bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Some Potentially Bioactive Compounds From Visnaginone
Authors: Abdel Hafez O.  M. , Ahmed Kh.  M. , Haggag E.  E.
Published: October 2008

The reaction of 5-acetyl-6-hydroxy-4-methoxybenzo[b]furan (visnaginone Ia) with 2-diethylaminoethylchloride led to the formation of 5-acetyl-6-diethylamino-ethoxy-4-methoxybenzo[b]furan (II), whereas condensation of compound II with some aromatic aldehydes afforded the corresponding chalcones IIIa-c. Methylation of visnaginone (Ia) gave 5-acetyl-4,6-dimethoxybenzo[b]furan (Ib), which in turn reacted with some aromatic aldehydes to give the corresponding chalcones IIId,e. The reaction of chalcones IIId,e with hydrazine hydrate in alcohol gave the pyrazoline derivatives IVa,b, whereas when the same reaction was carried out in acetic acid it afforded the N-acetylpyrazoline derivatives Va,b. Similarly, the reaction of IIId,e with phenyl hydrazine in acetic acid led to the formation of phenylpyrazoline derivatives VIa,b, whereas condensation of chalcones IIId,e with hydroxyl amine hydrochloride gave the isoxazoline derivatives VIIa,b. The reaction of compound II with phenylhydrazine and 2,4,6-trichlorophenylhydrazine afforded the corresponding phenyl hydrazone derivatives VIIIa,b. Mannich bases IXa,b were synthesized by the reaction of visnaginone (Ia) with piperidine and benzylamine in the presence of formaline.
Bis-Porphyrin Racks with Space-Separated Co-Planar Porphyrin Rings
Authors: Johnston Martin  R.
Published: October 2008

A porphyrin appended norbornenyl building block 8 has been isolated and coupled, using a 1,3-dipolar ACE reaction, to yield bis-porphyrin compounds in which the porphyrin moietes are angled upward relative to the norbornane backbone.
Synthesis and Characterization of Two New p-tert-Butylcalix[4]-arene Schiff Bases
Authors: Alemi Abdol  Ali , Shaabani Behrouz , Dilmaghani Karim  Akbari , Ganjali Saeed  Taghvaee
Published: October 2008

Synthesis and characterization of two new Schiff bases of p-tertbuthylcalix[4]arene (H2L1 and HL2) is described. The synthesis of H2L1 and HL2 has been achieved by the condensation of salicylaldehyde with the amine group of upper rim monoamine p-tert-butylcalix[4]arene in ethanol. These compounds have been characterized on the basis of elemental analysis and spectral data. Solvatochromicity and fluorescence properties were observed and measured for H2L1 and HL2. Solvatochromicity of these ligands indicates their potential for NLO applications.
On the Additions of Lithium Methyl p-Tolyl Sulfoxide to N-(PMP)Arylaldimines
Authors: Zucca Cristina , Bravo Pierfrancesco , Corradi Eleonora , Meille Stefano  V. , Volonterio Alessandro , Zanda Matteo
Published: October 2008

The results presented in this paper confirm that the stereochemical outcome of the reversible additions of lithium (R)-methyl p-tolyl sulfoxide to N-arylidene-p-anisidines (NPMP imines) depends on: (a) the reaction conditions used and (b) the electronic properties of the arylidene moiety on the starting imine. In particular, we show that under kinetic control (-70 °C) the additions involving electron-rich N-arylidene groups occur with very high stereocontrol in favor of the (2S,RS)-diastereomers, whereas an electron-deficient group favors the opposite stereochemical outcome. Based on the observations above, a mechanistic hypothesis is proposed.
Molecular and Crystal Structures of Three Berberine Derivatives
Authors: Man Stanislav , Potáček Milan , Nečas Marek , Žák Zdirad , Dostál Jiří
Published: October 2008

Berberine azide, berberine thiocyanate, and 8-cyano-8H-berberine were prepared from berberine chloride, a quaternary protoberberine alkaloid. The molecular and crystal structures of all compounds are reported and discussed.
Facile and Fast Pinacol Rearrangement by AlCl3 in the Solid State
Authors: Rashidi-Ranjbar Parviz , Kianmehr Ebrahim
Published: October 2008

A facile and efficient synthetic procedure for effecting the pinacol rearrangement catalyzed by AlCl3 in the absence of solvent is developed. The rearrangement product is obtained at room temperature in a few minutes and in almost quantitative yield. Benzylic pinacols rearrange under these conditions, while aliphatic pinacols do not react.
Characterisation of Neuropeptide Y Receptor Subtypes by Synthetic NPY Analogues and by Anti-receptor Antibodies
Authors: Eckard Christophe P. , Cabrele Chiara , Wieland Heike A. , Beck-Sickinger Annette G.
Published: October 2008

Neuropeptide Y (NPY), a 36-mer neuromodulator, binds to the receptors Y1, Y2, Y4 and Y5 with nanomolar affinity. They all belong to the rhodopsin-like G-protein coupled, seven transmembrane helix spanning receptors. In this study, Ala-substituted and centrally truncated NPY analogues were compared with respect to affinity to the Yreceptors. Furthermore, antibodies against the second (E2) and the third (E3) extracellular loop of NPY Y1-, Y2- and Y5-receptor subtypes were raised and affinity to intact cells was tested by immunofluorescence assays. Both methods were applied in order to receive subtype selective tools and to characterise ligand binding. The analogues [A13]-pNPY and [A27]-pNPY showed subtype selectivity for the Y2-receptor. Sera against the E2 loop of the Y1-receptor and against the E2 loop of the Y2-receptor were subtype selective. Two antibodies against the Y5 E2 and E3 loop recognised the Y5- and Y2-receptor subtypes. In combination, these sera are able to distinguish between the Y1-, Y2-, and Y5-receptor subtypes. The analogues and antibodies represent valuable tools to distinguish NPY receptors on membranes and intact cells.
Facile and efficient synthesis of 3β-hydroxy-eupholanost-8-en-24-one
Authors: El Aouad N. , Benharref A. , Gree R.
Published: October 2008

The epoxidation of the natural product α-euphol followed by cleavage of the obtained epoxide with BF3-etherate, provides 3β-hydroxy-eupholanost-8-en-24-one in satisfactory overall yield.
Generation and Cycloaddition of o-Quinodimethane in Aqueous Medium
Authors: Bieber Lothar  W. , Da Silva Margarete  F.
Published: October 2008

o-Quinodimethane can be generated from =α,α'-dihalo-o-xylenes using zinc in aqueous solution. In the presence of activated dienophiles cycloadducts can be obtained directly. Catalysis with tris-triphenylphosphine ruthenium(II) dichloride reduces side reactions such as reduction and polymerisation and improves the yield. This is the first example of an organometallic cyclisation in aqueous medium using dihalo compounds.
Synthesis of 2,4,6-Tris(4-N-isopropylamidinophenyl)pyrimidine trihydrochloride
Authors: Bajić Miroslav , Boykin David  W.
Published: October 2008

