Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
  • C07C5/22—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by isomerisation
  • C07C5/27—Rearrangement of carbon atoms in the hydrocarbon skeleton
  • C07C5/31—Rearrangement of carbon atoms in the hydrocarbon skeleton changing the number of rings
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
  • C07C5/32—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by dehydrogenation with formation of free hydrogen
  • C07C5/373—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by dehydrogenation with formation of free hydrogen with simultaneous isomerisation

Definitions

• This invention is directed to the preparation of cycloolefins from open chain conjugated diolefins. More particularly, it is directed to the preparation of cyclopentene and cyclopentadiene from 1,3-pentadiene and methyl substituted cyclopentadiene and methyl substituted cyclopentenes from methyl substituted 1,3-pentadienes and methyl substituted cyclopentenes and methyl substituted cyclopentadienes and cyclohexadienes from open chain conjugated hexadienes, such as 1,3-hexadiene and 2,4- hexadiene.
• Cycloolefins and cyclo diolefins are presently obtained in limited quantities as by-products as naphtha and gas oil cracking.
• the naphtha and gas oil crackers are operated in a manner to produce maximum amounts of ethylene and other cycloolefins. Therefore, only limited quantities of cycloolefin and cyclo diolefin are available for use as starting materials to prepare other products such as resins, insecticides and the like.
• 1,3-pentadiene and methyl substituted 1,3-pentadiene which are not now utilized could be employed to produce more valuable products.
• 1,3- and 2,4-hexadiene could be utilized in accordance with this invention to produce more valuable methyl substituted cyclopentadiene and cyclohexadienes.
• 2,438,400 there is described that 1,3- pentadiene in pure form or admixed with normal pentane and normal pentene can be converted to 1,3-cyclopentadiene on contact with a catalyst such as CR O on alumina at 400 C. to 700 C. at 10 to 100 millimeters of pressure.
• a catalyst such as CR O on alumina at 400 C. to 700 C. at 10 to 100 millimeters of pressure.
• 2,438,401 is described a process for the production of cyclopentadiene-1,3 by contact of 1,3- pentadiene with SiC at 450 C. to 650 C. and 10 to 200 millimeters of pressure.
• 2,438,402 is described the cyclization of 1,3-pentadiene to form 1,3- cyclopentadiene by bringing 1,3-pentadiene into contact with fused alumina at 400 C. to 700 C. at 10 to 200 millimeters of pressure.
• 2,438,403 cyclopentadiene is derived from 1,3-pentadiene by contact with sub-divided iron or steel at 450 C. to 650 C. and at pressures from 10 to 200 millimeters.
• thermo-dehydrogenation processes either were truly thermo-dehydrogenation processes or were processes which employed fixed bed catalyst systems such as the activated silica gel, the chromium oxide on alumina or the silica carbide or fused alumina or sub-divided iron or steel.
• fixed bed catalyst systems such as the activated silica gel, the chromium oxide on alumina or the silica carbide or fused alumina or sub-divided iron or steel.
• the present invention uses a homogeneous catalyst system.
• cyclic olefins and cyclic diolefins are prepared from open-chain diolefins by heating in the presence of homogeneous catalysts.
• All that is required to perform the present invention is to pass the open-chain diolefin, for instance, 1,3-pentadiene and the homogeneous catalyst system, through a tubular reactor heated to the desired temperature.
• the open-chain diolefins which are useful as the reactants in this invention are 1,3-pentadiene from which can be formed cyclopentene and cyclopentadiene; 4-methyl-l,3- pentadiene from which can be formed a methyl substituted cyclopentene and a methyl substituted cyclopentadiene; 2- methyl-l,3-pentadiene may be employed from which can be obtained methyl substituted cyclopentadiene and cyclopentene; 3-methyl-l,3-pentadiene may be employed and methyl-substituted cyclopentenes and methyl substituted cyclopentadienes are obtained.
• 1,3- and 2,4hexadienes from which there can be obtained
• the catalyst employed in this invention can be a variety of catalysts which are homogeneous in nature.
• Representative of the catalysts which can be employed in this invention are: methyl mercaptan, ethyl mercaptan, ammonium sulfide, ammonium hydrosulfide, hydrogen bromide, ammonium bromide, dibromo methane, bromo chloro methane, allyl bromide, bromine, hydrogen iodide, iodo methane, iodine, ammonium iodide, carbon disulfide, dimethyldisulfide and carbonyl sulfide.
