Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C69/00—Esters of carboxylic acids; Esters of carbonic or haloformic acids
  • C07C69/02—Esters of acyclic saturated monocarboxylic acids having the carboxyl group bound to an acyclic carbon atom or to hydrogen
  • C07C69/04—Formic acid esters
  • C07C69/10—Formic acid esters of trihydroxylic compounds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/10—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with ester groups or with a carbon-halogen bond
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/48—Separation; Purification; Stabilisation; Use of additives
  • C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
  • C07C67/54—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation

Definitions

• the present invention relates to a process for preparing an alXenyl derivative of a Bronsted acid by the
• RX + R'CH CH 2 catalyst
• RCH CH 2 + R'X wherein R is carboxy, amido, aroxy, alkoxy, and the like; X is hydrogen, hydroxyl, alkyl, aryl, and the like; and R' is carboxyl, amido, alkyl, substituted alkyl, aryl or substituted aryl.
• the experimental portion discloses the use of only palladium or carbon, copper on carbon, iron on carbon, palladium/copper carbon, palladium/copper/iron on silica, mercuric acetate carbon, and mercuric chloride on carbon. Hg and Pd are cited, at col. 1, line 67, as the preferred metals.
• ruthenium compositions are useful transvinylation catalysts for numerous Bronsted acids and derivatives of Bronsted acids as disclosed in U.S. application Serial Mo. 213,697, filed June 30, 1988, and assigned to the assignee of the present application.
• the invention disclosed therein relates to a process for the transvinylation of a vinyl derivative of a first Bronsted acid with a second Bronsted acid which comprises providing a liquid phase mixture containing the vinyl derivative of the first Bronsted acid and the second Bronsted acid in the presence of a ruthenium compound at a temperature at which transvinylation occurs, and recovering as a product of transvinylation the vinyl derivative of the second Bronsted acid.
• the beneficial use of ruthenium-containing compounds as catalysts for transvinylation processes overcomes several deficiencies noted for other catalysts that had been used in transvinylation processes.
• transvinylation reaction mixture including the starting reactants, the conjugate acid of the vinyl derivative of the first Bronsted acid and other side products produced by the reaction.
• distillation, fractional distillation, vacuum distillation and rotary evaporation have been used.
• vacuum distillation Examples 1-3
• fractional distillation Examples 4, 7
• distillation Example 13
• U.K. Patent 1,486,443 describes a process for making high boiling point vinyl esters whose separation is facilitated by fractional distillation as the reaction
• transvinylation reaction resulted in high losses of the vinyl product derivative due to polymerization, particularly when mercury catalysts were employed, as well as the loss of starting materials. It was also recognized that losses of vinyl product derivative, especially high boiling esters, was intensified in separations involving the distillation of mixtures of close boiling materials. The difficulty of separating close boiling materials was also recognized.
• the solution to the separation problem taught in U.S. Patent No. 3,337,611 involves the use of a molar excess of the carboxylic acid relative to the molar concentration of the vinyl ester reactant in the transvinylation reaction. Distillation of the vinyl product derivative remained the method of choice for the recovery of total ester. See Col. 2, 11s. 48-51, Col. 4, 11s. 50-59, and Example 1.
• transvinylation technology has not achieved widespread commercial significance because of the inefficient and economically unattractive methods that have been
• the vinyl product derivative has a boiling point very close the boiling point of the conjugate acid, i.e., the acid formed from the vinyl derivative of the Bronsted acid used as the starting material during transvinylation, and/or the other components of the transvinylation reaction mixture.
• the separation by fractional distillation can be accomplished only by the use of very large, complex, and expensive distillation columns or not at all. The cost of such columns and the expense of operating them thus makes the use of transvinylation technology commercially unattractive for the production of many monomers.
• a need for a transvinylation process in which the alkenyl product derivative, and in particular the vinyl product derivative can be readily, facilely and economically separated from the other components of the transvinylation reaction mixture, and, in particular, the conjugate acid of the alkenyl derivative of the first Bronsted acid.
• a need for such a process is especially acute where the conjugate acid and alkenyl product derivative are close boilers, i.e., they have a boiling point close to one another, such as on the order of within 15 degrees of one another, especially within 5 degrees of one another.
• transvinylation process which includes a means for separating desirable transvinylation reaction product monomers and mixtures of monomers economically so as to permit the commercial production of many monomers and monomer mixtures that would otherwise not be produced or that could be produced only at significantly greater expense.
