bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactivity of p‐phenyl substituted β‐enamino compounds using k‐10/ultrasound. I. synthesis of pyrazoles and pyrazolinones
Authors: Valduga Claudete J. , Braibante Hugo S. , Braibante Mara E. F. 
Published: March 2009

AbstractThe reactivity of the β‐enamino ketones, 3‐amino‐1‐(p‐phenyl‐substituted)‐2‐buten‐1‐ones 1a‐d and β‐enamino esters. Ethyl‐3‐amino‐3‐(p‐phenyl‐substituted)‐2‐propenoates 5a‐d were evaluated by systematic studies of the reactions with hydrazine and methylhydrazine by reactions with solid support K‐10/ultrasound and homogeneous media (reflux in ethanol or dichloromethane) yielding pyrazole rings 2a‐d, N‐methylpyrazoles 3a‐d, 4a‐d and N‐methylpyrazolinones 6a‐c and 7a‐c. The regiochemistry of the cyclization showed dependence of the reaction conditions employed as well as the substituent in the aromatic ring.
The synthesis of aminimide‐containing azole antifungals
Authors: Abel Mark D. , Hewgill Randy T. , Malczyk Katherine J. , Micetich Ronald G. , Daneshtalab Mohsen 
Published: March 2009

AbstractThe synthesis of a series of azole antifungal compounds which incorporate the aminimide functional moiety is described. The procedure involves the reaction of an epoxide intermediate with 1,1‐disubstituted hydrazines to form aminimines which are subsequently treated with acyl chlorides resulting in the desired zwitterionic aminimides. The aminimides were tested for in vitro antifungal activity and found to be moderately active against Candida and Cryptococcus species, but inactive versus Aspergillus.
Synthesis and properties of a new series of trögerophanes
Authors: Ibrahim Alhussein A. , Matsumoto Mutsumi , Miyahara Yuji , Izumi Kenji , Suenaga Masahiko , Shimizu Nobujiro , Inazu Takahiko 
Published: March 2009

AbstractA new series of macrocyclic compounds with one or two Tröger base skeletons has been synthesized by condensing mono‐, di‐, tri‐, and teraethyleneglycol bis(p‐aminophenoxy) ethers with formalin in the presence of concentrated hydrochloric acid in ethanol at room temperature for 13 days. This simple one‐step cyclization provided 19 in remarkably high yield (46%) and 17, 18, and 20 in yields reflecting the strain of the rings and statistical factors. Complexation with lithium thiocyanate was observed for 20, the structure of which was elucidated by X‐ray crystallography.
Synthesis of 2,3,8,9‐Dibenzo‐5,6‐(substituted)benzo‐1,4‐dithio‐7‐oxacyclonona‐2,5,8‐trienes and some electrophilic substitution reactions
Authors: Kim Man Nyoung , Kim Kyongtae 
Published: March 2009

AbstractTreatment of 5‐(2‐hydroxyaryl)thianthreniumyl perchlorates 1 with sodium hydride in tetrahydrofuran at reflux gave the title compounds 5 in excellent yields. For the reactivities of the compounds 5, the selected compounds 5 were subjected under the conditions of electrophilic substitution reactions. Bromination of 5,6‐{3‐(2‐butyl)benzo}‐2,3,8,9‐dibenzo‐1,4‐dithio‐7‐oxacyclonona‐2,5,8‐triene (5f) in acetic acid at 60° afforded two bromo compounds 9 (22%) and 10 (69%), which were oxidized by m‐chloroperbenzoic acid to give tetraoxides 11 (95%) and 12 (97%), respectively. Treatment of 5f with acetyl chloride in the presence of aluminum chloride in carbon disulfide at 0° gave an acetylated compound 13 (58%). Nitration of 5f with nitric acid in acetic acid at 50° gave a nitro compound 17 (15%) together with 1,4‐dioxide 7e (22%) and a 5‐oxide 18 (3%) whose regiochemistry has not been established. On the other hand, 5,6‐(3‐methylbenzo)‐2,3,8,9‐dibenzo‐1,4‐dithio‐7‐oxacyclonona‐2,5,8‐triene (5a) reacted with acetyl chloride under the same conditions to give two acetylated compounds 15 (33%) and 16 (18%). The mechanism for the formation of 5 and the structural elucidation of these compounds are discussed.
Structural assignment of 2,3,7,8‐tetrahydro‐5H,10H‐[1,5,3]dioxazepino[3,2‐c]indolo[3,2‐g]pteridin‐7‐one, a New heterocyclic ring system
Authors: Ge Ping , Kalman Thomas I. 
Published: March 2009

