bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on potentially bioactive aza and thiaza polycyclic compounds containing a bridgehead nitrogen atom. III. Synthesis and antimicrobial activity of some 1,4‐benzothiazines and pyrrolobenzothiazines
Authors: Armenise Domenico , Trapani Giuseppe , Arrivo Vittorio , Laraspata Elena , Morlacchi Flaviano
Published: March 2009

Cyclization reactions of N‐(2,2‐dialkoxyethyl)‐1,4‐benzothiazine lactams 2 and 1,4‐benzothiazine‐sulfones 10 lead to the corresponding pyrrolo[1,2,3‐de]‐1,4‐benzothiazines 4 and 12, respectively, by using the dioxane/p‐toluenesulfonic acid or polyphosphoric acid/chloroform systems. In contrast, in the same reaction conditions, 1,4‐benzothiazines 5a‐h do not provide the expected pyrrolobenzothiazines 7, and as for 5c‐h considerable amount of the 2‐amino‐phenyl‐sulfide 8 was obtained. The results of microbiological assays are reported.
A long‐range 15N‐NMR study of the oxazolidinone antibiotic zyvox® and the major thermal degradation products
Authors: Hadden C. E. , Bowman P. B. , Duholke W. H. , Guido J. E. , Kaluzny B. D. , Robins R. H. , Russell D. J. , Sims S. M. , Thamann T. J. , Martin G. E.
Published: March 2009

The structures of the major thermal degradation products of linezolid (Zyvox®, PNU‐100766) are reported. Following hydrolytic decarboxylation, the remaining oxazolidinone‐derived skeleton of the antibiotic underwent a variety of acetyl migrations prior to deacetylation. Three of the degradation products are structural isomers. Structural characterization of the degradants was accomplished via the concerted analysis of 2D NMR, mass spectrometric, and infrared data. Direct and long‐range 1H‐15N heteronuclear shift correlation experiments at natural abundance were performed on linezolid as well as each of the isolated products of the degradation cascade. 15N chemical shifts for linezolid and each of the degradants, as well as the observed long‐range 1H‐15N coupling pathways are reported.
New precursors for hexanitrohexaazaisowurtzitane (HNIW, CL‐20)
Authors: Chung Kyoo‐Hyun , Kil Hee‐Sup , Choi In‐Young , Chu Chan‐Kook , Lee Ik‐Mo
Published: March 2009

Two new polyacylhexaazaisowurtzitanes were synthesized. Pentaacetyl‐ or pentaacetylformylhexaazaisowurtzitane can be a precursor in the preparation of HNIW, recently developed highly energetic material.
An improved synthesis of pyrazolo[3,4‐b][1,5]benzoxazepine, ‐benzothiazepine and ‐benzodiazepine derivatives via a convenient one‐pot synthesis
Authors: Abd El Latif Fawi M.
Published: March 2009

An improved and simple method for the preparation of pyrazolo[3,4‐b][1,5]benzoxazepine, ‐benzothiazepine and ‐benzodiazepine derivatives was established by the reaction of 5‐chloro‐1‐phenylpyrazole‐4‐carbaldehydes, ethyl 3‐(5‐chloro‐1,3‐diphenylpyrazol‐4‐yl)‐2‐cyanoacrylate and 1,4‐diacetyl‐3‐methyl‐2‐pyrazolin‐5‐one with o‐aminophenol derivatives and o‐phenylendiamine.
Synthesis and central nervous system stimulant activity of camphor‐1,2,3‐triazine fused with diphenylcyclopropenone and camphor‐1,2,3‐triazine n‐oxides
Authors: Nagai Shin‐Ichi , Ueda Taisei
Published: March 2009

Reactions of camphor‐1,2,3‐triazine 1 with diphenylcyclopropenone 2 gave two cycloadducts; 6,9‐methanopyrazolo[1,2‐b][1,2,3]benzotriazinones 3–4. Oxidation of 1 with 3‐chloroperbenzoic acid gave 1‐oxide 5 as the major compound along with a trace of 1,2‐dioxide 6.
Syntheses and photophysical properties of some 4‐arylpyridinium salts
Authors: Kelley Charles J. , Ansu Kwabena , Budisusetyo Wiranto , Ghiorghis Alem , Qin Yuanxi , Kauffman Joel M.
Published: March 2009

A number of 4‐arylpyridines, many methoxy substituted, were prepared by an efficient two‐step method involving aryl Grignard addition to 1‐methyl‐4‐piperidone and direct aromatization of the resulting 4‐aryl‐4‐piperidinols. The pyridines were N‐alkylated to give sulfonate salts desired for their fluorescent properties. Study of selected compounds as laser dyes revealed several structures to be efficient dyes lasing in the 530‐550 nm range. Two new diazaquaterphenyls were prepared and were quaternized. These salts exhibited intense fluorescence in the 420‐450 nm range, but would not lase. A phenolic azaterphenyl suitably substituted for excited state intramolecular proton transfer (ESIPT) did not fluoresce at all.
Thieno[2′,3′:5,6]azepino[2,1‐a]isoindolones from hydroxylactam‐alcohols via N‐acyliminium ion olefin cyclization
Authors: Pigeon Pascal , Othman Mohamed , Decroix Bernard
Published: March 2009

A one pot synthesis of thienoazepinoisoindolones from the reaction of hydroxylactam‐alcohols, under acidic treatment, is described via an N‐acyliminium olefin cyclization.
Metalation and halogen‐metal exchange in the imidazo[1,2‐a]quinoxaline series
Authors: Parra Stéphanie , Vitse Olivier , Bénézech Véronique , Deleuze‐Masquéfa Carine , Subra Guy , Bompart Jacques , Escale Roger , Chapat Jean P. , Bonnet Pierre A.
Published: March 2009

The n‐butyllithium and lithium 2,2,6,6‐tetramethylpiperidide metalation and the halogen‐metal exchange of imidazo[1,2‐a]quinoxaline derivatives followed by quenching with various electrophiles were studied. The reaction conditions have been optimized and various C1 substituted imidazo[1,2‐a]quinoxalines were obtained in high yields.
Synthesis and reaction of 5,6,7,8‐tetrahydro‐4H‐oxazolo[4,5‐c]azepin‐4‐ones
Authors: Koh Young Kook , Bang Ki‐Hwan , Kim Hong‐Seok
Published: March 2009

The synthesis of 5,6,7,8‐tetrahydro‐4H‐oxazolo[4,5‐c]azepin‐4‐ones 5a,b and 1,3‐benzoxazol‐4‐amines 4a,b are described starting from 4,5,6,7‐tetrahydro‐1,3‐benzoxazol‐4‐ones. Thionation of 5a,b followed by alkylation with ethyl bromoacetate led to the corresponding S‐alkyl azepines 7a,b.
Synthesis of indole and indolenine derivatives starting from indoline‐2‐thiones
Authors: Nishio Takehiko , Saku Osamu , Yamamoto Hiroshi
Published: March 2009

