Showing papers on "Epoxide published in 1978"

Activation of Carbon Dioxide by Tetraphenylporphinatoaluminium Methoxide. Reaction with Epoxide

Abstract: α,β,γ,δ-Tetraphenylporphinatoaluminium methoxide reacts reversibly with carbon dioxide in the presence of 1-methylimidazole, and this carbon dioxide is activated to react with propylene oxide to produce propylene carbonate under atmospheric pressure and at room temperature.

Surface-coating binders for cathodic electrocoating

Abstract: Surface-coating binders for cathodic electrocoating which comprise a protonized heat-curable reaction product (A), substantially free from epoxide groups, of (a) one or more Mannich bases, prepared from (a 1 ) one or more polyhydric condensed phenols which may or may not contain ether groups. (a 2 ) one or more secondary amines which contain one or more hydroxyalkyl groups, with or without one or more secondary amines which do not contain such groups, and (a 3 ) formaldehyde or a formaldehyde donor, with (b) one or more epoxy resins, Which binder also contains from 1 to 40% by weight, based on the total of (A) + (B), of a water-insoluble non-ionic resin (B), free from epoxide groups and containing urethane groups, which resin has been obtained by reacting a partially blocked diisocyanate or higher polyisocyanate with a reaction product of a polyepoxide and one or more low molecular weight compounds containing SH and/or OH groups. These surface-coating binders are especially used for the cathodic electrocoating of metal articles.

The Mechanism of Action of Cytochrome P‐450. Occurrence of the ‘NIH Shift’ during Hydroperoxide‐Dependent Aromatic Hydroxylations

Abstract: The mechanism of liver microsomal aromatic hydroxylation has been investigated by using cumene hydroperoxide as the hydroxylating agent and comparing this reaction with the NADPH-dependent reaction. The conversion of [4-3H]acetanilide to 4-hydroxyacetanilide by rat liver microsomes (or purified cytochrome P-450) in the presence of either cumenc hydroperoxide or NADPH is attended by comparable ‘NIH shifts’. This indicates that hydroxylation in the two systems proceeds via a common intermediate, presumably an arene oxide. The intermediacy of an arene oxide, phenanthrene-9,10-oxide, is established by incubating [3-3H]-phenanthrene with rat-liver microsomes and cumene hydroperoxide in the presence of either non-radioactive phenanthrene-9,10-oxide as a ‘trap’ or in the presence of cyclohexene oxide, an inhibitor of the enzyme epoxide hydrase. Incubation of phenanthrene with cumene hydroperoxide in an 18O-enriched medium has confirmed that the oxygen atom in phenanthrene-9,10-oxide is derived from the hydroperoxide and not from the medium.

Radioactive assay of aryl hydrocarbon monooxygenase and epoxide hydrase.

Abstract: Publisher Summary The purpose of this chapter is to provide information on the radioactive assay of aryl hydrocarbon monooxygenase and epoxide hydrase. Polycyclic hydrocarbons are found in cigarette smoke and in the waste products of our technology and may be a major cause of cancer in human beings. Assay of epoxide hydrase using styrene oxide is very simple; extraction with petroleum ether removes remaining substrate, while the product styrene glycol is retained in the aqueous incubation medium. The first step in the metabolism of these compounds by mammalian tissues is catalyzed by the NADPH-dependent, cytochrome P-450-1inked monooxygenase system localized on the endoplasmic reticulum, and the first product is an epoxide. A number of alternative assay procedures for epoxide hydrase are also reported, including procedures where an epoxide of a polycyclic hydrocarbon is used as substrate and the products are separated from remaining substrate by gas chromatography or by high-pressure liquid chromatography.

Chelate resins prepared from the cured reaction product of a polyalkylenepolyamine and epoxide

Abstract: Chelate resins are obtained by introducing an effective amount of chelate active groups into the cured reaction product of an epoxide and a polyalkylenepolyamine. For example, an alkali metal salt of a halogenated carboxylic acid such as sodium chloroacetate, is reacted with the reaction product of triethylenetetraamine and diglycidyl ether of bisphenol A to form a chelate resin.

Bonding method employing film adhesives containing an epoxide resin

Abstract: A layer of a liquid composition containing an epoxide resin as the sole photopolymerizable component, a heat-activated curing agent for epoxide resins, and preferably a photopolymerization catalyst, is exposed to actinic radiation until the layer solidifies to form an essentially solid, continuous film due to photopolymerization of the epoxide resin through epoxide groups, the resin remaining, however, still thermosettable by virtue of residual epoxide groups. The film so formed is sandwiched between, and in contact with, surfaces to be bonded together, and the assembly is heated to cure the epoxide resin.

A direct synthesis of monocarbamic ester of 1,2-diol from carbon dioxide, epoxide and amine

Abstract: Monocarbamic ester of 1,2-diol derived from the corresponding 1,2-epoxide was obtained directly in a good yield by the reaction of epoxide, carbon dioxide, and primary or secondary amine.