AbstractThe structure of a new heterocyclic ring system, 2,3,7,8‐tetrahydro‐5H,10H‐[1,5,3]dioxazepino[3,2‐c]‐indolo[3,2‐g]pteridin‐7‐one, derived from isatins and 5‐aminocytidine was assigned by establishing the regiochemistry with the aid of model reactions and 13C nmr techniques.
Furopyridines. XXVII. Reactions of 2‐methyl and 2‐cyano derivatives of furo[2,3‐b]‐, ‐[3,2‐b]‐, ‐ [2,3‐c]‐ and ‐[3,2‐c]pyridine
Authors: Yamaguchi Seiji , Kurosaki Masahide , Orito Keiko , Yokayama Hajime , Hirai Yoshiro , Shiotani Shunsaku 
Published: March 2009

AbstractBromination of 2‐methylfuropyridines 1a‐d‐Me gave the 3‐bromo derivatives 2a‐d, while the 2‐cyano compounds 1a‐d‐CN resulted in the recovery of the starting compounds. Nitration of 1a‐d‐Me and 1a‐d‐CN did not yield the corresponding nitro derivative, except for 1‐c‐CN giving 3‐nitro derivative 3c in 7% yield. N‐Oxidation of 1a‐d‐Me and 1b‐d‐CN with m‐chloroperbenzoic acid yielded the N‐oxides 4a‐d‐Me and 4b‐d‐CN, whereas 1a‐CN did not afford the N‐oxide. Cyanation of N‐oxides 4a‐d‐Me and 4b‐d‐CN with trimethylsilyl cyanide gave the corresponding α‐cyanopyridine compounds 5a‐d‐Me and 5b‐d‐CN. Chlorination of 4a‐d‐Me and 4b‐d‐CN with phosphorus oxychloride also gave the α‐chloropyridine compounds 6b‐d‐Me and 6b‐d‐CN, accompanying formation of γ‐chloropyridine 6a‐Me, 6′b‐Me and 6′b‐CN, β‐chloropyridine 6′b‐CN, and α'‐chloropyridine derivatives 6′c‐Me and 6′c‐CN. Acetoxylation of 4a‐d‐Me and 4b‐d‐CN with acetic anhydride yielded α‐acetoxypyridine compounds 7a‐Me and 7b‐CN, pyridone compounds 11d‐Me, 11c‐CN and 11d‐CN, 3‐acetoxy compounds 8, 9b, 9c, and 2‐acetoxymethyl derivatives 10b and 10c.
Furopyridines. XXVIII. Reactions of 3‐bromo derivatives of furo[2,3‐b]‐, ‐[3,2‐b]‐, ‐[2,3‐c]‐ and ‐[3,2‐c]pyridine and their N‐oxides
Authors: Yamaguchi Seiji , Awajima Kazuaki , Hirai Yoshiro , Yokoyama Hajime , Shiotani Shunsaku 
Published: March 2009

AbstractBromination of 3‐bromofuro[2,3‐b]‐ 1a, ‐[3,2‐b]‐ 1b and ‐ [3,2‐c]pyridine 1d afforded the 2,3‐dibromo derivatives 2a, 2b and 2d, while the ‐[2,3‐c]‐ compound 1c did not give the dibromo derivative. Nitration of 1a‐d gave the 2‐nitro‐3‐bromo compounds 3a‐d. The N‐oxides 4a‐d of 1a‐d were submitted to the cyanation with trimethylsilyl cyanide to yield the corresponding α‐cyanopyridine compound 6a‐d. Chlorination of 4a and 4d with phosphorus oxychloride gave mainly the chloropyridine derivatives 7a, 7′a and 7d, while 4b and 4c gave mainly the chlorofuran derivatives 7′b and 7′c accompanying formation of the chloropyridine derivatives 7b, 7′b and 7c. Acetoxylation of 4a and 4b with acetic anhydride yielded the acetoxypyridine compounds 8a, 8′a and 8b, while 4c and 4d gave the acetoxypyridine 8′c, 8′d and 8′d, pyridone 8c and 8d, acetoxyfuran 8′c and dibromo compound 9c and 9′c.
Reaction of 1‐chloromethyl‐4,5‐dichloropyridazin‐6‐one
Authors: Chung Hyun‐A , Kang Young‐Jin , Yoon Yong‐Jin 
Published: March 2009