Indoline‐2‐thiones 1a‐b,d,f,h, which have at least one hydrogen at the 3‐position reacted with α‐halo ester 2a‐d, α‐halo ketones 2e‐f, and a‐bromoacetonitrile 2g to give 2‐alkylthioindole derivatives 3–11. In a similar manner treatment of 3,3‐disubstituted indoline‐2‐thiones 1c,e with α‐halo esters 2a,c,d and α‐halo ketone 2e gave 2‐alkylthioindolenines 12–16. Treatment of 1,3,3‐ trisubstituted indoline‐2‐thiones 1g,i with ethyl bromo‐acetate 2a resulted in recovery of starting materials. Desulfurization of indolenine 14 with triphenylphosphine gave 2‐alkylideneindoline 19.
Preparation of 1,6‐naphthyridine‐2,5(1H,6H)‐diones
Authors: Ohta Tetsuo , Fujisawa Hironori , Kawazome Mitsuru , Nakai Yasuto , Furukawa Isao
Published: March 2009

Novel method for the synthesis of 3‐acyl‐1,6‐dialkyl‐7‐methyl‐1,6‐naphthyridine‐2,5(1H,6H)‐diones (2) was developed. The reaction of 2‐acyl‐1‐alkylamino‐1‐ethoxyethylenes (1) with acetyl chloride or β‐keto amide 3 with acetyl chloride in the presence of p‐toluenesulfonic acid gave 2 in moderate yield (14‐59% yield).
Free radical 4‐nitrophenylation of thieno[2,3‐b]pyridine. Part 1: General experimental procedure and prediction of isomeric ratios of products
Authors: Klemm Leroy H. , Miller Kristi
Published: March 2009

Thieno[2,3‐b]pyridine (1) was warmed at 45 ± 7° with diazotized 4‐nitroaniline (2) (molar ratio 1:2 = 3.6:1) in buffered (sodium acetate‐acetic acid) aqueous solution until gas evolution ceased. The reaction mixture was separated into these fractions: (a) water‐soluble (discarded), (b) acetone‐soluble (tars), (c) ether‐soluble, and (d) ether‐ and chloroform‐soluble, but acetone‐insoluble (rust‐colored solids, Y, 12% yield as 4‐nitrophenyl‐1 isomers, 3). Fractional evaporative distillations of (b) and (c) gave recovered 1 (69%) and yellow‐red sublimates (Z, 20% yield as 3). Y and Z were handled separately for isolation and identification of isomers [2]. Three general methods for predicting the isomeric ratios of 3 which one should obtain are presented, viz. (1) an amalgamation of reported free‐radical phenylation results for quinoline and benzo[b]thiophene, (2) calculations of Frontier Radical Densities for positions 2‐6 only, and (3) Molecular Orbital calculations for electron densities and superdelocalizabilities for free‐radical attack at positions 1‐7, as modified by a proposed rearrangement of the attacking group from the heteroatomic N and S positions to adjacent alpha positions.
Pyranopyrazoles III synthesis of 1H‐pyrano[2,3‐c]pyrazol‐4‐ones
Authors: Khan Misbahul Ain , Ellis Gwynn Pennant , Pagotto Mario Celso
Published: March 2009

Various derivatives of title ring system were synthesized by Claisen condensation of 4 acetyl‐5 ‐hydroxy‐pyrazoles with appropriate esters, followed by acid‐catalyzed ring closure.
Attempted synthesis of ethyl 3,4‐dihydro‐2H‐1,4‐benzoxazine‐3‐carboxylate and 3‐acetate derivatives
Authors: Mayer Stanislas , Arrault Axelle , Guillaumet GÉRald , Mérour Jean‐Yves
Published: March 2009

Ethyl 3,4‐dihydro‐2H‐1,4‐benzoxazine‐3‐carboxylate derivatives 2 were obtained and isolated in low yields from the condensation of 2‐aminophenol and ethyl 2,3‐dibromopropanoate. They can be obtained by hydrogenation of ethyl 2H‐1,4‐benzoxazine‐3‐carboxylate in satisfactory yield. Using 2‐iminophenol did not direct the condensation with ethyl 2,3‐dibromopropanoate towards 2 but was fruitfull for the preparation of ethyl 2‐(4‐benzyl‐3,4‐dihydro‐2H‐1,4‐benzoxazin‐3‐yl)acetate from ethyl bromocrotonate.
Study of the reactions of 3‐acetoacetyl‐7‐methyl‐2H,5H‐pyrano[4,3‐b]pyran‐2,5‐dione with aromatic amines
Authors: Boutemeur‐Kheddis Baya , Hamdi Maamar , Sellier Nicole , Silva Artur M. S.
Published: March 2009

The reactions of 3‐acetoacetyl‐7‐methyl‐2H,5H‐pyrano[4,3‐b]pyran‐2,5‐dione with aromatic amines afforded 3‐(arylaminomethylene)‐6‐methylpyran‐2,4‐dione. Our results allowed the correction of the structures reported in the literature for the products of these reactions.
Transformations of schiff bases derived from quinoline‐8‐carbaldehyde. Synthesis of C‐8 substituted quinolines
Authors: Ocal Nüket , Yolaçan ÇIgdem , Kaban ŞEniz , Leonor Vargas M. , Kouznetsov Vladimir
Published: March 2009

The Schiff bases derived from quinoline‐8‐carbaldehyde and substituted aromatic amines were used in the synthesis of C‐8 substituted quinolines. 3‐Aryl‐2‐(8‐quinolinyl)‐4‐thiazolidinones were prepared from obtained aldimines by means of the cyclocondensation of mercapto acids. A series of 4‐N‐arylamino‐4‐(8‐quinolinyl)‐1‐butenes was synthesized through the addition of the Grignard reagent (allylmagnesium bromide) to the double bond C=N of these aldimines. The structure of the prepared compounds was established on the basis of their elemental analyses and spectral data.
On triazoles XLII . A new convenient method for the N‐alkylation of highly insoluble cyclic amides
Authors: Berecz GÁBor , Reiter JÓZsef
Published: March 2009

A simple N‐alkylation method of highly insoluble cyclic amides based on the high solubility of their easily isolable tetraalkylammonium and tetraalkylphosphonium salts was elaborated. The method has a rather wide scope, it is not influenced by the identity of the different rings attached to the 1,2,4‐triazolo[1,5‐a]‐pyrimidinone moiety of isomers 1 and 2, nor the presence of the triazole substituents. It proceeds smoothly without any unwanted by‐products, at relatively low temperatures, and is not sensitive to moisture. The method allows an easy isolation of all possible N‐alkylated derivatives 3, 7, and 8. Spectral analysis of isomers 3, 7, and 8 showed that our previous results concerning the formation of 3 type N‐alkylated derivatives as main products of the N‐alkylations as well as the tautomeric structure of the non‐alkylated isomers 1 and 2 is correct. However, it also showed that the isolation of a single N‐alkylated isomer 3 and its comparison with the corresponding non‐alkylated derivative to prove its tautomeric structure may lead to mistakes.
Synthesis of a new series of purine derivatives and their anti‐cyclin‐dependent kinase activities
Authors: Legraverend Michel , Ludwig Odile , Leclerc Sophie , Meijer Laurent
Published: March 2009

The synthesis of new purine derivatives designed to inhibit cell cycle regulating cyclin‐dependent kinases (CDKs), is reported. These compounds, related to olomoucine and roscovitine, are characterised by the presence of apyrrolidine methanol substituent at C‐2 and a variety of ortho, meta and/or para substituents on the C‐6 arylamino group.
Crown type macrocycles from a polyether with 4‐pyrone subunit
Authors: Löwe Werner , Brätter Stefanie A. , Buddrus Joachim
Published: March 2009

