Die Phlorglucide von Dryopteris viliarii (Bell.) Woynar und anderer Farne der Gattung Dryopteris sowie die mögliche Abstammung von D. filix-mas (L.) Schott

The phloroglucides of the ferns of the Dryopteris filix-mas complex; i.e. D. abbreviata, D. filix-mas s. str. and D. borreri (diploid and triploid) as well as those of D. villarii, subspvillarii and subsp. pallida were reinvestigated with improved semiquantitative analytical methods. The phloroglucides of D. aitoniana and D. athamantica were examined for the first time. The results (table 1) are compatible with the hypothesis, without proving it, that the allotetraploid species D. filix-mas s. str. originated from a hybrid of D. abbreviata with D. villard (with subsequent doubling of its chromosomes) and the apogamous triploid D. remota from D. assimils with diploid D. borreri, and the equally apogamous triploid D. borreri from a hybrid of D. abbreviata (or a related diploid sexual taxon) with diploid D. borreri. D. aitoniana contains a large amount of trisflavaspidic acid but no filixic acid and differs in this respect from the three representatives of the D. filix-mas complex.     

Derivatives Of ditraizinylamine and tritriazinylamine

2-Arylamino-4,6-dichloro-s-triazine reacts with cyanuric chloride in the presence of alkali to yield N,N-bis(4,6-dichloro-s-triazin-2-yl)-arylamine. In like manner, 2-substituted o-chloro-, p-chloro-, o-nitro- and p-carbomethoxyphenylamino-4,6-dimethoxy-s-triazines react with cyanuric chloride to yield the corresponding 4,6-dichloro-s-triazin-2-yl-4′,6′-dimethoxy-s-triazin-2′-ylaryl-amine, while anilino-, p-toluidino, o- and p-methoxyphenylamino and o-carbomethoxyphenylamino derivatives did not. The reaction of cyanuric chloride with 2,4-dichloro-6-ethylamino-s-triazine in the presence of alkali yields the condensation product of the ditriazinylamine type and the reaction of cyanuric chloride with ammonia yields N,N-bis(4,6-dichloro-s-triazin-2-yl)- or tris(4,6-dichloro-s-triazin-2-yl)amine.     

β-Thiopeptides: Synthesis,NMR Solution Structure,CD Spectra,and Photochemistry

To test the effect of NH−C=S groups (Scheme 1) on the stability of β-peptide secondary structures, we have synthesized three β-thiohexapeptide analogues of H-(β-HVal-β-HAla-β-HLeu)₂-OH ( 1 ) with one, two, and three C=S groups in the N-terminal positions (cf. 2 – 4 and model in Fig. 1). The first C=S group was introduced selectively by treatment with Lawesson reagent of Boc-β-dipeptide esters ( 6 and 8 ). A series of fragment-coupling steps (with reagents as for the corresponding sulfur-free building blocks) and another thionation reaction led to the title compounds with a C=S group in residues 1, 1, and 3, as well as 1, 2, and 3 of the β-hexapeptide (Schemes 2 and 3). The sulfur derivatives, especially those with three C=S groups, were much more soluble in organic media than the sulfur-free analogues (>1000-fold in CHCl₃; Table 1). The UV and CD spectra (in CHCl₃, MeOH, and H₂O) of the new compounds were recorded and compared with those of the parent β-hexapeptide 1 (Figs. 2 – 4); they indicate the presence of more than one secondary structure under the various conditions. Most striking is a pronounced exciton splitting (Δλ ca. 20 nm, amplitude up to +121000) of the ππ*_C=S band near 270 nm with the β-trithiohexapeptide (with and without terminal protecting groups), and strong, so-called `primary solvent effects', in the CD spectra. The CD spectrum of the β-dithiohexapeptide 3 undergoes drastic changes upon irradiation with 266-nm laser light of a MeOH solution (Fig. 5). The NMR structure in CD₃OH of the unprotected β-trithiohexapeptide 4 was determined to be an (M)-3₁₄-helix (Fig. 7), very similar to that of the non-thionated analogue (cf. 1 ). NMR and mass spectra of the β-hexapeptides with C=S and with C=O groups are compared (Figs. 6 and 8).     

