bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amine‐induced rearrangements of 2‐bromo‐1‐(1H‐indol‐3‐yl)‐2‐methyl‐1‐propanones: A new route to α‐substituted indole‐3‐acetamides, β‐substituted tryptamines, α‐substituted indole‐3‐acetic acids and indole β‐aminoketones
Authors: Sanchez Joseph P. , Parcell Robert F. 
Published: March 2009

AbstractThe reaction of 2‐bromo‐1‐(1H‐indol‐3‐yl)‐2‐methyl‐1‐propanone (1) and 2‐bromo‐1‐(1‐methyl‐1H‐indol‐3‐yl)‐2‐methyl‐1‐propanone (2) with primary amines proceeds in good yields to produce rearranged amides by a proposed pseudo‐Favorskii mechanism. These amides in turn can either be reduced to produce β‐substituted tryptamines or hydrolyzed to produce substituted indole‐3‐acetic acids. When the reaction is carried out using bulky primary or secondary amines, β‐aminoketones are produced by elimination of hydrogen bromide followed by Michael addition. When hindered secondary amines or tertiary amines are used, elimination to the α,β‐unsaturated ketones occurs.
Synthesis of 5‐methyl‐4‐oxo‐quinolinecarboxylic acids
Authors: Hagen Susan E. , Domagala John M. 
Published: March 2009

AbstractA series of 5‐methyl‐4‐oxo‐3‐quinolinecarboxylic acids was prepared in which the eight‐position was substituted with fluorine, chlorine, methyl, or hydrogen. These quinolones were synthesized from the appropriate 2‐methyl‐3,4,6‐trifluorobenzoic acids which were derived from oxazolines 8 and 16. The oxazoline moiety served as both an ortho‐director (where feasible) and a protecting group; a trimethylsilyl moiety was used to block the most acidic site in the molecule.
An improved synthesis of 5,15‐diaryloctaalkylporphyrins
Authors: Osuka Atsuhiro , Nagata Toshi , Kobayashi Fumikazu , Maruyama Kazuhiro 
Published: March 2009

AbstractThe title compounds were prepared from an aromatic aldehyde and bis(3‐ethyl‐4‐methyl‐2‐pyrrolyl)‐methane in acetonitrile in the presence of catalytic amount of trichloroacetic acid, followed by p‐chloranil oxidation. The reaction conditions employed here are milder than those previously reported, allowing efficient preparation of porphyrins with acid‐labile groups such as cyclic acetals, for which the previous method provided no direct synthetic access. Using the new method, aromatic aldehydes with acid‐labile groups, as well as sterically hindered aldehydes, gave the corresponding porphyrins in satisfactory yields (50–90%). This method therefore can be widely utilized for synthesis of 5,15‐diaryloctaalkylporphyrins.
Synthesis, stereochemistry and conformational properties of diastereomeric cyclic dipeptides containing tetrahydro‐1,4‐thiazine‐3,5‐dicarboxylic acid
Authors: Paradisi Mario Paglialunga , Zecchini Giampiero Pagani , Torrini Ines , Lucente Gino 
Published: March 2009

AbstractThe synthesis of linear dipeptides containing N‐protected L‐phenylalanine and (3R‐cis)‐tetrahydro‐1,4‐thiazine‐3,5‐dicarboxylic acid dialkyl diester residues is described. N‐Deprotection of these dipeptides by hydrogenolysis on palladium afforded directly a mixture of cis and trans dioxopiperazines. The stereochemistry and the solution conformational properties of the cyclic dipeptides are determined.
Preparation of pyrazolo[5,1‐c][1,4]benzoxazines by intramolecular [3+ + 2] cycloaddition reaction of hydrazonium chlorides with alkenes
Authors: Shimizu Tomio , Hayashi Yoshiyuki , Miki Masayuki , Teramura Kazuhiro 
Published: March 2009

AbstractPyrazolo[5,1‐c][1,4]benzoxazines were prepared by the reaction of 2‐(allyloxy)phenylhydrazine with arylaldehydes in the presence of hydrochloric acid. The formation of the fused heterocycles can be explained by intramolecular 1,3‐dipolar cycloaddition reaction of cationic dipole, i.e‥, hydrazonium chlorides.
Derivation of fluorine‐containing pyridine dicarboxylates IV. N‐substituted dihydropyridine derivatives
Authors: Chupp John P. 
Published: March 2009

