124-04-9

Basic information

• Product Name: Adipic acid
• Synonyms: RARECHEM AL BO 0180;AKOS BBS-00004308;ADIPIC ACID;adipinic acid;1,6-HEXANEDIOIC ACID;1,4-BUTANEDICARBOXYLIC ACID;BUTANE-1,4-DICARBOXYLIC ACID;DICARBOXYLIC ACID C6
• CAS NO: 124-04-9
• Molecular Formula: C₆H₁₀O₄
• Molecular Weight: 146.14
• EINECS: 204-673-3
• Product Categories: Industrial/Fine Chemicals;alpha,omega-Alkanedicarboxylic Acids;alpha,omega-Bifunctional Alkanes;Monofunctional & alpha,omega-Bifunctional Alkanes;Food additive and acidulant;plasticizer
• Mol File: 124-04-9.mol
• Article Data: 508

Chemical Properties

• Melting Point: 151-154 °C(lit.)
• Boiling Point: 265 °C100 mm Hg(lit.)
• Flash Point: 385 °F
• Appearance: White/Solid
• Density: 1,36 g/cm3
• Vapor Density: 5 (vs air)
• Vapor Pressure: 1 mm Hg ( 159.5 °C)
• Refractive Index: 1.4880
• Storage Temp.: Store below +30°C.
• Solubility: methanol: 0.1 g/mL, clear, colorless
• PKA: 4.43(at 25℃)
• Water Solubility: 1.44 g/100 mL (15 ºC)
• Stability: Stable. Substances to be avoided include ammonia, strong oxidizing agents.
• Merck: 14,162
• BRN: 1209788
• CAS DataBase Reference: Adipic acid(CAS DataBase Reference)
• NIST Chemistry Reference: Adipic acid(124-04-9)
• EPA Substance Registry System: Adipic acid(124-04-9)

Safety Data

• Hazard Codes: Xi
• Statements: 36-41
• Safety Statements: 26-39-24/25
• RIDADR: UN 9077
• WGK Germany: 1
• RTECS: AU8400000
• TSCA: Yes
• Hazardous Substances Data: 124-04-9(Hazardous Substances Data)

Usage

Description

Adipic acid is a crystalline powder with practically no odor. It has the lowest acidity of any of the acids commonly used in foods and has excellent buffering capacity in the range of pH 2.5 to 3.0. Like succinic and fumaric acid, adipic acid is practically nonhygroscopic. Its addition to foods imparts a smooth, tart taste. In grape-flavored products, it adds a lingering supplementary flavor and gives an excellent set to food powders containing gelatin. As a result, adipic acid has found a wide number of uses as an accidulant in dry powdered food mixtures, especially in those products having delicate flavors and where addition of tang to the flavor is undesirable. Its aqueous solutions have the lowest acidity of any of the common food acids. For concentrations from 0.5 to 2.4 g/100 mL, the pH of its solution varies less than half a unit. Hence, it can be used as a buffering agent to maintain acidities within the range of 2.5 to 3.0. This is highly desirable in certain foods, yet the pH is low enough to inhibit the browning of most fruits and other foodstuffs.

Chemical Properties

Adipic acid is the organic compound with the formula (CH2)4(COOH)2. From the industrial perspective, it is the most important dicarboxylic acid: About 2.5 billion kilograms of this white crystalline powder are produced annually, mainly as a precursor for the production of nylon. Adipic acid otherwise rarely occurs in nature.

Physical properties

Adipic acid is a straight-chain dicarboxylic acid that exists as a white crystalline compound at standard temperature and pressure. Adipic acid is one of the most important industrial chemicals and typically ranks in the top 10 in terms of volume used annually by the chemical industry.

Occurrence

Reported found as a minor constituent in butter, and has been found in other fats as a product of oxidative rancidity. It also occurs in beet juice, pork fat, guava fruit (Psidium guajava L.), papaya (Carica papaya L.) and raspberry (Rubus idaeus L.).

Uses

Different sources of media describe the Uses of 124-04-9 differently. You can refer to the following data:
1. Adipic acid’s main use is in the production of 6,6 nylon. It is also used in resins, plasticizers, lubricants, polyurethanes, and food additives.
2. Adipic Acid is primarily used in the synthesis of nylon. It has been used as a reagent in the solid-state polymerization of nylon analogs.
3. Adipic Acid is an acidulant and flavoring agent. it is characterized as stable, nonhygroscopic, and slightly soluble, with a water solubility of 1.9 g/100 ml at 20°c. it has a ph of 2.86 at 0.6% usage level at 25°c. it is used in powdered drinks, beverages, gelatin desserts, loz- enges, and canned vegetables. it is also used as a leavening acidulant in baking powder. it can be used as a buffering agent to maintain acidities within a range of ph 2.5–3.0. it is occasionally used in edi- ble oils to prevent rancidity.

Production Methods

Different sources of media describe the Production Methods of 124-04-9 differently. You can refer to the following data:
1. Adipic acid is prepared by nitric acid oxidation of cyclohexanol or cyclohexanone or a mixture of the two compounds. Recently, oxidation of cyclohexene with 30% aqueous hydrogen peroxide under organic solvent- and halide-free conditions has been proposed as an environmentally friendly alternative for obtaining colorless crystalline adipic acid.
2. Adipic acid can be manufactured using several methods, but the traditional and main route of preparation is by the two-step oxidation of cyclohexane (C6H12). In the first step, cyclohexane is oxidized to cyclohexanone and cyclohexanol with oxygen or air. This occurs at a temperature of approximately 150°C in the presence of cobalt or manganese catalysts. The second oxidation is done with nitric acid and air using copper or vanadium catalysts. In this step, the ring structure is opened and adipic acid and nitrous oxide are formed. Other feedstocks such as benzene and phenol may be use to synthesize adipic acid. Adipic acid production used to be a large emitter of nitrous oxide, a greenhouse gas, but these have been controlled in recent years using pollution abatement technology.

Definition

ChEBI: An alpha,omega-dicarboxylic acid that is the 1,4-dicarboxy derivative of butane.

