bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of 2‐N‐(benzo[b]thiophen‐2‐yl)benzo and heterofused‐1,2,3‐triazoles
Authors: Sabnis R. W. , Rangnekar D. W. 
Published: March 2009

AbstractA novel efficient synthesis of 2‐N‐(benzo[b]thiophen‐2‐yl)benzo and heterofused‐1,2,3‐triazoles was achieved by the diazotisation of 2‐amino‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carbonitrile and ethyl‐2‐amino‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carboxylate and coupling with selected aromatic and heterocyclic amines followed by air oxidation in the presence of cupric acetate.
A convenient synthesis of pyridazine‐3,4‐dicarboxylic acid by a hetero diels‐alder reaction
Authors: Vors Jean‐Pierre 
Published: March 2009

AbstractA convenient route to prepare unsubstituted pyridazine‐3,4‐dicarboxylic acid on a preparative scale is described. The synthesis involves a hetero Diels‐Alder reaction between a new 1,2‐diaza‐1,3‐diene and ethyl vinyl ether and oxidation of the intermediate 1,4,5,6‐tetrahydropyridazine as the key step.
Synthesis of 1‐aryl‐1,2,3‐triazole‐4,5‐dimethanol‐4,5‐bis(isopropylcarbamates) as potential antineoplastic agents
Authors: Lalezari I. , Gomez L. A. , Khorshidi M. 
Published: March 2009

AbstractStarting with aryl azides, 1‐aryl‐1,2,3‐triazole‐4,5‐dimethanol‐4,5‐bis(isopropylcarbamates), a new class of potential antineoplastic agents, were synthesized. In vitro antileukemic and antitumor actmües of the compounds synthesized were also evaluated.
Syntheses of 6‐fluoro‐7‐piperazin‐1‐yl‐9‐cyclopropyl‐2,3,4,9‐tetrahydroisothiazolo[5,4‐b]quinoline‐3,4‐dione and 6‐fluoro‐7‐piperazin‐1‐yl‐9‐p‐fluorophenyl‐2,3,4,9‐tetrahydroisothiazolo[5,4‐b]quinoline‐3,4‐dione
Authors: Chu Daniel T. W. 
Published: March 2009

AbstractThe syntheses of 6‐fluoro‐7‐piperazin‐1‐yl‐9‐cyclopropyl (or 9‐p‐fluorophenyl)‐2,3,4,9‐tetrahydroisothiazolo[5,4‐b]quinoline‐3,4‐diones as well as novel synthesis of isothiazolo‐3(2H)‐one system are described. Key steps include the regiospecific displacement of a sulfinyl group and the amination of the resultant mercapto derivative followed by an intramolecular nucleophilic displacement cyclization reaction to generate the novel 2,3,4,9‐tetrahydroisothiazolo[5,4‐b]quinoline‐3,4‐dione nucleus.
One step synthesis of pyrimido[1,2‐a][1,8]naphthyridinones, pyrido[1,2‐a]pyrimidinones and 1,8‐naphthyridinones. Antihypertensive agents. V
Authors: Ferrarini Pier Luigi , Mori Claudio , Primofiore Giampaolo , Calzolari Lorella 
Published: March 2009

AbstractThe condensation of 2,6‐diaminopyridine and 2‐acetamido‐6‐aminopyridine with β‐keto esters in polyphosphophoric acid was studied. In this reaction some 1,8‐naphthyridinones, pyrido[1,2‐a]pyrimidinones and pyrimido[1,2‐a][1,8]naphthyridinones variously substituted were obtained.
Methyl 2‐benzoylamino‐3‐dimethylaminopropenoate in the synthesis of fused pyranones. The synthesis of derivatives of tetrahydro‐2H‐1‐benzopyran‐2‐one, isomeric 2H‐naphtho[1,2‐b]pyran‐2‐one and 3H‐naphtho[2,1‐b]pyran‐3‐one, pyrano[3,2‐c]benzopyran‐2,5‐dione, and 7H‐pyrano[2,3‐d]pyrimidin‐7‐one
Authors: Ornik Brina , Čadež Zvonko , Stanovnik Branko , Tišler Miha 
Published: March 2009