Synthesis of 1H-pyrazolo[3,4-e]-s-triazolo[3,4-c]-as-triazines, 8H-pyrazolo[3,4-e]tetrazolo[5,1-c]-as-triazine and 1,7-dihydro-8H-pyrazolo[3,4-e]-as-triazine derivatives

3-Hydrazino-7-methyl-5-phenyl-5H-pyrazolo[3,4-c]-as-triazine 1 underwent ring closure and/or condensation reaction with formic acid, acetic acid, acetic anhydride and benzoyl chloride to afford 1H-pyrazolo-[3,4-d]-s-triazolo[3,4-c]-as-triazines 2, 5 and 7a and/or N-acyl derivatives 3, 4 and 6 . N-Acyl derivatives 3 and 6 underwent cyclisation reaction on treatment with phosphoryl chloride to give 5 and 7a . 3-Methyl-1-phenyl-8-aryl-1H-pyrazolo[3,4-e]-s-triazolo[34,-c]-as-triazines 7 were also prepared by the reaction of the hydrazono derivatives 8 wit thionyl chloride. On treatment of 1 with nitrous acid gave the 8H-pyrazolo[3,4-e]tetrazolo-[5,1-c]-as-triazine 9 . Compound 1 underwent ring closure with carbon disulphide or ethyl chloroformate to 1,7-dihydro-8H-pyrazolo[3,4-e]-s-triazolo[3,4-c]-as-triazine derivatives 10 and 12 . Reaction of 1 with ethyl acetoacetate or acetylacetone gave 3-pyrazolo derivatives 13 and 14 .     

Electron transfer reactions. Reactions of epoxyketones and benzoylaziridines with potassium

The results of our studies on the reaction of some epoxyketones and aziridines with potassium in tetrahydrofuran (THF) are presented. Treatment of trans-l,3-diphenyl-2,3-epozypropan-1-one (1a.) with, potassium, for example, gives a mixture of acetophenone (9), the chalcone 4a, the dihydrochalcone 14a, the cyclopentene isomers 20a and 21a, the hydroxy acid 10a and benzoic acid 6, whereas the reaction of 1a with potassium, under oxygen saturation, gives a mixture of 4a, 14a, 6, the diketone 17a, the dihydroxycarboxylic acid 7a and the hydroxyfuranone 19a. The reaction of 1a. with potassium superoxide, however gives a mixture of 6, 7a and 19a. Similar results are obtained in the reaction of trans-2,3-epoxy-1-phenyl-3-p-tolylpropan-1-one 1b with potassuum. The reaction of 7-oxa-2,3-dibenzoylbtcyclo[2 2 1]hepta-2,5-diene (22a) with potassium gives a mixture of 6 and o-dibenzoylbenzene (26a), whereas 2,3-dibenzoyl-1,4-dihydro-1,4-diphenyl-1,4-epoxynaphthalene (22b), under analogous conditions, gives a mixture of 6, 1,3-diphenylisobenzofuran (25b), 26a, 2,3-dibenzoyl-1,4-diphenylnapntnelene (26b) and 2-benzoyl-1,4-dtphenylnaphthalene (27b). Treatment of the benzoylaztridines 28a-d with potassium gives the stilbenes, 33a,c, the hydroxy amides, 34,a,c,d, and carboxylic acids 6, 11b, whereas the aziridine 35, on treatment with potassium, gives a mixture of the isoquinoline 37 and the phthalimidine 39. Cyclic voltammetric and pulse radiolysis studies have been carried out, in an attempt to characterize the radical anion intermediates involved in these reactions. Document No. NDRL-3120 from the Notre Dame Radiation Laboratory and No. RRLT-PRU-5 from the Regional Research Laboratory Trivandrum.     