Preparation

Adipic acid is produced from a mixture of cyclohexanol and cyclohexanone called "KA oil", the abbreviation of "ketone-alcohol oil." The KA oil is oxidized with nitric acid to give adipic acid, via a multistep pathway. Early in the reaction the cyclohexanol is converted to the ketone, releasing nitrous acid: HOC6H11 + HNO3 → OC6H10 + HNO2 + H2O Among its many reactions, the cyclohexanone is nitrosated, setting the stage for the scission of the C- C bond: HNO2 + HNO3 → NO+NO3- + H2O OC6H10 + NO+→ OC6H9-2 - NO + H+ Side products of the method include glutaric and succinic acids. Related processes start from cyclohexanol, which is obtained from the hydrogenation of phenol.

Reactions

Adipic acid is a dibasic acid (can be deprotonated twice). Its pKa's are 4.41 and 5.41. With the carboxylate groups separated by four methylene groups, adipic acid is suited for intramolecular condensation reactions. Upon treatment with barium hydroxide at elevated temperatures, it undergoes ketonization to give cyclopentanone.

Biotechnological Production

Adipic acid is industrially produced by chemical synthesis. However, there are new efforts to develop an adipic acid production process using biorenewable sources. A direct biosynthesis route has not yet been reported. The possible precursors Z,Z-muconic acid and glucaric acid can be produced biotechnologically by fermentation. Z,Z-muconic acid can be made from benzoate with concentrations up to 130 mM with a yield of close to 100 % (mol/mol) by Pseudomonas putida KT2440-JD1 grown on glucose. Alternatively, it can be produced by engineered E. coli directly from glucose at up to 260 mM with a yield of 0.2 mol Z,Zmuconic acid per mole glucose . The production of the second possible precursor, glucaric acid, by engineered E. coli growing on glucose has been reported. However, the product titers were low (e.g. 4.8 and 12 mM. To overcome the problem of low product concentrations, an alternative synthetic pathway has been suggested but not yet demonstrated . In a hydrogenation process, Z,Z-muconic acid and glucaric acid could be converted chemically into adipic acid. Therefore, bimetallic nanoparticles or platinum on activated carbon as catalysts have been studied . In particular, nanoparticles of Ru10Pt2 anchored within pores of mesoporous silica showed high selectivity and conversion rates, greater than 0.90 mol adipic acid per mole Z,Zmuconicacid. With platinum on activated carbon, conversion rates of 0.97 mol.mol-1 of Z,Z-muconic acid into adipic acid have been shown. Another possibility would be the production of adipic acid from glucose via the a–aminoadipate pathway ]. Finally, the production of adipic acid from longchain carbon substrates has been suggested. The conversion of fatty acids into dicarboxylic acids by engineered yeast strains has been reported.

General Description

Adipic acid is a white crystalline solid. Adipic acid is insoluble in water. The primary hazard is the threat to the environment. Immediate steps should be taken to limit its spread to the environment. Adipic acid is used to make plastics and foams and for other uses.

Air & Water Reactions

Dust may form explosive mixture with air [USCG, 1999]. Insoluble in water.

Reactivity Profile

Adipic acid is a carboxylic acid. Carboxylic acids donate hydrogen ions if a base is present to accept them. They react in this way with all bases, both organic (for example, the amines) and inorganic. Their reactions with bases, called "neutralizations", are accompanied by the evolution of substantial amounts of heat. Neutralization between an acid and a base produces water plus a salt. Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water; those with more than six carbons are slightly soluble in water. Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions. The pH of solutions of carboxylic acids is therefore less than 7.0. Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt. Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for solid carboxylic acids as well, but are slow if the solid acid remains dry. Even "insoluble" carboxylic acids may absorb enough water from the air and dissolve sufficiently in Adipic acid to corrode or dissolve iron, steel, and aluminum parts and containers. Carboxylic acids, like other acids, react with cyanide salts to generate gaseous hydrogen cyanide. The reaction is slower for dry, solid carboxylic acids. Insoluble carboxylic acids react with solutions of cyanides to cause the release of gaseous hydrogen cyanide. Flammable and/or toxic gases and heat are generated by the reaction of carboxylic acids with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Carboxylic acids, especially in aqueous solution, also react with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Their reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still heat. Like other organic compounds, carboxylic acids can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. A wide variety of products is possible. Like other acids, carboxylic acids may initiate polymerization reactions; like other acids, they often catalyze (increase the rate of) chemical reactions. Behavior in Fire: Melts and may decompose to give volatile acidic vapors of valeric acid and other substances.

Health Hazard

Exposures to adipic acid cause pain, redness of the skin and eyes, tearing or lacrimation. Adipic acid has been reported as a non-toxic chemical. Excessive concentrations of adipic acid dust are known to cause moderate eye irritation, irritation to the skin, and dermatitis.It may be harmful if swallowed or inhaled. It causes respiratory tract irritation with symptoms of coughing, sneezing, and blood-tinged mucous.

Flammability and Explosibility

Nonflammable

Pharmaceutical Applications

Adipic acid is used as an acidifying and buffering agent in intramuscular, intravenous and vaginal formulations. It is also used in food products as a leavening, pH-controlling, or flavoring agent. Adipic acid has been incorporated into controlled-release formulation matrix tablets to obtain pH-independent release for both weakly basicand weakly acidic drugs.It has also been incorporated into the polymeric coating of hydrophilic monolithic systems to modulate the intragel pH, resulting in zero-order release of a hydrophilic drug.The disintegration at intestinal pH of the enteric polymer shellac has been reported to improve when adipic acid was used as a pore-forming agent without affecting release in the acidic media.Other controlled-release formulations have included adipic acid with the intention of obtaining a late-burst release profile.

Safety Profile

Poison by intraperitoneal route. Moderately toxic by other routes. A severe eye irritant. Combustible when exposed to heat or flame; can react with oxidzing materials. When heated to decomposition it emits acrid smoke and fumes.

Safety

Adipic acid is used in pharmaceutical formulations and food products. The pure form of adipic acid is toxic by the IP route, and moderately toxic by other routes. It is a severe eye irritant, and may cause occupational asthma. LD50 (mouse, IP): 0.28 g/kg LD50 (mouse, IV): 0.68 g/kg LD50 (mouse, oral): 1.9 g/kg LD50 (rat, IP): 0.28 g/kg LD50 (rat, oral): >11 g/kg

Synthesis

By oxidation of cyclohexanol with concentrated nitric acid; by catalytic oxidation of cyclohexanone with air.

Potential Exposure

Workers in manufacture of nylon, plasticizers, urethanes, adhesives, and food additives

storage

Adipic acid is normally stable but decomposes above boiling point. It should be stored in a tightly closed container in a cool, dry place, and should be kept away from heat, sparks, and open flame.

