JPH08333307A - Production of diaryl carbonate - Google Patents

Abstract

PURPOSE: To readily obtain a diaryl carbonate useful as a raw material of polycarbonate at low temperature without using poisonous phosgene, safely in high selectivity and yield by thermal decarbonylation of a diaryl oxalate in the presence of a specific catalyst. CONSTITUTION: (A) A diaryl oxalate is subjected to thermal decarbonylation in the presence of (B) an organic phosphorus compound of formula I [R<1> to R<4> are each an aryl, a 1-16C alkyl, a 7-22C aralkyl, a 4-16C heterocycle and an aryloxy; X is atom (or group) forming the counter ion to phosphonium salt], formula II (R<5> to R<7> are the same as R<1> ), formula III (R<8> to R<10> are the same as R<1> ; Y<1> and Y<2> are each a halogen) and formula IV (R<11> to R<13> the same as R<1> ) and if necessary (C) a halogen compound (for example an aluminum halide or a platinum-group metal halide).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a diaryl carbonate useful as a raw material for producing polycarbonate.

[0002]

As a method for producing a diaryl carbonate, a method of reacting phosgene with an aromatic hydroxy compound in the presence of an alkali (JP-A-62-190146).
Or the like) or a method of transesterifying a dialkyl carbonate and an aromatic hydroxy compound in the presence of a catalyst (Japanese Patent Publication No. 56-42577, Japanese Patent Publication No. 1-558).
No. 8, etc.) are well known. However, the former method using phosgene is not necessarily an industrially excellent method because phosgene itself is a highly toxic compound and a large amount of alkali is used. Also, the latter transesterification method, as described in many patents relating to this method, does not have a sufficient reaction rate in spite of the use of a highly active catalyst, and therefore a large-scale reaction is required to compensate for this. It has a problem that it requires a device.

As another method, there is known a method in which a diaryl oxalate is subjected to a decarbonylation reaction to produce a diaryl carbonate. In this method, the selectivity and yield of the diaryl carbonate are low and the reaction temperature is high. Therefore, it has a problem that it is industrially very disadvantageous. That is, a method for producing diphenyl carbonate (diphenyl carbonate) by boiling diphenyl oxalate (diphenyl oxalate) in a distillation flask without a catalyst (Organic Synthesis Society, 5, 47 (1948), 7).
In 0), since no catalyst is used and the reaction temperature is high, phenol and carbon dioxide are by-produced, and the selectivity and yield of diphenyl carbonate are remarkably reduced. Conversely, when the reaction temperature is low, diphenyl carbonate is hardly obtained. There is a problem (see Comparative Examples 1 and 2).

Further, a method for producing a dialkyl carbonate by heating a dialkyl oxalate or the like in the liquid phase at 50 to 150 ° C. in the presence of an alcoholate catalyst has been reported (US Pat. No. 4,544,507). However, according to the examples described in this publication, even if diphenyl oxalate is heated in the presence of a potassium phenoxide catalyst, what is obtained as a main product is the raw material diphenyl oxalate.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for easily obtaining a diaryl carbonate without using phosgene which is a highly toxic compound. That is, in the method for producing a diaryl carbonate from a diaryl oxalate, the diaryl carbonate can be produced with a high selectivity even at an industrially suitable low reaction temperature, and if an appropriate condition is selected, a high yield is produced. It is an object to provide a method that can also do.

[0006]

The object of the present invention is achieved by a method for producing a diaryl carbonate, which comprises heating a diaryl oxalate in the presence of an organic phosphorus compound to carry out a decarbonylation reaction.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a diaryl carbonate is produced by a decarbonylation reaction of a diaryl oxalate represented by the following formula.

[0008]

Embedded image (In the formula, Ar represents an aryl group.)

In the present invention, an organophosphorus compound is used as a catalyst in the decarbonylation reaction of diaryl oxalate. Furthermore, in the decarbonylation reaction of the present invention, the reaction can be carried out in the presence of a halogen compound described below in addition to the organic phosphorus compound. Hereinafter, the present invention will be described in detail.