AbstractThe bio‐activity observed for certain Hantzsch derived fluorine‐containing dihydropyridinecarboxylates 6, 11 and 12 and pyridinecarboxylates 10 prompted the preparation of a number of related N‐substituted dihydropyridines for the first time. One method involved a mixed Hantzsch sequence to give 2 from which unexpected side products 3–5 were also isolated and identified. A second preparative method relied on lithiobase deprotonation of 6, 11 and 12 followed by alkylation or acylation to give products 7–9 and 13–15. Structure determination and stereo‐assignments are discussed in terms of their spectral properties, and reaction mode.
Synthesis and single‐crystal X‐ray diffraction analysis of 2‐sulfamoyladenosine (6‐amino‐9‐β‐D‐ribofuranosylpurine‐2‐sulfonamide)
Authors: Hanna Naeem B. , Larson Steven B. , Robins Roland K. , Revankar Ganapathi R. 
Published: March 2009

Abstract2‐Amino‐9‐β‐D‐ribofuranosylpurine‐2‐sulfonamide (2‐sulfamoyladenosine, 4), a congener of sulfonosine (3), was synthesized by four different routes. Acid catalyzed fusion of 6‐chloropurine‐2‐sulfonyl fluoride (5) with 1,2,3,5‐tetra‐O‐acetyl‐β‐D‐ribofuranose (8) gave a good yield of 6‐chloro‐9‐(2,3,5‐tri‐O‐acetyl‐β‐D‐ribofuranosyl)purine‐2‐sulfonyl fluoride (9). Ammonolysis of 9 furnished 4. Lewis acid catalyzed glycosylation of the trimethylsilyl derivative of either 6‐chloropurine‐2‐sulfonamide (6) or 6‐aminopurine‐2‐sulfonamide (7) with 8 gave the corresponding N9‐glycosylated products, 10 and 11, respectively, which on ammonolysis gave 4. Amination of 2‐thioadenosine (12) with chloramine solution gave the sulfenamide derivative 13, which on subsequent oxidation with m‐chloroperoxybenzoic acid furnished an alternate route to 4. The structure of 4 was established by single‐crystal X‐ray diffraction studies. 2‐Sulfamoyladenosine (4) is devoid of significant inhibitory activity against L1210 leukemia in mice.
The reaction of amines with isoflavones. 2.. Formation of phenolic sulphonamidopyrimidines
Authors: Olugbade T. A. , Usifoh C. O. , Oluwadiya J. O. , Reisch J. 
Published: March 2009

AbstractIsoflavones in alkaline dimethylsulphoxide at 100° under a nitrogen atmosphere reacted with sulphaguanidine to give phenolic sulphonamidopyrimidines.
Synthesis of the penta‐glutamyl derivative of N‐[4‐[N‐[3‐(2,4‐diamino‐1,6‐dihydro‐6‐oxo‐5‐pyrimidinyl)‐propyl]amino]benzoyl]‐L‐glutamic acid (5‐DACTHF). An acyclic analogue of tetrahydrofolic acid
Authors: Styles Virgil L. , Kelley James L. 
Published: March 2009

