bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and properties of furo[4,3,2‐de][1]benzopyran
Authors: Tanemura Kiyoshi , Suzuki Tsuneo , Horaguchi Takaaki , Sudo Mikio 
Published: March 2009

AbstractA new heterocycle, furo[4,3,2‐de][1]benzopyran (2), was synthesized. A key step in the sequence was the allylic bromination of 3,4‐dihydrofuro[4,3,2‐de][1]benzopyran (8) to give 3‐bromo‐3,4‐dihydrofuro[4,3,2‐de][1]‐benzopyran (10) using N‐bromosuccinimide under irradiation and high dilution conditions. Bromide 10 was dealt with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene to afford compound 2. Several reactions of 2 were examined. Protonation of 2 in trifluoroacetic acid occurred at the 2‐position to form a pyrylium ion 12. Catalytic hydrogenation of 2 with palladium on charcoal proceeded smoothly to give 8. Reduction of 2 by sodium and ethanol afforded 3‐ethyl‐4‐hydroxybenzofuran (14). Electrophilic substitutions of 2 such as formylation, acetylation, and bromination, occurred easily at the 2‐position. The above results show that compound 2 has both properties of benzofuran and 4‐methylenepyran.
Cycloaddition‐elimination reactions of 4‐methyl‐5‐phenylimino‐Δ2‐1,2,3,4‐thiatriazoline with electrophilic nitriles
Authors: L'abbé Gerrit , Sannen Ingrid 
Published: March 2009

Abstract4‐Methyl‐5‐phenyliminothiatriazoline 4 undergoes two consecutive cycloaddition‐elimination reactions with ethyl cyanoformate and p‐toluenesulfonyl cyanide in refluxing chloroform, and yields the 1,2,4‐thiadiazolines 6a,b via the isomers 5a,b. In acetone as the solvent, the reactions occur at room temperature, due to the formation of the 1,2,4‐oxathiazolidine 12 as the intermediate. When trichloroacetonitrile was used, only the decomposition products of 4, namely 7 and 8 were obtained.
Nitration of dithieno[3,4‐b:3′,2′‐d]pyridine and dithieno[2,3‐b:3′,2′‐d]pyridine
Authors: Gronowitz Salo , Szabo Kalman J. , Oluwadiya James O. 
Published: March 2009

AbstractThe nitration of dithieno[3,4‐b:3′,2′‐d]pyridine (2) and dithieno[2,3‐b:3′,2′‐d]pyridine (3) has been studied. Nitration of 2 occurred in both positions of the c‐fused thiophene ring, while 3 was predominantly substituted in the 2‐position. The structures of the nitro derivatives were proven by extensive use of 1H and 13C nmr spectroscopy.
A convenient synthesis of new aminomethylenedioxypyrroloindoles via an iminium salt
Authors: Bouyazza Lahboub , Lancelot Jean‐Charles , Rault Sylvain , Robba Max , Quermonne Marie Anne 
Published: March 2009

AbstractCyclization of 2‐(1‐pyrrolyl)piperonylcarboxamide derivatives gave iminium perchlorates which afforded 9‐(N‐substituted‐imino) and 9‐(N‐substituted amino)‐6,7‐methylenedioxypyrrolo[1,2‐a]indoles.
Potential DNA bis‐intercalating agents. Bridged bis‐(6‐chloropurines) and related compounds
Authors: Párkányi Cyril , Yuan Hui Liang , Tsai Meng‐Kan Michael 
Published: March 2009

AbstractTwo bis‐(6‐chloropurines) bridged by conformationally restricted tethers were synthesized as potential DNA bis‐intercalating agents. Reduction of 4,6‐dichloro‐5‐nitropyrimidine (1) afforded 5‐amino‐4,6‐dichloropyrimidine (2) which was then used as the starting material. Reaction of 2 with 4,4′‐diaminodiphenylmethane (3) and bis‐(4‐aminophenyl) ether (4) yielded bis‐[4‐(N‐5‐amino‐4‐chloro‐6‐pyrimidyl)aminophenyl]methane (5) and bis‐[4‐(N‐5‐amino‐4‐chloro‐6‐pyrimidyl)aminophenyl] ether (6), respectively. Acid‐catalyzed condensation of the above pyrimidines, 5 and 6, with triethyl orthoformate in N,N‐dimethylacetamide gave bis‐[4‐(6‐chloro‐9‐purinyl)phenyl]methane (7) and bis‐[4‐(6‐chloro‐9‐purinyl)phenyl] ether (8). The spectral data on the new compounds will be discussed.
Palladium‐catalyzed conjugate addition type reaction of 5‐iodopyrimidines with α,β‐unsaturated ketones
Authors: Wada Akimori , Ohki Kazuhiro , Nagai Sotoo , Kanatomo Shōichi 
Published: March 2009