Our aim to enlarge the ring of the crown type compound 1, using the two component dilution principle, leads to hitherto unknown macrocycles 6 and 7.
Synthesis of 2‐amino‐1,4‐dihydro‐4‐quinolinones and diaminomethylene meldrum's acids derivatives as potential potassium channel openers
Authors: Erb Béanéadicte , Rigo Benoît , Pirotte Bernard , Couturier Daniel
Published: March 2009

Starting from 5‐bismethylthiomethylene Meldrum's acid, the synthesis of 5‐diaminomethylene Meldrum's acids and 2‐aminoquinolone derivatives, structurally related to potassium channels openers pinacidil and diazoxide, is described.
On the photochemical dimerization of some 5‐substituted 2‐styryl‐4‐pyrones. The effect of 5‐hydroxy‐/ 5‐methoxy‐substitution
Authors: Stiplošek Zdenka , Šindler‐Kulyk Marija , Jakopčić KreŠImir , Višnjevac Aleksandar , KojiĆ‐ProdiĆ Biserka
Published: March 2009

Irradiation of styryl‐4‐pyrones 1a‐1d or 2a‐2e (6‐9 × 10−3 M, methanol solution) with filtered (RAYONET photochemical reactor, 300 nm) or unfiltered uv‐light (high‐pressure mercury arc lamp) under aerobic conditions led mainly to dimeric products. Parent 5‐hydroxy‐substituted compounds 1a‐1d yielded exclusively “half‐cage” dimers 3a‐d characteristic for 4‐pyrone dimerization. 5‐Methoxy‐analogues 2a‐2e behave like typical stilbene structures and the mixture of tetrasubstituted cyclobutanes 4 and 5 accompanied with minor amount of phenanthrene‐like compound 6 were the only isolable products of the irradiation. The structure elucidation of products is based on spectral data obtained from MS, IR, 1H NMR and 13C NMR spectra applying COSY, APT, HETCOR, HMBC and NOESY techniques.
A convenient one‐pot synthesis and antimicrobial activity of pyrimido[1,2‐b][1,2,4,5]tetrazines
Authors: Shawali Ahmad S. , Abdallah Magda A. , Zayed Mohie M.
Published: March 2009

The synthesis of the hitherto unreported 3‐amino‐2,3‐dihydro‐6‐phenyl‐2‐thioxo‐4(1H)‐pyrimidine 2 and 3‐amino‐2‐methylthio‐6‐phenyl‐4(3H)‐pyrimidinone 3 is described. Reactions of hydrazonoyl halides 1 with either 2 or 3 afforded 6H‐pyrimido[1,2‐b][1,2,4,5]tetrazin‐6‐ones 6. The latter products were screened for their antifungal and antibacterial properties. The mechanism of the studied reactions is discussed.
Synthesis of 6‐(2‐hydroxybenzoyl)pyrazolo[1,5‐a]pyrimidines by reaction of 5‐amino‐1h‐pyrazoles and 3‐formylchromone
Authors: Quiroga Jairo , Mejía Diana , Insuasty Braulio , Abonía Rodrigo , Nogueras Manuel , Sánchez Adolfo , Cobo Justo , Low J. N.
Published: March 2009

Reaction of 3‐formylchromone (1) with 5‐amino‐1H‐pyrazoles (2) in ethanol, afforded 6‐(2‐hydroxy‐benzoyl)pyrazolo[1,5‐a]pyrimidines (3a‐g) in good yields. The structures and the regiospecificity of the reaction were established by nmr measurements and X‐ray analysis, in which soft intermolecular hydrogen‐bonded networks were found.
Synthesis and spectral properties of 11‐[(o‐; and p‐substituted)‐phenyl]‐8‐[(o‐; m‐;p‐methoxy)phenylthio]‐3,3‐dimethyl‐2,3,4,5,10,11‐hexahydro‐1h‐dibenzo[b,e][1,4]diazepin‐1‐ones
Authors: Cortéas Eduardo Cortéas , Sanabria Ana María Hernández , Mellado Olivia García
Published: March 2009

The preparation of twelve novel 2,3,4,5,10,11‐hexahydro‐1H‐dibenzo[b,e] [1,4]diazepin‐l‐ones which have potentially useful pharmacological properties; by condensation and cyclization between 3‐{[4‐(o‐; m‐; p‐methoxy)phenylthio]‐1,2‐phenylenediamine}‐5,5‐dimethyl‐2‐cyclohexenone with (o‐; and p‐substi‐tuted)benzaldehyde. The structure of all final products were corroborated by ir, 1H‐nmr, 13C‐nmr and ms.
Photocyclization reactions. Part 8. Synthesis of 2‐quinolone, quinoline and coumarin derivatives using trans‐cis isomerization by photoreaction
Authors: Horaguchi Takaaki , Hosokawa Nobuyuki , Tanemura Kiyoshi , Suzuki Tsuneo
Published: March 2009

2‐Quinolone 2, quinoline 3, coumarin (2H‐1‐benzopyran‐2‐one) 5, and 2H‐1‐benzopyran hemiacetal 6 were synthesized by photocyclization reaction of traans‐o‐aminocinnamoyl derivatives trans‐1 and trans‐o‐hydroxycinnamoyl derivatives trans‐4. The reaction proceeds through trans‐cis isomerization followed by intramolecular cyclization.
Synthesis and characterization of the novel l‐(substituted phenoxy/phenyl)‐2‐phospholene and phospholane 1‐oxide derivatives
Authors: Reddy Vallum Krishna , Onogawa Jun‐Ichi , Rao Lakonda Nagaprasada , Oshikawa Tatsuo , Takahashi Masaki , Yamashita Mitsuji
Published: March 2009

The synthesis of the novel 1‐(substituted phenoxy/phenyl)‐2‐phospholene and phospholane 1‐oxide derivatives, which are analogs of sugars having a phosphorus atom in place of the ring oxygen of normal sugars, is described. All of the synthesized derivatives are structurally characterized by multi nuclear NMR, mass, and IR spectral data, elemental and X‐ray crystallographic analyses.
Studies on pyrrolidinones: Some attempts to improve the anticancer properties of methyl n‐(3,4,4′,5‐tetramethoxybenzhydryl)pyroglutamate (HEI 81)
Authors: Bourry Anne , Rigo Benoît , Sanz Géarard , Couturier Daniel
Published: March 2009

The synthesis of esters, amides, pyrrolidinone and succinimide analogs of a new inhibitor of tubulin polymerization, methyl N‐(3,4,4′,5‐tetramethoxybenzhydryl)pyroglutamate (HEI 81) was studied.
Synthesis of nitrogen‐containing heterocycles 10. Reaction of 2‐amino‐1h‐imidazole derivatives with ethoxymethylene compounds
Authors: Miyamoto Yoshiko
Published: March 2009