Acyl iodides in organic synthesis. Reactions with morpholine,piperidine, and <Emphasis Type="Italic">N</Emphasis>-hydrocarbylpiperidines

Acyl iodides RCOI (R = Me, Ph) reacted with morpholine and piperidine to give the corresponding N-acyl derivatives and morpholine or piperidine hydroiodides. Reactions of acyl iodides with N-methyl- and N-ethylpiperidines involved cleavage of the exocyclic R-N bond with formation of N-acylpiperidine and alkyl iodide and were accompanied (to insignificant extent) by cleavage of the endocyclic N-C bond, leading to N-alkyl-N-(5-iodopentyl)acylamides. In the reaction of acetyl iodide with N-phenylpiperidine, the main process was cleavage of just endocyclic N-C bond to produce N-(5-iodopentyl)-N-phenylacetamide and its dehydroiodination product, N-(pent-4-en-1-yl)-N-phenylacetamide. Analogous reaction with benzoyl iodide afforded N-(5-iodopentyl)-N-phenylbenzamide in a poor yield.     

Benzofuranyl-pyran-2-ones, -pyridazines,and -pyridones from naturally occurring furochromones (visnagin and khellin)

The novel and versatile enaminones 2a,b were synthesized by treatment of visnaginone methyl ether 1a or khellinone methyl ether 1b with N,N-dimethylformamide dimethylacetal. They were reacted with hippuric acid or N-acetylglycine to yield benzofuran-5-yl-2H-pyran-2-ones 3a–d . The reaction of 2a,b with cyanoacetamide and malononitrile dimer in sodium ethoxide gave benzofuran-5-yl-pyridones 4a,b and [benzofuran-5-yl-1H-pyridine-2-ylidene] malononitrile 5a , respectively. Refluxing 2a,b with hydrazine hydrate or with hydroxyla- mine afforded benzofuran-5-yl-1H-pyrazoles 6a,b and benzofuran-5-yl-isoxazoles 7a,b , respectively. Moreover, 2a,b coupled with aryl diazonium salt in the presence of sodium hydroxide to yield 3-(benzofuran-5-yl)-2-aryl-hydrazono-3-oxo-propanals 8a,b which were excellent precursors for the synthesis of pyridazines 9–12 . © 2003 Wiley Periodicals, Inc. 15:85–91, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10219     

Synthesis of multifunctional copolyamides with both cyclobutane ring and conjugated double bond in the main chain

Copolyamides 1,9 , and 10 containing both cyclobutane rings and conjugated double bonds in the main chain were synthesized by polycondensation of 1,3-di(4-piperidyl)propane (DPP) with β-truxinate (β-BNPT), with di(p-nitrophenyl) p-phenylenebis(acrylate) (p-NPDA), with di(p-nitrophenyl) p-phenylenebis (α-cyanoacrylate) (p-NPDC), and with di(p-nitrophenyl) p-phenylenebis (α-cyanobutadienecarboxylate) (p-NPDCB) in aprotic polar solvents at room temperature, respectively. Reduced viscosity of copolyamide 1 was strongly affected by the reaction process, the molar ratio of two ester monomers, and reaction time. The copolyamide 1 with the highest viscosity was prepared by the reaction of DPP with 70–50 mol % of β-BNPT for 24 h followed by the polycondensation of the resulting precursor with 30–50 mol % of p-NPDA for 24–96 h. Although copolyamide 9 with high viscosity was not obtained by the polycondensation with β-BNPT and p-NPDC, copolyamide 10 with relatively high viscosity was obtained by the reaction with β-BNPT and p-NPDCB under the same conditions applied for the synthesis of copolyamide 1 . The solubility of copolyamides 1,9 , and 10 decreased gradually with increasing p-NPDA, p-NPDC, and p-NPDCB units in the copolymers. Furthermore, it was found that copolyamides 1,9 , and 10 crosslinked upon irradiation with 313 or 365 nm light, and these copolyamides also decomposed upon irradiation with 254 nm light. That is, the photochemical property of these copolyamides can be controlled by the selection of wavelength of the photoirradiation.     