AbstractMethyl 2‐benzoylamino‐3‐dimethylaminopropenoate (1) reacts with carbocyclic and heterocyclic 1,3‐diketones or potential 1,3‐diketones, such as 1,3‐cyclohexanediones 2–4, and 4‐hydroxy‐2H‐1‐benzopyran‐2‐one derivative 17, in acetic acid to afford the corresponding 3‐benzoylamino substituted 5‐oxo‐5,6,7,8‐tetrahydro‐2H‐1‐benzopyran‐2‐ones 5–7, and 2H,5H‐pyrano[3,2‐c][1]benzopyran‐2,5‐dione derivative 18. 1‐Naphthol (12) and 2‐naphthol (13) produce the isomeric 2H‐naphtho[1,2‐b]pyran‐2‐one (14) and 3H‐naphtho[2,1‐b]pyran‐3‐one (15) derivatives, respectively. Ethyl cyclopentanone‐2‐carboxylate (8) and ethyl cyclohexanone‐2‐carboxylate (9) do not react under these conditions, while in polyphosphoric acid the cyclization of the reagent 1 is taking place to give 4‐dimethylaminomethylene‐2‐phenyl‐5(4H)‐oxazolone (10). 4,6‐Dihydroxypyrimidine derivative 19 affords in acetic acid the noncyclized intermediate 20, which can be further transformed in polyphosphoric acid into 7H‐pyrano[2,3‐d]pyrimidin‐7‐one derivative 21.
Synthesis, anticancer and antimicrobiological activities of pyrrolo[2,3‐d]pyrimidines
Authors: Quijano M. Luisa , Nogueras Manuel , Sánchez Aldolfo , De Cienfuegos Gerardo Alvarez , Melgarejo Miguel 
Published: March 2009

AbstractReactions of 6‐amino‐3,4‐dihydro‐2‐methoxy‐4‐oxopyrimidine 1a and its 3‐methyl derivative 1b with chloroacetaldehyde and chloroacetyl chloride are discussed in this paper. Amongst others compounds, we have obtained, in low yield, the novel ring system oxazolo[3,2‐c]pyrrolo[3,2‐e]pyrimidine. The anticancer and antimicrobial activities of some of the obtained products are described.
New cyclobutyl analogs of adenosine and guanosine. Part 1. Synthesis of the 9‐[3,3‐bis(hydroxymethyl)cyclobutyl]purine nucleoside analogs
Authors: Boumchita Hassane , Legraverend Michel , Bisagni Emile , Huel Christiane 
Published: March 2009

AbstractThe synthesis of 1‐amino‐3,3‐bis(benzyloxymethyl)cyclobutane has been performed from 3,3‐bis(benzyloxymethyl)cyclobutanone, via the corresponding oxime which was reduced with lithium aluminum hydride. The amine thus obtained led to two new cyclobutyl analogs of adenosine and guanosine which were devoid of antiviral activity against HSV‐1, HCMV and HIV in cell culture.
Synthesis of 6‐quinoxalinyldihydropyrazolo[1,5‐a]pyrimidin‐7‐ones by a ring transformation. Tautomeric structure of dihydropyrazolo[1,5‐a]pyrimidin‐7‐ones in a solution
Authors: Kurasawa Yoshihisa , Kim Ho Sik , Takada Atsushi , Okamoto Yoshihisa 
Published: March 2009

AbstractThe reaction of 3‐(N,N‐dimethylcarbamoyl)furo[2,3‐b]quinoxaline hydrochloride 1 with the 5‐aminopyrazoles 6a‐e gave 6‐quinoxalinyldihydropyrazolo[1,5‐a]pyrimidin‐7‐ones 7a‐e, respectively. Compounds 7a‐e were found to predominate as the 4,7‐dihydro‐7‐oxo form in a solution based on the NOE data.
Polycyclic N‐hetero compounds. XXXVIII. Synthesis and evaluation of antidepressive activity of [1]benzothieno[2′,3′:4,5]furo[3,2‐d]primidines and their precursors
Authors: Sasaki Kenji , Tashima Yohsuke , Nakayama Taiji , Hirota Takashi 
Published: March 2009