AbstractReaction of 1‐chloromethyl‐4,5‐dichloropyridazin‐6‐one with some nucleophiles such as sodium methoxide, sodium azide, 2‐mercaptopyrimidine and phenol gave 2, 3, 4, 7, 8 and 10. 5‐Chloro‐4‐phenoxypyridazin‐6‐one (10) was also synthesized from 8 through 9.
The synthesis of ethyl 2‐[(2,2‐dibenzoyl)ethenyl]amino‐3‐dimethyl‐aminopropenoate and its application to the synthesis of fused 3‐aminopyran‐2‐ones and 3‐aminoazolo‐ and ‐azinopyrimidin‐4(4H)‐ones
Authors: Soršak Gorazd , Stanovnik Branko , Grdadolnik Simona GoliČ 
Published: March 2009

AbstractEthyl 2‐[(2,2‐dibenzoyl)ethenyl]amino‐3‐dimethylaminopropenoate (3) was prepared from dibenzoylmethane (1) in two steps, and used as a reagent for preparation of fused substituted 3‐aminopyranones 12–15 in over 90% yield, quinolizin‐4‐one 16 in over 79% yield, and fused pyrimidin‐4‐ones 17–19 in 40–50% yield. Deprotection of (2,2‐dibenzoyl)ethenyl group with either diethylamine or hydrazine hydrate produced free amino compounds 20, 21 and 22 in 35%, 91% and 71% yield, respectively.
Transformation of 4‐(1‐dimethylaminoethylidene)‐2‐phenyl‐5(4H)‐oxazolone into methyl 2‐benzoylamino‐3‐oxobutanoate. The synthesis of 1‐substituted 4‐benzoylamino‐3‐methyl‐5(2H)‐pyrazolones
Authors: Bratušek UrŠKa , Hvala AleŠ , Stanovnik Branko 
Published: March 2009

AbstractMethyl 2‐benzoylamino‐3‐oxobutanoate (3) was prepared from hippuric acid (1) which was converted with N,N‐dimethylacetamide and phosphorus oxychloride into 4‐(1‐dimethylaminoethylidene)‐2‐phenyl‐5(4H)‐oxazolone (2) followed by hydrolysis with hydrochloric acid in methanol. Compound 3 was treated with hydrazines 4 to give 4‐benzoylamino‐3‐methyl‐1H‐pyrazol‐5(2H)‐one (6a) and its 1‐substituted derivatives 6b‐j. The corresponding hydrazones 5f, i, j were isolated as intermediates.
The birch reduction of heterocyclic compounds. IV. Birch reduction of 3‐acylfurans. Competition between ring reduction, carbonyl reduction, and dimer formation
Authors: Takano Daisuke , Nakajima Yoshitaka , Miyahara Ikuko , Hirotsu Ken , Tanaka Rika , Okada Keiji , Morimoto Yoshiki , Kinoshita Takamasa , Yoshihara Kazuo 
Published: March 2009

AbstractThe Birch reduction of 3‐acylfurans 1, 3 and 10 and their reaction path ways are described.
Furopyridines. XXV. Synthesis of 5‐substituted furo [2,3‐b]pyridines
Authors: Yamaguchi Seiji , Kurosaki Masahide , Yokoyama Hajime , Hirai Yoshiro , Shiotani Shunsaku 
Published: March 2009

AbstractDerivatives (2–8) of furo[2,3‐b]pyridine having a substituent at the β‐position to the ring nitrogen were prepared from the 5‐nitro compound 1 via the Sandmeyer reaction.
A new tautomeric zwitterion form of 2‐acylamino‐4H‐1,3,4‐oxadiazino[5,6‐b]quinoxalines in solution
Authors: Kurasawa Yoshihisa , Mitomi Takako , Okamoto Yoshihisa , Kim Ho Sik 
Published: March 2009

