bluuebunny/crossref_metadata_2025_split huggingface dataset:
New symmetric and unsymmetric polyfunctionalized 2,2′‐bipyridines
Authors: De Vains J. B. Regnouf , Papet A. L. , Marsura A. 
Published: March 2009

AbstractRecently, a large number of biheterocycles have been synthesized in order to build macrobicyclic cryp‐tates. To pursue investigations in this field, we prepared new symmetric and unsymmetric functionalized bi‐pyridines and we describe here two synthetic strategies leading to new tetrasubstituted 3 to 15 and trisubsti‐tuted 17 to 29 bipyridines. Modification at the α,α'‐methyl groups and introduction of functionalities in the 4,4′‐positions have been performed after N‐O activation of the starting 6,6′‐dimethyl‐2,2′‐bipyridine unit. In the case of cyano and hydroxymethyl groups, alkylation of the N‐O function followed by a nucleophilic attack with the CN anion or an hydroxymethyl radical allowed us to obtain the dissymmetric species. To understand observed differencies between cyanation and hydroxymethylation processes, the unstable and hygroscopic N‐methoxybipyridinium salt 30 has been isolated and characterized by nmr. Dibromomethyl compounds 8, 15, 29 were finally obtained in good to moderate yields by the Boekelheide rearrangement followed by a pseudohalogen exchange.
Reaction of 2‐trifluoromethyl‐4H‐3,1‐benzoxazin‐4‐one derivatives with carboethoxymethylenetriphenylphosphorane
Authors: Murphy Steven M. , Stanforth Stephen P. 
Published: March 2009

AbstractTreatment of a series of 2‐trifluoromethyl‐4H‐3,1‐benzoxazin‐4‐one derivatives 1 with carboethoxymethyl‐enetriphenylphosphorane 2 yielded the phosphoranes 3 in boiling toluene solution. Thermolysis of these phosphoranes 3 gave esters 6.
Reactivity of 3,3′‐methylenebis(5‐phenyl)oxazolidine with urea, thiourea and cyanamide. An alternative mechanism for the α‐ureidoalkylation of 2‐amino‐l‐phenylethanol
Authors: Pevarello Paolo , Pinciroli Vittorio , Varasi Mario 
Published: March 2009

AbstractThe title compound 1 reacts with urea, thiourea and cyanamide, yielding the corresponding 1,3,5‐triazine‐2‐one 3a, ‐2‐thione 3b and an N,N‐dicyanobisaminal 4 derivative, respectively. An alternative mechanism for this class of α‐ureidoaikylations is proposed.
Dichloromethylenation of substituted 1H‐isoindole‐1,3‐(2H)‐diones (phthalimides)
Authors: Robinson Denise , Stanley Alan L. , Stanforth Stephen P. 
Published: March 2009

AbstractA number of substituted 1H‐isoindole‐1,3‐(2H)‐dione derivatives (phthalimides) underwent dichloro‐methylenation when reacted with a mixture of triphenylphosphine and carbon tetrachloride.
Reaction of tetrahydrobenz[a]acridinones with hydroxylamine hydrochloride. VII
Authors: Martínez Roberto , Rubio Manuel F. , Guillermo Ramírez G. , Camacho Tomas , Irma Linzaga E. , Mancera Claudia 
Published: March 2009

AbstractOximation of ortho‐substituted phenylbenz[a]acridinones using hydroxylamine hydrochloride, sodium hydroxide and ethanol as the solvent gave always the benzoquinacridine N‐oxide 2. Oximation of para‐substituted phenylbenz[a]acridinones, however, gave only the corresponding oximes. The structure of all products was corroborated by ir, 1H and 13C‐nmr and mass spectral data. Theoretical calculations support the experimental findings.
Abnormal ring closure and oxidation in situ of 2‐hydroxy‐5‐nitrobenzaldehyde in the hantzsch synthesis
Authors: Menconi Italo , Angeles E. , Martínez Luisa , Posada Maria E. , Toscano Rubén A. , Martínez Roberto 
Published: March 2009