AbstractSynthesis of [1]benzothieno[2′,3′:4,5]furo[3,2‐d]pyrimidines is described. Antidepressive evaluation of these compounds and their precursors were screened by inhibitory action of reserpine‐induced hypothermia.
Reaction of 2‐dimethylaminomethylene‐1,3‐diones with dinucleophiles. X. synthesis of 5‐substituted ethyl or methyl 4‐isoxazolecarboxylates and methyl 4‐(2,2‐dimethyl‐1‐oxopropyl)‐5‐isoxazolecarboxylate
Authors: Schenone Pietro , Fossa Paola , Menozzi Giulia 
Published: March 2009

AbstractReaction of ethyl or methyl 2‐dimethylaminomethylene‐3‐oxoalkanoates with hydroxylamine hydrochloride in methanol solution afforded in high yields the relative esters of 5‐substituted 4‐isoxazolecarboxylic acids II. These esters were hydrolyzed generally with concentrated hydrochloric acid‐acetic acid mixtures to the corresponding carboxylic acids in satisfactory yields.Ethyl or methyl esters II isomerized with sodium ethoxide or methoxide, respectively, to the corresponding esters or hemiesters of 2‐cyano‐3‐oxoalkanoic acids generally in excellent to satisfactory yields.Reaction of methyl 5,5‐dimethyl‐3‐dimethylaminomethylene‐2,4‐dioxohexanoate with hydroxylamine hydrochloride afforded in moderate yield methyl 4‐(2,2‐dimethyl‐1‐oxopropyl)‐5‐isoxazolecarboxylate, which was converted by acid hydrolysis as above to 4‐t‐butyl‐4‐hydroxyfuro[3,4‐d]isoxazol‐6‐(4H)‐one.
Triphenodioxazine‐1,8‐dicarboxylic acid as an oxidation product of 3‐hydroxyanthranilic acid
Authors: Hick Larry A. , Manthey Michael K. , Truscott Roger J. W. 
Published: March 2009

AbstractThe oxidation of 3‐hydroxyanthranilic acid (30HA) 1 by aqueous buffered potassium ferricyanide produces a number of coloured compounds. These include cinnabarinic acid 2 (yellow), a p‐quinone dimer 3 (red) and 9‐carboxy‐2‐hydroxy‐3H‐phenoxazin‐3‐one 4 (brown). Also present by tlc is a bright pink compound. The structure of this compound has been demonstrated to be triphenodioxazine‐1,8‐dicarboxylic acid 5a.
Synthesis of novel acyclonucleosides. Reactions of 1‐(1‐bromo or 3‐bromo‐2‐oxopropyl)pyridazin‐6‐ones
Authors: Choi Sam‐Yong , Lee Sang‐Gyeong , Yoon Yong‐Jin 
Published: March 2009

