EP0198722B1 - Verfahren zur Herstellung von Aminoalkoholen durch elektrochemische Reduktion von Nitroalkoholen - Google Patents

Verfahren zur Herstellung von Aminoalkoholen durch elektrochemische Reduktion von Nitroalkoholen Download PDF

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Publication number
EP0198722B1
EP0198722B1 EP86400162A EP86400162A EP0198722B1 EP 0198722 B1 EP0198722 B1 EP 0198722B1 EP 86400162 A EP86400162 A EP 86400162A EP 86400162 A EP86400162 A EP 86400162A EP 0198722 B1 EP0198722 B1 EP 0198722B1
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Prior art keywords
alcohols
amino
nitro
manufacture
solution
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French (fr)
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EP0198722A3 (en
EP0198722A2 (de
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Maurice Rignon
Jean-Claude Catonne
Françoise Denisard
Jean Malafosse
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LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B3/00—Electrolytic production of organic compounds
    • C25B3/20—Processes
    • C25B3/25—Reduction

Definitions

  • the present invention relates to the manufacture of amino alcohols by electrochemical reduction of nitro alcohols.
  • Nitro-alcohols are derivatives easily obtained by addition of formaldehyde on nitro-paraffins. Several processes have been described for transforming them into amino-alcohols (alkanol-amines) used in the manufacture of cosmetics, detergents or as intermediates for the synthesis of bactericides and pharmaceutical products.
  • the reduction of the -NO2 group can be carried out by the Fe-Fe ++ pair in sulfuric or acetic acid medium, but the weight of reagent used is approximately three times that of the nitro derivative to be reduced; this results in a large amount of solid residue to be removed and it is necessary to rectify the liquid phase containing the amine in order to obtain a pure product; the yield is around 80%
  • the only raw material consumed stoichiometrically is nitro-alcohol; the consumption of sulfuric acid being reduced to a minimum and in certain cases possibly being zero. There is little or no release to the environment. And, the conversion of the nitro derivative into an amino derivative can reach 95-98% and in most cases remains above 90%.
  • reaction conditions make it impossible to form derivatives (R) 2-N-CH par, by Mannich reaction, often undesirable in the applications of amino alcohols, because of their physical properties and structure close to theirs, which increases the difficulty and the cost of the amino alcohol purification operations.
  • the reduction of the R-N02 group and the acid-amino derivative separation are carried out by electroreduction in sulfuric medium in three stages.
  • the invention relates to a process for the production of amino alcohols by electrochemical reduction of nitro-alcohols in sulfuric medium in three stages.
  • the nitro group is reduced on a cathode made of a material with a high hydrogen overvoltage by treating a sulfuric solution of the nitro derivative, the reaction being carried out on a cathode whose voltage is moderately electronegative.
  • the electronegative voltage is higher in absolute value.
  • the sulfuric amino alcohol solution obtained is subjected to a purification operation by electro-electrodialysis and elimination of water.
  • the first step there is a reduction to four electrons which transforms R-N02 into R-NOH.
  • This reduction of the nitro group is carried out on a cathode produced from a material with a high hydrogen overvoltage by treating an aqueous sulfuric solution of the nitro derivative. This reaction is effective on a cathode whose voltage is moderately electronegative.
  • the hydroxylamine amine is reduced to 2 electrons on a cathode whose electronegative voltage is higher in absolute value than previously.