AbstractThe reaction of 2‐acyiamino‐8‐chloro‐4‐methyl‐4H‐1,3,4‐oxadiazino[5,6‐b]quinoxalines 2a‐d with methyl iodide/base gave the 8‐chloro‐4,10‐dimethyl‐4H‐1,3,4‐oxadiazino[5,6‐b]quinoxalin‐10‐ium‐2‐acylamidates 4a‐d, respectively. Comparison of the nmr spectral data between compounds 2a‐d and 4a‐d in deuteriodimethyl sulfoxide or in deuteriotrifluoroacetic acid established that compounds 2a‐d existed as the zwitterionic tautomers 2′a‐d in solution.
Synthesis of 2‐styrylthiazolo[4,5‐b]quinoxaline based fluorescent dyes
Authors: Rangnekar D. W. , Sonawane N. D. , Sabnis R. W. 
Published: March 2009

AbstractA novel efficient synthesis of 2‐styrylthiazolo[4,5‐b]quinoxaline based fluorescent dyes was achieved by the condensation of 2‐alkylthiazolo[4,5‐b]quinoxaline with selected 4‐N,N‐dialkylamino‐substituted aryl‐aldehydes or hetarylaldehydes in the presence of piperidine or acid anhydride. The coloristic, fluorophoric and dyeing properties of these dyes were studied.
Stereoselective photo[4+2]cycloadditions of 2‐pyrone‐5‐carboxylates with maleimides in the solid state and in solution
Authors: Obata Tom , Shimo Tetsuro , Suishu Takaaki , Somekawa Kenichi 
Published: March 2009

AbstractSolid state photoreactions and thermal reactions of 2‐pyrone‐5‐carboxylates with maleimides gave endo‐[4+2]cycloadducts, while the sensitized photoreactions gave exo‐[4+2]cycloadducts stereo‐selectively.
Synthesis of new heterocyclic derivatives of retinoids
Authors: Sottofattori Enzo , Anzaldi Maria , Balbi Alessandro 
Published: March 2009

AbstractReaction of α‐ and β‐ionones 1 and 2 with dialkylformamide/phosphorus oxychloride affords enamines 6 and 7 along with the expected chloro derivatives 4 and 5. Reaction of 6a with hydrazines, hydroxylamine and guanidine furnished pyrazoles, isoxazole, pyrimidine 8–10 showing the potential of these enaminones as key intermediates in the synthesis of synthetic retinoids.
Synthesis of new proton‐ionizable and neutral macrocyclic, macrobicyclic and macrotricyclic crown compounds containing dibenzo‐16‐crown‐5 units
Authors: Xia Michael X. B. , Wai Chien M. , Natale N. R. , Elshani Sadik , Bartsch Richard A. , Bartsch Richard A. , Widener Rexford W. 
Published: March 2009

AbstractFifteen new macrocyclic, macrobicyclic and macrotricyclic crown ether compounds with sym‐dibenzo‐16‐crown‐5 units have been prepared. The series includes macrocyclic polyether and bis(crown ether) compounds with proton‐ionizable carboxylic or phosphonic acid monoethyl ester groups and bis(crown ether) and macrotricyclic polyether compounds with two sym‐dibenzo‐16‐crown‐5 units linked by amide, diamide, or diester functions.
Synthesis of 4‐aryl‐2,3,6,7‐tetrahydro‐1H‐pyrimido[4,5‐b][1,4]‐diazepin‐6‐ones from 4,5‐diamino‐1H‐pyrimidin‐6‐ones and 1‐aryl‐3‐(dimethylamino)‐1‐propanones
Authors: Insuasty Braulio , Quiroga Jairo , Argoti Juan Carlos , Gómez Samuel , Martínez Roberto , Angeles Enrique , Gabiño Rubén , Nogueras Manuel , Sánchez Adolfo 
Published: March 2009

