Abstract: Synthesis of dialkyl oxalates by the heterogeneous catalyzed oxidative carbonylation of liquid monohydric saturated alcohols of from 1 to 20 carbon atoms with carbon monoxide and oxygen or an oxygen-containing gas in the presence of a catalytic amount of a catalyst comprising palladium or a salt thereof in combination with a crystalline vanadium-phosphorus-manganese containing compound.

Abstract: .beta.,.gamma.-Unsaturated esters are prepared by the reaction of the corresponding .beta.,.gamma.-unsaturated carbonate with carbon monoxide in the presence of a group VIII metal catalyst.

Abstract: 11-Deoxoglycyrrhetinic acid hydrogen maleate of the following formula ##STR1## and its salts, and this compound is prepared by reacting 11-deoxoglycyrrhetinic acid with maleic anhydride, and if desired, converting the resulting 11-deoxoglycyrrhetinic acid hydrogen maleate to its salt. The compound is useful as medicament for treating an ulcer or inflammation in man or another animal or activating the cellular immunity of man or the animal.

Abstract: Synthesis of dialkyl oxalates by the heterogeneous catalyzed oxidative carbonylation of liquid monohydric saturated alcohols of from 1 to 20 carbon atoms with carbon monoxide and oxygen or an oxygen-containing gas in the presence of a catalytic amount of a catalyst comprising palladium or a salt thereof in combination with a crystalline vanadium-phosphorus-titanium containing compound.

Abstract: Synthesis of dialkyl oxalates by the heterogeneous catalyzed oxidative carbonylation of liquid monohydric saturated alcohols of from 1 to 20 carbon atoms with carbon monoxide and oxygen or an oxygen-containing gas in the presence of a catalytic amount of a catalyst comprising palladium or a salt thereof in combination with a crystalline vanadium-phosphorus-iron containing compound.

Abstract: Production of malonic acid dialkyl esters by reacting halogen acetic acid alkyl ester with carbon monoxide, and alkali metal alcoholate, alkaline earth metal alcoholate or a solution of alkali metal hydroxide in an alcohol at a pH of up to 8.5 in the presence of a cobalt compound which is a catalyst for the reaction.

Abstract: In one of its embodiments this invention provides a process for recovering C.sub.4 -C.sub.6 dicarboxylic acid components contained in a waste byproduct stream derived from a reaction system in which adipic acid is produced by nitric acid oxidation of cyclohexanone/cyclohexanol.An important aspect of the process is the esterification and extraction of the C.sub.4 -C.sub.6 dicarboxylic acids in the aqueous byproduct stream with a mixture of C.sub.1 -C.sub.3 alkanol and C.sub.6 -C.sub.20 alkanol, and the subsequent recovery of di(C.sub.6 -C.sub.20 alkyl) esters of succinic acid, glutaric acid and adipic acid.In a broader aspect this invention provides a process for recovery of water miscible organic acid components contained in an aqueous solution as C.sub.6 -C.sub.20 alkyl esters of the organic acids.

Abstract: The activity of cation-exchangeable layered clay or crystalline aluminosilicate catalyst in esterification, etherification, hydration, and cracking reactions is promoted by addition of a strong acid such as sulphuric acid, phosphoric acid, hydrochloric acid, hydrofluoric acid or para-toluene sulphonic acid. The further addition of water to the reaction can extend the life of the clay catalyst and in some cases its catalytic activity.

Abstract: A process is herein described for preparing carboxylated organic compounds (acids, esters, alkaline salts) of formula ##STR1## wherein R is a hydrocarbyl group having up to 11 carbon atoms (an aliphatic, alicyclic, aryl- or heteroarylalkyl group), also substituted, in its turn, by groups inert under the reaction conditions (alkyl, aryl, etheric, thioetheric, halogen, nitrile, ester, amide, ketonic groups), and R' is a hydrogen atom or an alkyl C.sub.1 -C.sub.8 group, by reaction of carbon monoxide with the corresponding hydrocarbyl halides, having the halogen bound to a non-tertiary carbon atom, in the presence of catalysts which are salts of cobalt hydrocarbonyl, or precursors thereof, in a hydro-alcoholic or alcoholic solvent and in the presence of bases.The process is characterized in that the catalytic system composed by the salt of cobalt hydrocarbonyl is supported on an anion exchange resin.