The synthesis of 2,4,6-tris(4-N-isopropylamidinophenyl)pyrimidine from 1,3-di(4-bromophenyl)propen-3-one and 4-bromobenzamidine is reported.
Thermal Rearrangement of Allyl Substituted Unsymmetric 4H-1,2,4-Triazoles to the Corresponding 1H-1,2,4-triazoles
Authors: Jørgensen Kåre  B. , Olsen Ragnhild  B. , Carlsen Per  H.J.
Published: October 2008

A series of neat 4-(2-alkenyl) substituted 5-methyl-3-phenyl-4H-1,2,4-triazoles were thermolyzed at 320 oC producing a rearrangement products, of which the regioisomeric 1- and 2-substituted triazoles were the main products. The group migrations were rationalized in terms of consecutive SN2-type reactions. This mechanism was supported by a study of the alkylations of the triazoles which gave similar product mixtures. 4-(2-alkenyl) substituted 3-phenyl-4H-1,2,4-triazoles, on the other hand, gave predominantly elimination products.
Molecular Polarizability of Sc and C (Fullerene and Graphite) Clusters
Authors: Torrens Francisco
Published: October 2008

A method (POLAR) for the calculation of the molecular polarizability is presented. It uses the interacting induced dipoles polarization model. As an example, the method is applied to Scn and Cn (fullerene and one-shell graphite) model clusters. On varying the number of atoms, the clusters show numbers indicative of particularly polarizable structures. The are compared with reference calculations (PAPID). In general, the Scn calculated (POLAR) and Cn computed (POLAR and PAPID) are less polarizable than what is inferred from the bulk. However, the Scn calculated (PAPID) are more polarizable than what is inferred. Moreover, previous theoretical work yielded the same trend for Sin, Gen and GanAsm small clusters. The high polarizability of the Scn clusters (PAPID) is attributed to arise from dangling bonds at the surface of the cluster.
Reactions of 5-Aroylmethylene-3-benzyl-4-oxo-2-thioxo-1,3-thiazolidines with Nitrile Oxides
Authors: Kandeel Kamal  A. , Youssef Ahmed  S. A.
Published: October 2008

E,Z-5-Aroylmethylene-3-benzyl-4-oxo-2-thioxo-1,3-thiazolidines (3a-c) react with 4-methoxy and 4-chlorophenylnitrile oxides (4a and b) in pyridine solution to afford one or more of the following compounds: Z-3, Z-2,4-dioxo analogues 5 and 3,6-diaryl-1,4,2,5-dioxadiazines (6a-b). The interconversion route is discussed and the structures of all of the synthesised compounds are proven by microanalytical and spectral data.
Heteroaromatization with 4-Hydroxycoumarin Part II: Synthesis of Some New Pyrano[2,3-d]pyrimidines, [1,2,4]triazolo[1,5-c]pyrimidines and Pyrimido[1,6-b]-[1,2,4]triazine Derivatives
Authors: El-Agrody A. M. , Abd El-Latif M. S. , El-Hady N. A. , Fakery A.  H. , Bedair A. H.
Published: October 2008

A variety of novel [1,2,4]triazolo[1,5-c]pyrimidine-13-ones (4a-f) and (5b-d) could be obtained via reaction of 9-amino-7-(4’-chlorophenyl)-8,9-dihydro-8-imino-6H,7H-[1]benzopyrano[3`,4`:5,6]pyrano[2,3-d]pyrimidine-6-one (3) with a variety of reagents. Pyrano[2,3-d]pyrimidine-6-ones 5a, 8a-c and pyrimido[1,6-b][1,2,4]-triazine-3,14-dione (6) were also prepared. The antimicrobial activity of some of the synthesized compounds was tested.
Synthesis of Bis (2,2,6,6-tetramethyl-4-piperidinyl) Maleate
Authors: Wang Fu , Zhu Jiqin , Song Jianchi , Zhai Shengli , Wang Lei
Published: October 2008

Bis (2,2,6,6-tetramethyl-4-piperidinyl) maleate is a key intermediate for the synthesis of new types of hindered amine light stabilizers (HALS), so new synthetic routes to this compound are desirable. Through an orthogonal design and follow-up single factor experiments optimal reaction conditions were determined for synthesizing bis (2,2,6,6-tetramethyl-4-piperidiny) maleate using dimethyl maleate, 2,2,6,6-tetramethyl-4-piperidinol and zeolite supported tetraisopropyl titanate as catalyst. Under the selected conditions, the reaction rate and the yield are high, the selectivity is good, the catalyst can be recycled, and there are fewer wastes. The product was characterized and quantitatively analyzed by elemental analysis, mass spectrometry, infrared spectroscopy, nuclear magnetic resonance spectroscopy and ion suppression chromatography.
Synthesis of 5-(4-X-Phenyl)-10,15,20-tris(Substituted Phenyl) Porphyrins Using Dipyrromethanes
Authors: Durantini Edgardo N.
Published: October 2008

5-(4-X-Phenyl)-10,15,20-tris(substituted phenyl) porphyrins (4-6) were synthesized from meso-(substituted phenyl) dipyrromethanes (1-3), which in turn were prepared in yields of 75-92 %. This synthetic pathway was compared with the binary mixed aldehyde and pyrrole condensation method. The reported dipyrromethane approach is advantageous for porphyrins substituted by –OCH3 (4) and -F (6) groups (12-14 %), while the yield of porphyrins bearing –N(CH3)2 (5) groups was similar (~0.3 %) by both methods.
Alkylation of Zwitterionic Thiooxalic Acid Derivatives
Authors: Martens Klaus , Scheunemann Anke , Drexler Kerstin , Dehne Heinz , Reinke Helmut , Michalik Manfred
Published: October 2008

The new S-alkyl thiooxal-1-hydrazono-2-amidrazonium halides 2-4 were synthesized by reaction of the corresponding zwitterionic thiooxalic acid derivatives 1 with alkyl halides in methanol. The structures of compounds 4b and 4d were proven by X-ray structural analysis. Both compounds form an interesting intermolecular network of hydrogen bonds in the solid state.
Photomediated Transformation of Salannin, a Tetranortriterpenoid from Azadirachta indica A. Juss
Authors: Gopalakrishnan Geetha , Pradeep Singh N. D. , Kasinath V.
Published: October 2008

