Showing papers on "Ether published in 1987"

Quaternary ammonium compounds

Abstract: Quaternary ammonium compounds corresponding to the formula ##STR1## are produced by esterification of ether amines corresponding to the formula ##STR2## with a fatty acid of the formula R 2 --COOH and quaternization of the product obtained with an alkyl halide or a dialkyl sulfate. They are suitable for use as conditioning and revitalizing agents in hair-cosmetic preparations.

Cation or solvent-induced supermolecular phthalocyanine formation: crown ether substituted phthalocyanines

Abstract: : Phthalocyanies with four 15-crown-5 ether voids at the 3,4 positions (MtCRPc) (Mt = H2, Zn, Co, Ni and Cu) have been synthesized and characterised. Dimerization of MtCRPC is induced in solvents such as methanol and by addition of some cations (K(+), Ca(2+), and NH4(+), especially K(+). Cofacial dimer formation in the presence of these cations proceeds in a two-step three stage process, as indicated by absorption and emission spectroscopy. These species have a highly specific D4h eclipsed configuration providing well defined dimeric species for spectroscopic analysis. The ESR spectrum of the cation induced dimeric CuCRPc shows axial symmetry and may be analysed in terms of an inter-planar separation of 4.1 Angstroms. The 1H NMR spectra of the cation induced metal free and zinc dimers are consistent with an eclipsed configuration. Upper excited state (Soret, S2) emission is observed for the first time in the phthalocyanine series.

Ether Cleavage with Organo‐Alkali‐Metal Compounds and Alkali Metals

Abstract: Reactions with organo-alkali-metal compounds are mostly carried out in ether-type solvents. It has long been known that ether cleavage takes place at the same time. The mechanism of the cleavage, in particular the fact that dialkyl ethers can be decomposed by a variety of mechanisms acting simultaneously, has only become clear in the most recent investigations. The observation that even with purely aliphatic ethers a considerable amount of Wittig ether rearrangement can occur is remarkable. Unusual secondary reactions can also occur by means of which alkyl- and aryllithium compounds in ether or tetrahydrofuran yield new organolithium compounds—sometimes with rearrangement. The reactions of alkyl aryl ethers with alkali metals are also varied and five different mechanisms for them have been discussed in the literature. It is interesting, for example, that the cleavage of anisole can be directed simply by changing the solvent so that in one case only cleavage of the aryl-oxygen bond occurs and in the other almost 100% cleavage of the alkyl-oxygen bond results. The formation of biphenyl as a by-product upon cleavage of the alkyl-oxygen bond in anisole was also puzzling. This was later shown to occur not through the dimerization of phenyl radicals but via 2-methoxybiphenyl. The number of cleavage mechanisms reduces to two if one assumes two different σ*-radical anions as being intermediates in the kinetically controlled reaction. Comparison of the reactivity of thioethers and ethers reveals not only gradual but also fundamental differences—the cleavage of the thioethers is thermodynamically controlled.

Ether carboxylate detergent builders and process for their preparation

Abstract: Provided herein are ether carboxylate builder compositions comprising a combination of tartrate monosuccinic acid (or salts thereof) and tartrate disuccinic acid (or salts thereof). Such mixtures can be prepared by reacting water-soluble, mixed maleic acid salts with mixed tartaric acid salts. Both components of the resulting ether carboxylate mixture act as sequestering agents and are useful as detergency builders. Detergent and laundry additive compositions incorporating these ether carboxylates can be prepared without use of detergent builder components containing phosphorus or nitrogen.

4-Vinyl-, 6-vinyl-, and 4'-vinyl-2,2':6',2"-terpyridinyl ligands: their synthesis and the electrochemistry of their transition-metal coordination complexes

Abstract: 4'-Vinyl-2,2':6',2''-terpyridinyl was conveniently prepared from 2-acetylpyridine via -oxoketene dithioacetal methodology, the intermediate 4'-(methylthio)-2,2':6',2''-terpyridinyl being converted into the corresponding 4'-methyl derivative with methylmagnesium bromide and bis(triphenylphosphino)nickel(II) dichloride followed by generation of the methyl anion with lithium tetramethylpiperidide, reaction of the anion with chloromethyl methyl ether, and introduction of the vinyl group by treatment of the ether with potassium tert-butoxide/THF. Analogous reactions led to the 4-vinyl- and 6-vinyl isomers by using the appropriate methyl-substituted 2-acetylpyridine except that in these instances desulfurization of the 4'-methylthio group with nickel boride was an addition step. These vinyl-substituted ligands formed a variety of readily electropolymerizable simple and mixed-ligand complex monomers with cobalt, ruthenium, and iron with polymerization rates whose magnitude varied with position and number of vinyl substituents.