AbstractThe penta‐glutamyl derivative of N‐[4‐[N‐[3‐(2,4‐diamino‐1,6‐dihydro‐6‐oxo‐5‐pyrimidinyl)propyl]amino]‐benzoyl)‐L‐glutamic acid (1, 5‐DACTHF, 543U76) was synthesized by a convergent route. L‐γ‐Glutamyl‐L‐γ‐glutamyl‐L‐γ‐glutamyl‐L‐γ‐glutamyl‐L‐γ‐glutamyl‐L‐glutamic acid heptakis t‐butyl ester (20) was prepared in ten steps from L‐glutamic acid di‐t‐butyl ester and N‐(benzyloxycarbonyl)‐L‐glutamic acid α‐t‐butyl ester. 4‐[N‐[3‐(2,4‐Diamino‐1,6‐dihydro‐6‐oxo‐5‐pyrimidinyl)propyl]trifluoroacetamido]benzoic acid (6), which was synthesized from pyrimidinylpropionaldehyde 3 in three steps, was condensed with 20, followed by deprotection to provide N‐[4‐[N‐[3‐(2,4‐diamino‐1,6‐dihydro‐6‐oxo‐5‐pyrimidinyl)propyl]amino]benzoyl]‐L‐γ‐glutamyl‐L‐γ‐glutamyl‐L‐γ‐glutamyl‐L‐γ‐glutamyl‐L‐γ‐glutamyl‐L‐glutamic acid (2). Hexaglutamate 2 is a potent inhibitor of glycinamide ribonucleotide transformylase.
Synthesis of 6‐[[(hydroxyimino)phenyl]methyl]‐1‐[(1‐methylethyl)sulfonyl]‐1H‐imidazo[4,5‐b]pyridin‐2‐amine. An aza analogue of enviroxime
Authors: Kelley James L. , Mclean Ed W. , Davis Ronda G. , Crouch Ronald 
Published: March 2009

Abstract6‐[[(Hydroxyimino)phenyl]methyl]‐1‐[(1‐methylethyl)sulfonyl]‐1H‐imidazo[4,5‐b]pyridin‐2‐amine (1), an aza analogue of enviroxime, was synthesized in eight steps from 6‐hydroxynicotinic acid (2). Acid 2 was nitrated, chlorinated with phosphorus pentachloride, and subjected to Friedel‐Crafts aroylation to give 6‐chloro‐5‐nitro‐3‐pyridyl phenyl ketone (5). Amination of 5 was followed by reduction of the nitro group and condensation with ethoxycarbonylisothiocyanate to give 6‐benzyl‐2‐ethoxycarbonylamino‐1H‐imidazo[4,5‐d]pyridine (8). The ethoxycarbonyl moiety of 8 was cleaved, N‐1 was isopropylsulfonylated, and the carbonyl moiety was condensed with hydroxylamine to give 1. Compound 1 was inactive against rhinovirus 1B and poliovirus type 1.
Synthesis of 7‐alkyl‐2,4‐dimethoxy‐5‐oxo‐5H‐pyrano[4,3‐d]pyrimidines
Authors: Wada Akimori , Kanatomo Shōchi 
Published: March 2009

AbstractA convenient synthesis of 7‐alkyl‐2,4‐dimethoxy‐5‐oxo‐5H‐pyrano[4,3‐d]pyrimidines from methyl 2,4‐dimethoxy‐6‐phenylselenylmethyl (or 6‐phenylthiomethyl)‐5‐pyrimidinecarboxylate with alkylaldehydes is described.
Régiospécificit de l'action des arylnitriloxydes sur la 4‐cyano 1‐methyl 1,4‐dihydro quinoline
Authors: Soufiaoui M. , Jazouli H. 
Published: March 2009

AbstractLes réactions de cycloaddition dipolaires‐1,3 des arylnitriloxydes sur la 4‐cyano 1‐méthyl 1,2‐dihydro quinoline sont régiospécifiques. La structure des cycloadduits est démontrée par rmn du proton et du carbone‐13.
Synthesis of 3‐(1,5‐diphenyl‐3‐pyrazolyl)aryl propanoates
Authors: Murray William V. , Hadden Susan K. , Wachter Michael P. 
Published: March 2009

AbstractNew procedures for the synthesis of 3‐(1,5‐diphenyl‐3‐pyrazolyl)aryl propanoates and related 2‐(1,5‐diphenyl‐3‐pyrazolyl)aryl propanoates from a common 3‐hydroxymethylpyrazole intermediate are described. These new procedures include an improved method for carrying out pyridinium chlorochromate oxidations under ultrasonic conditions. These syntheses also utilize lithium triethylphosphonoacetate formed from n‐butyllithium and triethylphosphonoacetate as a Wittig‐Horner reagent to improve olefination yields.
Etude des conditions D'accés aux 6,11‐dihydro‐5H‐pyrimidino[4,5‐a]carbazoles
Authors: Gazengel Jean‐Marie , Lancelot Jean‐Charles , Rault Sylvain , Robba Max 
Published: March 2009