• the present invention provides an improved
• transvinylation process for the preparation of an alkenyl derivative of a Bronsted acid.
• the improved transvinylation process of the present invention includes the use of
• components of the transvinylation reaction mixture including the starting reactants, and especially the conjugate acid of the alkenyl derivative of the Bronsted acid employed as one of the starting reactants, and to facilitate recovery of the alkenyl product derivative.
• Transvinylation as used herein includes both vinyl interchange and allyl interchange reactions. The novel process of the present invention applies equally to both types of interchange reactions.
• the invention thus provides a process for the preparation of an alkenyl derivative of a Bronsted acid formed by the transvinylation reaction of an alkenyl derivative of a first Bronsted acid with a second Bronsted acid which comprises reacting an alkenyl derivative of the first Bronsted acid with a second Bronsted acid in the presence of a catalyst capable of catalyzing the transvinylation reaction, adding to the transvinylation reaction mixture an azeotropic agent capable of forming an azeotrope with at least the alkenyl product derivative of the second Bronsted acid and recovering by azeotropic distillation as a product of the transvinylation reaction an alkenyl derivative of the second Bronsted acid.
• the azeotropic agent and the alkenyl product derivative form an azeotrope whose boiling point is sufficiently different from the boiling point of at least the conjugate acid of the alkenyl derivative of the first Bronsted acid to permit the azeotrope and the conjugate acid to be separated by
• the azeotropic assisted transvinylation process in accordance with the present invention is versatile.
• the process may be used to prepare a single monomer of relatively high purity or it may be used to produce mixtures of monomers.
• the product objectives can be achieved by proper selection the azeotropic agent and separation tasks performed on the transvinylation reaction mixture prior to azeotropic
• Figure 1 is a schematic illustration of the
• transvinylation process of the present invention including recovery of the alkenyl product derivative by azeotropic distillation, and Bronsted acid recycle.
• RX + R' (CH 2 ) a CR 2 CR 0 R 1 catalyst
• RCR 2 CR 0 R 1 + R'X
• R is carboxy, amido, aroxy, alkoxy, or the like
• X is hydrogen, hydroxyl, alkyl, aryl, or the like
• n is zero or one
• R' is carboxyl, amido, alkyl, substituted alkyl, aryl or substituted aryl
• R 0 , R 1 and R 2 are each individually one of hydrogen, alkyl of 1 to about 12 carbon atoms, cycloalkyl, aryl, alleyl ethers, and the like.
• the equilibrium reaction may be shifted to favor production of one of the reaction products by appropriate adjustment of the reactants and/or by removal of one or both the reaction products. Accordingly, the design parameters and product desired will determine whether the equilibrium is to be shifted and the manner in which it is to be shifted.
• the primary objective of azeotropic distillation is the recovery of the alkenyl product derivative or mixtures of the alkenyl product derivative and the alkenyl derivative of the first Bronsted acid. Stated another way, either the alkenyl product
• an azeotropic agent is added to the transvinylation reaction mixture to form an azeotrope with the alkenyl product derivative so that upon azeotropic distillation, at least the alkenyl product
• the azeotrope has a boiling point at a temperature sufficiently different from the boiling point of at least the conjugate acid (R'X) to allow the azeotrope to be separated from the transvinylation
• the azeotropic agent selected must be compatible with the alkenyl product derivative.
• the azeotropic agent forms with the alkenyl product derivative an azeotrope which has a boiling point sufficiently different from the other components of the transvinylation reaction mixture to permit the separation of the azeotrope from those components by azeotropic distillation in a suitable column.
• the difference in the boiling point of the azeotrope and the boiling point of the other components of the transvinylation reaction mixture from which the azeotrope is to be separated be on the order of several degrees centigrade, most preferably about 10 degrees centigrade or more.
• the azeotropic agent and alkenyl product derivative may form either a minimum boiling point azeotrope or a maximum boiling point azeotrope.
• the azeotropic agent may form either a heterogeneous or a
• azeotropic agent and alkenyl product derivative in one another is minimal.
• the azeotropic agent and alkenyl product derivative will separate into two phases, so separation of the azeotropic agent from the alkenyl product derivative is facilitated. It is thus preferred that the azeotropic agent forms a heterogeneous azeotrope with the alkenyl product derivative.