Concentrated aqueous surfactant compositions

Abstract: Surfactant mixtures are prepared in a fluid "G" phase of more than 50% concentration, the mixtures comprise different surfactant products selected respectively from at least two of the following classes, that is to say alkyl sulphates, alkyl ether sulphates, olefin sulphonates, alkyl benzene sulphonates, alkyl sulphosuccinates, alkyl ether sulphosuccinates, alkyl sulphosuccinamates, paraffin sulphonates, fatty carboxylates, alkyl ether carboxylates, alkyl phosphates, alkyl ether phosphates, alkyl phenol sulphates, alkyl phenyl ether sulphates, alkyl phenyl ether sulphonates, fatty ester sulphonates, fatty acid sulphonates, acyl sarcosinates and acyl taurides.

Simple preparation of chiral acetylenic ethers

Abstract: Transformation d'alcools en les alcyne-1yl ethers correspondants, par reaction avec KH-trichloroethylene- butyl- lithium-, iodure d'alkyle dans le THF

Polyimide resin composition

Abstract: A polyimide resin composition, which comprises 100 parts by weight of a polyimide having repeating units represented by general formula (I), (wherein Y represents a direct bond, a divalent hydrocarbyl group having 1 to 10 carbon atoms, a hexafluoroisopropylidene group, a carbonyl group, a thio group, a sulfinyl group, a sulfonyl group or an oxido group, and R represents a tetravalent aliphatic group having 2 or more carbon atoms, alicyclic group, monocylic aromatic group, fused polycyclic aromatic group or non-fused cyclic aromatic group wherein aromatic groups are linked to each other directly or via a linking member) and 5 to 100 parts by weight of fibrous reinforcing material such as glass fibers, carbon fibers, potassium titanate fibers, aromatic polymide fibers, etc. This resin composition has excellent heat resistance, dimensional stability, and mechanical strength and is a useful material for manufacturing electric or electronic components, precision machine parts, etc. The polyimide to be used can be prepared from an aromatic ether diamine and a tetracarboxylic acid dianhydride, using 4,4'-bis(3-aminophenoxy)biphenyl, 2,2'-bis(4-(3-aminophenoxy)phenyl)propane, bis(4-(3-aminophenoxy)phenyl) sulfide, etc. as the ether diamine and pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, etc. as the tetracarboxylic acid dianhydride.

Regiocontrolled opening of cyclic ethers using dimethylboron bromide

Abstract: La reaction d'ethers cycliques avec le (bromo dimethyl) borane, en presence de triethylamine dans le dichloromethane conduit ω-bromoalcanols-1 correspondants

Acetylenes disubstituted with a phenyl group and a heterobicyclic group having retinoid-like activity

Abstract: Retinoid-like activity is exhibited by compounds of the formula ##STR1## where X is S, O or NR 1 where R 1 is hydrogen or lower alkyl; n is 0-5; R is H or lower alkyl and A is H, --COOH or a pharmaceutically acceptable salt, ester or amide thereof, --CH 2 OH or an ether or ester derivative thereof, or --CHO or an acetal derivative thereof, or --COR 2 or a ketal derivative thereof where R 2 is --(CH 2 ) m CH 3 where m is 0-4; or a pharmaceutically acceptable salt.

Enantioselective ring construction: synthesis of (+)-estrone methyl ether

Abstract: The chiral 2-oxocyclopentanecarboxylates (II) are prepared by Rh-catalyzed ring closure of the α-diazo-β-ketoesters (I).

Activation of mouse peritoneal macrophages by lysophospholipids and ether derivatives of neutral lipids and phospholipids.

Abstract: Cellular damage and inflammatory processes cause activation of phospholipase A in plasma membranes resulting in the production of various lysophospholipids Treatment of mice with L-alpha-lysophosphatidylcholine, a decomposition product of phosphatidylcholine, greatly stimulates mouse peritoneal macrophages to ingest target cells via the Fc receptors Similarly, treatment of mice with L-alpha-lysophosphatidylethanolamine and L-alpha-lysophosphatidyl-L-serine resulted in an enhanced ingestion activity of macrophages Cancer cell membranes contain alkyl ether derivatives of phospholipids and neutral lipids Inflamed cancer cells release decomposition products of alkyl ether phospholipids and neutral lipids, alkyl-lysophospholipids and alkylglycerols, respectively Administration of alkyl ether analogues of lysophospholipids into mice were able to induce stimulation of macrophages for ingestion with Fc receptor preference Two synthetic alkylglycerols, dodecylglycerol and tridecylglycerol, were tested Dodecylglycerol induced an efficient stimulation of macrophages for Fc-mediated ingestion whereas tridecylglycerol induced a minimal level of activation Therefore, in vivo effect of dodecylglycerol on macrophage stimulation is similar to that of lysophospholipids and their alkyl analogues These in vivo stimulations of macrophages for Fc receptor-mediated ingestion activity were reproduced in in vitro activation of macrophages by treatment of peritoneal cells with the alkyl lipid derivatives Among these compounds, dodecylglycerol was found to be the most potent agent for macrophage stimulation Since macrophages are antigen-presenting cells, the degradation products of cancer cell membrane lipids may have immune potentiating capacity

Polyimides containing carbonyl and ether connecting groups

Abstract: New polyimides have been prepared from the reaction of aromatic dianhydrides with novel aromatic diamines containing carbonyl and ether connecting groups between the aromatic rings. Several of these polyimides were shown to be semi-crystalline as evidenced by wide angle x-ray diffraction and differential scanning calorimetry. Most of the semi-crystalline polyimides form tough solvent resistant films with high tensile properties. One of these materials exhibits very high fracture toughness and can be thermally processed.