AbstractLes tétrahydrocarbazolones 15‐27 sont obtenues par cyclisation des phénylhydrazones 2‐14. La cyclisation de ces carbazolones 15‐27 qui est opérée au moyen du triformarnidométhane dans le formamide fournit les dihydropyrimidinocarbazoles 28‐40. Les spectres de rmn enregistrés dans le DMSO‐d6 confirment la structure des dérivés obtenus.
Chemistry of condensed thiophenes. IV. Acetylation of phenanthro[4,5‐bcd]thiophene
Authors: Klemm L. H. , Lam Lee , Severns Bryon , Sur Sandip K. 
Published: March 2009

AbstractTreatment of phenanthro[4,5‐bcd]thiophene (2) with acetyl chloride and aluminum chloride in nitrobenzene gives acetylation of positions ortho and para to the heteroatomic sulfur atom. In separate experiments, mixtures of 1‐ and 3‐acetyl (50% yield, ratio 1.9:1) or of 1,5‐, 1,7‐, and 3,5‐diacetyl (79% yield, ratio 3:1:1) derivatives were obtained. Isolated as isomerically pure products were the 1‐acetyl and the 1,5‐diacetyl compounds, as well as the oximes of the 1‐ and 3‐acetyl derivatives. Comparison of these results is made with those reported for nitration of 2, which also occurs ortho and para to the sulfur atom, and with nitration and acetylation of pyrene (the benzolog of 2) which substitutes in the corresponding positions.
1,3‐Dipolar cycloaddition reactions of 1,4‐benzoquinones with nitrilimines
Authors: Argyropoulos N. G. , Mentzafos D. , Terzis A. 
Published: March 2009

AbstractThe cycloaddition reactions of some aryl conjugated p‐benzoquinones with nitrilimines were studied. Depending upon the reaction conditions mono‐ and/or bis‐ adducts were isolated only from carbon‐carbon double bond. The structure determination was unequivocally established by an X‐ray analysis carried out on a bis‐adduct. The observed regio‐, as well as site‐selectivity, was qualitatively correlated with frontier molecular orbitals of the reacting species.
Heterocycles. XXV Sodium borohydride reduction of flavanonols
Authors: Li Shaoshun , Onda Masayuki , Kagawa Hitoshi , Kawase Hiromi , Iguchi Mieko , Harigaya Yoshihiro 
Published: March 2009

AbstractSolvent effects on the stereochemistry in the sodium borohydride reduction of (±)‐flavanonols have been examined. The effects observed for the (±)‐flavanonols with 5‐OMe in 2‐propanol, dioxane and methanol are explainable by the differences between the steric interactions inherent in the product‐like transition states A and B. It has been also found that 5‐OAc peculiarly affects the stereochemistry in the reduction to produce the (±)‐catechin‐type compounds in a one‐pot process. The solvent and temperature effects are examined using a model analogous to the above.
Cyclopropyl‐substituted pyrylium salts
Authors: Fǎrcaşiu Dan , Kizirian Mark 
Published: March 2009

AbstractThe previously unknown 2,4,6‐trisubstituted pyrylium salts 1‐4, carrying cyclopropyl and methyl or phenyl substituents in the same molecule, and 5‐8, substituted with isopropyl groups instead of cyclopropyl, were synthesized as perchlorates. The electronic spectra and the C‐13 nmr spectra of the two groups of compounds were compared. A cyclopropyl group has a batochromic effect on the electronic spectrum roughly half that exerted by a phenyl; replacement of an alkyl by a cyclopropyl shifts the highest wavelength absorption band by about 20 nm. Presence of phenyl substituents reduces the batochromic effects of cyclopropyl substituents. The effects of both cyclopropyl and phenyl substituents on the electronic spectra are smaller for pyrylium than for tropylium. The nmr signals for all the ring carbons are shifted upfield upon replacement of isopropyl by cyclopropyl; in particular, the effect of substituents in position 2 upon the chemical shift of C(4) indicates that the electron‐releasing effect varies in the series alkyl < phenyl < cyclopropyl, in agreement with the findings for 2,6‐disubstituted pyrylium salts. The difference between the chemical shifts for the methine and methylene carbons of the three‐membered ring is a function of the electron demand of the cationic heterocycle.
The synthesis of difluoro[1]benzothieno[2,3‐c]quinolines and their N‐methyl quaternary salts
Authors: Luo Jiann‐Kuan , Castle Steven L. , Castle Raymond N. 
Published: March 2009