• heterogeneous azeotrope simplifies the separation, recovery and purification of the alkenyl product derivative.
• the azeotropic distillation assisted transvinylation process in accordance with the present invention is very versatile in that it allows for the preparation, separation and recovery of the alkenyl product derivative and of mixtures of the alkenyl product derivative and the alkenyl derivative of the first Bronsted acid.
• the specific product or product mixture to be produced will determine the manner in which the transvinylation reaction products are to be treated prior to azeotropic distillation.
• the transvinylation reaction products may be treated to remove all or only a portion of the alkenyl derivative of the first Bronsted acid prior to azeotropic distillation.
• the alkenyl product derivative is separated from the transvinylation reaction mixture by azeotropic distillation and is subsequently recovered by separating the alkenyl product derivative from the azeotropic agent. Where only a portion of the alkenyl derivative of the first Bronsted acid is removed prior to azeotropic
• azeotropic agent is capable of forming an azeotrope with the alkenyl product derivative
• an azeotropic agent that forms an azeotrope with both the alkenyl product derivative and the alkenyl derivative of the first Bronsted acid may also be satisfactorily
• an azeotropic agent capable of forming an azeotrope with both the alkenyl product derivative and with the alkenyl derivative of the first Bronsted acid allows a mixture of those two derivatives to be separated and recovered from the transvinylation reaction mixture.
• the transvinylation reaction is preferably carried out in the presence of a atalyst. Any of the well known
• transvinylation catalyst may be employed, including, for example, mercury and palladium based catalysts.
• Especially preferred transvinylation catalysts are the ruthenium-based catalysts disclosed and claimed in U.S. application Serial No. 213,697, filed June 30, 1988, entitled Transvinylation Reaction, assigned to the same assignee of the present application.
• Reactor 16 includes a catalyst for the transvinylation reaction. Reactor 16 is maintained at a temperature and pressure sufficient to effect the
• the transvinylation reaction mixture which contains concentrations of the alkenyl derivative of the first Bronsted acid, the second Bronsted acid, the alkenyl product derivative and conjugate acid of the alkenyl derivative of the first Bronsted acid, and possibly catalyst is transferred from reactor 16 to a separation zone 18 through transfer line 17
• separation zone 18 various separation tasks may be performed on the transvinylation reaction mixture prior to azeotropic distillation.
• separation zone IS may be used to separate a mixture of the alkenyl product derivative and the conjugate acid from the catalyst and any unreacted second Bronsted acid. The product objective of the reaction will determine whether the unreacted alkenyl
• separation zone 18 is designed to separate the unrelated alkenyl derivative ofthe first Bronsted acid and, optionally, to recycle that alkenyl derivative back to the reactor by transfer line 20.
• separation zone 18 is designed to separate only a portion of the alkenyl derivative (or none at all) from the alkenyl product derivative. In the illustrated embodiment, all, or at least a portion of the alkenyl
• separation zone 18 and is recycled to reactor 16 via transfer line 22.
• separation zone 18 may be included after azeotropic distillation, for example, where the separation zone is used primarily for the separation and recovery of catalyst after the alkenyl product derivative has been separated from the transvinylation reaction mixture.
• the alkenyl product derivative, conjugate acid and, optionally, unreacted alkenyl derivative of the first Bronsted acid are transferred from separation zone 18 to distillation column 24 via transfer line 23 for azeotropic distillation.
• the azeotropic agent is capable of forming an azeotrope with at least the alkenyl product derivative in order to enable the alkenyl product derivative to be separated from the conjugate acid.
• the azeotrope preferably has a boiling point at least 10oC different than the boiling point of the conjugate acid, although the azeotropic distillation assisted transvinylation process in accordance with the invention is useful where the difference in boiling point between the azeotrope and the conjugate acid (as well as other components of the
• transvinylation mixture from which the alkenyl product derivative is to be separated is significantly less.
• the present invention is useful even when the boiling point differential between the azeotrope and the conjugate acid (or the component) is on the order of two or three degrees centigrade, especially where the monomer to be recovered is commercially important.
• an azeotropic agent may or may not be necessary to use an azeotropic agent to form an azeotrope with the alkenyl derivative of the first Bronsted acid in order to separate the alkenyl derivative of the first Bronsted acid from the conjugate acid depending on the relative boiling point of the alkenyl derivative of the first Bronsted acid, the alkenyl product derivative and the conjugate acid.