Shipping

UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required

Purification Methods

For use as a volumetric standard, adipic acid is crystallised once from hot water with the addition of a little animal charcoal, dried at 120o for 2hours, then recrystallised from acetone and again dried at 120o for 2hours. Other purification procedures include crystallisation from ethyl acetate and from acetone/petroleum ether, fusion followed by filtration and crystallisation from the melt, and preliminary distillation under vacuum. [Beilstein 2 IV 1956.]

Incompatibilities

Adipic acid is incompatible with strong oxidizing agents as well as strong bases and reducing agents. Contact with alcohols, glycols, aldehydes, epoxides, or other polymerizing compounds can result in violent reactions.

Precautions

Occupational workers should avoid contact of the adipic acid with the eyes, avoid breathing dust, and keep the container closed. Workers should use adipic acid only with adequate ventilation. Workers should wash thoroughly after handling adipic acid and keep away from heat, sparks, and flame. Also, workers should use rubber gloves and laboratory coats, aprons, or coveralls, and avoid creating a dust cloud when handling, transferring, and cleaning up.

Regulatory Status

GRAS listed. Included in the FDA Inactive Ingredients Database (IM, IV, and vaginal preparations). Accepted for use as a food additive in Europe. Included in an oral pastille formulation available in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.

InChI:InChI=1/C6H10O4/c7-5(8)3-1-2-4-6(9)10/h1-4H2,(H,7,8)(H,9,10)/p-2

Synthetic route

1,2-Cyclohexanediol (931-17-9) → Adipic acid (124-04-9)

Conditions	Yield
With sodium bromate; 4 In water at 60℃; for 15h;	100%
With sodium hypochlorite; nickel dichloride In dichloromethane; water at 0 - 20℃; for 4h;	90%
With oxygen; sodium methylate; silver trifluoromethanesulfonate In tetrahydrofuran; methanol at 37℃; under 760.051 Torr; for 6h; Sealed tube;	88%

cyclohexanone (108-94-1) → Adipic acid (124-04-9)

Conditions	Yield
With sodium nitrite In trifluoroacetic acid	100%
With oxygen; trifluoroacetic acid; sodium nitrite at 0 - 20℃; for 5.25h; Product distribution / selectivity;	100%
With dihydrogen peroxide; ortho-tungstic acid In water at 90℃; for 20h; Product distribution / selectivity;	99%

cyclohexanol (108-93-0) → Adipic acid (124-04-9)

Conditions	Yield
With oxygen; sodium nitrite In trifluoroacetic acid at 0 - 20℃; for 5h;	100%
With oxygen; potassium nitrate; trifluoroacetic acid at 0 - 20℃; for 5.25h; Product distribution / selectivity;	100%
With potassium nitrite; oxygen; trifluoroacetic acid at 0 - 20℃; for 5.25h; Product distribution / selectivity;	100%

1,6-hexanediol (629-11-8) → Adipic acid (124-04-9)

Conditions	Yield
With dihydrogen peroxide; Na12[WZn3(H2O)2(ZnW9O34)2] at 75℃; for 7h;	100%
With C24H33IrN4O3; water; sodium hydroxide for 18h; Reflux;	97%
With Gluconobacter oxydans DSM 50049 In aq. phosphate buffer at 30℃; pH=4.3-7; Microbiological reaction;	95.5%

trans-1,2-cyclohexandiol (1460-57-7) → Adipic acid (124-04-9)

Conditions	Yield
With tert.-butylhydroperoxide; indium(III) chloride In water at 90℃;	100%
With hydrogenchloride; sodium tungstate; phosphoric acid; dihydrogen peroxide at 90℃; for 5h;	94%
With sodium tungstate (VI) dihydrate; dihydrogen peroxide at 87℃; for 16h;	79%

cyclohexane-1,2-epoxide (286-20-4) → Adipic acid (124-04-9)

Conditions	Yield
With tert.-butylhydroperoxide; indium(III) chloride In water at 90℃;	100%
With dodecyltrimethylammonium phosphotungstate; water; dihydrogen peroxide In toluene at 80℃; for 12h; Reagent/catalyst; chemoselective reaction;	94%
With dihydrogen peroxide; [WO(O2)2*1,10-phenanthroline] at 90℃; for 12h;	85.9%

tetrahydrofuran-2,5-dicarboxylic acid (6338-43-8) → Adipic acid (124-04-9)

Conditions	Yield
With hydrogen iodide; acetic acid In water at 160℃; under 37503.8 Torr; for 4.16667h; Temperature; Solvent; Reagent/catalyst; Inert atmosphere;	100%
With hydrogen iodide; hydrogen; 5percent Pd/Silica In acetic acid at 160℃; under 37478.5 Torr; for 3h; Product distribution / selectivity; Inert atmosphere;	99%
With hydrogen iodide; hydrogen In water; propionic acid at 160℃; under 25858.1 Torr; for 2h; Kinetics; Reagent/catalyst; Pressure; Concentration; Temperature; Solvent; Autoclave;	89%

6-hydroxyimino-6-nitrohexanoic acid (141895-69-4) → Adipic acid (124-04-9)

Conditions	Yield
With nitric acid; copper(II) ion; vanadium(5+) at 73℃;	99.9%

cyclohexane (110-82-7) → Adipic acid (124-04-9)

Conditions	Yield
With nitric acid; trifluoroacetic acid; N-hydroxy-5-carboxy-phthalimide at 23℃; for 18h; Reagent/catalyst;	99%
With 2-pyrazylcarboxylic acid; FeCl2(κ3-HC(C3H3N2)3); ozone at 20℃; for 6h; Catalytic behavior; Time; Reagent/catalyst; Schlenk technique; Green chemistry;	96%
In acetic acid at 115℃; under 22502.3 Torr; for 5h; Reagent/catalyst; Pressure;	95%

cyclohexanone-2-ol (533-60-8) → Adipic acid (124-04-9)

Conditions	Yield
With oxygen; acetic acid In water at 60℃; under 750.075 Torr; for 0.5h;	99%
With oxygen; H6[PMo9V3O40]*11H2O In methanol at 60℃; under 750.06 Torr; for 24h; Product distribution; Further Variations:; Catalysts; Temperatures;	90%
With sodium hypochlorite for 0.5h; Irradiation;	87%

tetraphenylantimonium adipinate → Adipic acid (124-04-9) + tetraphenylantimony(V) chloride (19638-17-6, 16894-68-1)