AbstractA series of difluoro[1]benzothieno[2,3‐c]quinolines has been prepared by photocyclization of the appropriate carboxamides. The lactams obtained were converted into the corresponding chloro derivatives which were catalytically dechlorinated into the difluoro[1] benzothieno[2,3‐c]quinolines. The latter compounds were transformed into the N‐methyl quaternary salts.
Synthesis and In vitro biological activity of some 7‐(5‐aminomethyl‐2‐isoxazolidinyl)quinolone‐3‐carboxylic acids
Authors: Ziegler Carl B. , Kuck Nydia A. , Strohmeyer Timothy W. , Lin Yang‐I 
Published: March 2009

AbstractThe synthesis of the title compounds via nitrone cycloaddition is described. The in vitro antibacterial activity of these compounds is compared against 1‐ethyl‐6,8‐difluoro‐7‐[3‐[(ethylamino)methyl]‐1‐pyrrolidinyl]‐1,4‐dihydro‐4‐oxoquinoline‐3‐carboxylic acid (CI‐934).
Synthetic route to 4‐(2‐aminoethyl)‐5‐hydroxyindole derivatives
Authors: Cannon Joseph G. , Roufos Ioannis 
Published: March 2009

AbstractIn synthetic studies leading to the title compounds, application of the Claisen rearrangement of 5‐allyloxyindole was investigated. Almost quantitative yields of Claisen rearrangement product were realized, and a strategy for oxidative cleavage of the allyl double bond to an indole‐4‐acetaldehyde derivative was developed. A new method for conversion of 2,3‐dihydroindoles into indoles was utilized: air oxidation in a strongly basic environment. The Claisen rearrangement of allyloxyindoles is presented as a method having considerable potential utility in synthesis of a variety of polysubstituted indoles.
1,3‐Dipolar cycloaddition reactions of 4‐arylidene‐2‐phenyl‐1,4‐dihydroimidazol‐5‐ones with nitrile oxides
Authors: Argyropoulos N. G. , Coutouli‐Argyropoulou E. , Siacavara C. 
Published: March 2009

AbstractStable nitrile oxides add regioselectively to the carbon‐carbon double bond of 4‐arylidene‐2‐phenyl‐1,4‐dihydroimidazol‐5‐ones to afford spiro isoxazolines 3. Compounds 3 are further hydrolysed to isoxazole derivatives.
Reaction of reissert anion with aldimines: A new approach to the imidazo[5,1‐α]isoquinoline ring system
Authors: Kant Joydeep 
Published: March 2009

AbstractThe carbanion derived from N‐alkoxycarbonyl Reissert compound readily undergoes addition‐cyclization reaction with aldimines to give imidazo[5,1‐a]isoquinolines. A detailed study of this new ring annelation chemistry is described.
Synthetic entries to 6‐fluoro‐7‐substituted indole derivatives
Authors: Mckittrick Brian , Failli Amedeo , Steffan Robert J. , Soll Richard M. , Hughes Philip , Schmid Jean , Asselin Andre A. , Shaw C. C. , Noureldin R. , Gavin G. 
Published: March 2009

AbstractThree practical synthetic entries of functionalized 6‐fluoro‐7‐substituted indole derivatives were developed in connection with the preparation of 7‐fluoro‐8‐substituted‐1,3,4,9‐tetrahydropyrano[3,4‐b]indole‐1‐acetic acid derivatives 11. The first route, which permits group modification about position 8 of the pyranoindole skeleton, employs 2‐bromo‐3‐fluoroaniline (18) as a key intermediate, the preparation of which was achieved by either a novel ortho metalation of 15 or via the intermediacy of 22. The second route utilizes 32 to append a terminally functionalized three carbon side chain onto the indole template and in addition leads to 43 from 40. The third route to the 7‐fluoro‐8‐substituted‐pyranoindole skeleton complements route two in that the synthetic pathway exploits 32 in a nucleophilic fashion to construct a terminally functionalized two carbon appendage onto the indole nucleus.
Synthesis and stereochemistry of the (9S,13S,14S)‐3‐hydroxy‐17‐methylmorphinan‐10‐ols
Authors: Mohacsi Erno , O'Brien Jay P. 
Published: March 2009