[19] Purification and assay of liver microsomal epoxide hydrase

Abstract: Publisher Summary This chapter describes the purification and assay of liver microsomal epoxide hydrase. Microsomal epoxide hydrase catalyzes the hydration of a variety of arene and alkene oxides. The most commonly used substrate is styrene oxide because of its relative stability, commercial availability, and ease of assay. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS) shows that the purified liver microsomal epoxide hydrase is nearly homogeneous and contains a single polypeptide with a molecular weight of 53,000-54,000. Other studies indicate that in the absence of SDS, the purified enzyme in aqueous solution exists as high-molecular-weight aggregates. In addition to styrene oxide, the purified epoxide hydrase can also catalyze the hydration of many simple epoxides, K-region and non-K-region arene oxides of polycyclic aromatic hydrocarbons. The assay of these substrates is facilitated by the development of a sensitive and rapid thin-layer chromatographic assay based on the separation of radioactive substrates and their dihydrodiol products on silica gel.

Studies on Steroids. LI. Stereoselective Introduction of 22- and 24-Hydroxyl Function in the Steroidal Side Chain

Abstract: Osmium tetroxide oxidation of the 22-olefin (4) and reaction of sodium dimethylsulfonium methylide with the 22-aldehyde (3a) afforded stereoselectively the 22S-and 22R-epoxides (7a and 7b), respectively. Those epoxide can be led to the 22R- and 22S-hydroxy steroides by Grignard reaction. Inversion of the configuration of hydroxyl group on C-22 and C-24 positions was achieved in high yield by means of superoxide displacement reaction.

Syntheses of 1,2-N-alkylimino-1,2,3,4-tetrahydronaphthalene derivatives and preparation of ring closed analog of salbutamol as a new beta-adrenoceptor agent.

Abstract: A method for preparing 5-substituted 2-tertiary-alkylamino-6-hydroxy-1, 2, 3, 4-tetrahydro-1-naphthalenols was described. The method involves the preparation of 1-alkylamino-2-hydroxy-1, 2, 3, 4-tetrahydronaphthalenes from 2-bromo-1-hydroxy derivatives via 1, 2-epoxides followed by the transposition of 1-alkylamino and 2-hydroxy groups via the ring closure to 1, 2-aziridines. Formation of the epoxides and aziridines and the reaction of epoxides with amines were examined in detail. The ring-opening reaction of epoxides was regioselective and the attacking position of a nucleophile was not affected by the electronic effects of substituents on the benzene ring. Cyclization into aziridine rings was best accomplished by the Wenker method using a sulfur trioxide-triethylamine adduct as the sulfating agent. Using our process, trans-2-tert-butylamino-6-hydroxy-5-hydroxymethyl-1, 2, 3, 4-tetrahydro-1-naphthalenol (70) was synthesized as conformationally fixed analog of salbutamol.

Process for the manufacture of crystalline, crosslinked epoxide resins

Abstract: The invention relates to the manufacture of crystalline epoxide resins which have at least two crystallite melt temperatures. The cause of the crystallites are molecule blocks which are derived from aliphatic polyesterpolycarboxylic acids. According to the invention, at least two aliphatic polyester-polycarboxylic acids (D and E), which bear a special relation to each other in respect of the number of --CH 2 groups in the primary chain member, are reacted under very specific quantitative conditions with epoxide compounds which contain at least 2 epoxide groups and optionally with curing agents. The synthetic resins thereby obtained are particularly suitable for use as storage material in latent heat accumulators.

Copolymerization of 2-Hydroxy.(2,3-epoxypropoxy)benzophenone with Phthalanhydride Catalyzed by Tertiary Amine

Abstract: The copolymerization of an epoxide, 2-hydroxy-4-(2,3-epoxy-propoxy)benzophenone, with cyclic anhydride catalyzed by tertiary amine in different solvents was studied. The copolymerization curves are sigmoidal in character with an induction period. In the region following the induction period, the loss in epoxide or anhydride may be correlated with the kinetic equation of the first order reaction provided the monomers are present in equimolar ratio or anhydride is in excess with respect to epoxide. The rate constant found experimentally after the induction period depends on the first power of the concentrations of amine, epoxide, and anhydride. The activation energy of copolymerization in o-xylene is 58.2 kJ/mole (13.9 kcal/mole) and log A = 3.6. The rate of copolymerization depends on polarity of the solvent and increases with dielectric constant. A reaction scheme has been proposed for the copolymerization of epoxides with cyclic anhydrides catalyzed by tertiary amines which involves the formatio...