Photolysis of Salannin (1), an important bioactive compound from Azadirachta indica A.Juss (Neem), affords Δ17-isosalanninolide (2), a hitherto unknown compound, along with isosalanninolide (3) and salanninolide (4). A probable mechanism has been suggested. While the mechanism of formation of 2 involves both a [4+2] cycloaddition and a [1,3] sigmatropic shift in the furan and D-rings, respectively, formation of 3 and 4 involves the decomposition of an ozonoide-like peroxide intermediate.
Regioselectivity of Electrophilic Attack on 4-Methyl-1-thioxo-1,2,4,5-tetrahydro[1,2,4]triazolo[4,3-a]quinazolin-5-one. Part 1: Reactions at the Sulfur Atom
Authors: Fathalla Walid , Čajan Michal , Pazdera Pavel
Published: October 2008

The regioselectivity of the model compound 4-methyl-1-thioxo-1,2,4,5-tetrahydro[1,2,4]triazolo[4,3-a]quinazolin-5-one (3) towards different electrophiles was studied. Compound 3 reacts with alkyl and aryl halides to give the corresponding S-substituted derivatives. The reaction of the model thioamide with acyl halides proceeds by the formation of kinetically controlled S-acyl derivatives followed by a transacylation reaction to give the N2-acyl derivatives as thermodynamically controlled products. Theoretical DFT computational studies supported the explanation of these results. The synthesized compounds were characterized by FTIR, 1H-NMR, 13C-NMR, and mass spectroscopy.
One-Pot Quinazolin-4-ylidenethiourea Synthesis via N-(2-Cyanophenyl)benzimidoyl isothiocyanate
Authors: Fathalla Walid M. , Čajan Michal , Marek Jaromír , Pazdera Pavel
Published: October 2008

1,1-Disubstituted-3-(2-phenyl-3H-quinazolin-4-ylidene)thioureas (8) were synthesized in a one pot reaction of N-(2-cyanophenyl)benzimidoyl isothicyanate (3) with secondary amines. The products underwent transamination reactions. Compounds 8a-8g were identified by FTIR, 1H-NMR, 13C-NMR, mass spectroscopy and X-ray crystallography.
One-Pot Quinazolin-4-yl-thiourea Synthesis via N-(2-Cyanophenyl) benzimidoyl isothiocyanate
Authors: Fathalla W. , Čajan M. , Marek J. , Pazdera P.
Published: October 2008

1-substituted-3-(2-phenylquinazolin-4-yl) thioureas (7) were produced by an intramolecular cycloaddition reaction of 1-substitued-3-[(2-cyanophenylimino) phenylmethyl] thioureas (3). These compounds in turn were prepared by the reaction of N-(2-cyanophenyl)benzimidoyl isothiocyanate (2) with primary amines. The structures of products 7 were confirmed by FTIR, 1H-NMR, 13C-NMR, mass spectroscopy and X-ray crystallography.
Some Anilides of 2-Alkylthio- and 2-Chloro-6-Alkylthio-4-Pyridinecarboxylic Acids: Synthesis and Photosynthesis-Inhibiting Activity
Authors: Miletín Miroslav , Doležal Martin , Opletalová Veronika , Hartl Jiří , Král’ová Katarína , Macháček Miloš
Published: October 2008

Many compounds containing a -CONH- group display photosynthesis inhibiting activity. Based on this structural feature, a group of anilides of 2-alkylthio-(1b-4f) or 2-chloro-6-alkylthio-4-pyridinecarboxylic acids (5a-6c) was synthesised. The prepared compounds were tested for their inhibition of the oxygen evolution rate (OER) in spinach chloroplasts. A quasi-parabolic dependence between photosynthesis-inhibiting activity and the lipophilicity of the compounds was determined for 1b-4f as well as for 5a-6c. The inhibitory activity of compounds 1b-4f was higher than that of 5a-6c for comparable lipophilicity values.
Nitration Of Phenols Under Mild And Heterogeneous Conditions
Authors: Zolfigol Mohammad Ali , Ghaemi Ezat , Madrakian Elahe
Published: October 2008

Nitrophenols can be obtained in moderate to high yields using a combination of Mg(HSO4)2 or NaHSO4.H2O, NaNO3 and wet SiO2 in dichloromethane at room temperature.
Heterocyclic o-Aminonitriles: Preparation of Pyrazolo[3,4-d]-pyrimidines with Modification of the Substituents at the 1- Position
Authors: Al-Afaleq Eljazi  I. , Abubshait Samar  A.
Published: October 2008

Novel 1-[6-(p-tolyl) pyridazin-3-yl]pyrazole-o-aminonitriles (3a-c) were formed using 3-hydrazino-6-(p-tolyl)pyridazine (2) and ketene S,S-acetals (1a), S,Nacetals (1b) or tetracyanoethylene (1c). The pyrazole-o-aminonitriles (3a-c) were in turn used as precursors for the preparation of previously unreported 1-[6-(p-tolyl)-pyridazin-3-yl]pyrazolo[3,4-d]pyrimidines (8, 9, 13-20) and 7-[6-( p-tolyl) pyridazin-3-yl]2-arylpyrazolo[3,4-d]1,2,4-triazolo[5,1-f]pyrimidines (10-12) which are expected to possess considerable chemical and pharmacological activities.
Electrochemical Study of Bromide in the Presence of 1,3-Indandione. Application to the Electrochemical Synthesis of Bromo Derivatives of 1,3-Indandione
Authors: Nematollahi D. , Akaberi N.
Published: October 2008

The electrochemical oxidation of bromide in the presence of 1,3-indandione (1) in water/acetic acid and methanol/acetic acid mixtures has been studied by cyclic voltammetry and controlled-potential coulometry. The results indicate the participation of 1,3-indandione in the bromination reaction. On the basis of the electroanalytical and preparative results a reaction mechanism including electron transfer, chemical reaction and regeneration of bromide was discussed. The electrochemical synthesis of bromo derivatives of 1,3-indandione (2-3) has been successfully performed at constant current, in an undivided cell, in good yield and purity.
Synthesis, Structure and Antitumor Activity of Dibutyltin Oxide Complexes with 5-Fluorouracil Derivatives. Crystal Structure of [(5-Fluorouracil)-1-CH2CH2COOSn(n-Bu) 2]4O2
Authors: Zuo Dai-shu , Jiang Tao , Guan Hua-shi , Wang Kui-qi , Qi Xin , Shi Zhan
Published: October 2008