AbstractO‐Demethylation of (9S,13S,14S)‐3‐methoxy‐17‐methylmorphinan‐10‐one (2) to (9S,13S,14S)‐3‐hydroxy‐17‐methylmorphinan‐10‐one (3) and reduction of 3 to 10α‐ and 10β‐hydroxylated morphinans 4 and 5, are described. The stereochemistry of these epimeric alcohols was established on the bases of 1H nmr data.
The synthesis of two benzo[c:d′]diisothiazoles
Authors: Mckinnon David M. , Abouzeid Azza 
Published: March 2009

AbstractTwo benzo[c:d']diisothiazoles, 8‐methylbenzo[1,2‐c:5,6‐d']diisothiazole and 3‐methylbenzo[1,2‐c:6,5‐d']diisothiazole, have been made by reaction of appropriate aminomethyl‐1,2‐benzisothiazoles with N‐sulfinylmeth‐anesulfonamide.
Synthesis of a proposed isomer of F420 having α‐glutamyl bonding
Authors: Kimachi Tetsutaro , Tanaka Kiyoshi , Yoneda Fumio 
Published: March 2009

AbstractA proposed isomer of redox coenzyme F420, having αglutamyl bonding, has been synthesized from 8‐benzyloxy‐10‐D‐ribityl‐5‐deazaflavin and α‐L‐glutamyl‐L‐glutamic acid moiety, by the phosphite triester approach followed by deprotection procedures.
Regio‐ and stereochemistry of the photo‐ring contraction of 4‐pyrones
Authors: Pavlik James W. , Kirincich Steven J. , Pires Richard M. 
Published: March 2009

AbstractIrradiation of 2‐ethyl‐3‐methyl‐4‐pyrone 3 in aqueous solution led to the formation of trans‐4‐ethyl‐5‐methy‐4,5‐dihydroxycyclopent‐2‐enone 4 and trans‐2‐methyl‐3‐ethyl‐4,5‐dihydroxycyclopent‐2‐enone 5. In the latter case 1H nmr analysis confirmed the trans‐configuration at C4 and C5. These results are consistent with trapping of a photochemically generated oxabicyclohexenyl zwitterion by nucleophilic attack of both sides of the oxyally system along a path anti to the epoxide ring.
A novel synthesis of 2‐arylaminothiazolo[4,5‐d]pyridazinones
Authors: Yamasaki Tetsuo , Kawaminami Eiji , Uchimura Fumi , Okawara Tadashi , Furukawa Mitsuru 
Published: March 2009

AbstractThe reaction of 5(4)‐amino‐4(5)‐chloropyridazin‐3(2H)‐ones 1 (9) with methyl dithiocarbamates 2 gave 2‐arylaminothiazolo[4,5‐d]pyridazinones 3 (10). Treatment of 5(4)‐alkylamino‐4(5)‐chloropyridazin‐3(2H)‐ones 5 (12) with 2 afforded the corresponding 2‐aryliminothiazolo[4,5‐d]pyridazinones 6 (13). Cyclization of 1a with phenylisothiocyanate produced 2‐amino‐ and 2‐iminothiazolo[4,5‐d]pyridazinones 3a and 16.
Diels‐alder reactions of methyl‐ and π‐acceptor‐substituted 2‐vinylindoles with dimethyl acetylenedicarboxylate and tetracyanoethylene: Novel functionalized carbazoles
Authors: Pindur Ulf , Eitel Manfred 
Published: March 2009

AbstractThe Diels‐Alder reactions of the 2‐vinylindoles 1a‐1d, which are now readily accessible, with dimethyl acetylenedicarboxylate and tetracyanoethylene give rise to the novel 1,2‐dihydro‐ and 1,2,3,4‐tetrahydrocarbazoles 2, 4, and 5 as well as the fully aromatized carbazoles 3. With regard to the product spectrum, the mechanistic rationale comprises a Diels‐Alder step, formal 1,3‐hydrogen shift, ene reaction, and dehydrogenation. Conformational aspects of the 1,2‐dihydrocarbazoles 2b and 2c are also discussed.
Synthesis of 10‐thia‐5‐deazafolic acid and 2‐desamino‐2‐oxo‐10‐thia‐5‐deazafolic acid
Authors: Singh Shyam K. , Hynes John B. 
Published: March 2009