  • the sulfuric amino alcohol solution obtained is subjected to a purification operation by electro-electrodialysis, then to elimination of water.
  • the two stages of electrochemical reduction can be implemented in a diaphragm cell consisting of a cation exchanger (MEC) or anion exchanger (MEA) membrane; the purification phase can be carried out in the same device or in a specific device.
  • MEC cation exchanger
  • MEA anion exchanger
  • the current flows through the migration of the H3O+ cation under an electric field, resulting in a dilution of the catholyte.
  • the current efficiency being total, the four protons generated at the anode by oxidation of water are consumed for cathodic reduction; there is no release of hydrogen.
  • the efficiency of the current is not complete and part of it will be used to reduce protons to H2. This consumption of protons will be compensated by a higher production at the anode and a higher H3O+ flux.
  • MEA diaphragm cell can be diagrammed in a similar manner.
  • the final purification by electro-electrodialysis can be carried out in a special apparatus as shown in Figure 1 (3rd step) which differs from the MEA cell only in the nature of the electrode materials.
  • the use of MEA membrane may have the advantage of a more strict suppression of the transfer by ion exchange of the cations R-NH3+ and R-NH2OH+ to the anolyte; one can also more easily use the anode compartment for carrying out the oxidation reaction.
  • it is simpler and more convenient to carry out the reduction operations in electrochemical cells provided with an MEC diaphragm and purification in an electro-electrodialysis machine provided with an MEA diaphragm.
  • the process is applicable to the nitro-alcohols represented by the formula in which R1 and R2 together or separately are hydrogen, the hydroxyalkyl group, such as hydroxymethyl, or a linear or branched alkyl group, in particular, methyl, ethyl, propyl or containing a number of carbon atoms greater than three.
  • nitro products leading to industrially important alkanol-amines such as, nitro-2-methyl-2-propanol-1, nitro-2-methyl-2-propanediol 1-3, nitro- 2-ethyl-2-propanediol 1-3, nitro-2-butanol-1, tris (hydroxymethyl) nitromethane.
  • the cathode is constructed from a material with a high hydrogen overvoltage such as pure or alloyed lead, mercury in the form of an amalgam (with copper, lead, Zn, etc.), zinc, zirconium. etc ...
  • the anode is made of a material chemically inert in the anodic solution and preferably with low oxygen overvoltage such as for example Pb, ruthenium titanium, platinum Pt, etc.
  • the diaphragm is made with a cation exchange membrane or commercial anion exchanger such as, for example, those sold under the brands “Nafion” (Du Pont) "IONAC” (Ionac), “ARP” and “CRP” (Rhône Poulenc) or those marketed by ASAHI Chem Ind or ASAHI CLASS CO etc ...
  • a cation exchange membrane or commercial anion exchanger such as, for example, those sold under the brands "Nafion” (Du Pont) "IONAC” (Ionac), “ARP” and “CRP” (Rhône Poulenc) or those marketed by ASAHI Chem Ind or ASAHI CLASS CO etc ...
  • the cathode current density has the maximum value compatible with the usable electrode voltages and the properties of the membrane; with lead or mercury and an "IONAC 3470" membrane, we can operate under 50A / dm2 and more.
  • the temperature of the cathode solution can be between 20 ° C and 100 ° C; it will preferably be carried out between 60 ° C. and 90 ° C. for the second step, in the case where Pb cathodes are used, and at 30 ° C. on amalgamated copper.
  • the catholyte is an aqueous sulfuric solution which can be saturated with nitro derivative; for nitro-2-methyl-2-propanediol, it is possible, for example, to operate at 333 g / l (or 286 g / kg).