Abstract: Process for the production of 3,3-dimethylglutaric acid or its esters from dimedone. Dimedone is converted with ozone into an ozone-addition product. The latter is converted by hydrolysis into 3,3-dimethylglutaric acid or by alcoholysis into one of its esters.

Abstract: The present invention provides for an improved process wherein an olefin, an alcohol, or an ester, halide or ether derivative of said alcohol is reacted with carbon monoxide in a liquid phase in the presence of a catalyst system containing a rhodium component and an iodine or bromine component. By passing at least a portion of the liquid reaction mass from the reaction zone to a separation zone of substantially lower CO partial pressure, at least a portion of the carbonylation products, as well as unreacted carbon monoxide, inert gases, and unreacted olefin, alcohol, or alcohol derivatives are vaporized and can be withdrawn from the separation zone. Precipitation of the rhodium catalyst under carbon monoxide deficient conditions is prevented or retarded by addition to the system of a stabilizer which is a tin component which may be tin or a tin compound.

Abstract: The present invention provides for an improved process wherein an olefin, an alcohol, or an ester, halide or ether derivative of said alcohol is reacted with carbon monoxide in a liquid phase in the presence of a catalyst system that contains (a) a rhodium component, and (b) an iodine or bromine component. By passing at least a portion of the liquid reaction mass from the reaction zone to a separation zone of substantially lower CO partial pressure, at least a portion of the carbonylation products, as well as unreacted carbon monoxide, inert gases, and unreacted olefin, alcohol, or alcohol derivatives are vaporized and can be withdrawn from the separation zone. Precipitation of the rhodium catalyst under carbon monoxide deficient conditions is prevented or retarded by addition to the system of a stabilizer component selected from N,N,N',N'-tetramethyl-o-phenylenediamine and 2,3'-dipyridyl.

Abstract: Esters of .beta.,.gamma.-unsaturated carboxylic acids, e.g., penten-3-oates, are prepared by carbonylating a necessarily conjugated diene, e.g., butadiene, with carbon monoxide, in the presence of (i) an alcohol corresponding to the desired ester, (ii) a halogen hydracid, (iii) a palladium catalyst which comprises palladium metal, a palladium oxide, or a salt of palladium, or ionic complex thereof, the anion coordinated with the palladium cation of which being a hard or intermediate base, and (iv) a quaternary onium salt of elemental nitrogen, phosphorus or arsenic, said elemental nitrogen, phosphorus or arsenic being tetracoordinated with carbon atoms and the anion of said salt comprising a hard or intermediate base.

Abstract: Organic esters, e.g., linear esters, including diesters, are prepared by carbonylating a monoolefin with carbon monoxide and an alcohol in the presence of a catalytically effective amount of a catalyst comprising cobalt, a tertiary amine base and ruthenium.

Abstract: Alkyl diesters of saturated dicarboxylic acids are prepared by catalytic reaction of olefinic hydrocarbons with carbon monoxide and alkoxylic copper salts, in the presence of a Palladium catalyst.The products obtained find useful applications in the field of plasticizers for synthetic resins, in the field of lubricants and of hydraulic fluids, etc.

Abstract: Improvement in the process of producing carboxylic acid esters or salts involving contacting a halogen alkyl compound with carbon monoxide and a basic substance in the presence of a carbonylation catalyst for carbonylation of the halogen alkyl and production of the corresponding ester or salt of the basic substance. The improvement involves performing the contacting in a reaction vessel, circulating a liquid mass of the halogen alkyl, basic substance and carbonylation catalyst through the vessel and maintaining a carbon monoxide atmosphere in the vessel, injecting the circulating liquid mass into the vessel with a nozzle to spray the liquid mass into the vessel and intimately mixing the liquid mass with carbon monoxide in the nozzle for injection of carbon monoxide into the vessel with the sprayed liquid mass.

Abstract: There is disclosed a novel process for the preparation of an ester of formic acid which comprises subjecting hydrogen, carbon monoxide and an ester of nitrous acid to a catalytic vapor phase reaction in the presence of a platinum group metal or a salt thereof. The product obtained by the process according to the present invention does not substantially contain water and free formic acid. The ester of formic acid formed by the process according to the present invention can be separated and purified in a simple manner, e.g., by conventional distillation procedure.