AbstractThe reaction of various 5‐iodopyrimidines with α,β‐unsaturated ketones in the presence of palladium diacetate‐triphenylphosphine complex in triethylamine are investigated. In the reaction of 2,4‐dialkoxy(or alkylthio)‐6‐methyl‐5‐iodopyrimidine the addition of pyrimidine to the carboncarbon double bond of α,β‐unsaturated ketones occurs. In the case of other pyrimidines, according to the decrease of steric hindrance at the 5‐position on the pyrimidine ring, the ratio of conjugate addition product was decreased and the usual olefinic substituted product was increased.
Synthesis of 1′‐substituted and 1′,3′‐disubstituted (±)‐2R*, 11bS*‐9,10‐Dimethoxy‐1,3,4,6,7,11 b‐Hexahydrospiro‐[benzo[a]quinolizin‐2,5′‐imidazolidine]‐2′,4′‐diones
Authors: Menéndez J. Carlos , Söllhuber Mónica M. 
Published: March 2009

AbstractThe results of the reaction between (±)‐2R*,11bS*‐2‐alkyl(aryl)amino‐1,3,4,6,7,11b‐hexahydrobenzo[a]‐quinolizine‐2‐carbonitriles 2 and isocyanates under a variety of experimental conditions are discussed. The ureides 3 and iminohydantoins 4 thus obtained were used to prepare N3‐monosubstituted and N1,N3‐disubstituted derivatives of the (±)‐2R*,11bS*‐9,10‐dimethoxy‐1,3,4,6,7,11b‐hexahydrospiro[benzo[a]quinolizin‐2,5′‐imidazolidine]‐2′,4′‐dione system 1. The stereochemistry of these compounds is discussed, on the basis of spectroscopic evidence and study of their chemical reactivity.
Studies of heterocyclic compounds.VIII. Synthesis, anti‐inflammatory and antiallergic activities ofn‐alkyl‐2,3,4,9‐tetrahydrofuro[2,3‐b]quinoline‐3,4‐diones and related compounds
Authors: Kuo Sheng‐Chu , Huang Shung‐Chieh , Huang Li‐Jiau , Cheng Hong‐Elk , Lin Tsung‐Ping , Wu Chun‐Hsiung , Ishii Katsumi , Nakamura Hideo 
Published: March 2009

AbstractA series of newN‐alkyl‐2,3,4,9‐tetrahydrofuro[2,3‐b]quinoline‐3,4‐dione andN‐alkyl‐4,9‐dihydrofuro[2,3‐b]‐quinolin‐4‐one derivatives were prepared and evaluated for their anti‐inflammatory activity by the carrageenin hind paw edema method and antiallergic activity by the rat passive cutaneous anaphylaxis method. Among those tested compounds,N‐ethyl‐2,3,4,9‐tetrahydrofuro[2,3‐b]quinoline‐3,4‐dione was the most promising agent which could provide a novel structural prototype for antiallergic agents.
Pentacyclic triazolodiazepines as PAF‐antagonists
Authors: Walser A. , Flynn T. , Mason C. 
Published: March 2009

AbstractThe syntheses of two novel pentacyclic ring systems, the thieno[3,2‐f][1,2,4]triazolo[4,3‐a][1,4]diazepino‐[4,5‐a]benzimidazole and the indazolo[2,3‐d][1,2,4]triazolo[4,3‐a][1,4]benzodiazepine are described. Attachment of a propargyl linked quinolinone resulted in compounds 6 and 16 which showed PAF‐antagonist activity by the intravenous route of administration in guinea pigs. The more potent compound 16 also exhibited good oral activity with an ID50 of 0.2 mg/kg in the bronchoconstriction assay.
The Synthesis of Octahydro‐7‐phenylpyrazino[2,1‐b][3]benzazepines
Authors: Ohnmacht Cyrus J. , Mclaren Frances M. 
Published: March 2009