Peculiarities of asphaltene precipitation in <Emphasis Type="Italic">n</Emphasis>-alkane-oil systems

n-Pentane-, n-hexane-, and n-heptane-insoluble asphaltenes obtained via a standard procedure by precipitating from oil solutions in n-pentane, n-hexane, and n-heptane, respectively, as well as n-pentane/n-hexane/n-heptane-insoluble and n-heptane/n-hexane/n-pentane-insoluble asphaltene constituents prepared through successive washing (fractional dissolution) of n-pentane-insoluble asphaltenes with n-hexane and n-heptane and n-heptane-insoluble asphaltenes with n-hexane and n-pentane, respectively, are studied. Asphaltenes and their constituents extracted from three oils distinguished by high contents of asphaltenes, resins, and paraffins, respectively, are investigated by ¹H NMR spectroscopy in carbon tetrachloride solutions. It is established that the mass fractions and the fragment compositions of asphaltenes and their constituents depend on both the type of oil and the procedure of their preparation; i.e., the precipitation from n-alkane-oil systems or the extraction through the successive washing with a series of n-alkanes. The obtained experimental data made it possible to formulate a hypothesis according to which the precipitation of asphaltenes from oils is controlled by not only the dissolving power of a solvent with respect to molecular components of initial oils, but also (and primarily) by the dissolving power of a solvent with respect to supramolecular structures of asphaltenes formed in n-alkane-oil systems.     

Synthesis of two novel bicyelic systems,imidazo[1,5-D]-as-triazine and imidazo[1,2-d]-as-triazine

4-Imidazolecarboxyaldehyde was condensed with methyl dithiocarbazinate and with ethyl carbazate, the resulting hydrazones were subjected to thermolysis in diphenyl ether at 175–240, to give imidazo[1,5-d]-as-triazine-4(3H)thione and imidazo[1,5-d]-as-triazin-4(3H)one, respectively. A number of 2-, 5-, and 2,5-substituted 4-imidazolecarboxaldehydes were also carried through this scheme. The same sequence of reactions with 2-imidazolecarboxaldehyde gave the novel system imidazo[1,2-d]-αs-triazine-5-(6H)-thione. Upon treatment with sodium hydride and methyl iodide, imidazo[1,5-d]-as-triazine-4(3H)thione and imidazo[1,2-d]-as-triazine-5(6H)-thione gave 4-methylthioimidazo[1,5-d]-as-triazine and 5-methylthioimidazo[1,2-d]-as-triazine, respectively. Displacement of the thiomethyl group was achieved with a selection of amine reagents in both of the above cases.     

Stereoselective Cyclopropanation of 2‐[(S)‐(4‐Methylphenyl)sulfinyl]cyclopent‐2‐en‐1‐one with Sulfur Ylides and α‐Halo Carbanions. Preliminary Communication

The cyclopropanation of the title compound (S)‐ 2 with various sulfur ylides has been examined. The reaction with methylenesulfonium ylides gave the corresponding cyclopropanes 4 with low diastereoselectivity. The formation of the second product 5 arising from the subsequent methylenation of the CO group was also observed. A clean cyclopropanation of (S)‐ 2 took place with ethyl (dimethylsulfanylidene)acetate affording the cyclopropanes 6 , with high π‐facial selectivity, but low endo/exo ratio. A high endo/exo selectivity, but low π‐facial selectivity was observed in the reaction of (S)‐ 2 with (2‐ethoxy‐2‐oxoethyl)(diphenyl)sulfonium tetrafluoroborate. The use of α‐bromoacetate carbanion as the cyclopropanation reagent resulted in the formation of 6 with very high facial and endo/exo‐selectivity. In a proposed explanation of the stereochemical outcome of the cyclopropanations investigated, the ground‐state conformation of the sulfoxide 2 and the transition‐state structure of the initial addition step were taken into account.     