Dibutyltin (IV) oxide complex reacts with the fluorouracil compounds 5-fluorouracil-1-propanonic or 5-fluorouracil-1-acetic acid (Fu) to give the complexes [(5-Fu)-1-(CH2)nCOOSn(n-Bu)2]4O2 (I, n=2; II, n=1) which were characterized by IR and 1H-NMR. The crystal structure of complex I shows that the molecular is a dimer, in which two [(5-Fu)-1-CH2CH2COOSn(n-Bu)2]2O units are linked by a bridging oxygen atom, and the tin atoms adopt distorted trigonal bipyramids via two carbons from a dibutyl moiety and three oxygen atoms from 5-Fu and bridging oxygen. These complexes have potential anti-tumour activity: in vitro tests showed that complexes I and II exhibit high cytotoxicity against OVCAR-3 and PC-14.
Use of Cyclic Allylic Bromides in the Zinc–Mediated Aqueous Barbier–Grignard Reaction
Authors: Breton Gary  W. , Shugart John  H. , Hughey Christine  A. , Conrad Brian  P. , Perala Suzanne  M.
Published: October 2008

The zinc–mediated aqueous Barbier–Grignard reaction of cyclic allylic bromide substrates with various aldehydes and ketones to afford homoallylic alcohols was investigated. Aromatic aldehydes and ketones afforded adducts in good yields (66–90%) and with good diastereoselectivities. Non–aromatic aldehydes also reacted well under these conditions, but only poor yields were obtained with non–aromatic ketones. Regioselectivity was high when some substituted cyclic allylic bromides were investigated.
Stilbenes and a New Acetophenone Derivative from Scirpus holoschoenus
Authors: Abdel-Mogib M. , Basaif S. A. , Sobahi T. R.
Published: October 2008

Separation of the extract of the tubers of Scirpus holoschoenus L. (family Cyperaceae), a species easily confused with Juncus plants, afforded 2-prenyl-3,5,4'-trimethoxystilbene, 2-prenyl-3-hydroxy-5,4'-dimethoxystilbene, 2-prenyl-3,4'-dihydroxy-5-methoxy-stilbene and 3,5,4'-trimethoxystilbene, in addition to a new acetophenone derivative. The isolated compounds were identified on the basis of spectral measurements.
Modified Methods for the Synthesis of Carbazole from Phenothiazine
Authors: Miller R.  Bryan , Farmer Steven  C.
Published: October 2008

Lithium, used in conjunction with triphenylphosphine or sodium metal, produces a high yield of carbazole when reacted with phenothiazine.
Synthesis of new Bis- and Tetra-Acridines
Authors: Sourdon Valérie , Mazoyer Stéphane , Pique Valérie , Galy Jean-Pierre
Published: October 2008

A new series of bis- and tetra-acridines has been prepared from 4-(bromomethyl) acridine; some of them exhibited encouraging in vitro cytotoxic activities against murine cell lines.
Rearrangement of o-Nitrobenzaldehyde in the Hantzsch Reaction
Authors: Angeles E. , Santillán H. , Menconi I. , Martínez I. , Ramírez A. , Velázquez A. , López- Castañares R. , Martínez R.
Published: October 2008

The reaction of 5-hydroxy-2-nitrobenzaldehyde with ethyl acetoacetate in ammonia gave the two expected isomeric 1,4- and 1,2-dihydropyridines resulting from the normal Hantzsch reaction. However, the combination of 2-nitrobenzaldehyde with ethyl acetoacetate under the same conditions yielded four products: the two normal isomeric dihydropyridines and two tricyclic compounds. When we attempted to independently synthesize the two tricyclic compounds by reductive cyclization of 4-(2-nitrophenyl)-2,6-dimethyl-3,5-dicarbetoxy-1,4-dihydropyridine and 2-(2-nitrophenyl)-4,6-dimethyl-3,5-dicarbetoxy-1,2-dihydropyridine with tin (II) chloride in hydrochloric acid media, we obtained instead an indole and a quinoline derivative, respectively.
An Efficient and Chemoselective Method for Oximination of β-Diketones Under Mild and Heterogeneous Conditions
Authors: Zolfigol Mohammad  Ali
Published: October 2008

A combination of oxalic acid dihydrate and sodium nitrite in the presence of wet SiO2 was used as an effective nitrosating agent for the nitrosation of β-diketones to their corresponding α-oximinoketones in moderate to excellent yields under mild and heterogenous conditions.
Solvent and Substituent Effects on the Kinetics of Thermolysis of cis-Fused 1,2,4-Trioxanes
Authors: Cafferata Lázaro  F. R. , Jefford Charles  W.
Published: October 2008

The kinetics of the thermal decomposition reaction of cis-6-phenyl-5,6-(2-phenylpropyliden)-3,3-pentamethylene-1,2,4-trioxacyclohexane (Ia) were investigated in benzene and methanol solutions in the temperature and concentration ranges of 353.3 – 413.2 K and (1.1 – 13.1)x10-3 M, respectively. First-order rate constant values were obtained for up to at least ca. 20% conversions of that cyclic peroxide. The activation parameter values for the initial unimolecular homolysis of that molecule, results supported by the effect of the addition of di-tert-butyl-p-cresol as a free radical scavenger, indicate a stepwise reaction mechanism which is in keeping with the reaction products analysis. The corresponding activation parameters for the reaction of Ia in methanol (ΔH# = 20.2 ± 0.6 kcal mol-1; ΔS# = 0.1 ± 1.6 cal mol-1 K-1; ΔG# = 20.2 ± 0.6 kcal mol-1) and in benzene (ΔH# = 15.4 ± 0.2 kcal mol-1; ΔS# = -13.2 ± 0.5 cal mol-1 K-1; ΔG# = 20.5 ± 0.2 kcal mol-1) solutions are compared with values obtained for cis-6-phenyl-5,6-(2-phenylpropyliden)-3,3-tetramethylene-1,2,4-trioxacyclohexane (Ib) thermolysis in the same solvents. The thermolysis kinetics of Ia are less sensitive to solvent changes compared to the behaviour already reported for the analogous reactions of Ib. Because both molecules in solution are flexible structures due to their configurations, the relatively small solvent effect found on the former trioxane reaction is attributed to the extent of the chain of methylene groups attached on C-3 of the corresponding molecular rings. Furthermore, the pertinent substituent effect on the peroxidic bond strength of those molecules in solution was evaluated.
Synthesis of 1-Benzyl-6-(4-chlorophenyl)-2-(4-R-phenyl)-4-(4-Rstyryl)-2,3-dihydropyrazolo[3,4-b][1,4]diazepines
Authors: Insuasty Braulio , Rodríguez Ricaurte , Quiroga Jairo , Abonía Rodrigo , Martínez Roberto , Toscano Alfredo , Angeles E.
Published: October 2008