AbstractOctahydro‐7‐phenylpyrazino[2,1‐b][3]benzazepine (1a) was prepared from 1‐methyl‐3‐phenylmethylpiperazine5aby reaction with styrene oxide followed by sulfuric acid cyclization of the resulting alcohol6a. The diastereomeric mixture1awas further separated into the diastereomers1a′and1a″. Similarly 1‐methyl‐3‐(3‐chloro‐4‐methoxyphenyl)piperazine was reacted with styrene oxide to yield6cwhich on cyclization with 1.5 equivalents of sulfuric acid in trifluoroacetic acid gave a 3:7 mixture of phenolic,1d, and methoxy,1c, octa‐hydropyrazino[2,1‐b][3]benzazepines. The reaction of the 2,5‐piperazinedione4cwith sodium acetoxyborohydride gave a 49% yield of the 2‐piperazinone7which was similarly carried on to the corresponding 1(2H)‐oxohexahydropyrazino[2,1‐b][3]benzazepine9.
On the synthesis of 3‐amino‐2,3‐dihydro‐1H‐pyrido[3,2,1‐kl]phenothiazine 5,5‐dioxide and of 3‐amino‐1,2‐dihydro‐3H‐dibenzo[c,jk]pyrido[2,1‐c]‐1,4‐thiazepine 7,7‐Dioxide
Authors: Catsoulacos P. , Pelecanou M. , Camoutsis Ch. 
Published: March 2009

Abstract3‐Amino‐2,3‐dihydro‐1H‐pyrido[3,2,1‐kl]phenothiazine 5,5‐dioxide and 3‐amino‐1,2‐dihydro‐3H‐dibenzo‐[c,jk]pyrido[2,1‐c]‐1,4‐thiazepine 7,7‐dioxide were synthesized from the corresponding 3‐oxime acetates by reduction with the borane‐tetrahydrofuran complex. Reduction was not successful in the case of 2,3‐dihydro‐1H‐pyrido[3,2,1‐kl]phenothiazine‐3‐oxime acetate.
Substituted γ‐lactones: On the structural elucidation of the reaction products from 4‐aroyl‐3‐hydroxy‐2(5H)‐furanones and 1,2‐diamines
Authors: Zimmer Hans , Amer Adel , Ho Douglas , Palmer‐Sungail R. 
Published: March 2009

AbstractThe reaction pathway of 4‐aroyl‐3‐hydroxy‐2(5H)‐furanones 1 with diamines depends on the nature of the amine as well as on the applied reaction conditions. Thus, the reaction of 1a‐d with 5,6‐diamino‐1,3‐dimethyluracil 5 led to the formation of two isomeric Schiff bases 7a‐d and 8a‐d. Conversely type 1 compounds reacted with 4,5‐diaminopyrimidine 9 or 2,3‐diaminopyridine 10 to form the mono acid‐base adducts 11a and 11b respectively. When type 1 compounds were reacted with aliphatic diamines 13a‐d or p‐phenylenediamine and p‐xylenediamine, respectively also an immediate formation of acid‐base adducts 15a‐f was observed. The reaction of a number of O‐methylated type 1 compounds with 1,2‐ethylenediamine afforded the novel seven‐membered ring compounds 18a‐d in good yields. The analogous reaction of O‐alkylated 1a with o‐phenylenediamine 2 or 2,3‐diaminonaphthalene gave the expected tricyclic ring systems 19 or 20.
A new procedure for regioselective synthesis of 8,9‐dichloro‐2,3,4,5‐tetrahydro‐1H‐2‐benzazepine (LY134046) and its 3‐methyl analogue as inhibitors of phenylethanolamine N‐methyltransferase (PNMT)
Authors: Grunewald Gary L. , Paradkar Vidyadhar M. , Stillions Duane M. , Ching Feei 
Published: March 2009