AbstractThe Hantzsch condensation of 2‐hydroxy‐5‐nitrobenzaldehyde, ethyl acetoacetate and ammonia gave the hitherto unknown 2‐methyl‐3‐ethoxycarbonyl‐4‐ethoxycarbonylmethyl‐6‐(2‐hydroxy‐5‐nitrophenyl)‐pyridine via an unusual condensation and oxidation in situ.
Preparation of 3‐hydroxyisoindolin‐1‐ones and o‐acylbenzamides. A study of ring‐chain tautomerism
Authors: Nishio Takehiko , Yamamoto Hiroshi 
Published: March 2009

Abstract3‐Hydroxyisoindolinones (ring form) as well as their chain tautomers, o‐acylbenzamides, were prepared from the reactions of 3‐benzalphthalide 1, 3‐halophthalides 3, and o‐acylbenzoic acids 6 or their esters 7 with amines 2, and those of phthalimides 4 with Grignard reagents 5. The characteristic spectroscopic properties of ring and chain forms are observed in the ir and 13C‐nmr spectra. The significance of the spectroscopic results is discussed, as is the relationship between the structure of the products and the position of the ring‐chain equilibrium.
A new route to the asymmetric cylindrical macrotricyclic ligands
Authors: Krakowiak Krzysztof E. , Bradshaw Jerald S. , Kou Xiaolan , Dalley N. Kent 
Published: March 2009

AbstractNew asymmeric cylindrical macrotricyclic ligands have been prepared containing two diaza‐12‐crown‐4 units connected by diethyleneoxy or triethyleneoxy and meta‐ or para‐xylylene bridges, 2‐4. These materials were prepared in three steps by first treating 6‐tosyl‐6‐aza‐3,9‐dioxa‐1,11‐undecanediyl ditosylate with 3‐oxa‐1,5‐pentanediamine or 3,6‐dioxa‐1,8‐octanediamine to form ditosyl‐substituted bis(diaza‐12‐crown‐4)s connected by a diethyleneoxy or triethylencoxy bridge. These latter compounds were detosylated and treated with either para‐ or meta‐α,α'‐dibromoxylene to give new asymmetric cylindrical macrotricycles 2‐4. The solid state structure of one of these ligands, 3, has been determined by X‐ray diffraction methods.
Reaction of amino substituted heterocycles with one heteroatom in a five‐membered ring as enamines. A revision
Authors: Almerico A. M. , Cirrincione G. , Diana P. , Grimaudo S. , Dattolo G. , Aiello E. , Mingoia F. 
Published: March 2009

Abstract2‐Aminoheterocycles (pyrrole, furan, and thiophene) exist in solution in the amino form of type 1 and 5. They undergo protonation at the exocyclic nitrogen in DMSO/TFA and protonation at position 5 in TFA. However when the electrophile is different from proton the 2‐aminoheterocyles do not react as enamines (C‐acylation is never observed), but their behavior is typical of aromatic amines, giving rise to N‐acylated product of type 9.
Retro‐ene reaction. II. Reaction of 4,5‐dichloro‐1‐hydroxy‐methylpyridazin‐6‐one with alkyl halides and carboxylic acid chlorides
Authors: Kim Sung‐Kyu , Cho Su‐Dong , Kweon Deok‐Heon , Lee Sang‐Gyeong , Chung Joo‐Wha , Shin Sung Chul , Yoon Yong‐Jin 
Published: March 2009

Abstract1‐Alkyl‐4,5‐dichloropyridazin‐6‐oncs and (4,5‐dichloro‐6‐oxopyridazin‐1‐yl)methylcarboxylates were synthesized from 4,5‐dichloro‐1‐hydroxymethylpyridazin‐6‐one and the corresponding alkyl halides or carboxylic acid chlorides. Also the reaction mechanisms via a fragmentation of retro‐ene type are discussed.
Synthesis of phenylpyrrolylpyrroles. Part II
Authors: Dumoulin H. , Rault S. , Robba M. 
Published: March 2009

AbstractA series of methyl or ethyl 3‐(N‐arylpyrrol‐3‐yl)‐1H‐pyrrole‐2‐carboxylates and 2,4‐dicarboxylates have been synthesized using an alkyl isocyanides addition‐cyclization with N‐arylpyrrole derivatives such as the carboxaldehydes and nitropropenes.
Synthesis of substituted azaoxindoles for the preparation of aza‐tenidap analogs
Authors: Robinson Ralph R. , Donahue Kathleen M. , Son Paul S. , Wagy Steven D. 
Published: March 2009