The reaction of 4-amino-5-benzylamino-3-(4-chlorophenyl)-1H-pyrazole (1) with substituted diarylidenketones (2) constitutes a convenient synthetic route to the hitherto unknown 1-benzyl-6-(4-chlorophenyl)-2-(4-R-phenyl)-4-(4-R-styryl)-2,3-dihydropyrazolo-[3,4-b][1,4]diazepines (3). Structures of all products were consistent with their IR, 1H-NMR, 13C-NMR and MS spectral data. X-ray crystallography data confirm the assigned structures.
Synthesis of Camalexin
Authors: Dzurilla M. , Kutschy P. , Zaletova J. , Ruzinsky M. , Kovacik V.
Published: October 2008

In this paper we describe a new method for the synthesis of camalexin (1) based on the reaction of 1-(tert-butoxycarbonyl)indole-3-carboxaldehyde with methyl Lcysteinate hydrochloride, followed by oxidation and decarboxylation. Compounds 1, and intermediates 5-7 were identified by elemental analysis, 1H NMR, 13C NMR and mass spectroscopy.
Chemistry of Pyrones, Part 5: New Crown Ether and Podand Derivatives of 3,5-Bis(bromomethyl)-2,6-diphenyl-4H-pyran-4-one
Authors: Shahrisa Aziz , Banaei Alireza
Published: October 2008

New podand and crown ether derivatives of 3,5-disubstituted 4H-pyran-4-one (8-11) were prepared by the nucleophilic substitution reaction of 3,5-bis(bromomethyl)-2,6-diphenyl-4H-pyran-4-one with o-nitrophenol, 8-hydroxyquinoline, 2-hydroxymethyl pyridine and triethyleneglycol, respectively. The yield of 3,5-bis[(2-formylphenoxy) methyl]-2,6-diphenyl-4H-pyran-4-one has been improved by modification of our previous method using NaOH instead of Et3N.
Synthesis of Furan Derivatives Condensed with Carbohydrates
Authors: De Almeida Mauro  V. , Le Hyaric Mireille , Siqueira Leonardo  J. A. , Pinto Luciana  D. , Valle Marcelo  S. , Alves Wendel  A.
Published: October 2008

Eight new furan derivatives have been prepared and characterized. These compounds were obtained by condensation of aminosugar and aminocyclitol intermediates with furan derivatives.
Tyrian Purple: 6,6’-Dibromoindigo and Related Compounds
Authors: Cooksey Christopher J.
Published: October 2008

The genesis of the purple dye from shellfish, its composition, origin, intermediates, analysis and synthesis of the components, 6,6’-dibromoindigo, 6-bromoindigo and 6,6’-dibromoindirubin are reviewed.
Niobium Pentachloride Catalysed Ring Opening of Epoxides
Authors: Constantino Mauricio  Gomes , Lacerda Valdemar , Aragão Valquiria
Published: October 2008

Epoxide ring opening is a frequently required transformation in Organic Synthesis. In this paper we describe the application of NbCl5 for this purpose using three different substrates. Chlorohydrins, 1,2-diols, products containing solvent residues as well as rearrangement products are obtained, depending on both the substrate structure and reaction conditions. Rationalizations to account for some of the results are suggested.
Crystal and molecular structure of cis-Dichlorobis(triphenylphosphite) Platinum(II)
Authors: Sabounchei Seyyed  Javad , Naghipour Ali
Published: October 2008

The single crystal structure of cis-dichlorobis(triphenyphosphite) platinum(II), [PtCl2(P(OPh)3)2] has been determined. This complex crystallises in the orthorhombic space group, P212121 with cell constant, a=10.4135(13), b=14.0635(16), c=23.505(3) Ǻ and v=3448.3(7) Ǻ 3. The Pt-Cl1 and Pt-Cl2 distances are 2.3390(10) Ǻ and 2.3256 Ǻ, which are longer than Pt-P1 and Pt-P2 with 2.1985(12) Ǻ and 2.1998(10) Ǻ respectively. These data together with bond angles suggest a distorted square planar geometry for this complex with two chlorine ligands in a cis configuration.
Biologically Active 1-Arylpiperazines. Synthesis of New N-(4-Aryl-1-piperazinyl)alkyl Derivatives of Quinazolidin-4(3H)-one, 2,3-Dihydrophthalazine-1,4-dione and 1,2-Dihydropyridazine-3,6-dione as Potential Serotonin Receptor Ligands
Authors: Kowalski Piotr , Kowalska Teresa , Mokrosz Maria  J. , Bojarski Andrzej  J. , Charakchieva-Minol Sijka
Published: October 2008

The synthesis of a series of new n-propyl and n-butyl chain containing 1-arylpiperazine derivatives of quinazolidin-4(3H)-one (7) 2-phenyl-2,3-dihydrophthalazine-1,4-dione (8) and 1-phenyl-1,2-dihydropyridazine-3,6-dione (9) as potential serotonin receptor ligands is described.
Unambiguous Assignment of the 1H- and 13C-NMR Spectra of Propafenone and a Thiophene Analogue
Authors: Holzer Wolfgang
Published: October 2008

Full and unambiguous asssignment of all 1H- and 13C-NMR resonances of the free bases as well as the hydrochloride salts of the antiarrhythmic agent propafenone and a thiophene analogue in different solutions (DMSO-d6, CDCl3) is reported.
Synthesis of the Aspidosperma Alkaloid Na-Formyl-16-α-Hydroxyaspidospermidine
Authors: Belferdi Fatiha , Belattar Abdelhamid
Published: October 2008

The first total synthesis of Na-formyl-16α-hydroxyaspidospermidine and its isomer via (±)-vincadifformine is described and their structure elucidation using different methods of analysis is reported.
Synthesis, Antibacterial and Antifungal Activity of 4-Substituted-5-Aryl-1,2,4-Triazoles
Authors: Colanceska-Ragenovic Katica , Dimova Vesna , Kakurinov Vlado , Molnar Dora  Gabor , Buzarovska Aleksandra
Published: October 2008