AbstractA regioselective synthesis of 8,9‐dichloro‐2,3,4,5‐tetrahydro‐1H‐2‐benzazepine (LY134046, 10) and its 3‐methyl analogue 26 from 6,7‐dichloro‐3‐hydroxyphthalide (16) is described. The key step involved 1,4‐hydride addition to the α,β‐unsaturated nitrile 17 to give the saturated nitrile 18 using sodium borohydride in 2‐propanol. In the preparation of LY134046 10, the COOH group in 18 was first esterified and then the nitrile function was selectively reduced with borane to yield the aminoester 20. The aminoester 20 was then cyclized to the azepinone 21 which on reduction with borane provided LY134046 10 in an overall yield of 22%. The route is adaptable to the preparation of hitherto unknown 3‐substituted‐2‐benzazepines as demonstrated by the preparation of the 3‐methyl analogue 26. In this case the nitrile 18 was reacted with an excess methylmagnesium iodide to give the ketoacid 22. Esterification of 22 followed by reductive amination with sodium cyanoborohydride and ammonium acetate provided the aminoester 24, which was then converted to the target benzazepine 26 as described earlier for the title compound. The reaction conditions and the reagents used throughout the sequence are fairly mild and many functional groups may be tolerated. The only limitation to this procedure is the availability of the corresponding hydroxyphthalide. A variation in the choice of reagent in the Grignard reaction of 18 should provide an access to a variety of 3‐substituted‐2‐benzazepines.
Synthesis of novel, substituted 4H‐imidazo[1,5‐a][1,4]benzodiazepines
Authors: Fryer R. Ian , Gu Zi‐Qiang , Wang Chen‐Guang 
Published: March 2009

AbstractSynthetic approaches to novel, substituted 4H‐imidazo[1,5‐a][1,4]benzodiazepines are described. The compounds prepared are, in general, derivatives of known ring systems and structures were assigned on the basis of spectroscopic evidence.
1,4,4a,10b‐Tetrahydro‐N,N‐dimethyl‐4‐phenanthridinamines and 1,4,4a,5,6,10b‐hexahydro‐N,N‐dimethyl‐4‐phenanthridinamines
Authors: Bobowski George , West Barbara , Omecinsky Diana 
Published: March 2009

AbstractSynthetic procedures to prepare the title compounds are described. Diels‐Alder cycloaddition of β‐nitrostyrene derivatives5toN,N‐dimethyl‐1,3‐butadien‐1‐amine,6, gave 5‐aryl‐N,N‐dimethyl‐6‐nitro‐2‐cyclohexen‐1‐amines 7. Reduction of 7 with zinc in acetic acid gave the diamino derivatives8. Schotten‐Baumann acylation of8gave amides9. Treatment of8with alkyl isocyanates gave the aminourea derivatives10. Bischler‐Napieralski cyclodehydration procudure of9and10gave 1,4,4a,10b‐tetrahydrophenanthridinamines3andN6‐alkyl‐1,4,4a,10b‐tetrahydro‐N4,N4‐dimethyl‐4,6‐phenanthridinediamines11, respectively. Condensation of diamines8with aryl aldehydes under azeotropic conditions gave imines12which on treatment with acids yielded 6‐aryl‐1,4,4a,5,6,10b‐hexahydro‐N,N‐dimethyl‐4‐phenanthridinamines4. The stereochemistry of these materials is assigned from the proton magnetic resonance studies.
Synthesis and insecticidal activity of 4‐(aminomethyl)‐2H‐1‐benzothiopyran‐2‐ones (thiocoumarins) and related compounds
Authors: Nakazumi Hiroyuki , Kobara Yuzoh , Kitao Teijiro 
Published: March 2009

AbstractBromination of 4‐methyl‐2H‐1‐benzothiopyran‐2‐ones (4‐methylthiocoumarins) with bromine under irradiation of high‐pressure mercury lamp gave 3‐bromo‐4‐methylthiocoumarin, which reacted with secondary amine to give 4‐(aminomethyl)thiocoumarins. The structure was determined by X‐ray crystallographic analysis. A series of 4‐methylthiocoumarin and related compounds were tested for insecticidal activity, and 4,6‐dimethylthiocoumarin shows the most significant insecticidal activity against Nilaparvata lugens and Aphis gossypii. An introduction of an aminomethyl group in thiocoumarin results in improvement of activity against Tetranychus urticae and Spodoptera litura.
1,4‐Benzothiazine‐2‐carboxylic acid 1‐oxides as analogues of antibacterial quinolones
Authors: Cecchetti Violetta , Fravolini Arnaldo , Schiaffella Fausto , Tabarrini Oriana , Zhou Weicheng , Pagella Pier Giuseppe 
Published: March 2009