The direct annelation reaction of 4‐substituted 2‐amino‐l‐benzylideneamino‐1H‐imidazoles (1) or 2‐amino‐1‐isopropylideneamino‐1H‐imidazole (8) with ethoxymethylenemalononitrile (I) gave successfully bicyclic imidazo[1,2‐a]pyrimidine compounds 2 and 9 in high yields. The reactions of other ethoxymethylene compounds of lower reactivity, i.e., ethyl ethoxymethylenecyanoacetate (II) and diethyl ethoxymethylenemalonate (III), with 2‐amino‐1H‐imidazoles under similar conditions afforded the corresponding enamines 3, 4 and 10, which, upon heating in the presence of an acid or a base, could readily be cyclized to form imidazopyrimidines except for 1‐isopropylideneamino compound 10. In general, the 3‐phenyl compounds (3b and 4b) did not cyclize to the type 2 compound resulting in a full recovery of the starting enamines.
Synthesis of thieno[2,3‐b][1,5]benzoxazepine derivatives
Authors: Kohara Toshiyuki , Tanaka Hiroshi , Kimura Koreichi , Horiuchi Hideki , Seio Kohji , Arita Masafumi , Fujimoto Tetsuya , Yamamoto Iwao
Published: March 2009

A new series of 4‐(4‐methylpiperazin‐1‐yl)thieno[2,3‐b][1,5]benzoxazepines 1a‐k has been synthesized from 4‐bromo‐2‐methylthiophene 6 or ethyl 2‐amino‐4,5‐dimethyl‐3‐thiophencarboxylate 10. Preparation of the key intermediate thieno[2,3‐b][1,5]benzoxazepine‐4(5H)‐ones 4a‐i, 4k were carried out by treatment of 2‐bromo‐N‐(2‐hydroxyphenyl)‐3‐thiophencarboxamides 5a‐i, 5k with potassium carbonate in DMSO. Compounds 1 are thienoanalogues of loxapine, a potent antipsychotic drug. Of these compounds, the neu‐roleptic activity of 2‐methyl‐4‐(4‐methylpiperazin‐l‐yl)thieno[2,3‐b][1,5]benzoxazepine 1a (R1, R3=H, R2=CH3) demonstrated potent antipsychotic activity.
Synthesis and photochromism of photochromic spiro compounds having a reactive pendant group
Authors: Zhang Peng , Meng Jiben , Li Xiaoliu , Wang Yongmei , Matsuura Teruo
Published: March 2009

The photochromic spiropyrans and spirooxazines having a reactive pendant group, including carboxyl, halide, succinimidyl ester and isothiocyanate, were synthesized. Their photochromic behaviors in solution and solid state were studied.
Arenesulfonylheterocycles (I): Synthesis and reactions of 2‐benzenesulfonyl‐4,5‐dichloropyridazin‐3‐ones with amines
Authors: Kweon Deok‐Heon , Kim Ho‐Kyun , Kim Jeum‐Jong , Chung Hyun A. , Yoon Yong‐Jin , Lee Woo Song , Kim Sung‐Kyu
Published: March 2009

The direct sulfonylation of 4,5‐dichloropyridazin‐3‐ones with some benzenesulfonyl chlorides in the presence of base in tetrahydrofuran gave only the corresponding N‐sulfonylated product. The reaction of 2‐benzenesulfonyl‐4,5‐dichloropyridazin‐3‐ones with some aliphatic amines under neutral conditions afforded 5‐alkylamino‐2‐benzenesulfonyl‐4‐chloropyridazin‐3‐ones and/or the corresponding N‐alkyl‐benzenesulfonamides.
Pictet‐spengler synthesis of pyrazole‐fused β‐carbolines
Authors: Fasfous Ismail I. , El‐Abadelah Mustafa M. , Sabri Salim S.
Published: March 2009

The synthesis of new pyrazolo[4,3‐c]β‐carbolines (8a,b) is achieved by condensation of the appropriate aldehyde with 3‐(4‐amino‐1,3‐dimethylpyrazol‐5‐yl)indole (4) under Pictet‐Spengler reaction conditions. Regioselective cyclization occurred at the usual indole C‐2 position as evidenced from the 1H‐and 13C nmr spectra of 8a,b which lack the pyrrolic H‐2 signal, present in 4 (δ 7.26, 1H, d, Jch‐NH = 2‐5 Hz).
New trans/cis tetrahydroisoquinolines. 1. trans‐2‐benzyl‐3‐(l‐methyl‐1h‐pyrrol‐2‐yl)‐4‐substituted‐1,2,3,4‐tetrahydroisoquinolin‐1‐ones and corresponding tetrahydroisoquinolines
Authors: Kozekov I. D. , Koleva R. I. , Palamareva M. D.
Published: March 2009

The reaction of homophthalic anhydride and N‐(1‐methyl‐1H‐pyrrol‐2‐yl‐methylidene)‐benzylamine in boiling benzene afforded as a main product the expected substituted trans‐1,2,3,4‐tetrahydroisoquinoline‐4‐carboxylic acid 5. The carboxylic group of 5 was transformed in four steps into cyclic amino‐methyl groups yielding numerous new tetrahydroisoquinolinones 11a‐j incorporating a given fragment of pharmacological interest. Reduction of 11a‐j was studied.
Synthesis and spectroscopic properties of 15n‐labelled 1,2,4‐thiadiazoles
Authors: Pavlik James W. , Changtong Chutchawin , Tantayanon Supawan
Published: March 2009

5‐Phenyl‐1,2,4‐thiadiazole‐4‐15N and 3‐methyl‐5‐phenyl‐1,2,4‐thiadiazole‐4‐15N were synthesized from commercially available benazmide‐15N. The mass spectra and the 1H, 13C, and 15N‐nmr spectra of these compounds, which show various long‐range heteronuclear coupling with the 15N‐nucleus, are discussed.
The ionization constants of 2‐substituted 4,6‐diamino‐s‐triazines: The applicability to the hammett and taft equations
Authors: Tashiro Tatsuo
Published: March 2009

The ionization (or basicity) constants (pKb) were determined for many 2‐substituted 4,6‐diamino‐s‐tri‐azines (I) by means of the electrometric titration. I includes 2‐alkoxy or aryloxy‐(Ia), 2‐alkyl‐ or 2‐aryl‐(Ib), and 2‐alkylamino‐ or 2‐arylamino‐4,6‐diamino‐s‐triazines (Ic). For the series with the same alkyl or aryl group, the order of the basicity was found to be Ic < Ib < Ia.

A study was made of relationships between the pKb, values of I, and the substituent constants, σp, σm, σp+, σm+, σpO, σmo, σI, σn, and σ*. The Hammett relationships were observed between the pKa values of I, and the substituent constants σm, (or the combination ones, [0.97σm + 0.03σp] as well as another [0.77σI + 0.23σR]). The Taft relationships were also found between the pKa values of Ia, Ib, and Ic and the constants σ*, respectively. Furthermore, in the case of Ic a linear relationship was observed between the pKa values and Σσ8.
Multi‐step synthesis of benzopyranones via a key step involving reaction of the intermediate compound with phenyltrimethylammonium tribromide
Authors: Javed T. , Kahlon S. S.
Published: March 2009

Base catalysed condensation of a substituted 2‐hydroxyacetophenone with acetic anhydride and sodium acetate followed by cyclization of the intermediate with acid gave substituted 3‐acetyl‐2‐methyl‐4H‐1‐benzopyran‐4‐ones. These were then brominated with phenyltrimethylammonium tribromide (PTT) to yield the desired 3‐(2‐bromoacetyl)benzopyran‐4‐ones. The latter compound on treatment with primary and secondary aryl or alkyl amines, gave the corresponding benzopyran‐4‐one derivatives.
Iodo cyclofunctionalization of 2,4‐dialkenyl‐1,3‐dicarbonyl compounds: Synthesis of substituted 3‐(2‐furylidene)‐2‐furanones
Authors: Valduga Claudete J. , Stefani Hélio A. , Petragnani Nicola
Published: March 2009