Aromatic-aliphatic azomethine ether polymers and fibers

Abstract: Preparation de trois series de polymeres thermotropes, filables par fusion contenant deux, trois ou quatre cycles aromatiques lies a l'azomethine, par reaction du bis(formyl-4 phenoxy)-1,2 ethane, terephtalaldehyde ou biphenyldicarboxaldehyde avec des bis(amino-4 methyl-3 phenoxy)-1,n alcane (n=1-10, 12, 14 et 16)

Chemistry of hematoporphyrin-derived photosensitizers.

Abstract: The hematoporphyrin-derived tumor-localizing preparation HPD consists of porphyrin monomers, which are‘inactive’(not tumor-localizing), and a dimer/oligomer fraction which is responsible for the localizing phenomenon. In an organic solvent system, gel-exclusion chromatography can separate HPD into fractions containing porphyrin monomers, dimers or oligomers. The relative amount of the dimer/oligomer fraction of HPD was a function of the pH of the mixture used to transform HP mono/di acetate to HPD. HPD prepared by the‘Upson’procedure contained dimer/oligomer linkages which are labile to 1 M NaOH (in 50% tetrahydrofuran), and are reduced by LiAlH4 to alcohols. These properties are characteristic of esters. But a commercial product, Photofrin II, contained approx. 50% of material refractory to both reagents described above. This behavior is characteristic of an ether linkage. These observations show that the nature of the linkage joining the porphyrin units is sensitive to conditions employed in HPD preparation. Tumor localization derives, in part, from affinity of these oligomers for plasma lipoprotein, and is associated with conformational alterations characteristic of these porphyrin-porphyrin linkages.

Lithium ion selective electrodes based on crown ethers for serum lithium assay.

Abstract: Previous Li/sup +/-selective polymeric membrane electrodes based on 14-crown-4 derivative 1 have been improved in the Li/sup +/ selectivities against Na/sup +/ and K/sup +/ by using 2 and 3 as the neutral carrier. Examination of the membrane solvents for the electrodes allowed further enhancement in the Li/sup +/ selectivities. An excellent k/sub LiNa//sup Pot/ value of 1.3 x 10/sup -3/ was attained with the poly(vinyl chloride) membrane containing 2 as the neutral carrier and o-nitrophenyl phenyl ether/tris(2-ethylhexyl) phosphate (98/2) as the solvent. Serum Li/sup +/ assay was successfully achieved with an electrode containing a combination of the optimized membrane based on the crown ether and a dialysis membrane, which eliminated interference by proteins in the samples.

Synthesis of high performance aromatic polymers via nucleophilic nitro displacement reaction

Abstract: Nucleophilic displacement reaction of activated aromatic nitro groups with various nucleophiles is a useful and versatile method for the synthesis of aromatic compounds such as ethers, thioethers and other functionalized intermediates and polymers. Various strong electron withdrawing groups can activate aromatic nitro groups. Effective activating groups include cyano, nitro, sulfone and carbonyl groups such as ester, ketone, anhydride, imide, etc. The reaction of activated nitro compounds with bisphenols and bisthiophenols yields bisethers and bisthioethers from which various aromatic polymers containing ether and sulfide groups can be derived. In many cases, nitro displacement reactions are essentially quantitative so that high molecular weight polymers are directly prepared by the displacement reaction of difunctional nitro compounds with bisphenols or bisthiophenols. Another type of unique nitro displacement occurs in the presence of catalytic amount of a nucleophile at higher temperatures resulting de-nitro coupling of two molecules of nitro compound to form substituted diarylethers.

Synthesis of aromatic poly(ether ketones)

Abstract: Preparation par polycondensation directe d'acides dicarboxyliques contenant des structures phenyle ether, avec le diphenoxybenzene ou par autopolycondensation d'acide phenoxybenzoique

Polyphenylene ether capped with salicylic acid ester

Abstract: Polyphenylene ethers are capped by reaction in the melt with an ester of salicylic acid, anthranilic acid or a substituted derivative thereof; esters of salicylic acid, and especially salicylic carbonate and linear polysalicylates, are preferred. The capping reaction typically takes place at a temperature in the range of about 225°-325° C., employing about 5-12% by weight of the ester based on polyphenylene ether.