AbstractThe synthesis of 1,4‐benzothiazine‐2‐carboxylic acid 1‐oxides as agents which mimic quinolone antibacterial, are described. The key step includes intramolecular cyclization of phenylsulfinyl acrylates 17 and 18 which are prepared in six steps from 11. None of new target compounds showed interesting antibacterial activity in vitro against the tested strains.
Furopyridines. XII. Reaction of 3‐bromo, 2‐phenylthio and 2‐phenylthio‐3‐bromo derivatives of furo[2,3‐b]‐, furo[3,2‐b]‐, furo[2,3‐c]‐ and furo[3,2‐c]pyridine with several alkyllithiums
Authors: Shiotani Shunsaku , Morita Hiroyuki 
Published: March 2009

AbstractThis paper describes reactions of 3‐bromo‐ 1a‐d, 2‐phenylthio‐ 5a‐d and 2‐phenylthio‐3‐bromofuropyridines 6a‐d with n‐butyl‐, t‐butyl‐ and methyllithium and lithioacetonitrile. Lithiation of compounds 1a‐d with n‐butyl‐ or methyllithium gave the parent furopyridines 2a‐d and o‐ethynylpyridinols 3a‐d. Reaction of compounds 5a‐d with methyllithium afforded o‐(phenylthioethynyl)pyridinols 7a‐d, which were also yielded by reaction of compounds 6a‐d with t‐butyl‐ or methyllithium. The phenylthio group in compounds 7a‐d were substituted with t‐butyl group by the reaction with excess t‐butyllithium. In contrast, 2‐phenylthio group in compounds 5a‐d and 6a‐d was substituted with cyanomethyl group by reaction with lithioacetonitrile to give compounds 11a‐d and 10b, c respectively.
Synthesis of porphyrinyl‐nucleosides
Authors: Czuchajowski Leszek , Habdas Jan , Niedbala Halina , Wandrekar Vinay 
Published: March 2009

AbstractSeveral porphyrinyl‐nucleosides were prepared in the reaction of the OH group of one, two or four meso‐p‐hydroxyphenyl substituents of porphyrin with 5′‐O‐tosylates of 2′,3′‐O‐isopropylidene‐adenosine or ‐uridine, or 5′‐O‐tosylthymidine; the remaining porphyrin meso‐substituents were p‐tolyl, p‐hydroxyphenyl or 4‐pyridyl. The following porphyrinyl‐nucleosides were obtained with 8–17% yield: meso‐di(p‐tolyl)di(p‐phenylene‐5′‐O‐2′,3′‐O‐isopropylidene‐adenosine) (or ‐uridine)porphyrins 1,2, the respective meso‐tetranucleosideporphyrins 3,4‐meso‐mono(p‐phenylene‐5′‐O‐thymidine)porphyrins 5–7, meso‐di(p‐tolyl)di(p‐phenylene‐5′‐O‐thymidine)porphyrins 8,9 and the meso‐di(p‐hydroxyphenyl)di(p‐phenylene‐5′‐O‐thymidine)porphyrins 10. Other compounds prepared belonged to the series: meso(4‐pyridyl)4−n(p‐phenylene‐5′‐O‐2′,3′‐O‐isopropylideneuridine)nporphyrin, n = 1, 2 or 4, 11–13. N‐Methylation gave the water soluble iodide salts: (N‐methyl‐4‐pyridinium)44−n(p‐phenylene‐5′‐O‐2′,3′‐isopropylideneuridine)nporphyrins, n = 1, 2 or 4, 14–16. The ms fab showed in most cases stepwise detachment of the CH2(5′)‐nucleoside fragments.The porphyrins meso disubstituted by thymidine represent a convenient substrate for the build‐up of both nucleoside units into the oligo/polynucleotide chains.
Pyrimidine derivatives. VII. Nucleophilic reactions of 5‐bromo‐1‐(bromoalkyl)‐6‐bromomethyl‐2,4(1H,3H)‐pyrimidinediones
Authors: Kinoshita Toshio , Takaishi Yumiko , Okunaka Tomoko , Ohwada Takehiro , Furukawa Sunao 
Published: March 2009