AbstractThe preparation of a set of eight azaoxindoles bearing substituents on the aromatic nucleus is outlined. These compounds were required for the preparation of aza‐analogs of the anti‐inflammatory oxindole tenidap. Two methods of synthesis were used, the first involving the addition of malonate to 2‐chloro‐3‐nitropyridine derivatives followed by nitro group reduction and one‐pot cyclization/hydrolysis/decarboxylation. The second method, utilizing the vicarious nucleophilic substitution (VNS) reaction of nitropyridine derivatives (followed by nitro group reduction and one‐pot cyclization/hydrolysis), constitutes a novel route to azaoxindoles.
Synthesis of condensed tricyclic pyrazolo[3,4‐b]thieno[2,3‐d]pyridine and related isostere derivatives
Authors: De Carvalho Alcione S. , Fraga Carlos A. M. , Barreiro Eliezer J. 
Published: March 2009

AbstractIn this paper we report the synthesis of an isosteric series of new heterotricyclic derivatives, corresponding to pyrazolo[3,4‐b]thieno[2,3‐d]pyridine (1), pyrazolo[3,4‐b]furano[2,3‐d]pyridine (2) and pyrazolo[3,4‐b]pyrrolo[2,3‐d]pyridine (3). These functionalized compounds were obtained, in high overall yield, by an ‘one‐pot’ reaction of the chloroester intermediate 4, possessing the pyrazolo[3,4‐b]pyridine system, with an adequate α‐hetero‐acetyl ester derivative, in SNAr/Dieckman cyclization type consecutive reactions.
Synthesis of azolylalkylquinolines with cytotoxic activity
Authors: Abel Mark D. , Luu Hiep T. , Micetich Ronald G. , Nguyen Dai Q. , Oreski A. Bernadette , Tempest Mark L. , Daneshtalab Mohsen 
Published: March 2009

AbstractThe syntheses of various azolylalkylquinoline derivatives in which the nature of the linkage between the quinoline and azolylalkyl moieties of the molecule were altered are described. The compounds were tested for cytotoxic activity towards cancer cells and compound 27 was found to exhibit moderate in vivo activity in a murine sarcoma model.
Synthesis and stereochemistry of oxazolo[4′,5′:1,2]benz[5,4,3‐c, d]‐indole derivatives as intermediates on the way to a selective dopamine autoreceptor agonist
Authors: Gmeiner Peter , Bollinger Bernd , Lotter Hermann 
Published: March 2009

AbstractAn expedient and practical variant of the synthesis of the selective dopamine autoreceptor agonist 5 from the benzindolone 1 is described. The reaction sequence includes a two‐fold epimerization at the α‐position of the lactam function. The structure of the intermediate 9a was confirmed by X‐ray structure analysis.
Synthesis and Complexation Properties of Pyrimidine‐Derived Crown Ether Ligands
Authors: Redd J. T. Y. , Bradshaw Jerald S. , Huszthy Peter , Izatt Reed M. , Dalley N. Kent 
Published: March 2009

AbstractFive new proton‐ionizable macrocyclic ligands containing a pyrimidone‐subcyclic unit, 6–10, were prepared from the previously prepared pyrimidinocrown ethers 1–5 (see Figure 1 and Scheme 1). One of the new proton‐ionizable crown ethers is chiral. The proton‐ionizable pyrimidonocrown ethers were prepared in high yields by treating the appropriate methoxy‐substituted pyrimidinocrown with 5 M sodium hydroxide in a 50% alcohol‐water mixture. Complexation properties of four of the pyrimidine‐derived macrocycles were studied by various nmr techniques. Pyrimidono‐18‐crown‐6 (9) forms a strong complex with benzylammonium perchlorate and also forms a complex with benzylamine. (S, S)‐Dimethyl‐substituted pyrimidino‐ and pyrimidono‐18‐crown‐6 ligands 4 and 9 form stronger complexes with the (R)‐form of α‐(1‐naphthyl)ethylammonium perchlorate than with the (S)‐form. (S, S)‐Dimethyl‐substituted pyrimidono‐18‐crown‐6 (9) also forms a stronger complex with (R)‐α‐(1‐naphthyl)ethylamine than with the (S)‐form. The crystal structure for compound 7 is reported.
Synthesis of 2,3‐dihydro‐3‐hydroxy‐2‐(pyrrol‐1‐ylmethyl)‐1H‐isoindol‐1‐one. An intermediate for the synthesis of tetracyclic systems
Authors: Korenova Anna , Netchitailo Pierre , Decroix Bernard 
Published: March 2009

