐Anhydro‐D‐allonamidine hydrochloride (3) was condensed with dimethyl cyanoiminodithiocarbonate (4) to give 4‐methylthio‐6‐(β‐D‐ribofuranosyl)[1,3,5]triazin‐2‐amine (5). Compound 5 was reacted with m‐chloroperbenzoic acid to give 4‐methylsulfinyl‐6‐(β‐D‐ribofuranosyl)[1,3,5]triazin‐2‐amine (6). Displacement of the methyl sulfinyl with the appropriate nucleophile gave 6‐(β‐D‐ribofuranosyl)[1,3,5]triazine‐2,4‐diamine (7), 4‐amino‐6‐(β‐D‐ribofuranosyl)[1,3,5]triazin‐2(1H)‐one (8), and 4‐amino‐6‐(β‐D‐ribofuranosyl)[1,3,5]triazine‐2(1H)‐thione (9). Dethiation of compound 5 with Raney nickel gave 4‐(β‐D‐ribofuranosyl)[1,3,5]triazin‐2‐amine (10). The crystal structure of 7 was determined by single crystal X‐ray.
Synthesis of 1‐(o‐substituted‐phenyl)‐3,4‐dimethylenepyrrolidines by the thermal elimination of sulfur dioxide
Authors: Ottenbrite Raphael M. , Chin Henry , Alston Peter V.
Published: March 2009

Precursors of 1‐(o‐substituted‐phenyl)‐3,4‐dimethylenepyrrolidines, 5‐(o‐substituted‐phenyl)‐1,3,4,6‐tetra‐hydrothieno[3,4‐c]pyrrole 2,2‐ dioxides 2, were synthesized by reacting o‐substituted anilines with 3,4‐bis(bromomethyl)‐2,5‐dihydrothiophene 1,1‐dioxide. A disubstitution product along with the desired 2 was obtained when excess amine was used to neutralize the amine salts that were formed from nucleophilic substitution. A 1,4‐HBr elimination product was obtained in three out of four cases when sodium carbonate was used to neutralize the amine salts. The 1,4‐HBr elimination product resulted from a competing base attack on the acidic sulfolene protons. The 3,4‐dimethylenepyrrolidines were obtained by thermal elimination of sulfur dioxide from 2.
Réactivité de β‐énaminones cycliques. II. Cyclocondensation directe d'amidines, d'hydrazines et de l'hydroxylamine sur la pyrrolidinométhylène‐3 chromanone‐4
Authors: Graffe Bernadette , Sacquet Marie‐Claude , Bellassoued‐Fargeau Marie‐Claude , Maitte Pierre
Published: March 2009

La réaction de la pyrrolidinométhylènechromanone 1 avec la guanidine et les amidines conduit avec de bons rendements aux benzopyrannopyrimidines 5. Le traitement de l'énaminone 1 par l'hydroxylamine en présence d'acide chlorhydrique conduit à la formation de l'isoxazole 9. L'emploi de l'hydrazine et de la phénylhydrazine comme agents de condensation, en milieu acide, donne les benzopyrannopyrazoles 11a et 11b; avec la méthylhydrazine il se forme un mélange de méthylpyrazoles isomères 11c et 11′c.
A new method of preparation of 1H‐1,2‐benzodiazepines by the rearrangement of 2,4,6‐trichlorophenylhydrazones
Authors: Campion C. , Dickens J. P. , Myers P. L.
Published: March 2009

A new method for preparing 1H‐1,2‐benzodiazepines is described. Hydrazones of generalised structure 1 undergo base catalysed cyclisation to form 4‐imidazolyl‐4,5‐dihydro‐1H‐1,2‐benzodiazepines of general structure 2. These compounds readily eliminate imidazole to form 1H‐1,2‐benzodiazepines of general structure 3.
Transformation of pyrazolo[4,3‐c]isothiazoles into 3,4‐disubstituted 1,2‐isothiazoles
Authors: Ueda Taisei , Shibata Yoshitsugu , Sakakibara Jinsaku
Published: March 2009