  • the H2SO4 content of the catholyte will be such that the molar ratio is between 1 and 1.5, preferably between 1.05 and 1.18.
  • the anolyte is an aqueous sulfuric solution; its composition will depend on the type and properties of the membrane used and in particular on its permeability to sulfuric acid.
  • H2SO4 in the anolyte will have a value such that the migration flow by diffusion of H2SO4 is minimized as well as the transfer of organic cations by ion exchange.
  • the sulfuric solution of nitro-alcohols used as a catholyte can be prepared from solid products obtained by crystallization and purified by recrystallization.
  • aqueous formaldehyde solution titrating from 35 to 40% is placed in a stirred reactor; it is brought to 40 ° C; we adjust the pH at 9 and the nitro paraffin is added dropwise while maintaining the temperature between 40 and 50 ° C and the pH at 9-10 by addition of a 15N aqueous NaOH solution; after one hour, the addition of nitro paraffin is complete; the mixture is stirred again for 1 hour at the same temperature while maintaining the pH above 9; the amount of nitro derivative is exactly stoichiometric or in slight excess (1 mol%) over the amount of formaldehyde.
  • the catholyte can then be prepared by adding H2SO4, and optionally H2O, in proportions such that the composition of the final solution is at the H+ / R-NO2 ratio corresponding to the optimum of the cathodic reduction.
  • the method can be implemented in an apparatus allowing continuous or discontinuous manufacture.
  • a multicell electrolyser comprising 3 cathode compartments alternating with 4 anode compartments; the cathodes are lead plates whose useful surface immersed in the electrolyte is 72 cm2 (2 x 36 cm2); the anodes are identical Pb plates.
  • Electrochemical oxidation 10 min in H2SO4 4%, 2 A / dm2
  • Electrochemical reduction 15 min in H2SO4
  • compartments are separated by 6 diaphragms of 37.5 cm2 useful cut from a membrane sold under the brand "IONAC 3475" consisting of a polypropylene support and anion exchange sites of the quaternary ammonium type.
  • the 7 compartments are polypropylene frames 20 mm thick, joined by threaded rods; sealing is obtained by polyvinyl chloride PVC seals; each compartment has a useful volume of 77 ml.
  • the cathode liquor is distributed in the three compartments from a thermal conditioning circuit consisting of a pump and a heat exchanger; this recirculation has the effect of causing agitation of the reaction medium; the compartments are not fitted with turbulence promoters.
  • the total volume of cathode liquor thus brought into play is 340 ml.
  • the anode liquor is not stirred.
  • the catholyte contains 500 mmol (67.6 g; 179.1 g / kg of nitro-2-methyl-2-propanediol-1-3 and 29 g H2SO4 (7.7% by weight).
  • the molar ratio H+ / R-NO2 is therefore 1.186.
  • the anolyte is a 39% aqueous solution of sulfuric acid.
  • the catholyte is brought to 50 ° C. and a cathode current density of 10 A / dm2 is established.
  • the voltage measured on the central cathode compared to a saturated calomel ECS electrode, thanks to an assembly consisting of a capillary tube and a sintered glass in contact with the cathode is close to -0.6V / ECS.
  • the variation of the cathode voltage is rapid; the cathode liquor is then brought to 80 ° C. and the operation is continued with the same current density; the cathode voltage takes a value close to - 1.5 V / DHW.
  • the progress of the reaction is checked in parallel by potentiometric analysis of the cathode liquor which measures the contents of free acidity, R-NHOH and R-NH2; a semi-quantitative phmetric test indicates the disappearance of R-NO2; the volume variations of catholyte and anolyte are also measured in which water is optionally added.