A few 4-allyl/amino-5-aryl-1,2,4-triazoles were synthesized and tested for antibacterial and antifungal effects against Escherichia coli, Bacillus subtilis, Salmonella enteritidis, Staphylococcus aureus, Aspergillus niger and Candida albicans. 4-Allyl-5-aryl-1,2,4-triazoles were obtained by the oxidative cyclization of the appropriate 1-substituted-4-allylthiosemicarbazides and 4-amino-5-aryl-1,2,4-triazoles were obtained by cyclization of the potassium salts of appropriately substituted dithiocarbazinic acids with hydrazine hydrate. The new synthesized compounds were characterized using IR, 1H- NMR, 13C-NMR and UV spectral data together with elemental analysis.
A Convenient Method to Prepare Labile FMN Derivatives
Authors: Müller Franz , Lee John
Published: October 2008

A simple method for selective phosphorylation of ribityl containing starting materials to afford FMN derivatives is presented. The method is in particular valuable for the synthesis of labile FMN derivatives.
Applications of Microwave in Organic Synthesis: An Improved One-step Synthesis of Metallophthalocyanines and a New Modified Microwave Oven for Dry Reactions
Authors: Villemin Didier , Hammadi Mohamed , Hachemi Messaoud , Bar Nathalie
Published: October 2008

Metallophthalocyanine complexes are obtained quickly and efficiently by the reaction of phthalodinitrile with hydrated metallic salts without solvent and under microwave irradiation. The use of a modified commercial microwave oven to perform this type of reactions under dry conditions is described. Metallophthalocyanines and metallododecachlorophthalocyanines of some divalent metals can be also obtained from phthalic or tetrachlorophthalic anhydrides with hydrated metallic salt and urea under microwave irradiation and without solvent.
Mg2+-Imidazole-Catalyzed Self-Condensation of Malonyl Thioesters: Getting Tuned for Biomimetic Polyketide Synthesis?
Authors: Sakai Naomi , Sordé Nathalie , Matile Stefan
Published: October 2008

We report that a subtle balance of carbanion reactivity, leaving group activation, and pKa of the catalyst is required for efficient self-condensation of thiomalonates to thioacetoacetates in up to 71% yield under “biomimetic” conditions originally proposed by Kobuke and Yoshida (Tetrahedron Lett. 1978, 19, 367).
Amine and Titanium (IV) Chloride, Boron (III) Chloride or Zirconium (IV) Chloride-Promoted Baylis-Hillman Reactions
Authors: Shi Min , Jiang Jian-Kang , Cui Shi-Cong
Published: October 2008

The Baylis-Hillman reactions of various aryl aldehydes with methyl vinyl ketone at temperatures below -20oC using Lewis acids such as titanium (IV) chloride, boron (III) chloride or zirconium (IV) chloride in the presence of a catalytic amount of selected amines used as a Lewis bases afford the chlorinated compounds 1 as the major product in very high yields. Acrylonitrile can also undergo the same reaction to give the corresponding chlorinated product in moderate yield. A plausible reaction mechanism is proposed. However, if the reaction was carried out at room temperature (ca. 20oC), then the Z-configuration of the elimination product 3, derived from 1, was formed as the major product.
One-Pot Procedures for Preparing (Dichloroiodo)arenes from Arenes and Diiodine, with Chromium(VI) Oxide as the Oxidant
Authors: Obeid Nicolas , Skulski Lech
Published: October 2008

Ten representative (dichloroiodo)arenes, ArICl2, were prepared from the corresponding arenes and diiodine in variable anhydrous mixtures, ArH/I2/CrO3/AcOH/Ac2O/conc. H2SO4, followed by the addition of conc. hydrochloric acid, used as the source of chlorine; ArICl2 are useful in organic synthesis as mild and selective chlorinating and/or oxidizing agents.
One-Pot Preparations of Diaryliodonium Bromides from Iodoarenes and Arenes, with Sodium Perborate as the Oxidant
Authors: Kryska Anna , Skulski Lech
Published: October 2008

This paper reports a one-pot synthesis of the title bromides from both activated and deactivated iodoarenes which are first oxidized with anhydrous NaBO3·H2O/Ac2O/conc.H2SO4 liquid mixtures, then coupled in situ with benzene and activated arenes and, finally, precipitated out with a KBr solution; this method is easy, cheap, safe and fairly effective.
Syntheses of (Diacetoxyiodo)arenes or Iodylarenes from Iodoarenes, with Sodium Periodate as the Oxidant
Authors: Kazmierczak Pawel , Skulski Lech , Kraszkiewicz Lukasz
Published: October 2008

- Easy, safe, and effective novel methods for preparing either (diacetoxyiodo)-arenes, ArI(OAc)2, or iodylarenes, ArIO2, from the corresponding iodoarenes, ArI, using sodium periodate as the oxidant are presented in this paper. In order to obtain 2- and 4-iodylbenzoic acids, the respective sodium salts of 2- and 4-iodobenzoic acids should be used as the starting substrates, because mixtures containing the corresponding iodosyl derivatives as the main products along with the intended iodyl compounds are produced from the free parent acids.
Captodative Formyl Enamines in a New Synthesis of Tertiary α-Amino Esters
Authors: Rulev Alexandre  Yu. , Larina Lyudmila I. , Voronkov Mikhail  G.
Published: October 2008

A strategy to create the –CH(NR2)CO- moiety from captodative formyl enamines was successfully applied to the synthesis of tertiary α-amino esters.
Efficient, Solvent-Free Oxidation of Organic Compounds with Potassium Dichromate in the Presence of Lewis Acids
Authors: Mohammadpoor-Baltork Iraj , Sadeghi Majid  M. , Adibi Abol-Hassan
Published: October 2008

The synthetic utility of potassium dichromate in the presence of Lewis acids under solid phase conditions is described. This reagent efficiently oxidizes alcohols, acyloins, oximes and semicarbazones to their corresponding carbonyl compounds, while trimethylsilyl and tetrahydropyranyl ethers, ethylene acetals and ketals undergo oxidative deprotection to produce carbonyl compounds efficiently.
Synthesis and Crystal Structure Determination of a Nickel(II) Complex of an Acyclic Pentadentate (N5) Mono Schiff Base Ligand
Authors: Keypour Hassan , Salehzadeh Sadegh , Pritchard R. G. , Parish R.  V.
Published: October 2008

The asymmetrical tripodal tetraamine ligand N[(CH2)3NH2]2[(CH2)2NH2] (ppe) was condensed with 2-acetylpyridine in the presence of nickel(II) ion. In ethanolwater solution the reaction stops after the first stage of condensation, and a new nickel(II) complex of an acyclic pentadentate (N5) mono Schiff base ligand was obtained. X-ray structure analysis of the resulting complex, [Ni(ppe-py)(H2O)](ClO4)2, indicates that condensation with 2-acetylpyridine is at the propylene chain of ppe. The geometry around the nickel ion is distorted octahedral in which the sixth co-ordination group is a solvent molecule.
A New Effective Algorithm for the Unambiguous Identification of the Stereochemical Characteristics of Compounds During Their Registration in Databases
Authors: Cieplak T. , Wisniewski J. L.
Published: October 2008