Conditions	Yield
With aq. HCl	A n/a B 99%

5-formylvaleric acid (928-81-4) → Adipic acid (124-04-9)

Conditions	Yield
With ozone In tetrachloromethane at 20℃; for 0.3h; UV-irradiation;	99%

cyclohexene (110-83-8) → Adipic acid (124-04-9)

Conditions	Yield
With (tetra-n-butyl-ammonium)3(tetra(oxodiperoxotungstato)phosphate); dihydrogen peroxide In water at 92℃; for 2.5h;	98%
With dihydrogen peroxide In water; acetonitrile at 90℃; for 8h; Temperature; Green chemistry;	97%
With phosphoric acid; sulfuric acid; water; dihydrogen peroxide; ortho-tungstic acid In water at 73℃; for 2h;	97.4%

cis,cis-Muconic acid (1119-72-8) → Adipic acid (124-04-9)

Conditions	Yield
With ethanol; palladium on activated charcoal; sodium hydroxide; silicon at 20℃; for 72h; Schlenk technique;	96%
With hydrogen In water at 80℃; under 22502.3 - 75007.5 Torr; for 12h; Autoclave;	95%
With hydrogen; palladium on activated charcoal for 3h; Ambient temperature;
With hydrogen; Ru10Pt2 In ethanol at 79.85℃; under 22501.8 Torr; for 5h;
With 2% Rh/C; hydrogen In water at 80℃; under 37503.8 Torr; pH=3; Reagent/catalyst; Pressure; Autoclave;

2,3,10,11,17,18,19,20-Octaoxa-tricyclo[10.4.2.24,9]icosane (74515-87-0) → Adipic acid (124-04-9)

Conditions	Yield
With hydrogen; Lindlar's catalyst In 1,4-dioxane Product distribution; other reagent - triphenylphosphine;	96%

cyclohexanone (108-94-1) + cyclohexanol (108-93-0) → Adipic acid (124-04-9)

Conditions	Yield
With nitric acid; sodium nitrite In water at 70℃; for 1h; Temperature; Time; Concentration;	95%
With H1Mn0.25Co0.75(3+)*Mo12O40P(3-); dihydrogen peroxide at 90℃; for 20h;	75%
With ammonium vanadate; copper (II)-salt; water; nitric acid

hexanedioic acid dimethyl ester (627-93-0) → Adipic acid (124-04-9)

Conditions	Yield
With amberlyst 15 In methanol; water at 80℃; for 2h; Solvent; High pressure; Green chemistry;	95%
With Dowex-50 In water for 12h; Heating;	78%
With trimethylsilyl bromide; iodine(I) bromide at 100℃; for 17h;	68%

6-nitrohexanoic acid (10269-96-2) → Adipic acid (124-04-9)

Conditions	Yield
With acetic acid; sodium nitrite In dimethyl sulfoxide at 35℃;	95%

(NH4)2WO4 + 1,7-Octadiene (3710-30-3) → Adipic acid (124-04-9)

Conditions	Yield
With manganese dioxide; dihydrogen peroxide In 1,4-dioxane; acetic acid	95%
With manganese dioxide; dihydrogen peroxide In 1,4-dioxane	51%

cis,cis-Muconic acid (1119-72-8) → γ-(carboxymethyl)-γ-butyrolactone (60551-20-4) + Adipic acid (124-04-9)

Conditions	Yield
With hydrogen In water at 80℃; under 22502.3 - 75007.5 Torr; for 12h; Autoclave;	A 5% B 95%

2-bromocyclohexylamine (10412-68-7) → Adipic acid (124-04-9)

Conditions	Yield
Stage #1: 2-bromocyclohexylamine With potassium sulfate at 40℃; for 3.16667h; Stage #2: With chromium(0) hexacarbonyl at 40℃; for 2h; Stage #3: With methyl heptanoate at 52℃; for 2.16667h;	95%

adipic acid di(3-pentyl) ester (101434-25-7) → Adipic acid (124-04-9)

Conditions	Yield
With sodium hydroxide In ethanol; water for 12h; Reflux;	94%

Cyclohexanone Cyclohexanol → Adipic acid (124-04-9)

Conditions	Yield
With nitric acid; toluene-4-sulfonic acid at 60℃; for 0.166667h; Temperature; Reagent/catalyst; Time;	94%

2-hydroxy-3-butene (598-32-3) + carbon monoxide (201230-82-2) → Adipic acid (124-04-9)

Conditions	Yield
With HeMaRaphos; water; toluene-4-sulfonic acid; palladium dichloride In tetrahydrofuran at 125℃; under 30003 Torr; for 24h; Autoclave; Green chemistry; regioselective reaction;	93%

cis-1,2-cyclohexane (1792-81-0) → Adipic acid (124-04-9)

Conditions	Yield
With hydrogenchloride; sodium tungstate; phosphoric acid; dihydrogen peroxide at 90℃; for 5h;	92%
Stage #1: cis-1,2-cyclohexane With 2,3,4,5,6-pentamethyliodobenzene; oxygen; isobutyraldehyde In 1,2-dichloro-ethane under 760.051 Torr; for 36h; Stage #2: With sodium chlorite; 2-methyl-but-2-ene In aq. phosphate buffer; 1,2-dichloro-ethane; tert-butyl alcohol at 25℃; for 14h;	80%
With potassium carbonate for 2.7h; Ambient temperature; electrolysis: nickel(III) oxide hydroxide electrode, 0.3 A;	74%

(2E,4E)-2,4-hexadienedioic acid (3588-17-8) → Adipic acid (124-04-9)

Conditions	Yield
With platinum on carbon; hydrogen In water at 24℃; under 5250.53 Torr; for 8h;	92%
With platinum on carbon; hydrogen In water at 24℃; under 5171.62 Torr; for 8h; Autoclave; Inert atmosphere;	92%
With hydrogen; palladium
With hydrogen; palladium
With 1% Pd on activated carbon; hydrogen In ethanol at 24℃; under 18001.8 Torr; Catalytic behavior; Reagent/catalyst; Flow reactor;

cyclohexene (110-83-8) → Adipic acid (124-04-9) + 1,2-Cyclohexanediol (931-17-9)