  • the anode compartments are emptied and immediately filled with pure water, leaving the electrodes energized ; the interpolar voltage takes a high value, then decreases because of the progressive increase in acidity of the anolyte, goes through a minimum and increases again because of the decrease in conductivity of the catholyte caused by its progressive depletion in ions.
  • the overall yield compared to the initial nitro derivative is greater than 95%; the current efficiency is 67% for electrochemical reduction.
  • Total energy expenditure (including electrodialysis) is 11 kWh / kg.
  • the anode solution collected is an aqueous sulfuric solution titrating 39% H2SO4 and it can be recycled.
  • the aqueous sulfuric solution collected after electro-electrodialysis can be used in part on the cathode side after delivery to the title in H2SO4 and addition of a new charge of nitro derivative.
  • the chemical yield compared to the initial nitro derivative is 91 mol%: the efficiency of the current is 55%; the energy consumption is 8.6 kwh / kg for electrolysis and 12.3 kwh / kg for the electrolysis-electro-electrodialysis unit.
  • a cell similar to the previous one is used, but having only one cathode compartment between two anode compartments; the cathode is made of Pb, the anodes of ruthenian titanium; the diaphragm is an anion exchange membrane, sold under the brand "IONAC" 3475.
  • nitro-2-methyl-2-propanediol is carried out by operating with a catholyte containing 1 mole / kg of nitro derivative; one operates at 20 A / dm2 at 80 ° C; the H+ / RX ratio varies from 1.5 to 1.1 during operation.
  • a solution containing 0.880 mole / kg of amino-2-methyl-2-propanediol-1-3 is obtained before electrodialysis.
  • the chemical yield compared to the nitro derivative is 94.6%
  • the efficiency of the current is 74.7%.
  • the energy consumption is 7.8 kwh / kg.
  • the solution obtained contains only the amino alcohol and sulfuric acid and it can be very easily purified and concentrated by electro-electrodialysis.
  • Example 3 The operation is carried out in the electrolysis cell used in Example 3 in which the Pb cathode has been replaced by a cathode consisting of a Cu-Hg amalgam prepared by immersion for 10 minutes of a Cu plate of thickness 1 mm in a solution of mercuric sulfate (3%) and H2SO4 (10%).
  • a cathode current density of 10 A / dm2 is used; the treated solution contains 0.737 mole / kg of methyl-2-nitro-2-propanediol-1-3; it is maintained at 30 ° C.
  • Example 3 The operation is carried out on a cell with three compartments, identical to that of Example 3, except that it is provided with a cation exchange membrane diaphragm, sold under the brand "IONAC” MC 3470.
  • the 2-nitro-2-methyl-propanediol 1-3 obtained in solution is reduced by adding nitroethane to a formaldehyde solution at 50 ° C., the pH being maintained at 9.5 by adding a 15 N sodium hydroxide solution. The concentration of the solution is then adjusted to 0.95 moles / kg of nitro derivative and 0.97 H2SO4 equivalent / kg.
  • the reduction is carried out on the amalgamated copper cathode at 10 A / dm2 on the cathode and 9.6 A / dm2 on the diaphragm.
  • the temperature of the catholyte is 30 ° C; it is an aqueous solution containing 1.075 mole / kg of nitro derivatives and 1.21 equ / kg H2SO4.
  • the overall efficiency of the current is 75% and the energy expenditure for electrolysis is 9 kWh / kg of amino derivatives; the chemical yield, compared to the initial nitro derivatives, is 90.9%.
  • An aqueous sulfuric solution is obtained containing 1.134 mol / kg of tris (methylhydroxy) amino methane, ie 137 g / kg and 1.391 eq / kg H2SO4; it is very easy to extract the pure amino alcohol by an EED treatment followed by dry evaporation; the overall efficiency of the electrolysis current is 65%.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Claims (13)