A new effective algorithm for handling of geometry at chiral centers for the processing of stereochemical structures during their unambiguous registration in databases was designed, programmed and implemented. The chemical and mathematical reasoning behind the algorithm are discussed in detail. Its advantages- in comparison to the methods used so far - are illustrated for the manual as well as for the computerassisted assignment of stereodescriptors based on the CIP ranking procedure.
Some Heteroaromatic Organomercurials, Their Syntheses and Reactions: A Review of Our Research (1980-2000)
Authors: Skulski Lech , Wroczynski Piotr
Published: October 2008

This review reports some novel (or improved) synthetic methods for preparing a number of aromatic (carbocyclic and predominantly heterocyclic) organomercurials, particularly those derived from theophylline, theobromine and uracil, as well as some novel halo- and cyano-demercuration reactions. We have also synthesized the first stable organic derivative of mercury(I), viz. 1,8-bis(acetoxydimercurio) theobromine, and studied its novel reactions. We have also improved the old Willgerodt method (1897), applicable for preparing various diaryliodonium chlorides from appropriate (dichloroiodo)arenes and symmetric aromatic mercurials. A full list of our works, published over the past twenty years (1980-2000), is also provided (see Refs. 1-16).
An Improved Synthesis of 5-(2,6-Dichlorophenyl)-2-(phenylthio)-6H-pyrimido[1,6-b]pyridazin-6-one (a VX-745 analog)
Authors: Treu Matthias , Jordis Ulrich , Lee Ving J.
Published: October 2008

An improved procedure for the synthesis an analog of the p38 inhibitor compound VX- 745 is reported.
Zn Mediated Regioselective Barbier Reaction of Propargylic Bromides in THF/aq. NH4Cl Solution
Authors: Jõgi Artur , Mäeorg Uno
Published: October 2008

The reaction of substituted and unsubstituted propargylic bromides with butanal in presence of zinc power in THF/saturated aqueous NH4Cl solution gave corresponding allenic and propargylic alcohols with high selectivity.
Regioselectivity in the Thermal Rearrangement of Unsymmetrical 4-Methyl-4H-1,2,4-triazoles to 1-Methyl-1H-1,2,4-triazoles
Authors: Gautun Odd R. , Carlsen Per H.J.
Published: October 2008

The rearrangement of 4-methyl-3,5-diaryl-4H-1,2,4-triazoles to the corresponding 1-methyl-3,5-diaryl-1H-1,2,4-triazoles showed regioselectivity comparable to that observed for the alkylation of 3,5-diaryl-1H-1,2,4-triazoles. This lends support to a proposed mechanism for the rearrangement that involves consecutive nucleophilic displacements steps.
Synthesis of Novel Diammonium Gemini Surfactants
Authors: Rist Øystein , Rike Anita , Ljones Liv , Carlsen Per  H.J.
Published: October 2008

Selective synthesis of linear and gemini quaternary ammonium surfactants was accomplished by reacting the corresponding alkyl alcohols with 2-chloro-N,N-dimethylethylamine under basic conditions. The amines were quaternized with methyl chloride or methyl iodide.
Novel Chiral Switching Ligands for Enantioselective Asymmetric Reductions of Prochiral Ketones
Authors: Narasimhan S. , Swarnalakshmi S. , Balakumar R. , Velmathi S.
Published: October 2008

The newly developed chiral ligands 1 and 4 show opposite enantioselectivity in the asymmetric reduction of prochiral ketones resulting in the production of either enantiomer depending on the metal complex with high enantiomeric excess.
Bi(TFA)3 and Bi(OTf)3 Catalyzed Conversions of Epoxides to Thiiranes with Ammonium Thiocyanate and Thiourea under Non-Aqueous Conditions
Authors: Mohammadpoor-Baltork Iraj , Khosropour Ahmad  R.
Published: October 2008

Various epoxides are converted to their corresponding thiiranes in excellent yields with ammonium thiocyanate and thiourea under non-aqueous conditions in the presence of catalytic amounts of Bi(TFA)3 and Bi(OTf)3.
Facile Synthesis of 1,6-Bis(2-furyl)-2,5-bis(2-hydroxy-3-formyl-5-methylbenzyl)-2,5-diazahexane: a New Dinucleating Ligand
Authors: Sun Gang-Chun , He Zhan-Hang , Li Zhong-Jun , Yuan Xiao-Dong , Yang Zhi-Juan , Wang Guo-Xi , Wang Liu-Fang , Liu Chang-Rang
Published: October 2008

A convenient three-step preparation of the dinucleating ligand, 1,6-bis(2-furyl)-2,5-bis(2-hydroxy-3-formyl-5-methylbenzyl)-2,5-diazahexane (3) starting from 2,6-bis(hydroxymethyl)-4-methylphenol (4) is reported. Compound 4 was partially oxidized with preactivated manganese dioxide to form compound 5, which was converted to 2-hydroxy-3-chloromethyl-5-ethylbenzaldehyde (6) with conc.HCl/EtOH. Compound 6 in turn reacted with N,N’-bis (2-furyl)-1,2-diaminoethane (7) in the presence of K2CO3 in ethanol to give the title compound 3. No protecting groups were required in the whole process and the conditions were mild.
Efficient Deprotection of Phenol Methoxymethyl Ethers Using a Solid Acid Catalyst with Wells-Dawson Structure
Authors: Romanelli G. , Autino J. C. , Baronetti G. , Thomas H.
Published: October 2008

Deprotection of various phenols from their respective methoxymethyl ethers using an heteropolyacid catalyst was studied. The catalyst was the Wells-Dawson heteropolyacid, used both in bulk or supported on silica. Yields were high to quantitative after less than one hour reaction time and the catalyst was easily recoverable and reusable.
Asymmetric Catalysis In Organic Synthesis
Authors: Nagoya Ryoji
Published: October 2008

The author Ryoji Nagoya shared the Nobel Prize in Chemistry for 2001.[...]
Catalytic Asymmetric Synthesis, 2nd Edition
Authors: Lin Shu-Kun
Published: October 2008