Abstract: Alkyl esters, such as ethyl acetate, are prepared by contacting the corresponding next lower carbon number alkyl ester, such as methyl acetate, with carbon monoxide and hydrogen in the presence of an iodine or iodide-free catalyst composition comprising a ruthenium-containing compound, a cobalt containing compound and a quaternary phosphonium salt or base, and heating the mixture to an elevated temperature and pressure for sufficient time to produce the desired higher alkyl ester, and then recovering the same from the reaction mixture.

Abstract: Carbonylation of olefins is carried out in the presence of a hydroxylic compound, carbon monoxide and a catalyst system comprising an organic phosphine liganded palladium compound and a perfluorosulfonic acid.

Abstract: In a process for preparing a diester of oxalic acid by the vapor phase catalytic reaction of carbon monoxide with an ester of nitrous acid in the presence of a catalyst composed of a solid carrier and a platinum-group metal or a salt thereof supported on the carrier, the improvement wherein said solid carrier is alumina having a specific surface area of not more than 90 m.sup.2 /g.

Abstract: A process for producing adipic acid diester which comprises the first step of reacting butadiene, carbon monoxide and an alcohol in the present of cobalt carbonyl catalyst at a temperature of from 80.degree. to 160.degree. C. to form a 3-pentenoic acid ester, andthe second step of reacting the 3-pentenoic acid ester in the reaction mixture, carbon monoxide and an alcohol at a temperature of from 160.degree. to 220.degree. C., characterized in that the first and second reactions are carried out in an amine solvent is disclosed.

Abstract: Production of malonic acid dialkyl esters by reacting halogen acetic acid alkyl ester with carbon monoxide, and alkali alcoholate, alkali earth alcoholate or a solution of alkali hydroxide in an alcohol at a pH of up to 8.5 in the presence of a cobalt compound which is a catalyst for the reaction.

Abstract: The present invention provides a process for the preparation of low molecular weight polyesters directly from hydroxypivaldehyde. The process comprises reacting dry hydroxypivaldehyde with a diester, a multifunctional ester, a diacid, a polyester, or a mixture thereof at a temperature of about 100.degree. C. to 230.degree. C. in the presence of a transesterification catalyst. Optionally, modifying glycols, triols, or polyols may also be added. Suitable catalysts include tetraisopropyl titanate, dibutyltin oxide, lithium hydroxide, and lithium alkoxide, with tetraisopropyl titanate being especially preferred. The reaction is preferably accomplished in two stages by heating the reaction mixture to about 130.degree. C. for about three hours and subsequently heating the reaction mixture to about 190.degree.-230.degree. C. until the reaction is essentially complete.

Abstract: In a process for preparing a diester of oxalic acid by the vapor phase catalytic reaction of carbon monoxide with an ester of nitrous acid in the presence of a catalyst composed of a solid carrier and a catalyst component supported on the carrier, the improvement wherein said catalyst component is composed of(a) a platinum-group metal or a salt thereof, and(b) at least one metal selected from the group consisting of Mo and Ni, or a salt thereof.

Abstract: A process for the preparation of nitrogen fertilizers, especially oxamide, either indirectly, or directly from oxalate esters, including the regeneration of the quinone oxidant utilized in the formation of the above esters.Preparation of oxalate esters as potential intermediates for nitrogen fertilizers by the oxidative carbonylation of alcohols with carbon monoxide in the presence of a catalytic amount of a platinum group metal salt with or without a corresponding metal oxidant salt and an optionally substituted quinone (substituted or unsubstituted 2,5-cyclohexadiene-1,4-dione). High yields of isolated dialkyl oxalates are obtained by regulating temperature and carbon monoxide pressure and by maintaining essentially anhydrous conditions. In addition, high yields of the hydroquinones (1,4-dihydroxybenzenes) are recovered.

Abstract: Waste streams from adipic acid manufacture containing nitric, succinic, glutaric and adipic acids and valuable catalytic metal as salts are treated with alcohols, thereby separating, as esters, succinic and glutaric acids which would contaminate pure adipic acid on recycling, and allowing the re-use of the resulting stream containing nitric acid and metal catalytic salts.

Abstract: The invention relates to an esterification process employing as a heterogeneous catalyst an inorganic oxide, e.g. silica, to which there is bonded by reaction with surface hydroxyl groups a sulphonic acid-functionalized silane.