AbstractN‐Chloromethylphthalimide 1 and the potassium salt of pyrrole gave N‐(pyrrol‐1‐ylmethyl)pbthalimide 2. Reduction of 2 led to the hydroxyisoindolone 3. This hydroxylactam cyclized under acidic conditions to lead to a pyrroloimidazoloisoindolone 4 via an acyliminium ion. Transformation of 3 with acetic acid derivatives provided 5, 7 and 9 which gave by intramolecular cyclization, tetracyclic compounds 6, 10 and 11.
Synthesis of 4‐(pyrazol‐5‐yl)‐1,2,4‐triazole‐3‐thiones
Authors: Vicentini Chiara B. , Manfrini Maurizio , Veronese Augusto C. , Guarneri Mario 
Published: March 2009

AbstractCondensation of pyrazolyl isothiocyanates 2 with N‐substituted hydrazines provided the 2‐methyl/phenyl‐4‐(pyrazol‐5‐yl)thiosemicarbazides 3. Cyclization of 3 with formic acid‐acetic anhydride or with triethyl orthoacetate‐acetic anhydride provided 4‐(pyrazol‐5‐yl)‐l,2,4‐triazole‐3‐thiones 4a‐f and 5‐methyl‐4‐(pyrazol‐5‐yl)‐1,2,4‐triazole‐3‐thiones 4g‐I respectively.
A new preparation of substituted 4H‐1‐benzothiopyran‐4‐ones from c(α)N‐benzoylhydrazones or c(α)N‐carboalkoxyhydrazones and methyl thiosalicylate
Authors: French Kristen L. , Angel April J. , Williams Angela R. , Hurst Douglas R. , Beam Charles F. 
Published: March 2009

AbstractC(α)N‐Benzoylhydrazones or C(α),N‐carboalkoxyhydrazones were dilithiated with excess lithium diisopropylamide, and the dianion‐type intermediates were condensed with lithiated methyl thiosalicylate, followed by cyclization/hydrolysis to substituted 4H‐1‐benzothiopyran‐4‐ones (thioflavones/thiochromones).
Synthesis of purinobenzothiazine and pyridothiazinopurine derivatives. Two new heterocyclic ring systems
Authors: Settimo Antonio Da , Marini Anna Maria , Primofiore Giampaolo , Settimo Federico Da , Bertini Daniele 
Published: March 2009

AbstractThe synthesis of derivatives of two new heterocyclic systems, purino[8,7‐b][1,3]benzothiazine and pyrido[3′,2′:5,6][1,3]thiazino[3,2‐f]purine, was effected by the Ullmann reaction between 8‐mercaptotheophylline or 8‐bromotheophylline with the appriopriately substituted benzoic or nicotinic acid, respectively. The 8,8′‐dithiobistheophylline is also reported.
Synthesis of aryl ω‐(1‐methyl‐5‐imidazolyl and 1H‐5‐tetrazolyl)alkyl ketones
Authors: Lee Jae Jeong , Huang Liang‐Fu , Zaw Kyaw , Bauer Ludwig 
Published: March 2009

AbstractSuccessful syntheses of 2,4‐dichlorophenyl 2‐(1‐methyl‐5‐imidazolyl)ethyl and 2,4‐dichlorophenyl 3‐(1‐methyl‐5‐imidazolyl)propyl ketones are described. In addition, syntheses of 2,4‐dichlorophenyl and 4‐chlorophenyl 3‐(1‐methyl‐1H‐5‐tetrazolyl)propyl ketones are reported.
Formation and structure of 1‐Amino‐4‐methyl‐4‐(4‐methyl‐5‐phenyl‐1H‐pyrazol‐3‐ylamino)‐3‐phenyl‐4,5‐dihydro‐1H‐pyrazol‐5‐one
Authors: Donati Donato , Fusi Stefania , Ponticelli Fabio 
Published: March 2009