  1. Verfahren zur Herstellung von Aminoalkoholen durch elektrochemische Reduktion von Nitroalkoholen in schwefelsaurem Milieu in drei Stufen, in denen man während der ersten Reduktionsstufe zu Hydroxylamin die Reduktion der Nitrogruppe an einer Kathode durchführt, die aus einem Material mit starker Überspannung gegen Wasserstoff besteht, indem man eine schwefelsaure Lösung des Nitroderivates behandelt, wobei die Reaktion an einer Kathode durchgeführt wird, deren Spannung im Mittel elektronegativ ist; während der zweiten Reduktionsstufe zu Aminoalkohol ist die elektronegative Spannung im absoluten Wert erhöht; und in der dritten Stufe unterwirft man die schwefelsaure erhaltene Aminoalkohollösung einer Reinigungsbehandlung durch Elektro-Elektrodialyse und Eliminierung des Wassers.
  2. Verfahren zur Herstellung von Aminoalkoholen nach Anspruch 1, dadurch gekennzeichnet, daß der der elektrochemischen Reduktion unterworfene Nitroalkohol durch die Formel
    Figure imgb0010
     dargestellt wird, in welcher R₁ und R₂ zusammen oder getrennt Wasserstoff, eine Hydroxyalkylgruppe, wie Hydroxymethyl, eine lineare oder verzweigte Alkylgruppe sind, insbesondere Methyl, Ethyl, Propyl oder eine solche, die mehr als 3 Kohlenstoffatome enthält.
  3. Verfahren zur Herstellung von Aminoalkoholen nach Anspruch 2, dadurch gekennzeichnet, daß der Nitroalkohol das Nitro-2-methyl-2-propanol-1, Nitro-2-methyl-2-propandiol-1,3, Nitro-2-ethyl-2-propandiol-1,3, Nitro-2-butanol-l, tris-(Hydroxymethyl)-nitromethan ist.
  4. Verfahren zur Herstellung von Aminoalkoholen nach einem der Ansprünche 1 bis 3, dadurch gekennzeichnet, daß das als erstes Ausgangsmaterial verwendete Nitroderivat in Form der Rohlösung durch Reaktion von Formaldehyd und von entsprechendem Nitroparaffin erhalten wird.
  5. Verfahren zur Herstellung von Aminoalkoholen nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß die kathodische Lösung der Elektrolyse mit einer Zusammensetzung unterworfen wird derart, daß das molare Verhältnis H+/R-N0₂ zwischen 1 und 1,5 liegt, wobei dessen Temperatur auf einen Wert zwischen 20 und 100 ° C festgelegt wird,
  6. Verfahren zur Herstellung von Aminoalkoholen nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die elektrochemische Reduktion von Nitroalkoholen in einem Apparat durchgeführt wird, in welchem die anodischen und kathodischen Kammern durch eine Kationenaustauschermembran getrennt sind.
  7. Verfahren zur Herstellung von Aminoalkoholen nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die elektrochemische Reduktion der Nitroalkohole in einem Apparat durchgeführt wird, in welchem die anodischen und kathodischen Kammern durch eine Anionenaustauschermembran getrennt sind.
  8. Verfahren zur Herstellung von Aminoalkoholen nach einem der Ansprüche 1 bis 5 und 7, dadurch gekennzeichnet, daß die Endreinigung durch Elektro-Elektrodialyse in einem Apparat erfolgt, dessen Anoden und Kathoden aus Materialien mit schwacher Überspannung gegen Sauerstoff bzw. Wasserstoff bestehen und in welchem die anodischen und kathodischen Kammern durch ein Diphragma getrennt sind, welches aus einer Anionenaustauschermembran besteht.
  9. Verfahren zur Herstellung von Aminoalkoholen nach einem der Ansprüche 1 bis 8, dadurch gekennzeichnet, daß man den Apparat der Elektro-Elektrodialyse an der kathodischen Seite mit der schwefelsauren Aminoalkohollösung und auf der anodischen Seit mit reinem Wasser versorgt.
  10. Verfahren zur Herstellung von Aminoalkoholen nach einem der Ansprüche 1 bis 5 un d7, dadurch gekennzeichnet, daß die Endreinigung des Katholyten in dem elektrochemischen Reaktor dadurch durchgeführt wird, daß man durch das reine Wasser die konzentrierte Schwefelsäurelösung ersetzt, die in der anodischen Kammer enthalten ist.
  11. Verfahren zur Herstellung von Aminoalkoholen nach Anspruch 1, dadurch gekennzeichnet, daß die Kathoden aus einem Material mit starker Überspannung gegen Wasserstoff bestehen, wie Quecksilber, in Form von Amalgam, Blei, Zirkonium.
  12. Verfahren zur Herstellung von Aminoalkoholen nach Anspruch 1, dadurch gekennzeichnet, daß die wäßrige konzentrierte schwefelsaure Lösung, welche den Anolyten bildet, aufgefangen und bei einem späteren Verfahren wieder verwendet wird.
  13. verfahren zur Herstellung von Aminoalkoholen nach Anspruch 1, dadurch gekennzeichnet, daß die wäBrige, verdünnte schwefelsaure Lösung an der anodischen Seite aufgefangen und an der kathodischen Seite nach einer neuen Zufuhr von Nitroalkohol wieder verwendet wird.
EP86400162A 1985-02-11 1986-01-28 Verfahren zur Herstellung von Aminoalkoholen durch elektrochemische Reduktion von Nitroalkoholen Expired - Lifetime EP0198722B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8501873A FR2577242B1 (fr) 1985-02-11 1985-02-11 Procede de fabrication d'amino-alcools par reduction electrochimique de nitro-alcools
FR8501873 1985-02-11