Abstract: This invention provides an improved process for the separation and recovery of byproducts associated with the isolation of C.sub.4 -C.sub.6 dicarboxylic acids contained in a waste byproduct stream derived from an adipic acid manufacturing operation involving nitric acid oxidation of a cyclohexanone/cyclohexanol feedstream.The main byproducts which are recovered are high purity dimethyl succinate, dimethyl glutarate and dimethyl adipate.

Abstract: A process for the production of alkyl esters of saturated aliphatic carboxylic acids by reacting in an alkoxycarbonylation stage olefins with carbon monoxide and alkanol in the presence of a catalyst consisting of a cobalt compound and a promoter from the group of pyridine, non-ortho-substituted alkylpyridine or mixtures thereof at elevated pressure and elevated temperature. The reaction mixture produced is reprocessed and the pyridine, non-ortho-substituted alkylpyridine, or mixture used as the promoter is rectified prior to its feedback into the alkoxycarbonylation stage in the presence of a given carboxylic acid which is thermally stable under the conditions of reprocessing and which forms a maximum azeotrope with the promoter under the conditions of rectification.

Abstract: Malonic anhydride and substituted malonic anhydrides are prepared by ozonolysis of the enol-lactone dimers of ketenes. The resulting malonic anhydrides can be hydrolyzed with water to form the corresponding acid, reacted with an alcohol to yield the monoester, or reacted with an amine to yield the monoamide.

Abstract: Process for the carbonylation of alkanols and/or ethers at elevated temperature and pressure in the presence of a Group VIII metal compound and pentachlorobenzenethiol and/or salts thereof, using a pentachlorobenzenethiol compound: Group VIII metal compound molar ratio of not more than 10. The process is of special interest for the production of methyl acetate from methanol using an active, iodine-free catalytic system.

Abstract: In one embodiment, this invention provides a process for converting a dilute aqueous filtrate byproduct stream from adipic acid manufacture into a concentrated methanolic solution which does not solidify at ambient temperatures.In another embodiment, this invention provides an improved process for the separation and recovery of byproducts associated with the isolation of C.sub.4 -C.sub.6 dicarboxylic acids contained in a waste byproduct stream derived from an adipic acid manufacturing operation involving nitric acid oxidation of a cyclohexanone/cyclohexanol feedstream in the presence of a catalyst.

Abstract: A process for producing a carboxylic acid and/or its ester, which comprises reacting an alcohol or ether with carbon monoxide in the presence of elemental nickel or a nickel compound, iodine or an iodine compound and an organic compound of a trivalent nitrogen-group element; wherein the iodine or iodine compound is selected from the following formulae (I) to (IV),RX.sub.n (I)wherein R represents a hydrogen atom or an alkyl or alkylene group, X represents an iodine or bromine atom, and n is an integer of 1 to 3, at least one of n.multidot.X's being an iodine atom,I.sub.2 or I.sub.3 - (II)RCOI (III)wherein R represents an alkyl group,MI.sub.2 (IV)wherein M represents an alkaline earth metal, and the amount of the iodine or iodine compound is such that the amount of the free iodine or iodine compound not chemically bonded to the nickel or nickel compound or the organic compound of a nitrogen-group element is at least 0.

Abstract: In the carbonylation of olefinic compounds in the presence of a cobalt carbonyl catalyst, the addition to the reaction system of a secondary phosphine oxide represented by the general formula ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and each is substituted or unsubstituted hydrocarbon residue having not more than about 20 carbon atoms, in an amount of 0.2 to 20 moles per gram atom of the cobalt makes it possible to separate the reaction product from the reaction mixture by direct distillation without any such special operation for the catalyst separation as required in the conventional processes. The distillation residue which contains the catalyst can be recycled for the reuse thereof in the carbonylation.

Abstract: Halogen-substituted olefin addition compounds that contain a carbonyl group are formed by oxidatively adducting an olefin and a carbonyl compound such as a ketone, aldehyde, or ester. The method consists of reacting the olefin and the carbonyl component, in solution, with an oxidizing ion of manganese, cerium or vanadium in the presence of fluoride, chloride or bromide ion. This ionic component is incorporated in the adduct and appears on the olefin-derived carbon atom gamma to the carbonyl group. The gamma halogen substituted adducts are readily converted to cyclopropane derivatives, including pyrethroid intermediate compounds.