AbstractReaction of 1‐(3‐bromo‐2‐oxopropyl)pyridazin‐6‐ones 1 and 2 with sodium azide at room temperature gave the corresponding 1‐(3‐azido‐2‐oxopropyl)pyridazin‐6‐ones 3 and 4, whereas reaction of 1‐(1‐bromo‐2‐oxo‐propyl)pyridazin‐6‐ones 5 and 6 with excess sodium azide afforded 4‐azido‐5‐chloropyridazin‐6‐one 7 and 4,5‐diazido‐3‐nitropyridazin‐6‐one 8 by dealkylation. Some 1‐(2‐hydroxypropyl)pyridazin‐6‐ones 9, 10, 11 were synthesized from the corresponding 1‐(2‐oxopropyl) derivatives 1, 2, 3. 4,5‐Dichloro‐1‐(2,3‐dihydroxypropyl)‐pyridazin‐6‐one 13 was also prepared from compound 9 via the corresponding 2,3‐epoxypropyl derivative 12. Treatment of compound 5 with thiourea gave 4,5‐dichloro‐1‐(2‐amino‐4‐methylthiazol‐5‐yl)pyridazin‐6‐one 14. Reaction of compounds 1 and 2 with thiourea at 20° afforded the corresponding 3‐formamidinylthio‐2‐oxo‐propyl derivatives 15 and 16, whereas treatment of compound 1 with thiourea at 45° gave 4,5‐dichloro‐1‐[(2‐aminothiazol‐5‐yl)methyl]pyridazin‐6‐one 17. Compound 17 was also prepared from compound 15 by refluxing in ethanol.
Photocyclization reactions. Part 1. Synthesis of dihydrobenzofuranols using photocyclization of 2‐alkoxybenzaldehydes, 2′‐alkoxyacetophenones, 2‐formylphenoxyacetic acids and 2‐acetylphenoxyacetic acids
Authors: Horaguchi Takaaki , Tsukada Chikara , Hasegawa Eietsu , Shimizu Takahachi , Suzuki Tsuneo , Tanemura Kiyoshi 
Published: March 2009

AbstractPhotocyclization reactions were carried out on 2‐alkoxybenzaldehydes 1a‐f, 2′‐alkoxyacetophenones 2a‐h, 2‐formylphenoxyacetic acids 1i‐l and 2‐acetylphenoxyacetic acids 2i‐m. Irradiation of 1a‐f and 2a‐h in acetonitrile gave the corresponding dihydrobenzofuranols 3, 5 and dihydroisobenzofuranols 4, 6. Using carboxylic acids 1i‐1, 2i‐m as starting materials, decarboxylation occurred immediately to give the corresponding ethers 1a‐d, 2a‐e. Further irradiation of the solution afforded dihydrobenzofuranols 3, 5 and dihydroisobenzofuranols 4, 6. Substituent effects on photocyclization and reaction pathways are discussed.
Synthesis of 7,8‐dihydro‐6H‐pyrazolo[3,4‐b]quinolin‐5‐ones and related derivatives
Authors: Gatta Franco , Pomponi Massimo , Marta Maurizio 
Published: March 2009

AbstractThis paper describes the synthesis of a new series of 4‐amino‐1‐(unsubstituted and chloro or fluoro substituted benzyl)‐7,8‐dihydro‐6H‐pyrazolo[3,4‐b]quinolin‐5‐ones 8 and the corresponding 7,8‐dihydro‐6H,9H‐pyrazolo[3,4‐b]quinoline‐4,5‐diones 13. The derivatives obtained by reaction of these compounds with sodium azide in concentrated sulfuric acid are also reported.
Synthesis of novel quino[2,3‐b][1,5]benzodiazepin‐12‐ones
Authors: Rao K. Rama , Bhanumathi N. , Sattur P. B. 
Published: March 2009

AbstractThe synthesis of potentially biologically biologically active quino[2,3‐b][1,5]benzodiazepin‐12‐ones has been reported for the first time by the reaction of 2‐chloroquinoline‐3‐carboxylic acids with o‐phenylenediamine.
Synthesis of novel c‐hetero‐fused thiophene derivatives
Authors: Rangnekar D. W. , Mavlankar S. V. 
Published: March 2009

AbstractAn efficient synthesis of novel 5‐(4‐nitrophenyl)‐2‐benzoxazol‐2‐yl‐c‐hetero‐fused thiophenes was achieved by the condensation of 5‐(4‐nitrophenyl)‐2‐benzoxazol‐2‐yl‐3,4‐dichlorothiophene with ethylene glycol, ethylenediamine, substituted thioamides and 2‐mercaptobenzimidazole using sodium carbonate in refluxing dimethyl formamide.
Furopyridines. XI. 13C NMR Spectra of 2‐ or 3‐Substituted Furo[2,3‐b]‐, Furo[3,2‐b]‐, Furo[2,3‐c]‐ and Furo[3,2‐c]pyridine
Authors: Shiotani Shunsaku , Morita Hiroyuki 
Published: March 2009