AbstractThe folate analogue, 10‐thia‐5‐deazafolic acid, was obtained via a multistep synthetic sequence beginning with the known intermediate, 2,4‐diaminopyrido[2,3‐d]pyrirnidine‐6‐carboxaldehyde. Reduction of this aldehyde with sodium borohydride gave 2,4‐diamino‐6‐(hydroxymethyl)pyrido[2,3‐d]pyrimidine, which when heated in base gave 2‐amino‐3,4‐dihydro‐6‐(hydroxymethyl)‐4‐oxopyrido[2,3‐d]pyrimidine. Treatment of the latter compound with phosphorus tribromide in tetrahydrofuran afforded 2‐amino‐6‐(bromomethyl)‐3,4‐dihydro‐4‐oxopyrido[2,3‐d]pyrimidine, thus constituting the first successful synthesis of this elusive intermediate. The aforementioned bromomethyl compound reacted smoothly with the sodium salt of ethyl 4‐mercaptobenzoate, and the resulting ester was saponified to give 10‐thia‐5‐deazapteroic acid. Conventional peptide bond coupling to di‐tert‐butyl L‐glutamate followed by treatment with trifluoroacetic acid afforded the target compound in respectable yield. Attempts to prepare its 5,6,7,8‐tetrahydro derivative by catalytic hydrogenation were unsuccessful.
Synthesis of 4‐phenyl‐2h‐benzopyrans
Authors: Jurd Leonard 
Published: March 2009

AbstractSesamol and other phenols react with equimolar quantities of cinnamaldehyde and morpholine in methanol to yield epimeric 2‐morpholinyl‐4‐phenylbenzopyran derivatives, which are useful intermediates for the synthesis of alcoholic neoflavanoid (4‐phenylbenzopyran) compounds.
Benzimidazole condensed ring systems. 7. An entry to substituted 1h,6h‐2,6a,10b‐triazafluoranthene‐1,3,6‐(2h)‐triones and related systems as possible chemotherapeutic agents
Authors: Badawey El‐Sayed A. M. , Kappe Thomas 
Published: March 2009

AbstractThe syntheses of some derivatives of three new benzimidazole condensed ring systems; namely, 1H,6H‐2,6a,10b‐triazafluoranthene‐1,3,6(2H)‐trione (3), 1H,8H,11H‐12‐oxa‐2,3a,7b‐triazabenz[e]acephenanthrylene‐1,3,8,11(2H)‐tetrone (4) and 1H,4H‐2,5,6a,10b‐tetrazafluoranthene‐1,3,4,6(2H,5H)‐tetrone (10) are described. Two compounds exhibited in vitro antibacterial activity. Four compounds were screened for in vitro anti‐HIV activity and three compounds were evaluated for antileukemic potency but were inactive.
An unusual labilization of a 4‐(trifluoromethyl)thiazole
Authors: South Michael S. 
Published: March 2009

AbstractN‐Chloro‐4‐(trifluoromethyl)‐5‐thiazolyl‐N',N'‐diethylurea 5 has been found to undergo a facile labilization of the trifluoromethyl group under mild conditions. The reaction relies on the assistance of the nitrogen substitution at the 4‐position of the thiazole ring. Treatment of 5 with triethylamine and either methanol or methanethiol replaced the trifluoromethyl group with a methyl ester or a trimethylorthothio ester respectively at room temperature. Combination of 5 with diethylamine led to an unusual thiazolidine with two exocyclic double bonds, 8.
α‐Hydroxyacylation of pyridine
Authors: Sliwa Henri , Randria‐Raharimanana Clarisse , Cordonnier Guy 
Published: March 2009

AbstractEfficient synthesis of 2‐α‐hydroxyacylpyridines 10 starting from pyridine N‐oxide and 2‐bromoaldehydes via base‐induced rearrangement of the resulting N‐alkoxypyridinium salts 6 is described.