Showing papers on "Norbornene published in 1972"

Studies in azide chemistry. Part V. Synthesis of 4-azido-2,3,5,6-tetrafluoro-, 4-azido-3-chloro-2,5,6-trifluoro-, and 4-azido-3,5-dichloro-2,6-difluoro-pyridine, and some thermal reactions of the tetrafluoro-compound

Abstract: 4-Azido-2,3,5,6-tetrafluoropyridine can be prepared by nitrosation of 2,3,5,6-tetrafluoro-4-hydrazinopyridine or, preferably, treatment of pentafluoropyridine with sodium azide in acetonitrile, a reagent that converts 3-chloro-2,4,5,6-tetrafluoro- and 3,5-dichloro-2,4,6-trifluoro-pyridine into 4-azido-3-chloro-2,5,6-trifluoro- and 4-azido-3,5-dichloro-2,6-difluoro-pyridine, respectively. 4-Azido-2,3,5,6-tetrafluoropyridine decomposes smoothly into nitrogen and an intractable solid at temperatures above ca. 130 °C, undergoes the Staudinger reaction with tri-phenylphosphine at room temperature, reacts with dimethyl sulphoxide at elevated temperatures to give a sulphoximide, partakes in 1,3-dipolar cycloaddition reactions with benzyne, diphenylacetylene, phenylacetylene, cyclopentadiene dimer, and norbornene, yields 4-anilino-2,3,5,6-tetrafluoropyridine with benzene at 175 °C, and reacts with cyclohexane to give the C–H ‘insertion’ product 4-(cyclohexylamino)-2,3,5,6-tetrafluoropyridine and 4-amino-2,3,5,6-tetrafluoropyridine. Thermal decomposition of the azide in a mixture of cyclo-hexane, -heptane, and -octane reveals that C–H ‘insertion’ is encouraged by increase in ring size, and thermolysis experiments with cis- and trans-1,2-dimethylcyclohexane show that this type of reaction lacks stereospecificity. The results of reactions between the azide and trans-4-methylpent-2-ene at elevated temperatures indicate that 1,3-dipolar cycloaddition occurs before nitrene generation can be achieved. Authentic samples of the new amino-pyridines [PhNHpyF, cyclo-CnH2n–1·NHpyF(n= 6, 7, or 8), cis- and trans-cyclo-1,2-Me2C6H9·NHpyF, and cis- and trans-Pri[graphic omitted]pyF(pyF= 2,3,5,6-tetrafluoro-4-pyridyl)] encountered in this work can be obtained via nucleophilic attack by the appropriate amines on pentafluoropyridine.

Radiation convertible norbornene polymers

Abstract: Polymers containing a norbornenyl group are readily crosslinked by irradiation to produce insoluble products. The crosslinked products are useful as coatings on wood, metal, etc., as selfsupporting films, wire insulation, for the treatment of fabrics to render them more durable and crease resistant, as well as in the many known areas in which synthetic polymers are employed such as the production of molded and extruded shaped articles.

The Stereochemistry of the Addition of Two Diazoalkanephosphonates to Norbornene and Norbornadiene; Photolysis of the Adducts. An Entry into the Dimethyl tricyclo[2.1.1.02.4]octyl Phosphonate System

Abstract: Dimethyl phenyldiazomethyl- and methyldiazomethylphosphonates were treated with norbornene and norbornadiene and the configuration of the Δ1-pyrazolines obtained (3–8) was deduced from n.m.r. by using the dihedral angular dependence relationship of vicinal 31P,1H couplings. The adducts were photolyzed under sensitized and non-sensitized conditions. The resulting cyclopropyl derivatives (9–12 and 14–17) were assigned configuration by using n.m.r. data. The results are discussed in terms of steric and electronic factors. The n.m.r. and mass spectral data are also discussed.

Crystal and molecular structure of 7-oxabicyclo[2,2,1]hept-5-ene-2,3-exo-dicarboxylic anhydride

Abstract: The crystal and molecular structure of the title compound (I) has been determined by three-dimensional X-ray analysis from 750 non-zero reflexions measured photographically. The compound crystallizes in the orthorhombic system, space group P212121 with a= 7·00 ± 0·02, b= 18·93 ± 0·03, and c= 5·38 ± 0·01 A, Z= 4. The crystal structure has been solved by the symbolic addition procedure applied to non-centrosymmetric crystals, and refined by least-squares calculations to R 0·087. The compound has the exo-conformation. The introduction of an oxygen atom in position 7 of the norbornene skeleton produces interesting modifications in some bond distances and angles.