AbstractThe 13C nmr spectra of 2‐ or 3‐monosubstituted furo[2,3‐b]‐ 1a‐1j, furo[3,2‐b]‐ 2a‐2j, furo[2,3‐c]‐ 3a‐3j and furo[3,2‐c]pyridine derivatives 4a‐4j are reported. Effects by change in annelation and substituent effects on 13C chemical shifts and carbon‐proton coupling constants are discussed. The spectra of benzo[b]furan derivatives 5a‐5j having the corresponding substituent are also reported for comparison.
A regiospecific synthesis of 8‐Methoxy‐1,2,3,4,5,6‐hexahydro‐1,6‐methano‐3‐benzazocines
Authors: Mazzocchi P. H. , Kordoski E. W. , Harrison A. M. 
Published: March 2009

AbstractA regiospecific synthesis of the 6‐methoxy‐1,2,3,4,5,6‐hexahydro‐1,6‐methano‐3‐benzazocine system is reported.
Synthesis and anticonvulsant activity of 3‐alkyl‐3,4‐dihydro‐2(1H)‐quinazolinones
Authors: Kornet Milton J. 
Published: March 2009

AbstractPreviously we reported the potent anticonvulsant activity of 3‐dimethylamino‐3,4‐dihydro‐2(1H)‐quinazolinone. In this report, a series of 3‐alkyl‐3,4‐dihydro‐2(1H)‐quinazolinones was synthesized in three steps from isatoic anhydrides or an anthranilic acid. Structure/activity investigations revealed optimal activity for the 3‐isopropyl and 3‐cyciohexyl analogs. These compounds were effective against seizures induced by maximal electroshock.
A novel non photochemical ring contraction of 4‐pyrones to cyclopent‐2‐enones
Authors: Jakopčic K. , Kojić J. , Orhanović Z. , Stiplošek Z. , Nagl A. , Hergold A. 
Published: March 2009

AbstractUnlike comenic acid or most other 4‐pyrones, methyl or ethyl comenate reacts with aromatic amines under mild conditions in the sense of ring contraction to 3‐arylamino‐2,4‐dihydroxy‐2‐cyclopentenone‐4‐carboxylates. The structure of the new cyclopentenone derivatives were determined from their characteristic spectroscopic behaviour and was confirmed by X‐ray crystallographic studies of compound Vb.
N‐bis(methylthio)methylene derivatives. 5. New synthesis of 2‐aminoindolizine and related compounds via a formal [3 + 3] cycloaddition reaction using N‐bis(ethoxycarbonylmethylthio)methylenephenylsulfonamides
Authors: Tominaga Yoshinori , Ueda Hiroshi , Ogata Koichiro , Kohra Shinya 
Published: March 2009

AbstractReaction of pyridinium N‐ylide 5a with N‐bis(ethoxycarbonyl)methylthio)(p‐substituted‐phenyl)sulfon‐amides 2a,c in the presence of triethylamine as a base in ethanol gave diethyl 2‐(p‐substituted‐phenylsulfonyl)aminoindolizine‐1,3‐dicarboxylates 9a,b via a new formal [3 + 3] cycloaddition reaction. In a similar manner, 2‐sulfonylaminopyrrolo[2,1‐a]isoquinoline derivatives 11a‐e were also obtained by the reaction of 2a‐c and 4a,b with the corresponding isoquinoline N‐ylides 10a.b with good results.
1,3‐dipolar cycloaddition of nitrile oxides with 2‐phenyl‐4‐ethoxymethylene‐5(4H)‐oxazolone
Authors: Coutouli‐Argyropoulou E. , Thessalonikeos E. 
Published: March 2009