Fiber lubricants derived from polyethoxylated and polyoxyalkylated reaction products of an alpha-olefin epoxide and a fatty alcohol

Abstract: FIBER LUBRICANTS DERIVED FROM POLYETHOXYLATEDAND POLYOXYALKYLATED REACTION PRODUCTS OF AN ALPHA-OLEFIN EPOXIDE AND A FATTY ALCOHOL Abstract of the Disclosure Lubricants and processing aids for thermoplastic synthetic fibers, particularly polyester and nylon fibers are disclosed together with processes therefor. Said lubri-cants comprise compounds having the structural formula: in which R and R1 are independently selected from straight or branched chain aliphatic radicals having about 7 to about 22 carbon atoms; A is oxyethylene or a heteric mixture of oxyethylene and oxypropylene residues derived from the reaction of ethylene oxide and 1,2-propylene oxide in the respective ratio by weight of about 3:7 to about 9:1; and n has a value to produce a compound having a molecular weight of about 300 to about 3000. Said compounds are the ethoxylated or alkoxylated reaction product of the reaction product of an alpha-olefin epoxide and a fatty alcohol. Where liquid products are desired which contain the higher numbered carbon chain residues, low viscosity compounds can be obtained by oxyalkylating the intermediate obtained by reacting an alpha-olefin epoxide with a fatty alcohol using an ethylene oxide and 1,2-propylene oxide mixture in the respective ratio as set forth above. By properly balancing the carbon chain length of the R and R1 groups in the lubricant compounds with the oxyethylene or oxyalkylene ratio, variation between insoluble and soluble products can be obtained.

Terpene hydroxysulfonic acids and corresponding hydroxysulfonate salts

Abstract: Optically active terpene hydroxysulfonate salts are made by sulfonating an optically active terpene epoxide of the p-menthane family, with a sulfonating agent selected from a sulfite, a bisulfite, or a thiosulfate.

Metal salt/amine complexes

Abstract: Novel carboxylic acid metal salt/amine complexes of the formula (A.sup.⊖).sub.2 Me.sup.2+ ·NH.sub.2 --R.sub.1 --NH.sub.2 in which A is the anion of cyanoacetic acid, pyrrolidonecarboxylic acid, maleimidylcarboxylic acid, succinylimidylcarboxylic acid, benzenesulphonic acid or toluenesulphonic acid or of a methanephosphonic acid monoester or benzenephosphonic acid monoester, Me 2+ is a divalent metal cation and R 1 is a long-chain polyoxyalkylene radical, are obtained by reacting 1 mol of a carboxylic acid metal salt of the formula (A.sup.⊖).sub.2 Me.sup.2+ with 1 mol of a diamine of the formula H.sub.2 N--R.sub.1 --NH.sub.2 in a polar organic solvent and in the temperature range of 25° to 200° C. to give the complex compounds of the formula. The novel complex compounds are valuable curing agents for epoxide resins and in mixtures with epoxide resins have an advantageous storage stability.

Cyanamides of organic primary amines as epoxy curing agents

Abstract: Curable compositions are prepared comprising an epoxide compound or a mixture of epoxide compounds having an average of at least two epoxide groups per molecule, and as a curing agent, a cyanamide of an organic primary amine or a mixture of cyanamides of organic primary amines having an average of more than one cyanamide moiety per molecule. Such compositions are useful in molding, casting, laminating and coating applications.

Photochemical and thermal reactions of heterocycles. Part 2. Photolysis of 2,3-diphenylnaphthoquinone 2,3-epoxide: trapping of a cyclic carbonyl ylide and photoisomerisation

Abstract: Photolysis of 2,3-diphenylnaphthoquinone epoxide (1) caused epoxy-carbon–carbon bond cleavage to form a cyclic carbonyl ylide (4), which was trapped by dipolarophiles. The norbornadiene primary adduct (3) underwent further photochemical isomerisation, via methylenephthalide derivatives (5), to spiro[oxetan-phthalide] derivatives (7), which reverted thermally to methylenephthalides (5). Thermal fragmentation of an oxabicycloheptadiene adduct (18a) gave a formal acetylene adduct (11) and a furan (21). Carbon-13 n.m.r. spectroscopy was useful in establishing the structures of the products. Photolysis of the epoxide (1) in the absence of a dipolarophile gave 3-(α-benzoylbenzylidene)phthalides (24).

Powder coating compositions containing an epoxide resin and an acid hardener

Abstract: Powder coating compositions comprise an epoxide resin and a carboxylic acid of formula ##STR1## where R1 represents a phenylene or naphthylene group or a group comprising 2 or 3 phenylene radicals linked by one or two carbon-carbon bonds, ether oxygen atoms, sulfur atoms, or sulfonyl, sulfoxide, carbonyl or alkylene groups, R2 represents a saturated alkyl group, a benzenoid group or an aralkyl group, and both n are the same and represent zero or 1.

Aluminum chloride catalyzed Friedel-Crafts reaction of anisole with epoxide accompanying isomerization.

Abstract: The reaction of anisole with propylene oxide by aluminum chloride has been studied in various kinds of solvents. While the normal Friedel-Crafts reaction yielded 2-(methoxyphenyl)-1-propanols, 1,1-bis(methoxyphenyl)-propanes were also formed in this reaction; these were not obtained by the subsequent reaction of mono(methoxyphenyl) products with another anisole. The yields of 1,1-bis(methoxyphenyl)propanes increased by increasing the basicity of solvents. The mechanism of the formation of 1,1-bis(methoxyphenyl)propanes can be explained by the isomerization of epoxide to aldehyde and the subsequent condensation with anisole. Various kinds of epoxides also gave 1,1-bis(methoxyphenyl)alkanes in nitromethane.