Abstract: Process industrially and economically useful for preparing difunctional aliphatic organic compounds of formulaX-(CH.sub.2).sub.n -Yin which n=6,7, X=--COOH, --COOR, Y=--CN, --COOH, --CONH.sub.2, --CH.sub.2 --NH.sub.2 --COOR wherein R is a linear or branched alkyl containing 1-6 carbon atoms.The process starts from a ketone of the formula ##STR1## in which n=2,3 and R.sub.1 =--CN, --COOH. The ketone (I) is changed to the corresponding hydroperoxide by means of H.sub.2 O.sub.2, the hydroperoxide is catalytically split by means of a catalyst Fe.sup.++ /Cu.sup.++ to give an unsaturated acid of the formulaHOOC--(CH.sub.2).sub.3 --CH.dbd.CH--(CH.sub.2).sub.2 -R.sub.1and this is catalytically hydrogenated to the compoundHOOC--(CH.sub.2).sub.n -R.sub.1When R.sub.1 is different from Y, R.sub.1 is changed to Y through known methods.

Abstract: Process for reducing the color forming tendency of alkanedioic acid esters by contact with an alkali metal borohydride in the presence of water.

Abstract: Monoesters of symmetrical dicarboxylic acids and symmetrical diols are prepared in high yield by reacting a diacid or a diol with a monohydric alcohol or monocarboxylic acid, respectively, in an aqueous solution. The resultant monoester is removed from the aqueous solution immediately after its formation by continuous extraction with a nonpolar solvent.

Abstract: A process for the preparation of butanedicarboxylic acid esters, wherein(a) an aqueous cobalt salt solution is treated with excess carbon monoxide and hydrogen in the presence of active charcoal laden with cobalt carbonyl,(b) the resulting aqueous solution of cobalt carbonyl hydride is extracted with butadiene or a butadiene containing hydrocarbon mixture and the aqueous phase is separated off,(c) the butadiene, or butadiene/hydrocarbon mixture, containing cobalt carbonyl hydride, cobalt carbonyl and butenyl-cobalt tricarbonyl, is reacted with carbon monoxide and excess C.sub.1 -C.sub.4 -alkanol in the presence of a tertiary nitrogen base,(d) the resulting reaction mixture is freed from the tertiary nitrogen base contained therein, down to a content of from 0.1 to 0.3 mole per mole of pentenoic acid ester, and from excess hydrocarbons, and the pentenoic acid ester remaining in the reaction mixture is reacted with carbon monoxide and excess C.sub.1 -C.sub.

Abstract: A process for preparing a brassylic diester of the formula:ROOC--CH.sub.2).sub.11 COORwherein R is a lower alkyl group by hydrocracking 6,6'-methylenebis-(6-hexanolide) in an alcohol of the formula:ROH(wherein R is as defined above) in the presence of a metal catalyst and an acid catalyst. A process for producing the hexanolide is also disclosed.

Abstract: This invention relates to a method of synthesizing 3-amino-2-hydroxy-2-cyclopentenones possessing an aliphatic substituent in the 4-position which comprises reacting cyanoacetamide with an aliphatic aldehyde to yield the corresponding .beta.-substituted-.alpha.,.alpha.'-dicyanoglutaramide, hydrolyzing the amide to the corresponding .beta.

Abstract: Carboxylic acids are esterified with ethylene gas, to effect the formation of ethyl esters, by acid catalysis in the presence of at least one dissociating, inert and stable solvent which increases the acidity of the reaction medium.

Abstract: A process for the preparation of an unsaturated diester having the formula ##STR1## wherein R is alkyl having 1 to 8 carbon atoms or aralkyl having 6 carbon atoms in the ring and from 1 to 4 carbon atoms in the alkyl moiety, and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the same or different and are each hydrogen, halogen, alkyl having 1 to 4 carbon atoms or aryl having 6 carbon atoms in the ring, by reacting carbon monoxide and oxygen with a diolefin having the formula ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are as aforesaid, in the presence of a catalytic amount of a platinum group metal compound, a copper or iron oxidant salt compound, a soluble vanadium salt and a stoichiometric amount of a dehydrating agent. Optionally, an anhydrous-halogen containing acid may be included.Alternatively, a ligand or coordination complex compound of the metal salt compound, and catalytic quantities of an alcohol may be employed.