A facile method for the synthesis of substituted 3‐(2‐furylidene)‐2‐furanones has been developed using cyclofunctionalization reactions of 2,4‐dialkenyl‐1,3‐dicarbonyl compounds and iodine as electrophile in the presence of Na2CO3, in refluxing chloroform. Compounds 4 are obtained in modest to good yields and their structural identification was established by 1H NMR, 1H COSY, 13C NMR and 1H‐13C COSY. A mechanism has been proposed to rationalize the formation of the ylidene furanone.
Synthesis and biological testing of 3‐phenyloctahydro‐pyrimido[1,2‐a]‐s‐triazine derivatives
Authors: Lucry Line , Enoma Ferdinand , Estour François , MÉnager Sabine , Lafont Olivier , Oulyadi Hassan
Published: March 2009

A series of 46 3‐phenyloctahydropyrimido[1,2‐a]‐s–triazine derivatives were synthesized. This synthesis was performedviaiminodimethylation of dialkylated 2‐aminopyrimidinedione synthons by substituted primary arylamines.In vitropharmacological evaluation of these compounds is reported. One of them exhibited antifungal activity againstMicrosporum canis(10−65010−5mol/L), and another showed affinity for serotoninergic 5‐HT1Aand 5‐HT2breceptors (10−85010−7mol/L).
Synthesis of [1,4]benzodioxino[2,3‐c and 2,3‐d]pyridazinones
Authors: Chung Hyun‐A , Kim Jeum‐Jong , Cho Su‐Dong , Lee Sang‐Gyeong , Yoon Yong‐Jin , Kim Sung‐Kyu
Published: March 2009

Reaction of chloropyridazin‐3‐one 1, 5 and 10 with catechol in the presence of potassium carbonate gave the corresponding [1,4]benzodioxino[2,3‐e and/or 2,3‐d]pyridazinones 2, 7, 8 and 11.
Synthesis and electrochemical studies of tetrathiafulvalene derivatives (TTFs) as redox active ligands
Authors: Sarhan Abd El‐Wareth A. O. , Murakami Makoto , Izumi Taeko
Published: March 2009

A simple route for synthesis of new tetrathiafulvalene dimethyl ester (TTF‐DME) is reported. The tetrathifulvalene dimethylester (TTF‐DME) has been prepared by introducing an ester coordination function as a bifunctional new donor. The redox behavior of the TTF‐DME was investigated in comparison to the well‐known dibenzotetrathiafulvene (DB‐TTF) by cyclic voltammetry. A two‐electron redox behavior was observed as a two waves.
On triazoles XLVI. Synthesis of 1,3a,5,6,10c‐pentaazaacephenanthrylenes
Authors: Berecz Gabor , Párkányi László , Reiter József , Kálmán Alajos
Published: March 2009

A novel route to the synthesis of 6,7,8,9‐tetrahydro‐[1,2,4]triazolo[5,l‐b]quinazoline derivatives 4 through 5 and 6 was elaborated. During the synthesis of derivatives 6 novel type tetracyclic 2,3,7,8,9,10‐hexahydro‐1,3a,5,6,10c‐pentaazaacephenanthrylenes 9 were formed as by‐products. Their structure was proved by spec‐troscopic methods and by X‐ray diffraction spectra. There were also elaborated direct synthetic routes to derivatives 9. Unexpectedly, the S‐alkyl groups of derivatives 9 could be easily replaced by different amines, which is contrary to all our previous results. Possible explanations to this enhanced reactivity are given.
Regioselective symmetrical bromination of protected 2,2′‐biimidazole
Authors: Sanchez‐Garcia David , Borros Salvador , Nonell Santi , Borrell Jose I. , Colominas Carles , Teixido Jordi
Published: March 2009

Treatment of the benzyl and (trimethylsilylethoxymethyl) SEM protected 2,2′‐biimidazoles, 2a and 2b, with 2 equivalents of N‐bromosuccinimide (NBS) allows obtaining the 5,5′‐dibromo and 4,4′‐dibromo substituted biimidazoles, 3a and 5b respectively. The use of 4 equivalents of NBS, followed by treatment of the corresponding tetrabromoderivatives 4a and 5b with butyl lithium (BuLi), yields the 4,4′‐dibromoderiva‐tives 5a (G=Bn) and 5b (G=SEM).
Synthesis of dihydrofuro[2,3‐b]pyridines by the reaction of 2‐amino‐4,5‐dihydro‐3‐furancarbonitriles with α,β‐unsaturated carbonyl compounds
Authors: Maruoka Hiroshi , Yamazaki Motoyoshi , Tomioka Yukihiko
Published: March 2009

The reactions of 2‐amino‐4,5‐dihydro‐3‐furancarbonitriles 1a‐d with α,β‐unsaturated carbonyl compounds in the presence of sodium ethoxide (0.1 equivalent) gave the corresponding Michael adducts 2a‐d, 3a‐d and 4a‐d. Compounds 2a‐d and 3a‐c reacted with sodium alkoxide (1 equivalent) to yield the corresponding 7a‐alkoxyhexahydrofuro[2,3‐b]pyridines 5a‐d, 6a‐d, 7a‐c and 8a‐c. Treatment of 5a‐d, 6a‐d, 7a‐c and 8a‐c with potassium tert‐butoxide produced the corresponding dihydrofuro[2,3‐b]pyridines 9a‐d and 10a‐c. The reaction of 4a‐c with sodium ethoxide (1 equivalent) afforded the corresponding dihydro‐furo[2,3‐b]pyridines 11a‐c.
Stereochemistry and opioid receptor affinity of 2,4‐dipyridine‐3,7‐diazabicyclo[3.3.1]nonanones ‐ influence of the substituent in position N7
Authors: Cambareri A. , Zlotos D. P. , Holzgrabe U. , Englberger W. , Haurand M.
Published: March 2009

The stereochemistry the 2,4‐di‐arene substituted 3,7‐diazabicyclo[3.3.1]nonan‐9‐one 1,5‐dicarboxylate skeleton was found to be regulated by the kind of substituents attached to the arene rings as well as to the nitrogens N3 and N7. Conformational isomers, i.e., chair/chair, boat/chair and chair/boat, in addition to cis/trans conflgurational isomerism with respect to the arene rings were reported. Since the analgesic potency of the diazabicyclononanones, which is related to their affinity toward the κ‐opioid receptor, is governed by the stereochemistry of the molecules, the influence of the substituents at nitrogen N7 was studied herein. The various differently N7 substituted diazabicyclononanones were found to crystallise in a highly symmetrical chair/chair conformation. However, beside HZ2 none of the compounds exhibits high affinity to the κ receptor. In contrast, some compounds with affinity to the μ receptor could be identified. In addition, the N7‐(4‐carboxybenzyl) substituted compound was found to have affinity to the δ receptor in the submi‐cromolar range of concentration.
An efficient synthesis of a class of novel N‐Alkyl‐N‐aryl‐4‐hydroxy‐1‐methyl‐2‐oxo‐1,2‐dihydro‐3‐quinolinecarbothioamides
Authors: Spears Glen W. , Tsuji Kiyoshi , Tojo Takashi , Nishimura Hiroaki , Ogino Takashi
Published: March 2009