AbstractThe title compound 3 was obtained during the rearrangement of isoxazol‐5‐yl hydrazine 1 to 1‐aminopyrazolone 2 at 115°. X‐ray analysis of the corresponding benzylidene derivative allowed us to achieve the structure assignment.
Syntheses of 4 and 5‐alkylsulfonylimidazoles
Authors: Shafiee A. , Akbarzadeh T. , Foroumadi A. , Hadizadeh F. 
Published: March 2009

AbstractA series of isomeric 4 and 5‐alkylsulfonyl, alkylsulfinylimidazoles 9,10 were prepared by two general methods. Chlorosulfonation of imidazole afforded 4(5)‐chlorosulfonylimidazoles 2, 4, 5. The chlorosulfonyl derivatives were reduced, alkylated and oxidized to give 9 and 10. In the second method 2, 4, 5 were converted to sodium sulfinate 8 and reacted with alkyl halides to afford the title compound 9.
Synthesis of 5‐dialkylaminothiocarbonylthiobarbituric acids and 5‐diethyiaminothiocarbonylthio‐6‐aminouracil
Authors: Neilands Ojars Y A. , Sudmale Ineta , Schnell Barbara , Georgieva Krassimira , Kappe Thomas 
Published: March 2009

AbstractThe title compounds are obtained by three different methods. The aminothiocarbonylthiolation of barbituric acids 1 and aminouracil (5) can be accomplished in one step by reaction with thiuram disulfides in the presence of potassium carbonate. On the other hand, compounds 4 can be obtained via the salt of chloro derivative 2 or the corresponding iodonium ylides 3. The aminouracil derivative 7 was obtained in a similar fashion from 5 directly or via iodonium betaine 6.
An efficient stereospecific preparation of (Z)‐3‐methylidene‐selenophthalides and (z)‐3‐methylidenetellurophthalides
Authors: Sashida Haruki , Kawamukai Atsusbi 
Published: March 2009

Abstract(Z)‐3‐Methylideneselenophthalides 5A and (Z)‐3‐methylidenetellurophthalides 5B were easily prepared by the regioselective and stereoselective reaction of 2‐ethynylbenzoyl chlorides 3 with sodium hydroselenide and sodium hydrotelluride in good yields, respectively.
Synthesis of hexaazacryptands containing furan and benzene groups in the bridging arms
Authors: Krakowiak Krzysztof E. , Bordunov Andrei V. , Bradshaw Jerald S. 
Published: March 2009

AbstractTwo new hexaazacryptands were prepared. One contains two propylene groups and a 2,5‐furandimethylene unit between the nitrogen atoms of each bridge. The other has two propylene groups and a p‐phenylene unit between the nitrogen atoms of each bridge.
(E)‐1‐benzotriazolyl‐3‐(phenylsulphonyl)‐1‐propene and its alkylation reactions
Authors: Katritzky Alan R. , Nichols Daniel A. , Qi Ming 
Published: March 2009

Abstract(E)‐1‐Benzotriazolyl‐3‐(phenylsulphonyl)‐1‐propene (6) has been synthesized and its alkylation was studied. The results showed that the phenylsulphonyl group is a more powerful α‐directing group than the benzotriazolyl group in the corresponding 1,3‐dihetero‐stabilized allyl anion.
Saturated heterocycles. 254. synthesis and stereochemistry of saturated or partially saturated pyridazino‐[6,1‐b]‐ and phthalazino[1,2‐b]quinazolinones
Authors: Bernáth GÁBor , Miklós Ferenc , Stájer GÉZa , Sohár PÁL , Böcskei Zsolt , Menyhárd DÓRa 
Published: March 2009