Hydrostannylation of phosphaalkenes [1]

Hydrostannylation reactions of the phosphaalkenes 9,11, and 21 with the triorganotin hydrides 1 proceed by different routes. Whereas the trior-ganotin hydrides 1a,b undergo regioselective 1,2-addition to the P/C double bond of the P-aminophosphaalkene 9 to furnish the 2-stannylphosphanes 17a,b, the 1,2-addition products to the P-halophosphaalkenes 11 and 21 can only be postulated as the reactive intermediates 20 and 23, respectively. The reactions of 11 with 1a,b proceed with cleavage of the triorganotin halide via the diphosphene 15 to furnish the cyclophosphanes 18 and 19. On the other hand, the hydrostannylation reactions of the phosphaalkene 21 are not selective, and the 1,3-diphosphetane 22 is isolated as one of the reaction products. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:453–460, 1998     

Reaction mechanism of the alternating copolymerization of aziridines with cyclic imides

The copolymerizations of N-substituted aziridines and cyclic imide were studied. N-Ethylsuccinimide copolymerized with ethylenimine, but N-ethylethylenimine did not copolymerize with succinimide and N-ethylsuccinimide without catalyst. The effect of additives on the copolymerization of ethylenimine with succinimide and that of N-ethylethylenimine with succinimide and N-ethylsuccinimide was also examined. The rate of copolymerization of ethylenimine with succinimide was accelerated by the addition of N-acetylethylenimine or water. The copolymerization of N-ethylethylenimine with succinimide was initiated only by water, but N-ethylethylenimine did not copolymerize with N-ethylsuccinimide in the presence of water. Gas evolved on heating the copolymer of ethylenimine and succinimide was analyzed and confirmed to be ammonia. On the basis of these results the reaction mechanisms of the copolymerization of ethylenimine with succinimide or N-ethylsuccinimide and of N-ethylethylenimine with succinimide initiated by water are discussed.     

Barium‐deficient celsian,Ba1−xAl2−2xSi2+2xO8 (x = 0.20 or 0.06)

Barium‐deficient forms of celsian (barium aluminium silicate) with the formula Ba_1−xAl_2−2xSi_2+2xO₈ (x = 0.20 and 0.06) have been identified. In contrast with the celsian–orthoclase solid solutions which have been reported previously, these forms, refined in the space group C2/m, with Ba and one O atom in the 4i sites with m site symmetry, and a further O atom in a 4g site with twofold axial symmetry, suggest a slight solid solution with silica. The serendipitous preparation of the compounds represents a possible hazard associated with solid‐state synthesis.     

Sulfur and selenium derivatives of 2-phosphaindolizines

The 2-phosphaindolizines 1 react with hydrogen sulfide and elemental sulfur to give the new zwitterionic heterocyclic systems 2 of the N-pyridiniomethyl dithiophosphinate type. In contrast, no reaction is observed with sulfur alone. MeI methylates 2e,f at sulfur. The analogous pyridiniodiselenophosphinate 5 results from the reaction of 1a with 1,3,2,4-diselenadiphosphetane-2,4-diselenide, 4a, in the absence of an additional base. As a further product, the perselenophosphinic anhydride 6 is identified. In the presence of triethylamine, 1a reacts with each of the diselenides 4a–c to give the new triethylammonium diselenophosphinates 7a–c, respectively. This reaction can be extended to 1-aza-2-phosphaindolizine, 8, which yields with each of 4a,b and NEt₃ the diselenophosphinates 9a,b, respectively. The anhydride 6 and the diselenophosphinates 7 and 9 result from an electrophilic substitution at the phosphaindolizine ring. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:445–452, 1998     

Rheological Properties of Nansocale Poly(Styrene-Maleic Acid) Encapsulated Organic Pigment Dispersion by Phase Separation Technique

Azo pigment yellow 14 (P.Y.14) was encapsulated into copolymer of styrene and maleic acid (PSMA) via phase separation technique followed by the preparation of composite dispersions. Herein, we mainly investigate its rheological properties. Our results showed that the apparent viscosity (n _a ) of composite dispersion first decreased and then increased with an increase of molar content of maleic acid in PSMA (F _M ), intrinsic viscosity of PSMA ([n]), and the weight ratio of PSMA to P.Y.14 (R _C/P ), respectively. The composite dispersion with low n _a was more close to Newtonian fluid when F _M , [n] and R _C/P were equal to 0.53, 79.65 mL/g, and 12%, respectively. n _a of the composite would increase with increasing the pH value, and first decreased and then increased with a raising of the electrolyte and alcohol concentration, respectively, especially with AlCl₃ and glycerol.     