Conditions	Yield
With phosphoric acid; sulfuric acid; water; dihydrogen peroxide; ortho-tungstic acid at 73℃; for 2h;	A 90.2% B 54%
With dihydrogen peroxide; ortho-tungstic acid In tert-butyl alcohol for 24h; Heating;	A 81% B 9%
With 1-butyl-3-methylimidazolium phosphotungstate; dihydrogen peroxide; acetophenone at 60℃; for 72h; Reagent/catalyst;	A 61% B 12 %Chromat.

hex-3-ene-1,6-dicarboxylic acid (4436-74-2) → Adipic acid (124-04-9)

Conditions	Yield
With hydrogen In water at 140℃; under 62819.5 Torr; for 4h; Inert atmosphere; Sealed tube; Autoclave;	90%
With sulfuric acid; water at 70℃; Electrochemical reaction; Nickel cathode/platinum anode;	68%

diethyl adipate (141-28-6) → Adipic acid (124-04-9)

Conditions	Yield
With sulfuric acid at 90℃; for 1h;	89%

methanol (67-56-1) + Adipic acid (124-04-9) → hexanedioic acid dimethyl ester (627-93-0)

Conditions	Yield
With boron trifluoride at 65℃; for 0.333333h;	100%
at 130℃; for 4h; Temperature;	99.81%
With aluminum(III) sulphate octadecahydrate at 110℃; for 0.166667h; Sealed tube; Microwave irradiation;	97.7%

Adipic acid (124-04-9) → 1,6-hexanediol (629-11-8)

Conditions	Yield
With hydrogen In water at 160℃; under 22502.3 Torr; for 18h; Molecular sieve; chemoselective reaction;	100%
With hydrogen In water at 130℃; under 37503.8 Torr; for 18h; Pressure; Reagent/catalyst; Autoclave;	89%
With hydrogen In water at 120℃; under 35409.9 Torr; for 2.5h; Reagent/catalyst; Pressure; Temperature;	88%

Adipic acid (124-04-9) + thiophenol (108-98-5) → di-S-phenyl thioadipate (41117-90-2)

Conditions	Yield
With PPE for 15h; Ambient temperature;	100%
(i) 2-fluoro-1-methyl-pyridinium toluene-4-sulfonate, Et3N, (ii) /BRN= 506523/, Et3N; Multistep reaction;

Adipic acid (124-04-9) + 2-(vinyloxy)ethyl isothiocyanate (59565-09-2) → hexanedioic acid bis-[1-(2-isothiocyanato-ethoxy)-ethyl] ester

Conditions	Yield
trifluoroacetic acid at 70 - 75℃; for 1h;	100%

Adipic acid (124-04-9) + allyl alcohol (107-18-6) → diallyl adipate (2998-04-1)

Conditions	Yield
With chloro-trimethyl-silane at 0 - 20℃; for 12h; Inert atmosphere;	100%
With sulfuric acid at 65℃; for 12h; Inert atmosphere;	90%
Stage #1: Adipic acid With trichloroisocyanuric acid; triphenylphosphine In dichloromethane at 0℃; for 0.75h; Stage #2: allyl alcohol With triethylamine In dichloromethane at 20℃; for 1h;	65%

Adipic acid (124-04-9) + metformin hydrochloride (1115-70-4) → metformin adipate (2:1)

Conditions	Yield
Stage #1: metformin hydrochloride With sodium hydroxide In water; acetonitrile at 20℃; Stage #2: Adipic acid In water; acetonitrile at 20℃; Product distribution / selectivity;	100%
Stage #1: metformin hydrochloride With sodium hydroxide In tetrahydrofuran; water at 20℃; Stage #2: Adipic acid In tetrahydrofuran; water at 20℃; Product distribution / selectivity;	97.7%
Stage #1: metformin hydrochloride With sodium hydroxide In water; acetone at 20℃; Stage #2: Adipic acid In water; acetone at 20℃; Product distribution / selectivity;	92.3%

Adipic acid (124-04-9) + cobalt(II) acetate (71-48-7, 917-69-1, 5931-89-5, 55881-15-7, 68931-68-0, 68931-69-1, 93029-27-7) + (R,R)-N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine (151433-25-9) → [(1-RR)-(Adipic acid)]

Conditions	Yield
Stage #1: cobalt(II) acetate; (R,R)-N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine In ethanol for 5h; Heating / reflux; Stage #2: Adipic acid With oxygen In dichloromethane; acetone at 20℃; for 3h;	100%

bis(4-vinyloxybutyl) isophathalate + Adipic acid (124-04-9) → C46H62O16

Conditions	Yield
In acetone at 80 - 150℃; for 0.666667h;	100%

Adipic acid (124-04-9) + bis(4-vinyloxy-butyl) adipate (135876-36-7) → C66H110O26 (1159876-46-6)

Conditions	Yield
In acetone at 80 - 150℃; for 0.666667h;	100%

Adipic acid (124-04-9) + meloxicam (71125-38-7) → meloxicam:adipic acid

Conditions	Yield
In tetrahydrofuran for 0.5h;	100%
In tetrahydrofuran Product distribution / selectivity;
Stage #1: Adipic acid; meloxicam for 0.25h; Milling; Stage #2: In acetone Solvent;

Adipic acid (124-04-9) + (3R,5R)-3-[1-methyl-1-(2-trifluoromethyl-pyrimidin-4-yl)-ethylamino]-5-(3-trifluoromethoxy-phenyl)-1-(4-trifluoromethyl-phenyl)-pyrrolidin-2-one (1192801-11-8) → (3R,5R)-3-[1-methyl-1-(2-trifluoromethyl-pyrimidin-4-yl)-ethylamino]-5-(3-trifluoromethoxy-phenyl)-1-(4-trifluoromethyl-phenyl)-pyrrolidin-2-one adipate

Conditions	Yield
In methanol; ethyl acetate at 20℃; Product distribution / selectivity;	100%

Adipic acid (124-04-9) + thiosemicarbazide (79-19-6) → 5,5′-(butane-1,4-diyl)bis(1,3,4-thiadiazol-2-amine) (98558-04-4)

Conditions	Yield
Stage #1: thiosemicarbazide With 1-ethyl-3-methylimidazolium hydrogensulfate at 50℃; for 0.25h; Stage #2: Adipic acid With sulfuric acid at 100℃;	100%
With phosphorus pentachloride at 20℃; for 0.333333h; Time; Milling;	95%
With trichlorophosphate for 5h; Reflux;	76.9%