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EP0198722A2 EP0198722A2 (de) 1986-10-22
EP0198722A3 EP0198722A3 (en) 1988-03-23
EP0198722B1 true EP0198722B1 (de) 1991-03-20

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US (1) US4678549A (de)
EP (1) EP0198722B1 (de)
JP (1) JPS61231189A (de)
CA (1) CA1251762A (de)
DE (1) DE3678189D1 (de)
ES (1) ES8702515A1 (de)
FR (1) FR2577242B1 (de)

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FR2614044B1 (fr) * 1987-04-16 1991-05-10 Air Liquide Procede d'electro-reduction de derives nitres aliphatiques
US5074974A (en) * 1990-06-08 1991-12-24 Reilly Industries, Inc. Electrochemical synthesis and simultaneous purification process
ES2108654B1 (es) * 1996-05-07 1998-07-01 Univ Alicante Procedimiento para la sintesis electroquimica de n-acetilcisteina a partir de cistina.
KR100730460B1 (ko) * 2002-06-19 2007-06-19 에스케이 주식회사 불균일 촉매를 이용한 2-아미노-2-메틸-1,3-프로판디올의연속제조방법
US20080200355A1 (en) * 2007-01-12 2008-08-21 Emmons Stuart A Aqueous Solution for Managing Microbes in Oil and Gas Production and Method for their Production
CN115611751A (zh) * 2022-11-08 2023-01-17 四平欧凯科技有限公司 一种三羟甲基氨基甲烷的制备方法
CN119101913B (zh) * 2024-09-02 2025-09-19 广州医科大学 一种远端氨基醇类化合物的合成方法

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US2485982A (en) * 1944-03-13 1949-10-25 Commercial Solvents Corp Electrolytic production of aminoalcohols
US2589635A (en) * 1945-03-13 1952-03-18 Polytechnic Inst Brooklyn Electrochemical process
US3338806A (en) * 1961-08-21 1967-08-29 Continental Oil Co Process of preparing p-aminophenol by electrolytically reducing nitrobenzene
GB1166363A (en) * 1966-02-02 1969-10-08 Miles Lab Process for Electrolytic Reduction of Aromatic Nitro Compounds
GB1308042A (en) * 1969-05-28 1973-02-21 Brown John Constr Process for the preparation of rho-amino phenol by the electrolytic reduction of nitrobenzene
GB1421118A (en) * 1971-11-16 1976-01-14 Albright & Wilson Electrolytic reduction of nitrosophenols
FR2472037A1 (fr) * 1979-12-18 1981-06-26 Elf Aquitaine Electrode poreuse percolante fibreuse modifiee en carbone ou graphite, son application a la realisation de reactions electrochimiques, et reacteurs electrochimiques equipes d'une telle electrode
US4584069A (en) * 1985-02-22 1986-04-22 Universite De Sherbrooke Electrode for catalytic electrohydrogenation of organic compounds
US4584070A (en) * 1985-03-29 1986-04-22 Ppg Industries, Inc. Process for preparing para-aminophenol

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CA1251762A (fr) 1989-03-28
EP0198722A3 (en) 1988-03-23
US4678549A (en) 1987-07-07
ES8702515A1 (es) 1986-12-16
ES551795A0 (es) 1986-12-16
JPS61231189A (ja) 1986-10-15
DE3678189D1 (de) 1991-04-25
FR2577242A1 (fr) 1986-08-14
EP0198722A2 (de) 1986-10-22
FR2577242B1 (fr) 1987-10-30

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