Pyrazolo[4,3‐c]isothiazoles 4 and 5 were synthesized by the reaction of 4‐aminoantipyrine 1 with thionyl chloride. Treatment of 4 or 5 with alkylamines underwent pyrazole ring opening to afford 3,4‐disubstituted 1,2‐isothiazoles 8a‐f.
Synthesis of 1‐(β‐D‐ribofuranosyl)indol‐3‐acetic acid
Authors: Chu Chung K. , Suh Jungjin , Cutler Horace G.
Published: March 2009

By condensation of ethyl indolin‐3‐acetate (4) and 2,3,5‐tri‐O‐benzoylribofuranosyl‐1‐acetate (5), ethyl 1‐(2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranosyl)indolin‐3‐acetate (6) was obtained in good yield. The indoline nucleoside 6 was aromatized to ethyl 1‐(2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranosyl)indol‐3‐acetate (7) with DDQ. The treatment of the indole nucleoside with barium hydroxide and methanol gave the methyl ester 8, which was further treated in water to give the desired 1‐(β‐D‐ribofuranosyl)indol‐3‐acetic acid (9).
Synthesis of large ring crown ethers
Authors: Chênevert Robert , D'Astous Linda
Published: March 2009

The synthesis of large ring crown compounds with the general structure 3n‐crown‐n where n is 9 to 20 is reported.
Synthesis of aminoquinolone derivatives
Authors: Krishnan Raghavan , Lang S. A. , Siegel Marshall M.
Published: March 2009

The synthesis of 3‐amino‐7‐chloro‐1‐ethyl‐6‐fluoro‐4(1H)quinolinone derivatives is described. These were investigated for their antibacterial activity.
Synthesis, renal vasodilator and dopamine‐sensitive adenylate cyclase activities ofO‐Methyl derivatives of 6‐chloro‐2,3,4,5‐tetr ahydro‐1‐(4‐hydroxyphenyl)‐1H‐3‐benzazepin‐7,8‐diol (SK&F 82526)
Authors: Ross Stephen T. , Franz Robert G. , Wilson James W. , Hahn Richard A. , Sarau Henry M.
Published: March 2009

The three possible mono‐O‐methyl derivatives of 6‐chloro‐2,3,4,5‐tetrahydro‐1‐(4‐hydroxyphenyl)‐1H‐3‐benzazepin‐7,8‐diol (SK&F 82526) (1) have been synthesized to facilitate the isolation and characterization of metabolites of this compound and for biological testing. The syntheses generally involved preparation of appropriately substituted benzaldehydes, conversion of these to phenylacetic acids and use of these toN‐acylate arylethanolamines. The phenylacetamides thus formed were reduced to amines and these were deprotected and cyclized to the desired final products. In one case deprotection followed cyclization. These compounds were tested as activators of dopamine‐sensitive adenylate cyclase (a measure of DA‐1 agonist activity) and as renal vasodilators. All threeO‐methyl derivatives were much less potent than1in cyclase activation and as renal vasodilators. Weak inhibition of adenyl cyclase was also observed for all three compounds and one showed weak renal vasoconstrictor activity. Preliminary investigation of the metabolism of1disclosed that two of the three monomethoxy compounds were formed in trace amounts in the rat and the dog. In a related investigation, the trimethoxy derivative of1was subjected to acid‐catalyzed hydrolysis conditions. The relative ease of cleavage of methoxy groups was 7 > > 4′ > 8.
Synthesis of new N‐aminoaziridine derivatives by the addition of dibenzyloxycarbonylaminonitrene to olefins
Authors: Milcent René , Guevrekian‐Soghomoniantz Marina , Barbier GÉO
Published: March 2009