AbstractBy the reaction of anthranilic hydrazide 1 with cis‐2‐(p‐methylbenzoyl)‐1‐cyclohexanecarboxylic acid 2a or diendo‐3‐(p‐methylbenzoyl)bicyclo[2.2.1]heptane‐2‐carboxylic acid 2b, fused tetra‐ and pentacyclic ring systems 3a, b were prepared, trans‐2‐Amino‐1‐cyclohexanecar‐bohydrazide 4b was reacted with 3‐(p‐chlorobenzoyl)propionic acid 5 to yield the pyridazino[6,1‐b]quinazolinone 6. From the reaction of cis‐2‐amino‐1‐cyclohexanecarbohydrazide 4a with 2a, three isomeric partially saturated 8H‐phthalazino[1,2‐b]quinazolin‐8‐ones 7a‐c were formed. The reaction of diexo‐2‐aminobicyclo[2.2.1]heptane‐3‐carbohydrazide 4c and 2a furnished the pentacyclic derivatives 8 and 9 containing a 3‐aryl‐4,5‐dihydropyridazine or 3‐arylhexahydropyridazine ring C with cis annelated C/D rings. The formation of 8 and 9 involving different ring systems can be rationalized by two reaction pathways: (i) in the bislactam 9 the carboxyl group acylates the hydrazide, while (ii) in 8 it forms a pyridazine ring with the cyclic amino group by cyclocondensation. The structures of the products were elucidated by 1H and 13C nmr methods, including DEPT, DNOE and 2D‐HSC measurements.
Synthesis of 4‐Aryl‐3‐(2‐chromonyl)‐2‐pyrazolines by the 1,3‐dipolar cycloaddition of 2‐styrylchromones with diazomethane
Authors: Pinto Diana C. G. A. , Silva Artur M. S. , Almeida Lúcia M. P. M. , Cavaleiro José A. S. , Lévai Albert , Patonay Tamás 
Published: March 2009

AbstractThe first reported 1,3‐dipolar cycloaddition of 2‐styrylchromones with diazomethane afforded 4‐aryl‐3‐(2‐chromonyl)‐2‐pyrazolines. However, 3‐aryl‐4‐(2‐chromonyl)‐1‐pyrazolines have been also found as minor products of this reaction. These two series of pyrazolines have been fully characterized.
Substituted N‐cyanomethyl‐2‐halo‐N‐methylarenecarboxamides as precursors of 1,4‐benzothiazepines
Authors: Dölling Wolfgang , Perjéssy Alexander , Schaller Ingrid , Kolbe Alfred 
Published: March 2009

Abstract2‐Halogeno substituted N‐cyanomethyl‐N‐methylbenzamides 1a‐1i were investigated in a correlation analysis by ir spectroscopy to determine the conformational behavior. Compound 1h gives 4‐methyl‐2‐methylthio‐8‐nitro‐5‐oxo‐4,5‐dihydro‐1,4‐benzothiazepine‐3‐carbonitrile 3 by dithiocarboxylation procedure whereas 1b was not able to react to heterocyclic seven‐membered ring system.
Synthesis of 3‐alkenylisoindolin‐1‐ones via palladium(0)‐catalyzed coupling and cyclization between 2‐iodobenzoyl chloride and aldimines
Authors: Cho Chan Sik , Wu Xue , Jiang Li Hong , Shim Sang Chul , Choi Heung‐Jin , Kim Tae Jeong 
Published: March 2009

Abstract2‐Iodobenzoyl chloride reacts with aldimines in acetonitrile at 100° under carbon monoxide in the presence of a catalytic amount of bis(triphenylphosphine)palladium(II) chloride together with triethylamine to give the corresponding 3‐alkenylisoindolin‐1‐ones in good yields.
Alkylation and arylation of pyrazoles under solvent‐free conditions: Conventional heating versus microwave irradiation
Authors: Almena Inés , Díz‐Barra Enrique , De La Hoz Antonio , Ruiz Juliana , Sínchez‐Migallón Ana , Elguero José 
Published: March 2009

AbstractThe use of sodium hydrogen carbonate under solvent‐free conditions and microwave irradiation is by far the best method for N‐alkylating pyrazoles. The yields are good and the method is devoid of side reactions (quaternization, isomerization, hydrogen halide elimination). Solvent‐free conditions are the only ones that allow us to prepare 1‐substituted pyrazoles from secondary halides. The procedure using quaternary salts in one‐pot provides an interesting alternative for the preparation of 1‐heteroarylpyrazoles.
Definitive structural assignment of condensation products from anthranilamide and 3‐amino‐2‐carbamoylthiophene with ketones. Formation of tetrahydroquinazolinones and their thiophene isosteres
Authors: Klemm Leroy H. , Weakley Timothy J. R. , Gilbertson Robert D. , Song Yang‐Heon 
Published: March 2009