Abstract2‐Phenyl‐4‐ethoxymethylene‐5(4H)‐oxazolone 1 reacts regioselectively with nitrile oxides to give cycloadducts 3. Reactions of the cycloadducts 3 with nucleophiles lead to 4‐aminoisoxazole derivatives.
Research on nitrogen containing heterocyclic compounds. XVIII. Synthesis of 9H‐pyrrolo[2,1‐c]‐s‐triazolo[4,3‐a][1,4]benzodiazepine, a novel tetracyclic ring of pharmaceutical interest
Authors: Stefancich Giorgio , Artico Marino , Silvestri Romano 
Published: March 2009

AbstractReaction of di‐4‐morpholinylphosphinic chloride on 5,10‐dihydro‐9H‐pyrrolo[2,1‐c][1,4]benzodiazepin‐11‐one 9 afforded 11‐(di‐4‐morpholinylphosphinyloxy)‐5H‐pyrrolo[2,1‐c][1,4]benzodiazepine 10. Displacement of di‐4‐morpholinylphosphinyloxy group of 10 by formylhydrazine with concomitant intramolecular cyclization led directly to 9H‐pyrrolo[2,1‐c]‐s‐triazolo[4,3‐a][1,4]benzodiazepine 7, a novel nitrogen heterocyclic ring of pharmaceutical interest. A new procedure for the synthesis of 9 is also described.
Configurational assignments of oximes derived from 5‐formyl and 5‐acyl‐1,2,4‐triazines
Authors: Rykowski Andrzej , Guzik Eliza , Makosza Mieczyslaw , Holzer Wolfgang 
Published: March 2009

AbstractThe configuration of (3‐substituted)‐1,2,4‐triazin‐5‐ylcarbaldoximes and (3‐substituted)alkyl‐1,2,4‐triazin‐5‐ylketoximes was determined by means of 1H‐nmr, 13C‐nmr, 15N‐nmr and homonuclear NOE‐difference spec‐troscopy. Oximes resulting from reaction of 1,2,4‐triazines with nitroalkanes were found to be either pure E‐isomers or E/Z‐mixtures with the amount of E‐isomer greatly predominating. Detailed 13C‐nmr data of the oximes investigated are presented.
Synthesis of 1,2,3,4‐tetraphenyl‐9,10,16,17, 23,24‐hexadodecyloxyphthalocyanine
Authors: Yang Jiang , Rogers Thomas C. , Van De Mark Michael R. 
Published: March 2009

AbstractThe unsymmetrical 1,2,3,4‐tetraphenyl‐9,10,16,17,23,24‐hexadodecyloxyphthalocyanine was synthesized utilizing steric hinderance of a tetraphenyl group to limit substitution.
The photolysis of 1‐(4,5‐dihydro‐1H‐imidazol‐2‐yl)benzotriazole
Authors: Döpp Dietrich , Orlewska Czeslawa , Saczewski Franciszek 
Published: March 2009

Abstract1‐(4,5‐Dihydro‐1H‐imidazolo‐2‐yl)benzotriazole was photolyzed at 254 nm yielding 1,2‐dihydro‐4H‐imidazo‐[1,2‐a]benzimidazole.
Synthesis of 1,6‐dihydro‐5‐hydroxy‐6‐oxo‐3‐(trifluoromethyl)‐4‐pyridazinecarboxylates
Authors: Hegde Shridhar G. , Jones Claude R. 
Published: March 2009

AbstractThe reaction of 2‐(alkylamino)‐3‐(trifluoroacetyl)butenedioates 2a‐b with alkyl and aryl hydrazines in ether provides 1,6‐dihydro‐6‐oxo‐3‐(trifluoromethyl)‐4‐pyridazinecarboxylates as their alkylamine salts 3a‐g. The structures of these products are substantiated using 2D nmr and 15N nmr techniques.
Oxidations of 3,6‐diamino‐1,2,4,5‐tetrazine and 3,6‐bis(s,s‐dimethylsulfilimino)‐1,2,4,5‐tetrazine
Authors: Coburn M. D. , Hiskey M. A. , Lee K.‐Y. , Ott D. G. , Stinecipher M. M. 
Published: March 2009