Adipic acid (124-04-9) + 2-chloroallyl alcohol (5976-47-6) → adipic acid bis-(2-chloro-allyl ester) (762-19-6)

Conditions	Yield
With toluene-4-sulfonic acid In benzene for 16h; Dean-Stark; Reflux; Inert atmosphere;	99%
With benzenesulfonic acid; benzene at 83 - 96℃;

Adipic acid (124-04-9) + 1,2-diamino-benzene (95-54-5) → 2,2'-(1,4-butanediyl)bis(1H-benzimidazole) (4746-56-9)

Conditions	Yield
With tetrafluoroboric acid In water at 150℃; for 2h;	99%
With hydrogenchloride In water for 12h; Reflux;	41%

Adipic acid (124-04-9) → adipic acid anhydride (66784-42-7)

Conditions	Yield
With N,N-bis[2-oxo-3-oxazolidinyl]phosphorodiamidic chloride; triethylamine In dichloromethane at 20℃; for 1h;	99%
With 1-ethyl-piperidine; p-toluenesulfonyl chloride In methanol
In acetic anhydride

Adipic acid (124-04-9) → hexanedial (1072-21-5)

Conditions	Yield
With thexylbromoborane dimethyl sulfide complex In carbon disulfide; dichloromethane at -20 - 20℃; for 1h;	99%
With 9-borabicyclo[3.3.1]nonane dimer; tert.-butyl lithium 1.) THF, room temp.; 2.) THF, pentane, -20 deg C, 10 min and room temp., 3 h; Yield given. Multistep reaction;

Adipic acid (124-04-9) + 1,1'-bis(4-pyridinyl)ferrocene (459142-93-9) → [(Fe(η5-C5H4-1-(4-C5H4N))2)2(1-adipic acid)2]

Conditions	Yield
In methanol 1:1 mixt. ground for 5 min, dissolved in methanol; crystd.;	99%

Adipic acid (124-04-9) + AZD4316 (1243324-08-4) → 1-[[5-(aminomethyl)-1-isopentyl-benzimidazol-2-yl]methyl]-3-cyclopropyl-4H-quinazolin-2-one adipate salt

Conditions	Yield
In acetonitrile Conversion of starting material;	99%

Upstream product

• 110-52-1 1,4-dibromo-butane 
• 151-50-8 potassium cyanide 
• 628-21-7 1,4-Diiodobutane 
• 56-23-5 tetrachloromethane 
• 123-23-9 peroxydicuccinic acid 
• 1128-65-0 [1,1']bicyclohexyl-1,1'-diene 
• 111-20-6 1,10-decanedioic acid 
• 78-18-2 1-hydroxycyclohexyl 1-hydroperoxycyclohexyl peroxide 
• 141-76-4 3-iodopropanoic acid 
• 506-25-2 octadec-17-ene-9,11-diynoic acid 
• 5264-33-5 5-cyanopentanoic acid 
• 3425-65-8 meso-2,5-dibromoadipic acid 
• 626-86-8 adipinic acid monoethyl ester 
• 4435-48-7 butane-1,1,4-tricarboxylic acid 

Downstream Products

• 22422-60-2 1,1'-hexanedioyl-bis-piperidine 
• 105-02-2 hexanedioic acid bis-tetrahydrofurfuryl ester 
• 5453-20-3 adipic acid bis-(3-tetrahydro[2]furyl-propyl ester) 
• 5453-25-8 adipic acid bis-(1-methyl-3-tetrahydro[2]furyl-propyl ester) 
• 627-93-0 hexanedioic acid dimethyl ester 
• 627-91-8 adipic acid monomethyl ester 
• 6939-72-6 Hexanedioic acid monopropyl ester 
• 106-19-4 di-n-propyl adipate 
• 55125-22-9 Adipinsaeure-bis-(1,3-dimethyl-butylester) 
• 109-44-4 adipic acid bis-(2-ethoxy-ethyl ester) 
• 3323-53-3 hexanediyldiamine; adipate 
• 18105-31-2 Bis(trimethylsilyl) adipate 
• 4074-90-2 divinyl adipate 
• 5538-18-1 adipic acid di-p-tolyl ester 

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Relevant articles and documents

Catalytic Oxidative Cleveage of Vicinal Diols and Related Oxidations by Ruthenium Pyrochlore Oxides: New Catalysts for Low-Temperature Oxidations with Molecular Oxygen

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Optimization of adiponitrile hydrolysis in subcritical water using an orthogonal array design

A study of the hydrolysis of adiponitrile (ADN) was performed in subcritical water to research the dependence on experimental conditions. An L25(56) orthogonal array design (OAD) with six factors at five levels using statistical analysis was employed to optimize the experimental conditions for each product in which the interactions between the variables were temporarily neglected. The six factors were adiponitrile concentration (ADN c, wt%), temperature (T), time (t h), percentage of additives (reactant/additive, wt/wt%), additives (A), and pressure (p, MPa). The effects of these parameters were investigated using the analysis of variance (ANOVA) to determine the relationship between experimental conditions and yield levels of different products. The results showed that (ADN c) and T had a significant influence on the yields of adipamide, adipamic acid, and adipic acid at p0.05. Time was the statistically significant factor for the yield of 5-cyanovalermic acid at p0.05 and (ADN c) was the significant factor for the yield of 5-cyanovaleramide at p0.1. Finally, five supplementary experiments were conducted under optimized conditions predicted by the Taguchi method; the results showed that the yield obtained of each product was no lower than that of the highest in the 25 experiments. Carbon balance was calculated to demonstrate the validity of the experimental technique and the reliability of the results. Based on the experimental results, a possible reaction mechanism was proposed.

Synthesis of AgWCNx Nanocomposites for the One-Step Conversion of Cyclohexene to Adipic Acid and Its Mechanistic Studies

A novel catalyst composed of silver nanoparticles grafted on WCNx has been prepared by using a facile pH-adjusted method. The material reported in this study presents a non-mineral acid route for the synthesis of the industrially significant monomer adipic acid through the selective oxidation of cyclohexene. Ag has been stabilized in the hydrophobic matrix during the formation of the mesoporous silica material by using aniline as stabilizing agent. A cyclohexene conversion of 92.2 % with 96.2 % selectivity for adipic acid was observed with the AgWCNx-2 catalyst, therefore, the AgWCNx catalyst was found to be efficient for the direct conversion to adipic acid with respect to their monometallic counterparts. The energy profile diagrams for each reaction path by using the AgWCNx catalyst were studied along with their monometallic counterparts by using the Gaussian 09 package. The reported material can avoid the use of harmful phase-transfer catalysts (PTC) and/or chlorinated additives, which are two among other benefits of the reported work.