AbstractThe reactions of 1‐(bromoalkyl)‐5‐bromo‐6‐bromomethyl‐3‐methyl‐2,4(1H,3H)‐pyrimidinedione (1) with several nucleophiles were examined as follows: by reaction with sodium methoxide, 6‐(bismethoxy)methyl‐5‐debrominated derivatives 2, 3, and 4 were prepared; the corresponding di‐substituted compounds (side chains in 1‐and 6‐positions) 5, 6, 7, and 9 were obtained by treatment with silver nitrate, silver acetate, potassium thiocyanate, and potassium thioacetate; the reaction with thioacetamide and iso‐butylamine gave bicyclic compounds [1,4]thiazino[4,3‐c]‐ 11, pyrazino[1,2‐c]‐ 12, and [1,4]diazepino[1,2‐c]pyrimidinedione 13, respectively; pyrrolidine, morpholine, and sodium azide afforded the corresponding 6‐substituted compounds 14, 15, and 16.
Synthesis and structure of N1‐e‐benzo‐4,7,13,16,21,26‐hexaoxa‐1,10‐diazabicyclo[8.8.8]hexacos‐23‐yl‐N2‐phenylthiourea. Derivative of a bifunctional complexing agent
Authors: Pettit William A. , Iwai Yoshihisa , Barfknecht Charles F. , Swenson Dale C. 
Published: March 2009

AbstractA cryptand with an aminobenzo group 4,7,13,16,21,24‐hexaoxa‐5,6‐(4′‐aminobenzo)‐1,10‐diazabicyclo‐[8.8.8]hexacosane, has been synthesized as a bifunctional complexing intermediate for investigation of the labeling of proteins with metal radionuclides. This amine, although unstable, can be prepared as the stable stannic salt. The free base was converted to the corresponding phenylthiourea by 1) reaction with phenyliso‐thiocyanate and 2) conversion to its isothiocyanate followed by reaction with aniline. The thiourea structure was confirmed by X‐ray crystallographic analysis.
Synthesis of some novel azido/tetrazolothienopyrimidines and their reduction to 2,4‐diaminothieno[2,3‐d]pyrimidines
Authors: Shishoo C. J. , Jain K. S. 
Published: March 2009

AbstractA variety of novel 2,4‐diaminothieno[2,3‐d]pyrimidines has been prepared through the reduction of the corresponding azido/tetrazolothienopyrimidines under acidic conditions.
N‐15 NMR analysis of 1,2,3‐thiadiazoles
Authors: L'abbé Gerrit , Delbeke Pieter , Bastin Lieve , Dehaen Wim , Toppet Suzanne 
Published: March 2009

AbstractThe 15N nmr spectra of a series of 1,2,3‐thiadiazoles reveal the strong influence of substituents at C‐5 on the N‐2 resonance. Upon methylation, the two thiadiazole nitrogen resonances are shielded, but the most dramatic shift is observed for the methylated nitrogen, Δδ > 140 ppm. The 15N chemical shifts of some mesoionic thiadiazoles were also determined and explained by the dual effect of 5‐substitution and salt formation. By disconnecting these effects, the 15N chemical shifts of 10 and 11 were found to be unusual and to reflect a thiapentalene character.
Reactivity of 4‐azido‐ and 4‐amino‐6‐methyl‐2H‐pyran‐2‐one. Preparation of 1‐(6‐methyl‐2‐oxopyran‐4‐yl)‐1,2,3‐triazoles and 5‐oxopyrano[4,3‐b]pyridines
Authors: Malet R. , Serra N. , Abramovitch R. A. , Moreno‐Mañas M. , Pleixats R. 
Published: March 2009

Abstract1,3‐Dipolar cycloadditions of stable 4‐azido‐6‐methyl‐2H‐pyran‐2‐one 1 with electron‐rich alkenes and alkynes lead to 4,5‐substituted 1‐(6‐methyl‐2‐oxopyran‐4‐yl)‐1,2,3‐triazoles. Iminophosphoranes derived from 1 have also been synthesized. 5‐Oxopyrano[4,3‐b]pyridines are prepared by reaction of 4‐amino‐6‐methyl‐2H‐pyran‐2‐one 2 with β‐dicarbonyl compounds.
Cis‐trans isomerization of styrylpyrroles by stray light
Authors: Lee Chang Kiu , Yu Ji Sook , Kim Young Hie 
Published: March 2009