Abstract: Preparation of dialkyl oxalates by the oxidative carbonylation of alcohols which comprises reacting a mixture of carbon monoxide and air with an alcohol in the presence of a catalytic amount of a catalyst comprising palladium in complex combination with a ligand, a small amount of a quinone, and a redox agent.Advantageously the reaction is carried out in the presence of a solvent.

Abstract: This invention provides a process for improving the recovery of byproducts associated with the isolation of C.sub.4 -C.sub.6 dicarboxylic acids contained in a waste byproduct stream, derived from an adipic acid manufacturing operation wherein there is involved nitric acid oxidation of a cyclohexanone/cyclohexanol feedstream.The main byproducts which are isolated are high purity dimethyl succinate, dimethyl glutarate and dimethyl adipate. Monomethyl esters of these dicarboxylic acids are recovered and recycled in the process.

Abstract: A process for preparing a diester of a dicarboxylic acid having two more carbon atoms than the unsaturated hydrocarbon used as a starting material, which comprises subjecting an unsaturated hydrocarbon, carbon monoxide and an ester of nitrous acid to catalytic vapor phase reaction at a temperature of 50.degree. to 200.degree. C. in the presence of a platinum group metal or a salt thereof and a halogen compound.

Abstract: In a process for the preparation of butanedicarboxylic acid esters by(a) reacting butadiene or hydrocarbon mixtures containing butadiene with carbon monoxide and a C.sub.1 -C.sub.4 -alkanol in the presence of a tertiary nitrogen base and a cobalt carbonyl catalyst at from 80.degree. to 150.degree. C. under superatmospheric pressure,(b) removing the greater part of the tertiary nitrogen base together with any excess hydrocarbon and(c) reacting the resulting pentenoic acid ester, in the presence of the catalyst remaining in the reaction mixture, and in the presence of the remaining amount of tertiary nitrogen base, with carbon monoxide and a C.sub.1 - to C.sub.4 -alkanol at from 140.degree. to 200.degree. C. under superatmospheric pressure, to give the butanedicarboxylic acid ester, the improvement wherein the reaction mixture in stage c) is substantially free from dissolved butadiene or butadiene bonded to the catalyst.Butanedicarboxylic acid esters may be used for the preparation of polymers.

Abstract: Conjugated diolefins (e.g., 1,3-butadiene) are carbonylated by the palladium-catalyzed addition of carbon monoxide and an alcohol of the formula ROH (e.g., benzyl alcohol) whereby polycarboxylic esters are formed in which the pair of double bonds of the conjugated diolefin has been transformed into a moiety having the formula: ##STR1## In the process, the olefin, carbon monoxide, and alcohol are reacted in the presence of a palladium(II) salt, a copper(II) salt, and a base, at certain concentrations and at a pressure and temperature sufficient to effect the carbonylation. The resulting unsaturated diester can be hydrolyzed and hydrogenated or vice versa to obtain the corresponding linear diacid (e.g., adipic acid).

Abstract: A process for the preparation of nitrogen fertilizers, especially oxamide, either indirectly or directly from oxalate esters, including the regeneration of the quinone oxidant utilized in the formation of the above esters.Preparation of oxalate esters by the oxidative carbonylation of alcohols with carbon monoxide in the presence of a catalytic amount of a platinum group metal salt with or without a corresponding metal oxidant salt and an optionally substituted quinone. High yields of isolated dialkyl oxalates are obtained by regulating temperature and carbon monoxide pressure and by maintaining essentially anhydrous conditions. In addition, high yields of the hydroquinones (1,4-dihydroxybenzenes) are recovered.

Abstract: A process for preparing a diester of oxalic acid which comprises bringing carbon monoxide into contact with an ester of nitrous acid or with an alcohol and a nitrogen oxide or a hydrate of the nitrogen oxide in the gaseous phase in the presence of a solid catalyst containing metallic palladium or a salt thereof, a gas containing molecular oxygen being introduced into the reaction system in cases where said nitrogen oxide or a hydrate of the nitrogen oxide requires molecular oxygen together with the alcohol to form an ester of nitrous acid.