• the alkenyl derivative of the first Bronsted acid and the boiling point of the conjugate acid are relatively close, i.e., on the order of less than 15 degrees, then it may well be desirable to form an azeotrope with the alkenyl derivative of the first Bronsted acid to effect efficient separation of the alkenyl derivative of the first Bronsted acid from the conjugate acid.
• the boiling point of the alkenyl derivative of the first Bronsted acid and the conjugate acid are not close, and the boiling points of the alkenyl derivative of the first Bronsted acid and azeotrope of the azeotropic agent and the alkenyl product derivative are both either lower or higher than the boiling point of the conjugate acid, then the alkenyl
• One azeotropic agent capable of forming an azeotrope with both the alkenyl product derivative and the alkenyl derivative of the first Bronsted acid may be used.
• a mixture of azeotropic agents may be used, one for the alkenyl product derivative and one for the alkenyl derivative of the first Bronsted acid.
• the azeotropic agent is shown to be fed near the top of column 24 through feed line 25. Additionally, azeotropic agent recovered from the
• decanter 30 (as described below) can, and preferably is, recycled to the azeotropic distillation column 24.
• the azeotroping agent In Independently of the source of the azeotropic agent, it is preferred to feed the azeotroping agent near the top of the azeotropic distillation column to assist in the separation of undesirable components during distillation. Because the temperature of the liquid near the top of the column is lower than it is at other locations, adding the azeotroping agent near the top allows the agent to cool and thereby knock down non-azeotroping components that may be near the top of the column. Also, where the azeotroping agent is water, there is less time and opportunity for the water to contact and
• the azeotropic agent may also be added to the feed to
• the azeotropic agent and alkenyl product derivative form a heterogeneous minimum boiling point azeotrope.
• the azeotrope is drawn off the top of column 24 through transfer line 28 and
• the azeotrope separates into two phases, the alkenyl product derivative and the azeotropic agent. Note that if a mixture of alkenyl product derivative and alkenyl derivative of the first Bronsted acid is separated from the conjugate acid, then one phase will consist of a mixture of the alkenyl product derivative and the alkenyl derivative of the first Bronsted acid and the other phase will consist of the azeotropic agent.
• the azeotropic agent is recycled for use in azeotropic distillation column 24 (as illustrated by transfer line 32). Some of the azeotropic agent may be removed as waste through transfer line 34.
• the alkenyl product derivative phase may, if desired, also be refluxed (as, for example, by return to distillation column 24 through transfer line 33) to enhance rectification.
• the alkenyl product derivative is transferred to drying column 36 via transfer line 38.
• drying column 36 the alkenyl product derivative is dried by azeotropic drying, the azeotrope being taken off the column and transferred to either the first decanter 30 and processed as described above, or transferred to a second decanter 40, in which phase separation of the alkenyl product derivative and azeotropic agent occurs.
• Alkenyl product derivative from the second decanter 40 is returned to drying column 36 via transfer line 42, while the azeotropic agent is processed as waste.
• Azeotropic agent from decanter 40 may also be recycled for use in distillation column 24.
• Dried alkenyl product derivative is transferred purification column 44 where alkenyl product derivative is recovered. If desired, the alkenyl product derivative may be neutralized with a suitable base, such as, sodium bicarbonate, to remove residual acid.
• the conjugate acid of the vinyl ester of the first Bronsted acid which is produced during the transvinylation reaction remain at the column bottom.
• the conjugate acid is transferred from azeotropic distillation column 24 via transfer line 25 to an acid separation column 46 where the conjugate acid is
• the second Bronsted acid is separated from the azeotrope in azeotropic distillation column 24 and is passed to acid separation column 46 with the conjugate acid.
• acid separation column 46 the second Bronsted acid is separated from the conjugate acid and recycled via transfer line 48 to reactor 16.
• azeotropic distillation column operating temperature and pressure are not particularly critical to the practice of the invention, but they are related, and they are highly dependent on the particular separation to be carried out.
• Azeotropic distillation may be carried out at atmospheric pressure or it may be carried out under vacuum or under pressure.
• the lower limit on the operating pressure is related to the economical limitations on condenser
• the upper pressure limit is dependent on the limitation of the column bottom temperature which, in turn, is dependent on the decomposition temperature of the components.
• Operating temperature in turn, depends on the condensation temperature of the column condenser and on the decomposition temperature of the components.