The novel title compounds have been prepared in high yield by an optimized amide coupling followed by a Dieckmann cyclization. Additionally, this new route is amenable to preparative scale synthesis.
Synthesis of N4‐substituted[1,3,4]oxadiazinan‐2‐ones derived from norephedrine
Authors: Casper David M. , Nora George P. , Blackburn Jennifer R. , Bentley Jeromy T. , Taylor Deanna C. , Hitchcock Shawn R.
Published: March 2009

[1,3,4]‐Oxadiazinan‐2‐ones bearing substitution at the N4‐position have been synthesized from norephedrine in good yield via N‐alkylation, nitrosation, reduction and cyclization.
2‐amino‐4‐oxo‐6‐substituted‐pyrrolo[2,3‐d]pynmidines as potential inhibitors of thymidylate synthase
Authors: Gangjee Aleem , Yu Jianming , Kisliuk Roy L.
Published: March 2009

Classical, antifolate inhibitors of thymidylate synthase often suffer from a number of potential disadvantages when used as antitumor agents. These include impaired uptake due to an alteration of the active transport system required for cellular uptake, as well as the formation of long acting, non‐effluxing polygluta‐mates via folypolyglutamate synthetase, which are responsible for toxicity to normal cells. To overcome some of the disadvantages of classical thymidylate synthase inhibitors, there has been considerable interest in the synthesis and evaluation of nonclassical inhibitors, which could enter cells via passive diffusion and are not substrates for folypolyglutamate synthetase. A series of eight nonclassical 6‐substituted 2‐amino‐4‐oxo‐pyrrolo[2,3‐d]pyrimidines 2a‐2h were designed as potential inhibitors of thymidylate synthase. The synthesis of the target compounds 2a‐2h was achieved via regioselective iodination at the 6‐position of 5, palladium‐catalyzed coupling with the appropriate phenylacetylenes, reduction of the C8‐C9 triple bond followed by saponification. Preliminary biological results indicated that none of the target compounds showed inhibitory activities against thymidylate synthase from Escherichia coli, Lactobacillus casei, rat or human thymidylate synthase at the concentrations tested. None of the target compounds showed inhibitory activity against dihydrofolate reductase from Escherichia coli, Lactobacillus casei, rat or human at 3.0 × 10−5 M. However, 50% inhibition of dihydrofolate reductase from Pneumocystis carinii and from Toxoplasma gondii was achieved with compound 2d and with compound 2g at 3.0 × 10−5 M.
Syntheses of substituted 2‐(2‐alkylthio‐1‐benzyl‐5‐imidazolyl)‐1,3,4‐oxadiazoles
Authors: Hadizadeh F. , Tafti F. I.
Published: March 2009

Starting from the readily available benzylamine hydrochloride a series of 2‐(2‐alkylthio‐1‐benzyl‐5imida‐zolyl)‐1,3,4‐oxadiazoles were prepared.
Azinoiminophosphorane mediated 1,2,4‐triazole synthesis
Authors: Lee Chang Hoon , Lee Kee‐Jung
Published: March 2009

The aza‐Wittig reaction of benzophenone‐ or acetophenone 1‐[(triphenylphosphoranylidene)amino]‐ethylidenehydrazone (4) with aromatic aldehydes provides a new route to 1,2,4‐triazoles 7 via the thermal reaction of the expected azinoimines 5.
FInfluence of the base stoichiometry on cyclocondensation of N‐(2‐bromoethyl)phthalimide with lithium ester enolates
Authors: Calmes M. , Juan E. , Rolland M. , Martinez J.
Published: March 2009

The cyclocondensation of N‐(2‐bromoethyl)phthalimide with the enolate of benzyl phenyl acetate afforded two possible compounds depending on the experimental conditions used.
Studies on the chemistry of thienoannelated O,N‐ and S,N‐containing heterocycles. 25. Synthesis of new imidazolyl and pyrazolyl derivatives of thiophene as inhibitors of nitric oxide synthase
Authors: Erker Thomas , Galanski Maria E. , Galanski Mathea S.
Published: March 2009

Some novel imidazolyl and pyrazolyl thiophene derivatives were synthesized. Different substituted N‐containing heterocycles were chosen with the aim of enhancing the activity or selectivity of the products towards inhibition of one of the three isoforms of nitric oxide synthase. One series of substances was prepared by substitution reactions of 3‐bromo‐2‐nitrothiophene with various heterocycles. In the other series introduction of a second heterocyclic substituent to pyrazolylthiophene compounds was attempted.
Studies on the reactions of cyclic oxalyl compounds with hydrazines or hydrazones : Synthesis and reactions of 4‐benzoyl‐1‐(3‐nitrophenyl)‐5‐phenyl‐1H‐pyrazole‐3‐carboxylic acid
Authors: Şener Ahmet , Kasim Şener M. , Bildmci Ishak , Kasimogullari Rahmi , Akçamur Yunus
Published: March 2009

The 1H‐pyrazole‐3‐carboxylic acid 2, obtained from the furan‐2,3‐dione 1 and N‐Benzylidene‐N'‐(3‐nitrophenyl) hydrazine, was converted via reactions of its acid chloride 3 with various alcohols or N‐nucleo‐philes into the corresponding ester or amide derivatives 4 or 5, respectively. Nitrile 6 and anilino‐pyrazole acid 7 derivatives of 2 were also obtained by dehydration of 5a in a mixture of SOCl2 with DMF and reduction of 2 with sodium polysulphide, respectively. While cyclocondensation reactions of 2 or 7 with phenyl hydrazine or hydrazine hydrate and 6 with only anhydrous hydrazine lead to derivatives of pyrazolo[3,4‐d]‐pyridazinone 8 and pyrazolo[3,4‐d]pyridazine amine 9, respectivel. The reaction of 2 with 2‐hydrazinopyri‐dine provided hydrazono‐pyrazole acid derivative 10, which was decarboxylated to give hydrazono‐pyra‐zole derivative 11. Pyrazolo[4,3‐d]oxazinone 12 and 2‐quinolyl pyrazolo[3,4‐d]pyridazine 13 derivatives were also prepared by cyclocondensation reactions of 2 with hydroxylamine hydrochloride and 7 with acetaldehyde, respectively.
Synthesis of 3‐alkylcarbonyloxymethyl derivatives of 5‐fluorouracil
Authors: Roberts William J. , Sloan Kenneth B.
Published: March 2009

3‐Alkylcarbonyloxymethyl derivatives of 5‐fluorouracil have been synthesized starting with 1‐ethyloxy‐carbonyl‐5‐fluorouracil. Alkylation of the starting material with alkylcarbonyloxymethyl iodides, generated from the corresponding chlorides by the Finkelstein reaction, in the presence of 1,8‐bis(dimethyl‐amino)naphthalene followed by deprotection with 1,1‐dimethylethylamine gave good yields (50‐60%) of the target derivatives after column chromatography. A 90% yield of 3‐acetyloxymethyl‐5‐fluorouracil was obtained when the corresponding commercially available bromide was used, instead of the in situ generated iodide, and the product could be isolated from the crude reaction by crystallization. An alternate path of sequential alkylation of 5‐fluorouracil with alkylcarbonyloxymethyl chlorides in the presence of tertiary amines, exhibiting different reactivities towards the chlorides, gave an excellent yield of 1‐acetyloxymethyl‐3‐propionyloxymethyl‐5‐fluorouracil in the one instance it was attempted, but subsequent deprotection of the 1‐position with methylamine gave only a 24% yield of 3‐propionyloxymethyl‐5‐fluorouracil.
Synthesis of 4‐(trihalomethyl)dipyrimidin‐2‐ylamines from β‐alkoxy‐α,β‐unsaturated trihalomethyl ketones
Authors: Zanatta Nilo , Lopes Elizandra C. S. , Fantinel Leonardo , Bonacorso Helio G. , Martins Marcos A. P.
Published: March 2009

