Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C249/00—Preparation of compounds containing nitrogen atoms doubly-bound to a carbon skeleton
  • C07C249/04—Preparation of compounds containing nitrogen atoms doubly-bound to a carbon skeleton of oximes
  • C07C249/06—Preparation of compounds containing nitrogen atoms doubly-bound to a carbon skeleton of oximes by nitrosation of hydrocarbons or substituted hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2601/00—Systems containing only non-condensed rings
  • C07C2601/12—Systems containing only non-condensed rings with a six-membered ring
  • C07C2601/14—The ring being saturated
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C2601/00—Systems containing only non-condensed rings
  • C07C2601/18—Systems containing only non-condensed rings with a ring being at least seven-membered
  • C07C2601/20—Systems containing only non-condensed rings with a ring being at least seven-membered the ring being twelve-membered

Definitions

• This invention relates to a photochemical process for the nitrosation of hydrocarbons, particularly of alkanes and cycloalkancs.
• the resulting reacted mixture is contacted with an aqueous solution of a strong mineral acid either inside or completely outside the irradiation zone, or both.
• a strong mineral acid either inside or completely outside the irradiation zone, or both.
• the solution of the oxime in the strong mineral acid may be neutralized in order to separate therefrom the oxirne or salts thereof. It may also be directly subjected to the Beckmann rearran ement by mere heating, where by the corresponding amide or lactame is obtained,
• Rh is the average hydraulic radius, i.e., in the case of a reaction vessel having an annular cross-section wherein D is the average external radius in centimeters of the reaction zone and d is the average internal radius in centimeters of the reaction zone;
• G is the weight of reaction mixture flowing through the reaction zone per unit of time and of area, expressed in grams per sq. centimeter and per second;
• a is the viscosity of the reaction mixture, expressed in poises.
• the Reynolds Number should preferably be higher than 1,000. the preferred values being comprised between 5,000 and 50,000.
• the reaction product may be advantageously extracted substantially as it is formed and for example less than 1 minute and preferably less than 10 seconds after being withdrawn from the reaction zone.
• the particular nitrosation agent of this invention is not of the essence thereof, but it is preferably a nitrosyl halide, particularly nitrosyi chloride, bromide or fluoride, although there may be used mixtures of halides with at least one nitrogen oxide such as nitric oxide, nitrous anhydride, or nitrogen peroxide.
• the nitrosyl halide may optionally be formed in situ by means of any convenient reaction therefor.
• the strong acid may be, for instance, from the group consisting of sulfuric acid, phosphoric acid, and hydrochloric acid.
• the concentration of the aqueous sulfuric acid solution is highly important and has to be kept Within the range of from 50 to 90% by weight, and preferably between 60 and Otherwise, there will be a considerable decrease in the yield, particularly with respect to the nitrosation agent, and of the output capacity, as well as a rapid deactivation.
• the step of contacting the reaction mixture with the strong mineral acid must be conducted outside of the irradiation zone, or substantially outside, i.e., at least in a zone where the irradiation intensity is very small as compared to that prevailing in the main irradiation Zone, and corresponds, for instance, to less than 10% of the latter.
• the reaction is preferably carried out in the presence of a gaseous hydrogen halide, such as, for instance, hydrogen chloride.
• a gaseous hydrogen halide such as, for instance, hydrogen chloride.
• gaseous halogen acid is unnecessary.
• the strong acid is to be used in preferable amounts, for instance, of 0.1 to 10 mols per nitrogen atom of the oxime obtained.
• the reaction temperature will be advantageously kept in the range of from l0 to 40 C. and preferably be tween 5 and 15 C.
• the liquid phase reaction mixture may consist only of the treated hydrocarbon together with the nitrosation agent, it may also contain a solvent substantially inert with respect to the nitrosation agent, particularly benzene, carbon tetrachloride or other chlorinated hydrocarbon solvents.
• a solvent substantially inert with respect to the nitrosation agent particularly benzene, carbon tetrachloride or other chlorinated hydrocarbon solvents.
• the use of such a solvent is practically necessary where the treated hydrocarbons are normally in a solid state (case for instance of the cyclododecane) in order to avoid the use of excessively high reaction temperatures.
• too dilute solutions of the hydrocarbon in the solvent for example concentrations lower than 2% by weight, should preferably be avoided.
• actinic light there is meant radiant energy having a wave length lower than about 7,500 A.
• source of actinic light there may be used, for instance, a mercury vapor lamp or a sodium vapor lamp.
• the preferred Wave length range is about 3,000-6,000 A.
• This process is applicable to alkanes and cycloalkanes, more particularly to the latter, and especially to those containing at least 5, and preferably from to 12 carbon atoms, such as heptane, cyclopentane, hexane, cyclohexane, octane, cyclooctane, dode-cane, and cyclododecane. It is to be understood, however, that this process is also applicable to alkanes and cycloalkanes having less than 5, and more than 12, carbon atoms.
• Example 1 There is used an apparatus comprising a central glass tube of a 70 cm. length having coaxially placed therein a tubular high pressure mercury vapor lamp of a 60 cm. useful length and a 2 kw. power. Cooling water is passed through said tube to prevent overheating.
• the reaction mixture is circulated through a space formed between said tube and an external coaxial tube of a larger diameter, surrounding the same.
• the cross-section of pas-sage for the reaction mixture is bout 3 dm. the useful volume of the rection zone being about 18 liters.