• the low end of the operating temperature is preferably only about 10°C or so higher than the temperature of the cooling media.
• the upper end of the operating temperature is preferably about 10°C lower than the decomposition temperature of the most decomposable component in the system.
• temperature and pressure are preferably chosen so that the condenser can be cooled easily and so that none of the components decompose.
• water is the azeotropic agent and the alkenyl product derivative may be susceptible to
• azeotropic distillation be carried out under a vacuum so that the distillation column can be operated at lower temperature.
• the type of azeotropic distillation column used to carry out the azeotropic distillation is not critical.
• the column may be a tray or a packed column.
• a packed column is
• the rate at which the azeotroping agent is fed to the azeotropic distillation column depends on both the rate at which the alkenyl product derivative is produced and the concentration of the alkenyl product derivative in the azeotrope.
• the feed rate of the azeotropic agent is preferably sufficient to permit all of the alkenyl product derivative fed to the column to form an azeotrope. While some excess of the azeotroping agent may be employed, it is preferred to match the feed rate of the azeotroping agent with the production rate of the alkenyl product derivative.
• the azeotropic agent fed to the distillation column is recovered from the two phase separation of the alkenyl product derivative and azeotropic agent in the decanter.
• Azeotropic agent from the decanter is simply recycled to the azeotropic distillation column to fill the needs of the distillation column, supplemented, if necessary, only to the extent that the azeotropic agent is removed from the system.
• the azeotropic distillation assisted transvinylation process of the present invention can be used for the
• alkenyl derivatives are compounds of the formula
• n is either zero or one, R 0 , R 1 and R 2 are each
• alkyl of 1 to about 12 carbon atoms individually one of hydrogen, alkyl of 1 to about 12 carbon atoms, cycloalkyl, aryl, alkyl ethers, and the like.
• alkenyl product derivatives 1-propenyl benzoate (cis and trans), 1-propenyl pivalate (cis and trans), 2-propenyl benzoate and 2-propenyl pivalate, allyl pivalate, allyl benzoate, allyl propionate, methallyl
• Azeotropic distillation assisted transvinylation can also be used for the preparation of numerous vinyl product
• the alkenyl product derivative may be any compound in which there is a vinyl group bonded to a Bronsted acid.
• Such compounds may be characterized as vinylated Bronsted acids, vinyl embraces groups of the formula
• R 0 R 1 C CR 2 - wherein R 0 , R 1 and R 2 are each individually one of hydrogen, alkyl of 1 to about 12 carbon atoms, cycloalkyl, aryl, alkyl ethers, and the like.
• the Bronsted acid is any species which can act as a source of protons.
• Bronsted acid for the practice of the invention are vinyl acetate, vinyl pivalate, vinyl benzoate, vinyl methacrylate, vinyl acrylate, vinyl propionate, vinyl cinnamate, vinyl cyclohexanoate, vinyl crotonate, vinyl butyrate, vinyl 2-methyl butyrate, vinyl isobutyrata, vinyl 2-methyl valerata, vinyl 2-ethylhexanoate, vinyl octanoata, vinyl decanoate, vinyl cyclohex-3-enoate, vinyl neodecanoate, vinyl
• Preferred alkenyl derivatives are the vinyl esters of carboxylie acids and the vinyl alkyl or aryl ethers, mainly because they are commercially available.
• Suitable Bronsted acids for the practice of the invention are carboxylic acids such as monocarboxylic and polycarboxylie acids illustrated by acetic acid, propionic acid, butyric acid, isobutyric acid, 2-methyl butyric acid, crotonic acid, pivalic acid and other neo-acids, stearic acid, benzoic acid, terephthalic acid, isophthalic acid, phthalic acid, adipic acid, succinic acid, malic acid, maleic acid, polyacrylic acids, acrylic acid, methacrylic acid, cinnamic acid, 2-ethylhexanoic acid, cyclohexanoic acid, and
• cyclohexenoic acid amides such as 2-pyrrolidinone, 2- pyrrolidone, e-caprolactam, 2-oxazolidinone, and succinimide; alcohols such as methanol, ethanol, n-propanol, isobutanol, fluorinated alkan ⁇ ls such as 1, 1, 1, 3 , 3 , 3-hexafluoro-2-propanol, monoethanolamine, diethanolamine, and
• hydroxy esters such as hydroxalkyl acrylates (e.g. , 2-hydroxyethyl aery late, 2 -hydroxy ethyl methacrylate) and hydroxyalkyl alkanoates (e.g. , 2-hydtox ⁇ ethyl acetate, 2-hydroxyethyl pivalate) ; silanols such as dimethyl silan diol,
• the preferred Bronsted acids are the carboxy lie acids , the alcohols , the amides, the imides, the phenolics, and the like.