The synthesis of a novel series of twelve 4‐(trihalomethyl)dipyrimidin‐2‐ylamines, from the cyclo‐condensation reaction of 4‐(trichloromethyl)‐2‐guanidinopyrimidine, with β‐alkoxyvinyl trihalomethyl ketones, of general formula: X3C‐C(O)‐C(R2)=C(R1)‐OR, where: X = F, Cl; R = Me, Et, ‐(CH2)2‐, ‐(CH2)3‐; R1 = H, Me; R2 = H, Me, ‐(CH2)2‐, ‐(CH2)3‐, is reported. The reactions were carried out in acetonitrile under reflux for 16 hours, leading to the dipyrimidin‐2‐ylamines in 65‐90% yield. Depending on the substituents of the vinyl ketone, tetrahydropyrimidines or aromatic pyrimidine rings were obtained from the cyclization reaction. When X = Cl, elimination of the trichloromethyl group was observed during the cyclization step. The structure of 4‐(trihalomethyl)dipyrimidin‐2‐ylamines was studied in detail by 1H‐, 13C‐ and 2D‐nmr spectroscopy.
Condensation of methylhydrazine with 4‐ethoxy‐1,1,1‐trifluoro‐3‐buten‐2‐one. A reinvestigation
Authors: Pavlik James W. , Na Ayudhya Theppawut Israsena , Tantayanon Supawan
Published: March 2009

In contrast to previous reports, 4‐ethoxy‐1,1,1‐trifluoro‐3‐buten‐2‐one (1) was observed to react with methylhydrazine (2) in refluxing ethanol to yield 1‐methyl‐3‐(trifluoromethyl)pyrazole (6) and 4,5‐dihydro‐1‐methyl‐5‐(trifluoromethyl)pyrazol‐5‐ol (4). The later compound undergoes acid catalyzed dehydration to 1‐methyl‐5‐(trifluoromethyl)pyrazole (3).
Reactions of 1,2‐dihydro‐4H‐3,1‐benzothiazine‐2,4‐dithiones (trithioisatoic anhydrides) with N‐substituted benzylamines and trialkyl phosphites
Authors: Takahashi Masahiko , Gunji Tomoko , Ichikawa Akiko
Published: March 2009

Reactions of 1,2‐dihydro‐4H‐3,1‐benzothiazine‐2,4‐dithiones (trithioisatoic anhydrides) 3 with N‐substi‐tuted benzylamines 9 gave 1,2‐dihydroquinazoline‐4‐thiones 10, o‐thioureidodithiobenzoic acid 11, o‐aminothiobenzamides 12, 2‐amino‐3,1‐benzothiazine‐4‐thiones 13, or quinazoline‐2,4‐dithiones 14, depending on the kinds of amine and the reaction solvent. On the other hand, reaction of 3 with trialkyl phosphites afforded dialkyl (1,2‐dihydro‐2‐thioxo‐4H‐3,1‐benzothiazin‐4‐yl)phosphonates 18.
Synthesis and antimicrobial activity of novel 2‐alkyl/arylcarbamato‐6‐(1,1‐dimethylethyl)‐3‐cyclohexyl‐3,4‐dihydro‐2H‐1,3,2‐benzoxazaphosphorine‐2‐oxides
Authors: Babu Y. Hari , Reddy P. Vasu Govardhana , Reddy C. Suresh , Reddy C. Devendranath , Devi P. Uma Maheswari
Published: March 2009

Novel 2‐alkyl/arylcarbamato‐6‐(1,1‐dimethylethyl)‐3‐cyclohexyl‐3,4‐dihydro‐2H‐1,3,2‐benzoxaza‐phosphorine‐2‐oxides (IV) have been synthesized from reactions of 2‐cyclohexylaminomethyl‐4‐t‐butylphenol I [8c] with various dichlorophosphinyl carbamates (III) [8a‐b] in dry toluene in the presence of triethylamine at 40‐50 °C. All the title compounds (IVa‐j) at reflux temperature are degraded to 2‐amino‐6‐(1,1‐dimethylethyl)‐3‐cyclohexyl‐3,4‐dihydro‐2H‐1,3,2‐benzoxazaphosphorine‐2‐oxide (IVk) exclusively. The structures are determined by ir, nmr and mass spectral studies. They were screened for antifungal activity against Penicillium notatum, Aspergillus niger and Helminthosporium sps, and antibacterial activity on Escherchia coli, Staphylococcus aureus and Pseudomonas aeruginosa. A few of them possess significant activity.
Potassium carbonate, a support for the green synthesis of azoles and diazines
Authors: Kidwai M. , Venkataramanan R. , Dave B.
Published: March 2009

A novel potassium carbonate mediated synthesis of 2‐amino‐1,3‐thia/oxa zoles, 2‐amino‐1,3,4‐thia/oxa diazines and 2‐hydrazino‐1,3,4‐thiadiazines has been described here. The use of K2CO3 allows for an aqueous workup thereby eliminating the organic solvent from both the reaction step and post reaction stage, without compromising the yield and reaction time.
Fused‐ring nitrogen and sulfur heterocycles by a tandem SN2‐michael addition reaction
Authors: Bunce Richard A. , Kotturi Sharadsrikar V. , Peeples Christopher J. , Holt Elizabeth M.
Published: March 2009

A tandem SN2‐Michael addition reaction has been developed for the synthesis of cis‐ and trans‐fused nitrogen and sulfur heterocycles from the cis and trans isomers of ethyl (±)‐(2E)‐3‐[2‐(iodomethyl)cyclo‐hexyl]‐2‐propenoate. Octahydro‐1H‐isoindole‐1‐acetic acid and octahydrobenzo[c]thiophene‐1‐acetic acid derivatives have been prepared and their stereochemistries elucidated using NMR and X‐ray crystallo‐graphic methods. Cyclization substrates for both the cis‐ and the trans‐fused rings are readily available in four steps from known compounds. Yields for the cyclization range from 80‐85% and stereochemical selec‐tivities with respect to the side chain vary from 12.5‐16:1 for the cis‐fused structures to 6‐7.5:1 for the trans‐fused structures. Steric interactions in the transition states for ring closure are proposed to rationalize the observed preferences.
A versatile synthesis of 2‐amino‐4H‐pyrido[1,2‐a][1,3,5]triazin‐4‐ones from 2‐aminopyridines
Authors: Kopp Marina , Lancelot Jean‐Charles , Dagdag Saïd , Miel Hugues , Rault Sylvain
Published: March 2009