In order to study the ring expansion of N‐aminoaziridines into N‐amino‐5‐membered heterocycles, N‐(dibenzyloxycarbonylamino)aziridines were synthesized. N, N‐Dibenzyloxycarbonylhydrazine was prepared. It was then oxidized with lead tetraacetate to a new diacylaminonitrene. This nitrene was added to various olefins to give the corresponding N‐protected aminoaziridines. Cleavage of the protecting groups was realized for one example.
The proton and carbon chemical shift assignments of 2‐substituted thioxanthones
Authors: Ternay A. L. , Harwood J. S.
Published: March 2009

The complete proton and carbon chemical shift assignments have been made for thioxanthone, 2‐fluorothioxanthone, 2‐chlorothioxanthone, 2‐bromothioxanthone, 2‐N, N‐dimethylsulfonamidothioxanthone, 2‐methylthioxanthone, 2‐methoxythioxanthone and 2‐acetylthioxanthone. Assignments were made with the aid of both COSY and CSCM two‐dimensional nmr techniques. The C2 substituent alters chemical shifts in the unsubstituted heterocyclic ring.
Reactions of piroxicam with alkyl iodides
Authors: Hammen Philip D. , Berke Helen , Bordner Jon , Braisted Andrew C. , Lombardino Joseph G. , Whipple Earl B.
Published: March 2009

Alkylation of piroxicam with a homologous series of alkyl iodides gave reversibly formed O‐alkyl products 1 as well as unexpected, irreversibly formed zwitterionic compounds 2, alkylated on the pyridine nitrogen, and O,N‐bis‐alkyl products 3. Proof of structure was accomplished by nmr and X‐ray crystal analysis. Product distribution ratios were determined by hplc and are explained by the Hard‐Soft Acid‐Base principle.
Reaction of 1,2‐diarylethylamides with ethyl polyphosphate (Epp): Correlation of the von braun, ritter and bischler‐napieralski reactions
Authors: Aguirre J. M. , Alesso E. N. , Ibañez A. F. , Tombari D. G. , Iglesias G. Y. Moltrasio
Published: March 2009

The Bischler‐Napieralski cyclization of the 1,2‐diaryiethylamides in a “one‐pot” process using ethyl poly‐phosphate as the reagent only yields the dihydroisoquinolines in certain cases. The trans‐stilbenes and in‐danes are obtained as neutral products and sometimes as sole products. Results clearly indicate the effect of aryl group substitution on the course of the reaction and the relationship between the Bischler‐Napieralski and Ritter reactions.
The synthesis of β‐heteroarylamino‐α,β‐dehydro‐α‐amino acid and β‐heteroarylamino‐α‐amino acid derivatives
Authors: Svete Jurij , Stanovnik Branko , Tišler Miha , Golič Ljubo , Leban Ivan
Published: March 2009

From heteroarylaminomethyleneoxazolones 4, obtained from N‐heteroarylformamidines 2 and 2‐phenyl‐5‐oxo‐4,5‐dihydro‐1,3‐oxazole (3), the following β‐heteroarylamino‐α,β‐dehydro‐α‐amino acid derivatives were prepared: methyl 8 and ethyl esters 9, amides 10 and 11, hydrazides 12, and azides 15. By catalytic hydrogenation the compounds 4 were converted into β‐heteroarylamino substituted amides 18 and β‐heteroarylamino‐α‐amino acids 20.
Synthesis of tetrahydrothiopyrano[3,2‐c]pyrazole derivatives from 3‐thianones
Authors: Nitti P. , Fatutta S. , Pitacco G. , Valentin E.
Published: March 2009

The synthesis of bicyclic pyrazoles and pyrazolones in which the fused ring contains a sulfur atom in different oxidation states is reported.
Studies on the chemistry of 1,4‐oxazines. 18. Synthesis of tricyclic 1,4‐benzoxazines via nucleophilic substitution of activated precursors
Authors: Bartsch Herbert , Erker Thomas , Neubauer Gustav
Published: March 2009

Starting from activated benzoxazines 1 and 2 new synthetic pathways to the tricyclic compounds 4, 9, 12 and 16 are described. Reaction of the hydrazides 17a,b with thionylchloride leads to the novel thiatriazolo‐benzoxazines 18a,b.