• One of the more preferred homogeneous catalyst is hydrogen sulfide.
• the temperature employed in the process of this invention can range from about 450 C. to about 1000 C. with a more preferred range of about 550 C. to about 800 C. and still more preferred range of about 575 C. to 750 C.
• the process can be employed with the reactants in the pure state or a diluent may be employed. It is usually desirable to employ a diluent for heat transfer purposes.
• a diluent for heat transfer purposes.
• the diluents which might be mentioned as suitable are steam, nitrogen, methane, ethane, pentane, and other hydrocarbon gases or inert gases which are stable under the conditions to be employed.
• the diluent to open chain diolefin mole ratio may vary over a very Wide range; that is, from 0 to 25/1.
• the residence time at which the open chain diolefin is heated is not critical and may vary from a low of 0.01 second up to 1 minute with a more preferred time being from 0.25 second to 10 seconds and a still more preferred range would be from 0.75 second to 5 seconds.
• the amount of catalyst required in the process of this invention has not been found to be too critical except that, of course, a catalytic amount must be employed. For instance, good results have been obtained when as little catalyst as 0.1 mole percent up to 200 mole percent based on the moles of the open-chain diolefin as the reactant. However, a more preferred range is from about 10 mole percent to about 100 mole percent with the most preferred being from about 15 mole percent to about mole percent.
• column 1 is the run number
• column 2 is the mole percent of hydrogen sulfide based on the piperylene
• column 3 is the temperature in degrees centigrade
• column 4 is the residence time in seconds
• column 5 is the cyclopentene yield in mole percent
• column 6 is the cyclopentadiene yield in mole percent
• column 7 is the reaction selectivity to cyclic unsaturated products including both cyclopentene and cyclopentadiene in percent
• column 8 is the piperylene in mole percent.
• pentene CPD percent percent As can be seen from the results set forth in the table above, when piperylene is heated in the presence of hydrogen sulfide, a very large increase in the percent yield of cyclopentene and cyclopentadiene is obtained as well as a vast improvement in reaction selectivity to cyclic olefins.
• column 1 is the run number
• column 2 is the catalyst and the amount of catalyst employed reported in mole percent based on the piperylene charged
• column 3 is the temperature in degrees centigrade
• column 4 is the residence time in seconds
• column 5 is the yield in mole percent of cyclopentadiene obtained
• column 6 is the mole percent of cyclopentadiene obtained
• column 7 is the reaction selectivity in percent of cyclic olefins obtained
• column 8 is the piperylene converted, represented in mole percent.
• the method of preparing cyclic olefins and cyclic diolefins comprising heating at least one acyclic diolefin from the group consisting of acyclic pentadienes, methyl substituted acyclic pentadienes and acyclic hexadienes to temperatures ranging from about 550 C.
• acyclic diolefins are in contact with the homogeneous catalyst selected from the group consisting of hydrogen sulfide, methyl mercaptan, ethyl mercaptan, ammonium sulfide, ammonium hydrosulfide, hydrogen bromide, ammonium bromide, dibromo methane, bromo chloro methane, allyl bromide, bromine, hydrogen iodide, iodo methane, iodine, ammonium iodide, carbon disulfide, dimethyl-disulfide and carbonyl sulfide.
• the homogeneous catalyst selected from the group consisting of hydrogen sulfide, methyl mercaptan, ethyl mercaptan, ammonium sulfide, ammonium hydrosulfide, hydrogen bromide, ammonium bromide, dibromo methane, bromo chloro methane,

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (10)

Cited By (9)

• 1970
  • 1970-06-22 US US48461A patent/US3631209A/en not_active Expired - Lifetime
• 1971
  • 1971-05-17 ZA ZA713172A patent/ZA713172B/xx unknown
  • 1971-05-18 GB GB1550371*[A patent/GB1347319A/en not_active Expired
  • 1971-05-25 CA CA113,741A patent/CA948218A/en not_active Expired
  • 1971-05-25 ES ES391520A patent/ES391520A1/es not_active Expired
  • 1971-05-27 DE DE2126857A patent/DE2126857C3/de not_active Expired
  • 1971-06-09 FR FR7120865A patent/FR2096110A5/fr not_active Expired
  • 1971-06-11 BE BE768444A patent/BE768444A/xx unknown
  • 1971-06-18 JP JP4339071A patent/JPS549197B1/ja active Pending
  • 1971-06-22 NL NL7108594A patent/NL7108594A/xx not_active Application Discontinuation

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