Production of polyalkenmers from monomers of norbornene structure containing polar groups

Abstract: Certain specified norbornene derivatives are polymerised with ring-opening using W, Mo or Ta compounds together with organoaluminum compounds.

Synthesis of norbornene episulfides using arenethiosulfenyl chlorides

Abstract: Preparation of new kinds of norbornene episulfides by use of arenethiosulfenyl chlorides has been investigated. Norbornene and 7,7-dimethylnorbornene afforded exo and endo epithio derivatives, respectively. Norbornadiene gave a mixture of exo and endo monoepithio compounds. The structure of the episulfides and of the intermediately formed adducts of the norbornenes with the chlorides is discussed on the basis of nmr spectra.

Addition of ICl to Norbornene. The Preparation and Photochemical Isomerization of syn-7-Iodonorbornene

Abstract: The addition of ICl to norbornene in the presence of pyridine yields nortricyclyl iodide (1c), endo-2-chloro-exo-3-iodonorbornane (2c), and syn-7-iodo-exo-2-chloronorbornane (3b) as the major products. Base-catalyzed elimination of HCl from 3b yields syn-7-iodonorbornene (6a) which is isomerized photochemically to anti-7-iodonorbornene (6b).

Studies in the norbornene series. Part I. Elucidation of the structure of norbornene derivatives by use of the nuclear magnetic resonance shift reagent trisdipivaloylmethanatoeuropium(III), the nuclear Overhauser effect, and mass spectrometry

Abstract: An assessment of n.m.r. and mass spectral methods shows that the nuclear Overhauser effect and the shift reagent trisdipivaloylmethanatoeuropium(III) are particularly valuable in assigning the structure and stereochemistry of substituted norbornenes and of norbornanes carrying a fused heterocycle. Mass spectra support the structural assignments.

The Reaction of Norbornene with Lead Tetraacetate and Thallium Trinitrate. Preliminary communication

Abstract: The reaction of norbornene with lead tetraacetate is found to be much more complex than previously reported. In acetic acid and in benzene, the syn-7-norbornenyl, 3-nortricyclyl, and syn and anti-7-acetoxy-exo-2-norbornyl acetates were characterized. In methanol, the isolated products represented most of those expected from the competition of methanol and acetate in the neutralization of the intermediate carbocations. The reaction of norbornene with thallium trinitrate in the above solvents yielded very complex mixtures besides the above mentioned products which were formed in about 50% yield.

Stereocontrolled synthesis of a prostanoid synthon by oxidative cleavage of substituted norbornene derivatives

Abstract: Novel cyclopentanoid precursors (±)-2α-cyanomethyl-1α,4α-diacetoxy-3β-methoxymethylcyclopentane (21) and (±)-2α-cyanomethyl-1α,4α-diacetoxy-3β-trityloxymethylcyclopentane (25) for the prostanoids have been prepared by oxidative cleavage of substituted norbornene diethers [(4) and (6)], and their utility demonstrated by conversion into the known prostaglandin intermediates (27) and (28).

Stereochemistry of Free-radical Additions in the Bicyclo[2.2.1]heptene and Bicyclo[2.2.1]heptadiene Series

Abstract: The stereochemistry of free-radical additions to norbornene and norbornadiene systems is examined. The dependence of the direction of radical attack on the degree of substitution of the bicyclene, and on the position and steric and electronic effects of the substituents is discussed. A mechanism of radical rearrangement of the corresponding norbornene radicals is considered. 109 references.

High‐resolution NMR spectra of the polysulfones of six monolefins

Abstract: 100-MHz NMR spectra are reported for solutions of the 1:1 copolymers of sulfur dioxide with hex-1-ene, cis- and trans-but-2-enes, cyclohexene, cyclopentene, and norbornene, including the deuterated polymers made from hex-1-ene-2-d1, cis- and trans-but-2-ene-2,3-d2, and cyclohexene-3,3,6,6-d4. The resolution of the spectrum of poly-(hex-1-ene sulfone) was very poor in CCl4 as solvent but good in polar solvents. The main-chain CH2 protons are nonequivalent, and their chemical shifts show sensitivity to dyad structure; the α-CH2 protons are also non-equivalent. The spectra of most of the other polymers are discussed in terms of possible preferential modes of addition as well as tacticity effects.