• reaction mixture is passed through a heat exchanger, and thereafter into a zone for absorption with 70% by weight sulfuric acid.
• the hydrocarbon mixture is recycled to the inlet of the reaction zone by a pump.
• the total capacity of the system is about 41 liters. There are initially introduced 40 liters of a mixture of cyclohexane with benzene having a 95% cyclohexane and a 5% benzene content, and to which is added 1% by weight of nitrosyl chloride, where as 1 liter of 70% by weight sulfuric acid is introduced into the absorption zone.
• This mixture is circulated by means of a pump so as to obtain in the reaction zone an average linear velocity of 0.5 cm. per second which corresponds to anaverage residence time of the cyclohexane in the reaction zone of 120 seconds.
• the Reynolds Number is about 1,500.
• the lamp is then illuminated, and the temperature at the inlet of the reaction zone is maintained at about C.
• Example 2 Example 2 is repeated except that the average velocity of the reactants into the reaction zone is brought to 5 cm. per second, which corresponds to an average residence time of 12 seconds, the other conditions being unchanged.
• the Reynolds Number is about 15,000.
• the cyclohexanone-oxime yield is 332 g., an increase of 48% as compared to Example 1, which increased yield is clearly attributable to the increased linear velocity.
• the molar yields are 75.5%, with respect to nitrosyl chloride, and 84.5% with respect to cyclohexane.
• Example 3 Example 2 is repeated except that the sulfuric acid solution is replaced by an aqueous solution of hydrochloric acid saturated at a temperature of 25 C.
• the cyclohexanone-oxime production amounts to 325 g. after one hour.
• the molar yields are 74.9% wit-h respect to nitrosyl chloride and 84% with respect to cyclohexane.
• Example 4 Example 2 is repeated, but in the absence of benzene.
• the cyclohexanone-oxime production amounts to 322 g. after one hour.
• the molar yields are 75.1% With respect to nitrosyl chloride and 85.2% with respect to cyclohexane.
• Example 5 Example 2 is repeated, except that an average linear velocity of 1 cm. per second is employed. The cyclohexanone-oxime production amounts to 280 g. after one hours. The molar yields remain unchanged.
• Example 6 Example 2 is repeated, except that an average linear velocity of 20 cm. per second is employed. The cyclohexanoneoxime production amounts to 340 g. after one hour. The molar yields are unchanged.
• Example 7 There is used an irradiated vessel of annular cross-section having a useful volume of 2 l. and a useful crosssection area of 40 cm. the lamp being an elongated high pressure mercury vapor lamp of a 700 W. power.
• This mixture is circulated at an average linear velocity of 1 cm./sec., a Reynolds Number of about 1,800 and a temperature of 5 C.
• the concentration of nitrosyl chloride is kept constant (1% by Weight) during the reaction.
• the molar yields are of 76% with respect to nitrosyl chloride and 84% with respect to hexane.
• Example 8 Example 7 is repeated, except that the average linear velocity is 10 cm./sec. and the Reynolds Number is 18,000. After one hour, 40 g. of the same oil as in Example 7 have been obtained. The molar yields remain unchanged.
• Example 9 Example 7 is repeated, except that hexane is replaced by heptane.
• the oxime as a viscous oil 5
• the molar yield is 74% with respect to nitrosyl chloride and 85% with respect to heptane.
• Example 10 Example 9 is repeated, except that the average linear velocity is 10 cm./sec. and the Reynolds Number is 18,000.
• Example 9 After one hour, 46 g. of the same oil as in Example 9 have been obtained. The molar yields are the same as in Example 9.
• Example 11 Example 12 Example 11 is repeated, except that the average linear velocity is 1-0 cm./ sec. and the Reynolds Number is 13,000.
• the amount of cyclododecanone-oxime obtained in one hour is 47 g., the molar yields being unchanged.
• a process for the production of a product selected from the group of oximes and salts thereof by nitrosation of a hydrocarbon selected from the group of alkanes and cycloalkanes, containing at least carbon atoms in the molecule comprising the steps of:
• a process for the production of a product selected from the group of oximes and salts thereof by nitrosation of a hydrocarbon selected from the group of alkanes and cycloalkanes containing at least 5 carbon atoms in their molecule comprising the steps of:
• a process according to claim 2 wherein the average linear velocity of the reaction mixture through the reaction zone is of at least 3 cm. per second.
• said strong mineral acid is an aqueous selected from the group consisting of 5090% by weight sulfuric acid, 5090% by weight phosphoric acid, and concentrated aqueous hydrochloric acid.
• a process for the production of a product selected from the group of oximes and salts thereof by nitrosation of a hydrocarbon selected from the group of alkanes and cycloalkanes containing at least 5 carbon atoms in their molecule comprising the steps of:
• a process for the production of a product selected from the group of oximes and salts thereof by nitrosation of a hydrocarbon selected from the group of alkanes and cycloalkanes containing at least 5 carbon atoms in their molecule comprising the steps of:
• a process for manufacturing a product selected from the group consisting of cyclohexanone-oxime and salts thereof by nitrosation of cyclohexane comprising the steps of:
• a process for the production of a product selected from the group of oximes and salts thereof by nitrosation of a hydrocarbon selected from the group of alkanes and cycloalkanes containing at least 5 carbon atoms in their molecule comprising the steps of:

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• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Cited By (2)

Citations (2)

• 1962
  • 1962-05-23 FR FR898554A patent/FR1354780A/fr not_active Expired
• 1963
  • 1963-05-09 US US279323A patent/US3320143A/en not_active Expired - Lifetime
  • 1963-05-23 GB GB20702/63A patent/GB1041056A/en not_active Expired
• 1964
  • 1964-12-31 OA OA51617A patent/OA01590A/fr unknown

Patent Citations (2)

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