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Liquid-phase catalytic oxidation of C6-C7 cycloolefins into carboxylic acids in a pseudohomogeneous system

Liquid-phase oxidation of cyclohexene, methylcyclohexene isomers, and norbornene with a 30% solution of hydrogen peroxide in a pseudohomogeneous system involving highly dispersed compounds of Group-VIb and -VIIIb metals supported by nanosize carbon particles was studied.

Oxidation of cyclohexene into adipic acid in aqueous dispersions of mesoporous oxides with built-in catalytical sites

Reactant incompatibility is a common problem in organic chemistry. This study investigates the use of concentrated aqueous dispersions of mesoporous oxides to overcome incompatibility. Oxidation of cyclohexene into adipic acid using aqueous hydrogen peroxide as oxidant has been performed in a range of ordered and disordered mesoporous materials. The different mesoporous oxides have been characterised with diffraction techniques (XRD and SAXS), electron microscopy (TEM and SEM) and nitrogen adsorption isotherms (BET and BJH methods). The catalyst used in the reaction was either soluble sodium tungstate added to a reaction system based on mesoporous silica, alumina or a silica/alumina mixture; or a catalytic oxide, tungsten oxide or titania, present in the framework of the mesoporous material. Tungsten oxide, either used as the sole oxide material or as a mixed oxide with silica turned out to be very efficient and gave almost quantitative yield of adipic acid. A major advantage with having the catalyst chemically incorporated in the walls of the porous material is that it can be easily reused. The results from recycling experiments show that the catalytic activity is retained.

The irradiation chemistry of dilute aqueous solutions of cyclohexanone.

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Alkene hydrogenation activity of enoate reductases for an environmentally benign biosynthesis of adipic acid

Adipic acid, a precursor for Nylon-6,6 polymer, is one of the most important commodity chemicals, which is currently produced from petroleum. The biosynthesis of adipic acid from glucose still remains challenging due to the absence of biocatalysts required for the hydrogenation of unsaturated six-carbon dicarboxylic acids to adipic acid. Here, we demonstrate the first enzymatic hydrogenation of 2-hexenedioic acid and muconic acid to adipic acid using enoate reductases (ERs). ERs can hydrogenate 2-hexenedioic acid and muconic acid producing adipic acid with a high conversion rate and yield in vivo and in vitro. Purified ERs exhibit a broad substrate spectrum including aromatic and aliphatic 2-enoates and a significant oxygen tolerance. The discovery of the hydrogenation activity of ERs contributes to an understanding of the catalytic mechanism of these poorly characterized enzymes and enables the environmentally benign biosynthesis of adipic acid and other chemicals from renewable resources.

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Direct oxidation of cyclohexene with inert polymeric membrane reactor

In this work, the use of PVDF flat membranes as contactors for direct solvent-free biphasic oxidation of cyclohexene to adipic acid has been reported. The oxidation has been carried out using 30% H2O2 and ammonium molybdate ((NH4)6Mo7O 24)inthe presence of succinic acid. The effect of different membranes as interfaces between the organic phase, containing cyclo- hexene, and the aqueous phase, with the oxidant and catalyst, has been studied and related to conversion and selectivity.

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Highly regioselective electrochemical synthesis of dioic acids from dienes and carbon dioxide

A simple and efficient electrochemical method has been developed for highly regioselective synthesis of unsaturated 1,6-dioic acids from 1,3-dienes and CO2. The electrosynthesis was successfully carried out by using a nickel cathode and an aluminum anode in an undivided cell containing n-Bu 4NBr-DMF electrolyte with a constant current under 3 MPa pressure of CO2, and the sole 1,4-addition products were obtained in good to excellent yields. The plausible mechanism for electrodicarboxylation reaction of 1,3-butadiene with CO2 was discussed briefly. In addition, further research shows that 3-hexene-1,6-dioic acid could be easily converted into adipic acid via the electroreduction in the diluted H2SO4 solution.

Natural phosphate modified by vanadium: A new catalyst for oxidation of cycloalkanones and α-ketols with oxygen molecular

In this work, we have studied the catalytic oxidative cleavage of C-C bonds of cycloalkanones and α-ketols, in the presence of natural phosphate (NP) type fluorapatite, Ca10(PO4)6F2, and dioxygen. The aim was to find a heterogeneous system clean and efficient alternative to the industrial oxidation of cyclohexanone to adipic acid with nitric acid. The modification of the NP by vanadium leads to the preparation of a new catalyst V/PN. The latter was characterized by: XRD, FTIR, SEM and BET. It appears that vanadium is well dispersed on the surface of the NP. Using 2-methylcyclohexanone as model substrate, we optimized the conditions of reaction in order to make the system 'V/PN/O2' more performance. The comparative study between the two catalytic systems 'PN/O2' and 'V/PN/O2' shows that the latter is more active. Finally, the system 'V/PN/O2' has been recycled but low leaching of vanadium was observed in the first use of the catalyst.

Intensification of cyclohexanone purification stage from impurities in caprolactam production using phase transfer catalysis

Impurities in the oxidate, which was produced in the oxidation of cyclohexane in an industrial environment, were analyzed and identified. It is found that the amount of esters and ethers is 30% of the impurities produced, among which a cyclohexyl ethers amount is more than 50%. The process of purifying the oxidate from the impurities by hydrolysis in the presence of phase transfer catalysts and without them was studied. It has been shown that the use of trioctylmethyl ammonium chloride (Aliquat-336) in the the stage of saponification of esters enabled a removal of 90-96% of esters with reducing of reaction time in a 1.5-fold, in contrast to non-catalytic process.

