- PROCESSES FOR PREPARING 4-METHYL-5-NONANONE AND 4-METHYL-5-NONANOL
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The present invention provides a process for preparing 4-methyl-5-nonanone of the following formula (3), the process comprising at least a step of subjecting pentanoic anhydride of the following formula (1) and a 2-pentyl nucleophilic reagent of the following general formula (2), in which M represents Li, MgZ1, or ZnZ1, wherein Z1 represents a halogen atom or a 2-pentyl group, to a nucleophilic substitution reaction to produce 4-methyl-5-nonanone (3), as well as a process for preparing 4-methyl-5-nonanol of the following formula (7), the process comprising at least steps of preparing 4-methyl-5-nonanone and subjecting the obtained 4-methyl-5-nonanone and a reducing agent to a reduction reaction to produce 4-methyl-5-nonanol (7).
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Paragraph 0161-0170
(2020/07/14)
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- Highly selective halogenation of unactivated C(sp3)-H with NaX under co-catalysis of visible light and Ag@AgX
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The direct selective halogenation of unactivated C(sp3)-H bonds into C-halogen bonds was achieved using a nano Ag/AgCl catalyst at RT under visible light or LED irradiation in the presence of an aqueous solution of NaX/HX as a halide source, in air. The halogenation of hydrocarbons provided mono-halide substituted products with 95% selectivity and yields higher than 90%, with the chlorination of toluene being 81%, far higher than the 40% conversion using dichlorine. Mechanistic studies demonstrated that the reaction is a free radical process using blue light (450-500 nm), with visible light being the most effective light source. Irradiation is proposed to cause AgCl bonding electrons to become excited and electron transfer from chloride ions induces chlorine radical formation which drives the substitution reaction. The reaction provides a potentially valuable method for the direct chlorination of saturated hydrocarbons.
- Liu, Shouxin,Zhang, Qi,Tian, Xia,Fan, Shiming,Huang, Jing,Whiting, Andrew
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p. 4729 - 4737
(2018/10/23)
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- Synthesis of chlorothioformates from xanthates
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The Vilsmeier reagent derived from N-formylmorpholine produces chlorothioformates from primary and secondary alkyl xanthates. The major side products are the corresponding alkyl chlorides. Secondary alkyl chlorothioformates give lower yields due to their instability. Treating xanthates with other common chlorinating agents (oxalyl chloride, thionyl chloride) gives only dialkyl thiodicarbonates. Georg Thieme Verlag Stuttgart.
- Fikse, Megan A.,Bylund, William E.,Holubowitch, Nicolas E.,Abelt, Christopher J.
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p. 4118 - 4120
(2008/03/13)
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- Process for preparing monochlorinated hydrocarbons having a high isomeric purity
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Monochlorinated hydrocarbons of high isomeric purity are prepared by a process, which comprises: reacting a monoalcohol having an alkyl radical having from 3 to 20 carbon atoms with cyanuric chloride; and purifying the resulting monochlorinated hydrocarbon by distillation after separation of salts and washing the monochlorinated hydrocarbon with alkali. The invention relates to a process for preparing monochlorinated hydrocarbons which contain an alkyl radical having from 3 to 20 carbon atoms and have a high isomeric purity by reacting a monoalcohol having a hydrocarbon radical containing an alkyl radical having from 3 to 20 carbon atoms to which additional cycloaliphatic radicals, aryl radicals, aralkyl radicals and alkylaryl radicals may be bound with cyanuric chloride, separating off salts, washing the reaction mixture with alkali and purifying the resulting monochlorinated hydrocarbons by distillation.
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- Reactivity of bismuth(III) halides towards alcohols. A tentative to mechanistic investigation
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The reactivity of bismuth(III) halides (BiX3; X=Cl, Br and I) towards a series of alcohols has been investigated. Three different reactions have been studied, namely: halogenation, dehydration and etherification. The behaviour of these bismuth derivatives was found to depend on the nature of the halide bonded to the bismuth atom. Their reactivities can be interpreted on the basis of the Hard and Soft Acids and Bases (HSAB) principle. A mechanism is proposed which involves the formation of a complex of the alcohol with Bi(III).
- Keramane, El Mehdi,Boyer, Bernard,Roque, Jean-Pierre
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p. 1909 - 1916
(2007/10/03)
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- Reactivity of Alkaneselenyl Bromide: Conversion of Alcohols into the Corresponding Alkyl Bromides with Dialkylselenium Dibromide
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The reaction of alcohols with dialkylselenium dibromide gave the corresponding bromides in moderate to high yields.Alkaneselenyl bromide, produced by the thermal decomposition from dialkylselenium dibromide, acts as a brominating agent.The reaction of alcohol with dialkylselenium dichloride afforded the corresponding chlorides, although the yields were realtively low compared with those of the bromide.
- Akabori, Sadatoshi,Takanohashi, Yoshinori
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p. 3482 - 3484
(2007/10/02)
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- HYDROCHLORINATION OF UNSATURATED COMPOUNDS BY THE ACTION OF CH2Cl2 OR CHCl3 AND RHODIUM COMPLEXES
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A new method has been developed for the catalytic hydrochlorination of olefins and acetylenes in the presence of Rh complexes by means of HCl generated in situ from CH2Cl2 and CHCl3 under the reaction conditions.The reaction was studied using the hydrochlorination of propylene, 1-hexene, 1-nonene, vinylcyclopropane, 1,1-dicyclopropylethylene, cyclohexene, cyclooctene, norbornene, and 1,5-cyclooctadiene as examples.