• the azeotropic agent may be any agent that is capable of forming an azeotrope with the alkenyl product derivative of the transvinylation reaction.
• the azeotropic agent may form a binary azeotrope with the alkenyl product derivative or, in the event it is
• azeotrope with the alkenyl product derivative and with the alkenyl derivative of the first Bronsted acid.
• the boiling point differential between the azeotrope and the conjugate acid (and the alkenyl derivative of the first Bronsted acid if it is not separated from the reaction mixture prior to azeotropic distillation, and if an azeotrope is needed for it separation) is sufficient to allow the desired product to be separated, and is preferably at least about 10°C.
• suitable azeotropic agents include water, either in the form of a liquid or as steam, cyclohexane, heptane, isopropanol, methanol and alkyl ether.
• water is especially preferred because it forms a heterogeneous
• R" is alkyl, aryl, cycloalkyl and has from 1 to about 12 carbon atoms.
• Water forms a minimum boiling point azeotrope with the alkenyl product derivative and with the alkenyl derivative of the first carboxylic acid, if present.
• the minimum boiling point azeotrope has a boiling point greater than 10oC different than the boiling point of the conjugate acid, the boiling point of the azeotrope being lower than the boiling point of the conjugate acid.
• an alkenyl derivative of a carboxylic acid having from 1 to 12 carbon atoms is prepared by the transvinylation reaction of vinyl acetate and a second carboxylic acid having of from 1 to about 7 carbon atoms in the presence of a
• acetic acid which has a boiling point of about 116-118oC is one of the products of the reaction. Water is used to produce a minimum boiling point heterogeneous
• the azeotrope has a boiling point lower than the boiling point of acetic acid. Removal of the alkenyl product derivative from the other components is facilitated.
• the present invention is particularly useful for the preparation of vinyl pivalate, vinyl butyrate, vinyl
• crotonate form azeotropes with water having boiling points, respectively, of about 94.9°C, about 87oC, and about 92oC.
• the azeotrope has a boiling pcint substantially below the boiling point of acetic acid which allows the vinyl ester to be separated readily from acetic acid.
• the azeotropic distillation assisted transvinylation process described herein can be used to make vinyl pivalate. vinyl butyrate, vinyl crotonate and vinyl propionate directly from vinyl acetate by transvinylation.
• the process is more economical than previously known transvinylation techniques because of the relative ease with which the vinyl ester can be separated from acetic acid.
• transvinylation reaction mixture after catalyst removal that would result from the preparation of vinyl propionate by the transvinylation of vinyl acetate and propionic acid.
• Water was used as the azeotropic agent.
• a mixture consisting of 28wt.% vinyl acetate, 30wt.% vinyl propionate, 18wt.% acetic acid and 24wt.% propionic acid was charged to a 2 liter kettle.
• the kettle was equipped with a 15-tray Oldershaw distillation column, a condensing column connected to the outlet (top) of the distillation column and collection flask connected to the outlet end of the condensing column.
• This Example illustrates the separating of vinyl acetate and vinyl crotonate from a mixture of vinyl acetate, acetic acid, vinyl crotonate and crotonic acid by azeotropic
• crotonate/water azeotropes were distilled at an overhead temperature ranging from 67°C-94oC. The following fractions were collected, and when analyzed by gas chromatography were found to have the composition (area %) set forth in Table III below:
• This Example illustrates the preparation of vinyl acrylate by azeotropic distillation assisted transvinylation of vinyl acetate and acrylic acid.
• the reactor was heated to 130-136°C for a total of 4 hours.
• the reactor was cooled, vented, and the transvinylation mixture, containing the catalyst, vinyl acrylate, acetic acid, acrylic acid, and vinyl acetate, was discharged from the reactor.
• transvinylation mixtures of each run were combined and the flashed distilled under vacuum to remove the transvinylation mixture (vinyl acetate, vinyl acrylate, acetic acid, and som acrylic acid) from the acrylic acid/ruthenium catalyst residue. The distillate was recovered.