Conformational Analysis of 1,2:3,4-Diepoxides: Ab Initio and semiempirical molecular-orbital calculations

Using semiempirical and ab initio procedures, the most stable conformations of meso- and rac-bioxirane and of some substituted 1,2:3,4-diepoxides were calculated. For threo-diepoxides (having the same relative configurations as rac-bioxirane, 3 ), two stable conformations with CCCC dihedral angles of ca. 90 and ca. 270° were found. For erythro-diepoxides (derivatives of meso-bioxirane, 4 ) the calculations suggest three preferred conformations with corresponding dihedral CCCC angles of ca. 90°, ca. 180°, and ca. 270°. The calculations are in fair agreement with the experimental data available for the unsubstituted compounds 3 and 4 .     

Reaction of 2-dimethylaminomethylene-1,3-diones with Dinucleophiles. IV. Synthesis of 5,7-dihydrothiopyrano[3,4-c]pyrazol-4(1H)-ones, 5H-Thiopyrano[4,3-d]isoxazol-4(7H)-one and 6H-Thiopyrano[3,4-d]pyrimidin-5(8H)-ones

The reaction of 2H-thiopyran-3,5(4H,6H)-dione with N,N-dimethylformamide dimethyl acetal gave in good yield 4-dimethylaminomethylene-2H-thiopyran-3,5(4H,6H)dione (II), which afforded 1-substituted 5,7-dihydrothiopyrano[3,4-c]pyrazol-4(1H)-ones with aliphatic and aromatic hydrazines, 5H-thiopyrano[4,3-d]isoxazol-4(7H)-one (IV) with hydroxylamine hydrochloride and 2-substituted 6H-thiopyrano[3,4-d]pyrimidin-5(8H)-ones with amidines and guanidines, generally in satisfactory yields. 4-(t-Butylhydrazonoformyl)-2H-thiopyran-3,5(4H,6H)-dione was isolated as an intermediate in the reaction of II with t-butylhydrazine, whereas formamidine gave with II 4-iminoformyl-2H-thiopyran-3,5(4H,6H)-dione as the sole product. The isoxazole IV isomerized easily with sodium methoxide to 3,4,5,6-tetrahydro-5,5-dihydroxy-3-oxo-2H-thiopyrano-4-carbonitrile.     

Spectral Study of the Reaction of Functionally Substituted Enehydrazides with Proton Donors

Reactions of new enehydrazides, N',N'-dimethyl-N-vinylpropenohydrazide and N',N'-dimethyl-N-vinylbenzohydrazide with chloroform, phenol, and hydrogen chloride in carbon tetrachloride were studied by IR spectroscopy. In the first two cases, molecular complexes are formed between the hydrazide and proton donor. The reaction of N',N'-dimethyl-N-vinylpropenohydrazide with HCl results in formation of dihydropyrazole derivative which exists as a tautomeric mixture of the major lactam and minor lactim forms. N',N'-dimethyl-N-vinylbenzohydrazide reacts with hydrogen chloride to give protonated form in which proton is localized on the amino nitrogen atom. The structure of the initial compounds and the products was analyzed in terms of AM1 quantum-chemical calculations.     

Temperature dependence of excess enthalpies for systems containing normal hexadecane

Excess enthalpies, and heat capacities derived therefrom, have been obtained between 25 and 65 or 75°C at a constant concentration for cyclohexane and octamethylcyclotetrasiloxane mixed with normal hexadecane and with a highly branched C₁₆ isomer, 2,2,4,4,6,8,8-heptamethylnonane, and also forcis-andtrans-decalin mixed withn-C₁₆. Theh ^E values withn-C₁₆ are positive and much larger than with the branched-C₁₆. They decrease rapidly withT so thatc _p ^E is large and negative. These results imply the presence of orientational order in then-C₁₆, which is destroyed on mixing with the other component and which decreases withT. Theh ^E fortrans-decalin+n-C₁₆ is much smaller than forcis-decalin+n-C₁₆, and becomes negative with increase ofT. This change of sign, which is unexplained by current theory, is interpreted as due to an interference of the flat, plateliketrans-decalin molecule with the molecular motion of then-C₁₆ chain.