Spectroscopic examination of ethylene–propylene–norbornenic diene terpolymers

Abstract: Infrared methods for the analysis of the third monomer in ethylene–propylene–norbornenic diene terpolymers were developed. They are based either on the CC stretching vibration near 6 μ or on the CH out-of-plane deformation vibration between 11 and 12 μ. Calibration was made by NMR on selected samples with high unsaturation content. Particular emphasis was laid on terpolymers with ethylidene norbornene, for which the reliability of the analysis for the third monomer was checked by several techniques, and the transferability to the determination of propylene of the calibration curves set up for the analysis of composition in ethylene–propylene copolymers was studied.

Petroleum crude oils having improved flow properties and reduced tendency to deposit wax

Abstract: 1,267,604. Olefin polymers. ESSO RESEARCH & ENG. CO. 1 Aug., 1969 [16 Sept., 1968], No. 38644/69. Heading C3P. [Also in Division C5] Additives for improving the flow characteristics of crude petroleum comprise of polymer of molecular weight 500 to 125,000 and comprising 20 to 100 weight per cent of a C 18-40 α-olefin and 0 to 80 weight per cent of C 3-16 α-olefin, or aryl or cycloaliphatic derivative thereof, and/or a C 6-28 diolefin, which may be prepared by polymerization in inert hydrocarbon diluents in the presence of catalysts comprising a compound of a Group IV, V or VI metal and an organo compound of a Group I, II or III metal. Many suitable monomers are listed and examples describe the preparation in the presence of catalysts comprising aluminium activated titanium trichloride and aluminium triethyl or tripropyl of polymers of (1) n-eicosene-1 (2) propylene and C 22-28 α-olefins, (3) butene-1 and C 22 α-olefin and (4) octadecene-1/propylene, eicosene-1/propylene, docosene-1, docosene-1/ butene-1, docosene-1/hexene-1, docosene-1/ hexene - 1/dicyclopentadiene, docosene - 1/ hexene-1/methylene norbornene, docosene- 1/ styrene, C 22-28 ½-olefin/styrene and C 22-28 a-olefin/4-methylpentene-1.

Sulfur dioxide removal via polymer formation

Abstract: SULFUR DIOXIDE IS SELECTIVELY REMOVED FROM A GAS MIXTURE SUCH AS FLUE GAS BY CONTACTING THE GAS MIXTURE WITH A DERIVATIVE OF NORBORNENE AT A TEMPERATURE OF ABOUT 0* TO 100*C. THE RESULTING POLYMER CAN BE THERMALLY DECOMPOSED AT TEMPERATURES ABOVE ABOUT 150*C., THEREBY MAKING REPEATED CYCLIC DESULFURIZATION AND REGENERATION POSSIBLE.

Vapor phase preparation of norbornenes

Abstract: NORBORNENE AND ALKYL SUBSTITUTED NORBORNENES ARE MADE BY CONDENSING OLEFINS SUCH AS ETHYLENE, PROPYLENE, ETC. WITH DICYCLOPENTADIENE IN THE VAPOR PHASE IN A PRESSURIZED REACTOR. THE USE OF A SUBSTANTIAL EXCESS OF OLEFIN AND THE USE OF CONDITIONS USCH THAT THE PRODUCTS AND THE REACTANTS ARE IN THE VAPOR PHASE SUBSTANTIALLY ELIMINATES BY-PRODUCTS.

1,3-Dipolar Addition Reactions of Some Bisdiazo Compounds with Mono and Diolefins

Abstract: : Bisdiazoterephthalaldehyde, para-bisdiazobenzoylbenzene and meta-bis-diazobenzoylbenzene were synthesized as dicarbene precursors. Simultaneous dicarbene formation and olefinic insertion was attempted. However, what was observed was 1,3-dipolar addition of the bisdiazo compounds and strained olefinic systems such as norbornene and norbornadiene. Nuclear magnetic resonance spectroscopy indicates that the stereo-chemistry of the adducts formed lead to some large chemical shifts. Polymerization was also attempted between meta-bisdiazobenzoylbenzene and norbornadiene.