AbstractThe reaction of 1‐aryl‐3‐(dimethylamino)‐1‐propanones 1 with one equivalent of 4,5‐diamino‐1H‐pyrimidin‐6‐ones 2, in acidic medium, leads to the formation of 4‐aryl‐2,3,6,7‐tetrahydro‐1H‐pyrimido[4,5‐b]‐[1,4]diazepin‐6‐ones 3. The structure elucidation of the products is based on detail nmr analysis of experiments such as 13C, 1H and DEPT including selective 13C{1H} decoupling experiments.
Reactions of 3‐acetyltropolone with benzaldehydes in trimethyl orthoformate in the presence of perchloric acid: Synthesis of 2‐aryl‐4‐methoxy‐9‐oxocyclohepta[b]pyrylium perchlorates
Authors: Wang Dao‐Lin , Imafuku Kimiaki 
Published: March 2009

Abstract3‐Acetyltropolone (1) reacted with benzaldehydes in trimethyl orthoformate in the presence of perchloric acid to afford 2‐aryl‐4‐methoxy‐9‐oxocyclohepta[b]pyrylium perchlorates 3a‐c in 25–37% yields. From the filtrates, 3‐(3,4‐diaryl‐3‐butenoyl)tropolones 4a,b and 3‐(2‐methoxycinnamoyl)tropolone (5) were also isolated.
Synthesis of perimidine and fused perimidine derivatives from reaction of 1,8‐naphthalenediamine with an iminoisocoumarin
Authors: Deady Leslie W. , Rodemann Thomas 
Published: March 2009

AbstractThe isocoumarin derivative 1H‐1‐acetylimino‐3‐methylbenzo[c]pyran‐4‐carbonitrile reacts with 1,8‐naphthalenediamine under basic conditions to give, primarily, 12‐acetylisoquino[2,1‐a]perimidin‐13‐amine. This undergoes a variety of reactions to give other isoquino[2,1‐a]perimidine derivatives, ring opening to 2‐(1H‐perimidin‐2‐yl)phenylacetic acid derivatives and, in polyphosphoric acid, a new hexacyclic system, 6‐methyl‐7,13,13d‐triazadibenzo[def,qr]chrysene.
Synthetic and spectroscopic study of 5‐amino‐2‐acyl‐1,2,4‐thiadiazolin‐3‐ones
Authors: Ra Do Young , Cho Nam Sook , Moon Jung Hyun , Kang Sung Kwon 
Published: March 2009

Abstract5‐Amino‐2‐acyl‐1,2,4‐thiadiazolin‐3‐ones 2–1 can be synthesized from 5‐amino‐2H‐1,2,4‐thiadiazolin‐3‐one (1–1) via a selective acylation with an acid anhydride in pyridine. The 1H nmr spectral characteristics of 5‐amino‐2‐acyl‐1,2,4‐thiadiazolin‐3‐ones 2–1 is in particular, compared with 5‐amino‐2H‐1,2,4‐thiadiazolin‐3‐one (1–1) and 5‐amino‐2‐alkyl‐1,2,4‐thiadiazolin‐3‐ones 1–2, 1–3. The 5‐amino group of 2–1 appeared as two peaks in its 1H nmr spectrum, which merged to a single peak at a higher temperature, while those of compound 1–1, 1–2 and 1–3 appear only as a single peak. The restricted rotation of the C(5)‐N(5) (at amino) bond of 5‐amino‐2‐acetyl‐1,2,4‐thiadiazolin‐3‐one (2a‐1) is about 14.5 Kcal/mol.
2,2‐Dioxo‐1H‐thieno[3,4‐c][1,2]thiazines. Synthesis and some reactions of a new heterocycle
Authors: Fanghänel Egon , Bartossek Hagen , Baumeister Ute , Biedermann Matthias , Hartung Helmut 
Published: March 2009

AbstractThe first synthesis of substituted 2,2‐dioxo‐1‐phenyl‐1H‐thieno[3,4‐c][1,2]thiazines 2 and some of their reactions are achieved. Compounds 2 were prepared from the 3,5‐dimethyl‐1,1‐dioxo‐1,2‐thiazine‐4‐carbaldehydes 1 by reaction with sulfur and triethyl amine in dimethylformamide under mild conditions. They were characterized spectroscopically and by X‐ray structure analysis. The formylation, chlorination and oxidation of 2 are reported.
3‐Benzoyl‐3,4‐dihydro‐2H,5H‐1‐benzopyrano[4,3‐b]pyran‐5‐ones by condensation of 4‐hydroxycoumarins with enone mannich bases
Authors: Girreser Ulrich , Heber Dieter , Schütt Martin 
Published: March 2009