AbstractOxidation of 3,6‐diamino‐1,2,4,5‐tetrazine (1) with most peracids gave 3,6‐diamino‐1,2,4,5‐tetrazine 1,4‐dioxide (3) as the major product; however, treatment of 1 with peroxytrifluoroacetic acid (PTFA) gave 3,6‐diamino‐1,2,4,5‐tetrazine 1‐oxide (4) as the major product along with a small amount of 3‐amino‐6‐nitro‐1,2,4,5‐tetrazine 2,4‐dioxide (5). Oxidation of 3,6‐bis(S,S‐dimethylsulfilimino)‐1,2,4,5‐tetrazine (6) with 3‐chloroperoxybenzoic acid (MCPBA) gave 3‐S,S‐(dimethylsulfilimino)‐6‐nitroso‐1,2,4,5‐tetrazine (7), which was oxidized further with dimethyldioxirane to 3‐(S,S‐dimethylsulfoximino)‐6‐nitro‐1,2,4,5‐tetrazine (8). All attempts to obtain 3,6‐dinitro‐1,2,4,5‐tetrazine (2) by further oxidation of 7 or 8 failed.
Ring opening reaction of 1,2‐diaryl‐3‐methyl‐1,4,5,6‐tetrahydropyrimidinium salts with metal hydride complexes
Authors: Maso MÓNica Dal , Orelli Liliana , Perillo Isabel A. 
Published: March 2009

AbstractThe reaction of a series of 1,2‐diaryl‐3‐methyl‐1,4,5,6‐tetrahydropyrimidinium iodides 1 with reducing agents acting by hydride ion transfer was studied. With excellent yields alkaline borohydrides readily reacted to form N'‐aryl‐N‐benzyl‐N‐methyltrimethylenediamines 3 by reductive cleavage of the intermediate hexahydropyrimidine 2. Ring opening is explained by the formation of a stabilized iminium ion, which also accounts for the cyclic aminal 2 hydrolysis observed in alcoholic solution after gradual addition of borohydride. Reactions with lithium aluminum hydride or with borane failed to render satisfactory results due to insolubility of the salt in solvents commonly employed. Comparisons are made with the behaviour of 1H‐4,5‐dihydroimidazolium salts which were studied in an earlier paper.
Synthesis of (‐)(s)‐2‐hydroxymethyl‐2,3‐dihydro‐1,4‐benzodioxine by enzyme‐catalyzed resolution in organic media
Authors: Mauleón David , Lobato Cinta , Carganico Germano 
Published: March 2009

AbstractThe chiral primary alcohol 2‐hydroxymethyl‐2,3‐dihydro‐1,4‐benzodioxine (1) has been resolved by enantioselective acetylation in vinyl acetate solution, using Pseudomonas sp. Amano PS lipase. Enantiomers (‐)‐S1 (99% ee) and (+)‐R‐1 (72% ee) were obtained in 45 and 65% yield, respectively.
Schmidt rearrangement of 1,2,3,5,10,10a‐hexahydropyrrolo[1,2‐b]‐isoquinoline‐3,10‐diones
Authors: Mérour Jean‐Yves , Cossais FranÇOise , Piroëlle Simone , Mazéas Daniel 
Published: March 2009

AbstractThe Schmidt rearrangement of 1,2,3,5,10,10a‐hexahydropyrrolo[1,2‐b]isoquinoline‐3,10‐diones has been studied. The structure of the lactams obtained has been determined by chemical reactivity and characterized by means of ir, 1H and 13C nmr spectroscopy.
Synthesis of thieno[3,2‐d]pyrimidine‐2,4‐diones cyclic and acyclic nucleosides as potential anti HIV agents
Authors: Jourdan Fabrice , Ladurée Daniel , Robba Max 
Published: March 2009