- Khusnutdinov, R. I.,Shchadneva, N. A.,Dzhemilev, U. M.,Tolstikov, G. A.
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p. 1213 - 1217
(2007/10/02)
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- α,α-DICHLOROALDEHYDES AND α,α-DICHLOROCARBOXYLIC ACIDS FROM LONG CHAIN 1-ALKANOLS. IMPROVED CHLORINATION IN THE SYSTEM DMF-CHCl3-MgCl2
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Production of α,α-dichloroaldehydes by direct chlorination of 1-alkanols with chlorine gas, catalyzed by DMF and DMF*HCl, was extended to long chain compounds (CnH2n+1OH; n = 5, 6, 8, 10, 12, 14, 16, 18).Two problems specific to the longer chains were solved to obtain isolated yields in the range 70-85 percent; a) parasitic radical chlorination was largely controlled by shielding from light; b) alkyl alkanoate side product (8 percent for n = 8 but 25 percent for n = 16 or 18) was decreased to 0-2 percent in the presence of MgCl2*H2O.Homogeneity of the reaction medium was improved with chloroform as a cosolvent.Oxidation of the aldehydes to dichlorocarboxylic acids proceeded smoothly with aqueous KMnO4 up to the tetradecanal.For the longer chains 30 percent hydrogen peroxide-NaHCO3 in acetone (overnight at 48-52 deg C) was the preferred oxidant.
- Buyck, L. De,Casaert, F.,Lepeleire, C. De,Schamp, N.
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p. 525 - 534
(2007/10/02)
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- Chlorine Atom/Benzene System. 1. The Role of the 6-Chlorocyclohexadienyl Radical
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The concept of radical reactivity mediated by solvation has rested mainly on the alteration of Cl. properties by aromatic solvents.For this reason, the full scope of the benzene/Cl. system has been reexamined to evaluate the discription of that system based largely on a ?-complex (solvation).At the present time, the ?-complex description rests narrowly on the assignment of a 490-nm absorption, which, even if correct, could not provide an unambiguous structure assignment.Results are presenteed which described the selectivities in alkane substitutions as a function of the concentrations of both benzene and the alkane.Selectivities increase with decreasing alkane concentrations, reaching a plateau below 0.1 M alkane.The change in selectivity is the result of variable contributions of both a low- and a high-selectivity intermediate, LSI and HSI, respectively.The observed selectivity at a given and is the consequence of a unique / ratio.A range of substrates and their effect of DMB selectivity were studied, and from these results details regarding the chemistry of the HSI were extracted.Several features of the LSI/HSI equilibrating system are realized. (1) Reaction of alkyl radicals with Cl2 in benzene produces the LSI, (2) the LSI does not exhibit the characteristics of free chlorine atom, and (3) at alkane concentrations and , added reagents (T) which react with CCH, such as maleic anhydride (MA) or Cl2, bring about an increase in the LSI/HSI ratio.Low-selectivity hydrogen abstractions (LSI function) are best ascribed to a mixture of chlorine atom and chlorine atom/benzene ?-complex.The chemistry of CCH is as follows: (1) loss of the ipso H to O2 yielding PhCl and HO2., (2) reactions of Cl2 or (3) maleic anhydride with the aromatic nucleus of CCH resulting in additions to the ring, (4) the transfer of Cl to alkenes, and (5) the highly selective retardation of rates of reaction with alkanes producing alkyl radicals, HCl, and benzene.The results of a kinetic analysis, accounting for the effect of , , and CCH trapping agents (T), are presented.For CCH, the following reactivity order is established: maleic anhydride (6) > trans-dichloroethene(5) > 2,3-dimethylbutane (2) > pentane (1) > Cl2 > neopentane ( 2 (27) > 1 .These properties can be rationalized with canonical structures for CCH wherein spin density at carbon, chlorine, and the ipso hydrogen makes contributions to the hybrid.
- Skell, Philip S.,Baxter, Harry N.,Tanko, James M.,Chebolu, Venkatasuryanarayana
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p. 6300 - 6311
(2007/10/02)
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- Silylaminyl Radicals. Part 2. Free Radical Chain Halogenation of Hydrocarbons using N-Halogenobis(trialkylsilyl)amines
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The liquid-phase halogenation of a number of hydrocarbons and of 1-chlorobutane by N-halogenobis(trialkylsilyl)amines has been studied using product analysis techniques.The reactions take place by free radical chain mechanisms which involve the propagation steps generalised in equations (A) and (B) (X=Br or Cl).At 353 K, the molar reactivities of toluene (benzylic C-H) and cyclohexane towards (R3Si)2N+RH(R3Si)2NH+R (A) R+(R3Si)2NXRX+(R3Si)2N (B) (Me3Si)2N are approximately equal and toluene is 5.2 times more reactive than perdeuteriotoluene.The relative rates of hydrogen abstraction by (Me3Si)2N and (ButMe2Si)2N from the primary, secondary, and tertiary C-H groups in 2-methylbutane show that the silylaminyl radicals are not only highly reactive but also sterically demanding.Thus, at 333 K the average primary C-H reactivity is 0.6 times that of the tertiary C-H towards attack by (Me3Si)2N, but 4.2 times that of the tertiary C-H towards attack by the more bulky (ButMe2Si)2N.Silylaminyl radicals are much more reactive in hydrogen abstraction than are analogous dialkylaminyl radicals and this difference is interpreted in terms of thermodynamic and polar effects which arise because of the ?-donor-?-acceptor nature of the trialkylsilyl substituent.
- Cook, Malcolm D.,Roberts, Brian P.,Singh, Karamjit
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p. 635 - 644
(2007/10/02)
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