AbstractStarting from 4‐hydroxycoumarins 4 and 1‐aryl‐2‐(dimethylaminomethyl)prop‐2‐en‐1‐ones 2 the title compounds 6 have been synthesized. The reaction is initiated by addition of the C‐3 carbon atom of 4‐hydroxycoumarin to the enone double bond of the Mannich base, subsequent deamination affords the intermediate 3‐(2‐benzoylallyl)‐4‐hydroxycoumarin 8, followed by ring closure. Depending on the reaction time, varying proportions of the ketones 6 and 8 are formed and support the mechanism defined. The spectroscopic data of all products unambiguously distinguish between the coumarin and the chromone structures in favor of the former.
Synthesis of isoindolo[1,3]benzoxazine derivatives through intramolecular arylation of N‐acyliminium ions
Authors: Hucher Nicolas , Daïch Adam , Decroix Bernard 
Published: March 2009

Abstract[1,3]Benzoxazines annulated to isoindole as 3 and 4 have been synthesized in three steps from N‐chloromethylphthalimide 5 and substituted phenols 6. The key step was the acid‐catalyzed cyclization of ω‐carbinol lactams 8 and 9.
Studies on the synthesis of some dihydropyridine derivatives possessing calcium antagonistic activity
Authors: Kilcigil Gülgün Ayhan , Ertan Rahmiye , Özbey Süheyla , Kendi Engin 
Published: March 2009

AbstractIn this study, it is aimed to investigate the synthesis and the calcium antagonistic activity of some flavone derivatives which contain the 1,4‐dihydropyridine ring system at the A ring of the flavone nucleus. For this purpose we first synthesized 6‐formylflavone and then twelve 1,4‐dihydropyridine derivatives were synthesized by the reaction of 6‐formylflavone with alkylacetoacetates, acetoacetanilide and methyl or ethyl aminocrotonate. Conformational analysis was performed for compound 3a. The calcium antagonistic activity of compound 2a was examined using nifedipine as the reference compound.
Benzofuran systems. Regioselective bromination and some other reactions of 1‐(3‐benzofuranyl)‐2‐phenylethanones
Authors: Kwiecień Halina , Baumann Ernst 
Published: March 2009

Abstract1‐[3‐(2‐Alkylbenzofuranyl)]‐2‐(3,5‐dibromo‐4‐hydroxyphenyl)ethanones 5a,b and 1‐[3‐(2‐alkylbenzofuranyl)‐2‐(3‐bromo‐4‐methoxyphenyl)ethanones 3a,b were readily prepared by selective bromination of hydroxy 1a,b and methoxy 1c,d ethanones, respectively. A successful method of O‐alkylamination of 5a with N‐(2‐chloroethyl)‐N,N‐diethylammonium chloride to 6a by a two‐phase reaction under phase transfer conditions has been applied. Lithium aluminium hydride reduction of the carbonyl group of 1b to carbinol 4b was carried out in good yields.
An alternative route to 2H‐naphtho[1,2‐b]thiete and its cycloaddition products
Authors: Rumpf Norbert , Gröschl Dieter , Meier Herbert , Oniciu Daniela C. , Katritzky Alan R. 
Published: March 2009

Abstract2‐(1H‐Benzotriazol‐1‐ylmethyl)‐1‐naphthalenol (1) can be transformed in high yields to the corresponding thiol 4. Flash vacuum pyrolysis of 4 leads to 2H‐naphtho[1,2‐b]thiete (5). The benzotriazolyl group proved to be a good leaving group; however, a subsequent nitrogen extrusion takes place under flash vacuum pyrolysis conditions and cyclopentadienecarbonitriles 6a,b are formed by a ring contraction (Scheme 1). Cycloaddition reactions of 5 and dienophiles or heterodienophiles yield the naphtho‐condensed sulfur heterocycles 8, 10, 12 and 14 (Scheme 2).
Studies on the chemistry of thienoannelated o,n‐ and s,n‐containing heterocycles. 16. Synthesis of some thieno[1,4]thiazine derivatives with potential calcium antagonistic activity
Authors: Erker Thomas 
Published: March 2009