AbstractSynthesis of cyclic and acyclic nucleosides was achieved by alkylation of 7‐methyl or arylthieno[3,2‐d]‐pyrimidine‐2,4‐diones following the Vorbrüggen and Niedballa's method [1]. After a possible deprotection, potential anti HIV agents were obtained.
Angular to linear rearrangement of an isoindolo[2,1‐a]quinazoline skeleton
Authors: Guillaumel Jean , Demerseman Pierre 
Published: March 2009

AbstractDemethylation of the angular 3‐methoxyisoindolo[2,1‐a]quinazolin‐11(5H)‐one by pyridinium chloride led to the rearranged linear 8‐hydroxyisoindolo[1,2‐b]quinazolin‐12(10H)‐one.
Reactivity of 1‐(2‐nitrophenyl)‐5‐aminopyrazoles under basic conditions and synthesis of new 3‐, 7‐, and 8‐substituted pyrazolo[5,1‐c][1,2,4]benzotriazine 5‐oxides, as benzodiazepine receptor ligands
Authors: Costanzo Annarella , Guerrini Gabriella , Bruni Fabrizio , Selleri Silvia 
Published: March 2009

AbstractThe reaction of 1‐(2‐nitrophenyl)‐5‐aminopyrazoles under basic conditions has been reinvestigated and the structures of the obtained pyrazolo[5,1‐c][1,2,4]benzotriazine 5‐oxides confirmed by spectroscopic means. In particular the different aromatic nucleophilic attack on 8‐chloro derivatives 4a and 6a and 7‐nitro derivatives 11a and 12a was determined. From these latter compounds unexpected (phenyl‐ONN‐azoxy)pyrazoles were isolated.
A simple procedure for the synthesis of 3‐(substituted‐sulfanyl)‐4‐hydroxy‐6‐substituted‐pyran‐2‐ones
Authors: Para K. S. , Ellsworth E. L. , Prasad J. V. N. Vara 
Published: March 2009

AbstractA series of 3‐(substituted sulfanyl)‐4‐hydroxy‐6‐substituted‐pyran‐2‐ones were synthesized for Human immunodeficiency virus‐1 protease inhibition. These compounds were synthesized in a simple and convergent fashion to allow us a rapid preparation of many structurally diversified analogues. Thus the condensation of trimethylsilyl enol ethers of corresponding ketones, with 2‐(S‐substituted)propane‐1,3‐dioates afforded the corresponding pyrones in 24–70% isolated yields.
The synthesis of biologically relevant 4(5)‐phosphono‐5(4)‐aminoimidazoles using a Pd‐catalyzed coupling reaction
Authors: Lin Jing , Thompson Charles M. 
Published: March 2009

AbstractRegiochemically defined 1‐benzyl‐4‐phosphono‐5‐carboalkoxyimidazoles were synthesized from the corresponding 4‐bromoimidazoles using a tetrakis(triphenylphosphine)palladium(0)‐catalyzed coupling reaction with diethyl phosphite. The corresponding Michaelis‐Arbusov reaction failed to give a phospho‐nylated product. The carbomethoxy moiety was converted to an amino group using a Curtius rearrangement to afford 1‐benzyl‐4‐phosphono‐5‐amino‐imidazoles. Following deprotection and hydrolysis, phos‐phonic acid‐linked aminoimidazoles were accessed that resemble intermediates formed during purine biosynthesis.
Synthesis of 2,3‐dihydropyrazolo[5,1‐b]thiazoles via a tandem condensation sulfur‐extrusion reaction
Authors: Hanefeld Wolfgang , Schlitzer Martin 
Published: March 2009

Abstract2,3‐Dihydropyrazolo[5,1‐b]thiazoles 3 are the first representatives of a heterocyclic system, which are conveniently prepared by heating 3‐aminorhodanines 1 with ethyl 2‐bromo‐3,3‐diethoxypropionate (2), via a tandem condensation‐sulfur extrusion reaction.