The quasi‐one pot synthesis of new 2‐aminopyrido[1,2‐a][1,3,5]triazin‐4‐ones starting from 2‐amino‐pyridine and 2‐aminopicolines is herein described in order to obtain a library of cyclic guanidines.
Syntheses of N‐diazinyl thiocarboxamides and of thiazolodiazines. Metalation studies. Diazines XXXIII
Authors: Fruit Corinne , Turck Alain , Plé Nelly , Quéguiner Guy
Published: March 2009

Two thiazolodiazines were prepared from the corresponding N‐diazinylcarboxamides by use of Lawesson's reagent. Two N‐diazinylthiocarboxamides were obtained from amino derivatives by reaction with methyl phenyldithiocarboxylate. The metalation of these four compounds was studied and the thiazolodiazines could be functionalized.
Solvent‐free condensation of aromatic aldehydes and 2,3‐dimethyl‐1‐phenyl‐3‐pyrazolin‐5‐one by p‐toruenesulfonic acid
Authors: Koshima Hideko , Hamada Mitsuo
Published: March 2009

Solvent‐free condensation easily occurred by mixing aromatic aldehydes and 2,3‐dimethyl‐1‐phenyl‐3‐pyrazoline‐5‐one (antipyrine) in the presence of p‐toluenesulfonic acid as a solid acid catalyst at room temperature to give the corresponding disubstituted products as sole products in high yields.
Novel synthesis of 2‐amino[1,4,5]benzoxadiazepine derivatives via a mild one‐pot reaction
Authors: El‐Rady Eman A.
Published: March 2009

The diazonium salt of 2‐aminophenol 2 was coupled in situ with malononitrile derivatives 3a‐d, 2‐cyanomethylthiazolin‐4‐one 9, 2‐cyanomethylbenzimidazole 11a, and 2‐cyanomethylbenzothiazole 11b to give 2‐amino[1,4,5]benzoxadiazepine derivatives 6a‐d, 10 and 12a,b via a one‐pot reaction.
Acid‐mediated regioselective alkylation of 1,2,3‐triazole
Authors: Korenm Andrei O.
Published: March 2009

1,2,3‐Triazole reacts with isopropyl alcohol in concentrated sulfuric acid to yield 1‐isopropyl‐1H‐1,2,3‐triazole as the only reaction product.
Palladium catalyzed cross‐methylation of bromoheterocycles with intramolecularly stabilized dimethyl indium reagents
Authors: Jaber Nimer , Blum Jochanan , Schumann Herbert
Published: March 2009

Although the intramolecularly stabilized [(3‐dimethylamino)propyl]dimethylaluminum (1a) fails to undergo palladium‐catalyzed cross‐coupling with bromopyridines and with bromofuran derivatives, the analogous gallium and indium reagent 1b and 1c smoothly cross‐methylate these and other bromoheterocycles. The cross‐coupling can be performed also with the dimeric indium and gallium compounds bis(μ‐[2‐(dimethylamino)ethanolato‐N,O:O]tetramethyldigallium and ‐diindium (2b and 2c, respectively). The indium reagent is fairly air‐stable and the reactions can be carried out under ambient conditions. The yields are generally very high but are influenced by steric and electronic effects.
Syntheses of two potential food mutagens
Authors: Tanga M. J. , Bradford W. W. , Bupp J. E. , Kozocas J. A.
Published: March 2009

The syntheses of the potential heterocyclic amine food mutagens l,4,6‐trimethyl‐2‐aminoimidazo[4,5‐c]‐pyridine and 1,5,7‐trimethyl‐2‐aminoimidazo[4,5‐b]pyridine are described.
Reaction of benzohydroximinoyl chlorides and β‐(trifluoromethyl)‐acetylenic esters: Synthesis of regioisomeric (trifluoromethyl)‐isoxazolecarboxylate esters and oxime addition products
Authors: Hamper Bruce C. , Leschinsky Kindrick L.
Published: March 2009

The triethylamine induced reaction of benzohydroximinoyl chlorides, precursors of nitrile oxides, with β‐trifluoromethylacetylenic esters gives rise to three products: 5‐trifluoromethyl‐4‐isoxozolecarboxylate esters, regioisomeric 4‐trifluoromethyl‐5‐isoxazolecarboxylate esters and an unexpected oxime 1,4‐addition adduct. Product distribution is rationalized in terms of two competing reaction modes, either 1,4 addition of the oxime anion to the acetylenic ester or formation of the nitrile oxide followed by 1,3‐dipolar cycloaddi‐tion. Anionic 1,4‐addition of the oximinoyl chloride to the acetylenic ester is preferred at low temperatures, while nitrile oxide formation followed by cycloaddition is preferred at temperatures above 0 °C. Regioisomeric products from addition of nitrile oxides to various perfluoroalkylacetylenes are compared and assigned by 13C NMR.
Studying the synthesis of 4‐tert‐butyl‐1,3‐dihydroimidazol‐2‐ones and their corresponding thiones
Authors: Loksha Yasser M. , Pedersen Erik B. , El‐Barbary Ahmed A. , El‐Badawi Mahmoud A. , Nielsen Claus
Published: March 2009

4‐tert‐Butyl‐1,3‐dihydroimidazol‐2‐ones and 1,3‐dihydroimidazol‐2‐thiones were synthesized from 1‐amino‐3,3‐dimethylbutanone and subjected to alkylation reactions. The latter compounds were S‐alkyl‐ated with iodoacetamide under alkaline conditions. The N1 N3‐unsubstituted derivative was iodinated and subsequently alkylated with alkylation reagents which previously have been used for the synthesis of anti‐HTV active imidazoles. Unfortunately, the present products were devoid of activity against HTV.
A convenient preparation of 3‐acetyl‐5‐methylisoxazole
Authors: Sauers Ronald R. , Van Arnum Susan D.
Published: March 2009

Starting from 2,5‐hexanedione (4), a one‐pot preparation of 3‐acetyl‐5‐methylisoxazole (1) is described. 3‐Acetyl‐5‐methylisoxazole (1) is a useful compound for the preparation of 3‐oxobutyronitrile (10) and for 3‐vinyl‐(5‐methyl isoxazolyl) ketone (2).
A simple synthesis of 5‐ethoxycarbonyl‐6‐phenyl‐1,3‐dioxin‐4‐ones and ethyl 3‐benzoyl‐4‐oxo‐2,6‐diphenylpyran‐5‐carboxylate
Authors: Şener Ahmet , Genç Hasan , Kasimşener M. , Yil Yüzüncü
Published: March 2009

4‐Ethoxycarbonyl‐5‐phenyl‐2,3‐dihydrofuran‐2,3‐dione 1 reacts with aldehydes via the acylketene intermediate 2 giving the 1,3‐dioxin‐4‐ones 3a‐e and the 1,4‐bis(5‐ethoxycarbonyl‐4‐oxo‐6‐phenyl‐4H‐1,3‐dioxin‐2‐yl)benzene 4, and a one step reaction between dibenzoylmethane and oxalylchloride gave 3,5‐dibenzoyl‐2,6‐diphenyl‐4‐pyrone 7. The reaction of 1 with dibenzoylmethane, a dicarbonyl compound, provided ethyl 3‐benzoyl‐4‐oxo‐2,6‐diphenylpyran‐5‐carboxylate derivative 9. Compound 9 was converted into the corresponding ethyl 3‐benzoyl‐4‐hydroxy‐2,6‐diphenylpyridine‐5‐carboxylate derivative 10 via its reaction with ammonium hydroxyde solution in 1‐butanol.