AbstractSubstituted thieno[1,4]thiazine derivatives have been synthesized. They are thienoanalogues of compound 3 [2], a potent cerebral protectant and calcium antagonist. Research activities concentrate on the preparation of structurally modified compounds of 3 to minimize its undesirable symptoms.
Transformations of methyl 2‐(2,2‐disubstituted‐ethenyl)amino‐3‐dimethylaminopropenoates. The synthesis of methyl 1‐heteroaryl‐1H‐imidazole‐4‐carboxylates
Authors: Selič Lovro , Stanovnik Branko 
Published: March 2009

AbstractTransformations of intermediates 4, prepared from methyl 2‐(2,2‐disubstituted‐ethenyl)amino‐3‐dimethylaminopropenoates 2 and sterically hindered heteroarylamines 3, into methyl 1‐heteroaryl‐1H‐imidazole‐4‐carboxylates 7 are described.
Pyrrolo[3,2‐c][1,2,5]benzotriazocine: A new ring system
Authors: Passannanti Alessandra , Diana Patrizia , Barraja Paola , Lauria Antonino , Cirrincione Girolamo , Mingoia Francesco 
Published: March 2009

AbstractA nucleophilic substitution reaction in the pyrrole series, achieved by a neutral nucleophile, led to the key intermediate 7 which by reduction and successive diazotization afforded the new ring system pyrrolo[3,2‐c][1,2,5]benzotriazocine 9 in good yield.
Photochemistry of mesoionic compounds. Photochemical conversion of 5‐azido‐1,3‐diaryltetrazolium salts to novel tricyclic mesoions with a tetrazolo[1,5‐a]benzimidazole skeleton
Authors: Araki Shuki , Hattori Hiromi , Shimizu Noriyuki , Ogawa Koji , Yamamura Hatsuo , Kawai Masao 
Published: March 2009

AbstractA new type of tetrazolium‐5‐amide mesoions 2 with a tricyclic tetrazolo[1,5‐a]benzimidazole skeleton has been synthesized via photolysis of 5‐azido‐1,3‐diaryltetrazolium salts 1.
Quaternization and dequaternization of pyrazoles in solvent‐free conditions: Conventional heating versus microwave irradiation
Authors: Díez‐Barra Enrique , De La Hoz Antonio , Sánchez‐Migallón Ana , Elguero José 
Published: March 2009

AbstractWe report a study on the quaternization and dequaternization of pyrazoles by conventional heating and microwave irradiation in solvent‐free conditions. Microwave irradiation produces an acceleration in the quaternization rate and a rapid equilibration between quaternized and non quaternized products. Dequaternization is also more rapid and a change on the selectivity is observed using symmetric pyrazolium salts.
Studies on pyrrolidinones. Synthesis of 1,2,3,5,11,11a‐hexahydroindolizino[7,6‐b]indole‐3,11‐dione
Authors: Ebrik Sahar Al Akoum , Legrand Anne , Rigo Benoît , Couturier Daniel 
Published: March 2009

AbstractCondensation of N‐trimethylsilylindole with methyl N‐trimethylsilyloxymethylpyroglutamate is the best method to obtain methyl N‐indolylmethylpyroglutamate. Friedel‐Crafts cyclization of the corresponding acid yields a new ketone (1,2,3,5,11,11a‐hexahydroindolizino[7,6‐b] indole‐3,11‐dione).
Synthesis of piperidine analogs of 1‐(3‐chlorophenyl)piperazine, a well known serotonin ligand
Authors: Rádl Stanislav , Hezký Petr , Taimr Jan , Proška Jan , Krejčí Ivan 
Published: March 2009

AbstractSynthesis of arylpiperideines 3a‐3d and arylpiperidines 4a‐4d as analogs of a well known serotonin ligand 1‐(3‐chlorophenyl)piperazine is reported. Starting aryllithium derivatives were treated with 1‐methyl‐piperdin‐4‐one to provide the corresponding hydroxy derivatives 6a and 6b.N‐Methylpiperideine derivatives 3a and 3c were obtained by their dehydration while the correspondingN‐unsubstituted compounds 3b and 3d were prepared indirectly by a three‐step procedure. Hydrogenation of piperideine 3a provided the corresponding piperidine derivative 4a which after demethylation yielded 4b. Similar 4‐pyridyl derivatives 4c and 4d were prepared by a similar strategyviathe corresponding methoxy derivatives.