Dawson-type polyoxometalates as green catalysts for adipic acid synthesis

Dawson-type POMs series of formula α- and β-K6P2W18O62 isomers, α1- and α2-K6P2Mo5W13O62 isomers, α-K6P2Mo6W12O62 isomer and α1-K7P2Mo5VW12O62 isomer, have been used as catalysts for the liquid phase oxidation of cyclohexanol, cyclohexanone and cyclohexanol/cyclohexanone mixture to form adipic acid in presence of hydrogen peroxide without solvent, without phase-transfer agents and without adding acid. 31P NMR spectroscopy of different POMs after cyclohexanol oxidation showed the formation of new active species that can be attributed to "peroxo-POMox" form. An adipic acid yield of 69% was obtained from the oxidation of a mixture of cyclohexanol (50%) and cyclohexanone (50%) with α-K6P2Mo6W12O62 isomer.

Selective hydroxylation of cyclohexene over Fe-bipyridine complexes encapsulated into Y-type zeolite under environment-friendly conditions

Fe-bipyridine complexes encapsulated into Na-Y ([Fe(bpy)3]2+@Y) were prepared and their catalytic activities for oxidation of cyclohexene with hydrogen peroxide in CH3CN and H2O solvents were investigated. The prepared [Fe(bpy)3]2+@Y was characterized by several methods and it was found that slightly distorted or compressed [Fe(bpy)3]2+ ions were formed within supercages of Y-type zeolite. [Fe(bpy)3]2+@Y catalyst exhibited both higher activity and higher selectivity to 2-cyclohexen-1-ol in water solvent than another Fe catalysts. In addition, the selective hydroxylation of cyclohexene to 2-cyclohexen-1-ol with molecular oxygen was successfully achieved for [Fe(bpy)3]2+@Y catalyst.

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Oxidative cleavage of cycloalkenes using hydrogen peroxide and a tungsten-based catalyst: Towards a complete mechanistic investigation

The identification of the intermediates and by-products produced during the oxidative cleavage of cycloalkenes in the presence of H2O2 and a tungsten-based catalyst for the production of dicarboxylic acids has been carried out under various experimental conditions. On the basis of this mechanistic investigation and previous studies from the literature, a complete reaction scheme for the formation of the reaction products and by-products is proposed. In this hypothetical mechanism, the production of a hydroperoxyalcohol intermediate accounts for the two pathways proposed by Noyori and Venturello for the formation of the targeted dicarboxylic acid. In addition, Baeyer-Villiger oxidation of the mono-aldehyde intermediate allows explaining the formation of short chain diacids observed as by-products during the reaction. Hence, the proposed mechanism constitutes a real tool for scientists looking for a better understanding and those heading to set up environmentally friendly conditions for the oxidative cleavage of cycloalkenes.

Electron-transfer Oxidation of Organic compounds. Part 5. Oxidation of cyclohexanone by the Tris-2,2'-bipyridylruthenium(III) Cation

Evidence is presented, from kinetic and product studies, that the rate-determining step in the oxidation of cyclohexanone by the trisbipyridylruthenium(III) cation is a non-bonded electron-transfer process from the enol form of the substrate.This gives rise to a free radical and a ruthenium(II) species.The subsequent fate of the radical has been investigated.

An efficient method for the catalytic aerobic oxidation of cycloalkanes using 3,4,5,6-Tetrafluoro-N-Hydroxyphthalimide (F4-NHPI)

N-Hydroxyphthalimide (NHPI) is known to be an effective catalyst for the oxidation of hydrocarbons. The catalytic activity of NHPI derivatives is generally increased by introducing an electron-withdrawing group on the benzene ring. In a previous report, two NHPI derivatives containing fluorinated alkyl chain were prepared and their catalytic activity was investigated in the oxidation of cycloalkanes. It was found that the fluorinated NHPI derivatives showed better yields for the oxidation reaction. As a continuation of our work with fluorinated NHPI derivatives, our next aim was to investigate the catalytic activity of the NHPI derivatives by introducing fluorine atoms in the benzene ring of NHPI. In the present research, 3,4,5,6-Tetrafluoro-N-Hydroxyphthalimide (F4-NHPI) is prepared and its catalytic activity has been investigated in the oxidation of two different cycloalkanes for the first time. It has been found that F4-NHPI showed higher catalytic efficiency compared with that of the parent NHPI catalyst in the present reactions. The presence of a fluorinated solvent and an additive was also found to accelerate the oxidation.

Oxidation of cyclohexanol and cyclohexanone by monochromate ions in organic solvents and on solvent free microwave irradiation under phase transfer catalysis - a comparative study

Oxidation of cyclohexanol and cyclohexanone were carried out by acidified monochromate ions in ethyl acetate and toluene under phase transfer catalysis and also in solvent free condition under microwave irradiation. The extraction of monochromate ions from aqueous medium to organic phase was carried by employing various phase transfer catalysts in the presence of mineral acids. The effect of [catalyst] and [mineral acid] on extraction of monochromate from aqueous phase to organic phase was also studied. The product obtained, namely adipic acid obtained with both reactants was characterized by its melting point and infrared spectral technique. The reaction was over within 15 min with more than 85% yield at a temperature of 323 K under microwave irradiation where as it gave around 70% yield at 353 K within 150 min under phase transfer catalysis condition. The enhanced reaction rate and high yield of product substantiate the application of phase transfer catalytic technique under microwave irradiation for organic synthesis. A suitable mechanism for the oxidation of substrates by monochromate under phase transfer catalysis is also suggested.

Efficient oxidation of cycloalkanes with simultaneously increased conversion and selectivity using O2 catalyzed by metalloporphyrins and boosted by Zn(AcO)2: A practical strategy to inhibit the formation of aliphatic diacids

The direct sources of aliphatic acids in cycloalkanes oxidation were investigated, and a strategy to suppress the formation of aliphatic acids was adopted through enhancing the catalytic transformation of oxidation intermediates cycloalkyl hydroperoxides to cycloalkanols by Zn(II) and delaying the emergence of cycloalkanones. Benefitted from the delayed formation of cycloalkanones and suppressed non-selective thermal decomposition of cycloalkyl hydroperoxides, the conversion of cycloalkanes and selectivity towards cycloalkanols and cycloalkanones were increased simultaneously with satisfying tolerance to both of metalloporphyrins and substrates. For cyclohexane, the selectivity towards KA-oil was increased from 80.1% to 96.9% meanwhile the conversion was increased from 3.83 % to 6.53 %, a very competitive conversion level with higher selectivity compared with current industrial process. This protocol is not only a valuable strategy to overcome the problems of low conversion and low selectivity lying in front of current cyclohexane oxidation in industry, but also an important reference to other alkanes oxidation.