The field of catalytic asymmetric synthesis has grown immensely since the first edition was published in 1993, spawning effective new methods for obtaining enantiomerically pure compounds on a large scale and stimulating new applications in diverse fields--from medicine to materials science.[...]
Advanced Organic Chemistry. Part B: Reactions and Synthesis. Fourth Edition
Authors: Carey Francis , Sundberg Richard
Published: October 2008

The control of reactivity to achieve specific syntheses is one of the overarching goals of organic chemistry.[...]
Molecular Switches
Authors: Lin Shu-Kun
Published: October 2008

“This book will appeal most to organic chemists, because of the way new structures are introduced through their synthesis, but it will also provide a useful introduction for other scientists, provided they are conversant with molecular structures.”(Perkin Transactions, No.19, 2001)[...]
The Biotechnology of Ethanol: Classical and Future Applications
Authors: Lin Shu-Kun
Published: October 2008

Focusing on the biotechnology of ethanol, this book highlights its industrial relevance as one of the most important products of primary metabolism.[...]
Marketing and Sales in the Chemical Industry
Authors: Lin Shu-Kun
Published: October 2008

*Editor's Note: The brief summary and the contents of the books are reported as provided by the author or the publishers. Authors and publishers are encouraged to send review copies of their recent books of potential interest to readers of Molecules to the Editor-in-Chief (Dr. Shu-Kun Lin, MDPI, Saengergasse 25, CH-4054 Basel, Switzerland. Tel. +41 79 322 3379, Fax +41 61 302 8918, E-mail: molinfo@mdpi.org).[...]
New Trends in Synthetic Medicinal Chemistry. (Methods and Principles in Medicinal Chemistry, Volume 7)
Authors: Lin Shu-Kun
Published: October 2008

The long-awaited volume on synthetic chemistry in the series "Methods and Principles in Medicinal Chemistry" is now available.[...]
Perspectives in Nucleoside and Nucleic Acid Chemistry
Authors: Lin Shu-Kun , Rosemeyer Helmut
Published: October 2008

The chemistry of nucleosides and nucleic acids is a rapidly developing field. Many of the most important recent advances in medicinal chemistry have occured in this field with the development of novel nucleosideand nucleotide-based antiviral and antitumor drugs.[...]
Chemistry for the 21st Century
Authors: Lin Shu-Kun , Schechter Israel
Published: October 2008

Here, numerous winners of the Wolf prize from all chemical disciplines provide an overview of the new ideas and approaches that will shape this dynamic science over the forthcoming decades and so will have a decisive influence on our living conditions.[...]
The Structure of the Nucleon
Authors: Lin Shu-Kun , Weise Wolfram
Published: October 2008

As the only stable baryon, the nucleon is of crucial importance in particle physics.[...]
Industrial Biotransformations
Authors: Lin Shu-Kun , Seelbach Karsten , Wandrey Christian
Published: October 2008

Industrial Biotransformations - a user-friendly and application-oriented up-to-date overview of one-step biotransformations of industrial importance.[...]
Organic Synthesis on Solid Phase. (Supports, Linkers, Reactions)
Authors: Lin Shu-Kun
Published: October 2008

Organic synthesis on solid supports is a rapidly developing methodology, which offers several advantages if compared to traditional synthesis in solution.[...]
Liquid Crystals :Experimental Study of Physical Properties and Phase Transitions
Authors: Kumar Satyendra
Published: October 2008

This book describes in detail various experimental techniques used in the study of liquid crystals.[...]
Shape and Structure, from Engineering to Nature
Authors: Lin Shu-Kun
Published: October 2008

Seemingly universal geometric forms unite the flow systems of engineering and nature.[...]
Statistics in Genetics and in the Environmental Sciences. (Trends in Mathematics)
Authors: Fernholz L. , Morgenthaler S. , Stahel W.
Published: October 2008

This book grew out of a workshop on statistics in the sciences held on Monte Verità, Switzerland, in the spring of 1999.[...]
Progress in Drug Research
Authors: Jucker E.
Published: October 2008

*Editor's Note: The brief summary and the contents of the books are reported as provided by the author or the publishers.[...]
Antiviral Agents: Advances and Problems. Progress in Drug Research
Authors: Jucker E.
Published: October 2008

This first Special Volume of the monograph series "Progress in Drug Research" is a compilation of most topical and concise reviews on virus research and drug development.[...]
Recombinant Protein Drugs.( Milestones in Drug Therapy)
Authors: Buckel P.
Published: October 2008

Recombinant protein drugs are intimately associated with the impressive success story of the Biotech Industry during the past thirty years, some of them belonging to the most successful pharmaceutical products.[...]
March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 5th Edition
Authors: Lin Shu-kun , March Jerry
Published: October 2008

"...the book remains tremendous value for money...more pages per buck than most other texts...so it will remain a firm favourite as a general organic text and an easy-to-use 1-volume reference...will undoubtedly appear in all organic chemistry libraries and probably on many chemists’ personal bookshelves too."[...]
Grundlagen der Life Sciences: Chemie - Biologie - Energetik
Authors: Lin Shu-Kun
Published: October 2008

Der Begriff Life Sciences hat in den letzten Jahren immer mehr an Bedeutung gewonnen.[...]
Natural Products from Three Nudibranchs: Nembrotha kubaryana, Hypselodoris infucata and Chromodoris petechialis
Authors: Karuso Peter , Scheuer Paul  J.
Published: October 2008

Nudibranchs are shell-less molluscs that are often brightly colored and seemingly defenseless against predation. However, these beautiful animals usually contain large amounts of diet-derived natural products that help defend them against predation. We have isolated a blue tetrapyrrole from Nembrotha kubaryana, the known nakafuran-8 and -9 from Hypselodoris infucata and spongiane-16-one from Chromodoris petechialis. These compounds have previously been found in other marine organisms, thus supporting a link between diet and natural products in the nudibranchs.
Preparation of Substituted Methyl o-Nitrophenyl Sulfides
Authors: Dudova Katerina , Castek Frantisek , Machacek Vladimir , Simunek Petr
Published: October 2008

The nucleophilic substitution of substituted o-nitrochlorobenzenes with substituted methanethiolates, catalysed with triethylamine or pyridine, has been used to prepare a series of appropriately substituted methyl-o-nitrophenylsulfides. The prepared compounds were identified by their 1H- and 13C-NMR spectra. The base catalysed ring closure of methyl 2-(methoxycarbonylmethylsulfanyl)-3,5-dinitrobenzenecarboxylate only results in an attack of carbanion on the ester group, not on a nitro group as with the other compounds prepared. The cyclisation product is methyl 3-hydroxy-5,7-dinitrobenzo[b]thiophene-2-carboxylate (11).