AbstractProducts formed from dehydrative cyclization of cyclopentanone, cyclohexanone, and cycloheptanone with anthranilamide (2) under neutral or acidic conditions are established as the spiro compounds 2,2‐polymethylene‐1,2,3,4‐tetrahydroquinazolin‐4‐ones 6 by means of (a) the presence of a 13C nmr signal at 66–79 ppm for atom C‐2 and (b) X‐ray crystallography on the tetramethylene compound 6a. Analogously, products from reactions of these cycloalkanones with 3‐amino‐2‐carbamoylthiophene are now shown by 13C nmr spectra to have structures isosteric to 6, i.e. 5,5‐polymethylene‐4,5,6,7‐tetrahydrothieno[2,3‐e]pyrimidin‐7‐ones 5, rather than the chelate ring structures previously proposed. Additionally, conflicting literature reports on product 3 from reaction of acetone with 2 are partially clarified. Correlation of 13C chemical shifts in systems 3, 5, and 6 is presented.
Synthesis of 7H‐tetrazolo[1,5‐c]pyrrolo[3,2‐e]pyrimidines and their reductive ring cleavage to 4‐aminopyrrolo[2,3‐d]pyrimidines
Authors: Dave Chaitanya G. , Shah Rina D. 
Published: March 2009

AbstractSome new 7,9‐disubstituted 7H‐1,2,3,4‐tetrazolo[1,5‐c]pyrrolo[3,2‐e]pyrimidines5have been synthesized either by diazotization of 4‐hydrazino‐5,7‐disubstituted‐7H‐pyrrolo[2,3‐d]pyrimidines4obtained by hydrazinolysis of 4‐chloro‐5,7‐disubstituted‐7H‐pyrrolo[2,3‐d]pyrimidines3orviaa substitution reaction between3and sodium azide. 5,7‐Disubstituted‐7H‐pyrrolo[2,3‐d]pyrimidin‐4(3H)‐ones2were obtained by cyclocondensation of 2‐amino‐3‐cyano‐1,4‐disubstituted pyrroles1with formic acid which on chlorination using phosphorus oxychloride afforded3. A novel route for the synthesis of 4‐amino‐5,7‐disubstituted‐7H‐pyrrolo[2,3‐d]pyrimidines6by the reductive ring cleavage of5has been reported.
Synthesis of 7‐benzoxazol‐2‐yl and 7‐benzothiazol‐2‐yl‐6‐fluoroquinolones
Authors: Richardson Thomas O. , Shanbhag Vinayak P. , Adair Kimberly , Smith Shantel 
Published: March 2009

AbstractThe fluoroquinolones, 7‐benzoxazol‐2‐yl‐1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acid and 7‐benzothiazol‐2‐yl‐1‐ethyl‐6‐fluoro‐1,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acid, were synthesized. The compounds were obtained by use of the Gould‐Jacobs route to the quinoline ring system. The required anilines, 3‐benzoxazol‐2‐yl‐4‐fluorophenylamine and 3‐benzothiazol‐2‐yl‐4‐fluorophenylamine were obtained by the cyclodehydration reaction of 5‐amino‐2‐fluorobenzoic acid with 2‐aminophenol or 2‐aminothiophenol respectively using polyphosphoric acid.
First synthesis of 5,6‐dihydro‐4H‐furo[3,2‐f]pyrrolo‐ [1,2‐a][1,4]diazepines
Authors: Feng Xiao , Lancelot Jean‐Charles , Gillard Alain‐Claude , Landelle Henriette , Rault Sylvain 
Published: March 2009

AbstractThe synthetic pathway leading to 5,6‐dihydro‐4H‐furo[3,2‐f]pyrrolo[1,2‐a][1,4]diazepines is described in four steps starting from α‐bromophenones via 2‐amino‐3‐furonitriles.