• the flash distilled transvinylation mixture was charged to a fractional distillation apparatus comprising a 12 L kettle equipped with a 24 tray Oldershaw column and a
• This Example illustrates the preparation of vinyl crotonate by azeotropic assisted transvinylation of vinyl acetate with crotonic acid.
• the reactor was heated to 127-133°C for a total of 12 hours.
• the reactor was cooled, vented and the transvinylation mixture, containing the catalyst, vinyl crotonate, acetic acid, crotonic acid, and vinyl acetate, was discharged from the reactor.
• the transvinylation mixture was flashed distilled under vacuum to remove the transvinylation products (vinyl acetate, vinyl crotonate, acetic acid, and some crotonic acid) from the crotonic acid/ruthenium catalyst residue.
• the flash distilled transvinylation mixture was charged to a fractional distillation apparatus comprising a 3000 ml kettle equipped with a 25 tray Oldershaw column and a
• phenothiazine inhibitor was added to the kettle and was fed down the column through the use of an addition funnel (phenothiazine dissolved in vinyl acetate).
• the unreacted vinyl acetate (b.p. 72-73°C) was fractionated from the transvinylation mixture at a reflux ratio ranging from 5/1 (initially) to 10/1 (at the end of the distillation).
• the last minor amounts of vinyl acetate were purged from the column at the high (10/1) reflux ratio by gradually and briefly raising the head temperature to 93oC.
• a reactor was charged with 5,082 pounds of vinyl acetate, 4,854 pounds of pivalic acid, and ruthenium dicarbonyl acetat homopolymer (530g). The reactor was pressurized to 25 psi carbon monoxide (containing an oxygen atmosphere of 500-1000 ppm in the reactor, as required by the inhibitor
• distillation residue containing catalyst and pivalic acid, was discharged from the reactor.
• Vinyl acetate was then fractionated from the distillate. After removal of vinyl acetate, the reaction mixture was subjected to azeotropic distillation to separate and recover vinyl pivalate.
• the column bottoms from the vinyl acetate removal step were distilled by azeotropic distillation.
• a Koch-Seltzer column was used in conjunction with a thirty gallon decanter.
• composition of the nine fractions from the azeotropic distillation is set forth in Table VIII below:
• distillation column was undesirably fast. Too rapid a water feed resulted in fractions of pivalic acid that were higher in pivalic acid and acetic acid content than were desirable.
• the present invention thus provides for an improved transvinylation process in which the separation and recovery of the alkenyl product derivative is efficient and economical.
• Azeotropic distillation assisted transvinylation has improved productivity, lower equipment costs and lower operating costs than conventional fractionation or distillation due, at least in part, to the efficiency and ease of the separation and recovery of the alkenyl product derivative.
• the process is capable of producing highly pure alkenyl product derivatives, low in acidity, directly and without the need for further processing.
• the invention makes economical the production of alkenyl product derivatives by transvinylation in a single stage reactor where the alkenyl product derivative and conjugate acid of the alkenyl derivative of the first Bronsted acid are close boilers.

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• 1991
  • 1991-11-19 EC EC1991000793A patent/ECSP910793A/es unknown
  • 1991-11-27 WO PCT/US1991/008757 patent/WO1992009554A1/en not_active Application Discontinuation
  • 1991-11-27 MC MC91US9108757D patent/MC2241A1/xx unknown
  • 1991-11-27 CA CA002075622A patent/CA2075622A1/en not_active Abandoned
  • 1991-11-27 JP JP4501986A patent/JPH05503948A/ja active Pending
  • 1991-11-27 KR KR1019920701790A patent/KR920703503A/ko not_active Application Discontinuation
  • 1991-11-27 AU AU91168/91A patent/AU9116891A/en not_active Abandoned
  • 1991-11-27 HU HU922264A patent/HUT63603A/hu unknown
  • 1991-11-27 BR BR919106065A patent/BR9106065A/pt not_active Application Discontinuation
  • 1991-11-27 EP EP92901814A patent/EP0513331A1/en not_active Withdrawn
  • 1991-11-29 ZA ZA919454A patent/ZA919454B/xx unknown
• 1992
  • 1992-07-28 NO NO92922980A patent/NO922980L/no unknown
  • 1992-07-29 FI FI923416A patent/FI923416A0/fi unknown

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