AbstractA series of substituted N‐methylstyrylpyrroles (H, p‐Br, p‐CN, o,p‐diCl, m‐CH3, m‐CN, m‐NO2) were prepared via the Wittig reaction of 1‐methylpyrrole‐2‐carboxaldehyde and substituted benzyltriphenylphosphonium bromides. Both cis and trans isomers were found to be present in the reaction mixture and they were separable by column chromatography in a few cases (H, p‐Br, m‐CN, m‐NO2). Photochemical isomerizations of cis‐styrylpyrroles to trans isomers were observed when the substituents were o,p‐diCl and m‐NO2, while the opposite was the case with compounds having H, p‐Br, m‐CH3, m‐CN. It was difficult to separate the cis and trans mixture of p‐cyanostyrylpyrroles and the equilibrium ratio did not change under similar photochemical reaction conditions.
Synthesis and analysis of 1,2,3,4‐tetrahydro‐(9H)‐pyrido[3,4‐b]indole
Authors: Rodríguez J. G. , Gil‐Lopetegui P. 
Published: March 2009

AbstractThe synthesis of 1,2,3,4‐tetrahydro‐(9H)‐pyrido[3,4‐b]indole derivatives was carried out in one pot, by condensation of tryptamin with cycloalkanones in the presence of a polyphosphate ester as the catalyst in moderate to low yields, the aldol condensation being the main products. Reaction of tryptamine and cyclic ketones was also carried out in two stage through the imine intermediate with protic catalysis giving the tetrahydro‐β‐carbolines 8–14, in good yields. 2‐Methyl derivatives 15–21, of the tetrahydro‐β‐carbolines, were obtained in good yields, using methyl iodide in dimethyl sulphoxide‐potassium carbonate.
Convenient synthesis of 4‐trifluoroacetylpyrazoles from aldehyde tert‐butylhydrazones
Authors: Kamitori Yasuhiro , Hojo Masaru , Masuda Ryōichi , Fujishiro Masaki , Nakamura Isao , Yamamoto Katsumasa 
Published: March 2009

AbstractSeveral 1‐(tert‐butyl)‐4‐trifluoroacetylpyrazoles 3 were synthesized by the reaction of aldehyde tert‐butylhy‐drazones 2 with 4‐ethoxy‐1,1,1‐trifluoro‐3‐buten‐2‐one (1). The tert‐butyl group could be readily removed by treatment of 3 with 90% sulfuric acid.
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 11. Synthesis and total assignment of the 1H and 13C NMR spectra of isomeric benzothienonaphthoquinolines using multiple inverse detected two‐dimensional NMR methods
Authors: Luo Jiann‐Kuan , Zektzer Andrew S. , Castle Raymond N. , Crouch Ronald C. , Shockcor John P. , Martin Gary E. 
Published: March 2009

AbstractTwo novel heterocyclic ring systems, namely, [1]benzothieno[2,3‐c]naphtho[1,2‐f]quinoline and [1]benzothieno[2,3‐c]naphtho[2,1‐g]quinoline have been synthesized and characterized by inverse detected two‐dimensional nmr methods. Unequivocal total assignments of the proton and carbon nmr spectra were made through the concerted utilization of HMQC (Heteronuclear Multiple Quantum Correlation) and a combination of HMBC (Heteronuclear Multiple Bond Correlation) and HMQC‐TOCSY (HMQC with proton TOtal Correlation Spectroscopy).
Research on nitrogen containing heterocyclic compounds. XIX: Synthesis of 8H‐imidazo[2,1‐c]‐s‐triazolo[4,3‐a]‐[1,4]benzodiazepine and its 1‐derivatives
Authors: Stefancich Giorgio , Silvestri Romano , Artico Marino 
Published: March 2009

AbstractReaction of 2‐nitrobenzyl iodide with 1H‐imidazole, in the presence of potassium tert‐butoxide and 18‐crown‐6, gave 1‐(2‐nitrobenzyl)‐1H‐imidazole. Trichloroacetylation of this compound furnished trichloroacet‐ylimidazole 8, which on treatment with sodium ethoxide was transformed into the corresponding ethoxycarbonyl derivative 9. Catalytic reduction of the nitro group to the amino group yielded 10, which was then cyclized to 10,11‐dihydro‐11‐oxo‐5H‐imidazo[2,1‐c][1,4]benzodiazepine 11. Treatment of this lactam with di‐4‐morpholinylphosphinic chloride followed by reaction of the intermediate 12 with formylhydrazine gave the title compound or its 1‐derivatives when acetylhydrazine or isonicotinoylhydrazine were used instead of formylhydrazine.