In the diaryl oxalate used in the present invention, the aryl group is (1) phenyl group, (2) (a) alkyl group having 1 to 12 carbon atoms such as methyl group and ethyl group, (b) A substituted phenyl group having a substituent group such as a methoxy group, an ethoxy group and the like, an alkoxy group having 1 to 12 carbon atoms, (c) a halogen atom such as a fluorine atom and a chlorine atom, or (d) a nitro group, or (3) naphthyl. Examples include groups such as groups.

The above-mentioned substituted phenyl group includes various isomers. These isomers include (a) o- (or m-, p
-) Methylphenyl group, o- (or m-, p-) ethylphenyl group and the like has 1 to 1 carbon atoms at the o- (or m-, p-) position.
An alkyl-substituted phenyl group having 12 alkyl groups,
(B) o- (or m-, p-) methoxyphenyl group, o
An alkoxy-substituted phenyl group having an alkoxy group having 1 to 12 carbon atoms at the o- (or m-, p-) position of a-(or m-, p-) ethoxyphenyl group, etc.
-, P-) fluorophenyl group, o- (or m-, p
-) A halogen-substituted phenyl group having a halogen atom at the o- (or m-, p-) position of a chlorophenyl group or the like, (d)
An o- (or m-, p-) nitrophenyl group etc. are mentioned.

Examples of the organic phosphorus compound used in the present invention include organic phosphorus compounds having a phosphorus atom with a valence of 3 or 5. In the organophosphorus compound in which the valence of the phosphorus atom is trivalent or pentavalent, an organophosphorus compound having at least one carbon-phosphorus (CP) bond is preferable,
Among them, an organic phosphorus compound having 3 or more carbon-phosphorus (CP) bonds is preferable.

Suitable examples of the organic phosphorus compound include phosphonium salts, phosphines, phosphine dihalides and phosphine oxides represented by the following general formula.

Embedded image (In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ ,
^{R 8, R 9, R 10} , R 11, R 12, R 13 is an aryl group, an alkyl group having 1 to 16 carbon atoms, an aralkyl group having 7 to 22 carbon atoms, heterocyclic group having 4 to 16 carbon atoms, or Represents an aryloxy group, X represents an atom or an atomic group capable of forming a counterion of a phosphonium salt, and Y ¹ and Y ² represent a halogen atom. )

A phosphonium salt represented by the general formula (A)
Then R¹, R², R³, R^FourIs an aryl group, alk
Group, aralkyl group, heterocyclic group, or aryloxy group
What is. In addition, these groups are R¹When
R², R²And R³, R³And R ^Four, Or R^FourAnd R¹Between
It may be crosslinked to form a ring containing a phosphorus atom.
Absent.

Examples of the aryl group, alkyl group, aralkyl group, heterocyclic group and aryloxy group represented by R ¹ , R ² , R ³ and R ⁴ include the following. That is, examples of the aryl group include an aryl group such as a phenyl group and naphthyl group which may have a substituent, and examples of the alkyl group include a methyl group which may have a substituent, 1 carbon atom such as ethyl group, n- (or i-) propyl group, n- (or i-, sec-, tert-) butyl group
To 16 alkyl groups, and examples of the aralkyl group include aralkyl groups having 7 to 22 carbon atoms, such as a benzyl group, a phenethyl group, and a naphthylmethyl group, which may have a substituent. Examples of the cyclic group include a heterocyclic group having 4 to 16 carbon atoms, which may have a substituent, such as a thienyl group, a furyl group and a pyridyl group. Examples of the aryloxy group include an aryl group which may have a substituent, such as a phenyl group and a naphthyl group.

The aryl group, aralkyl group, heterocyclic group and aryloxy group represented by R ¹ , R ² , R ³ and R ⁴ are
It may have one or more various substituents such as an alkyl group, an alkoxy group, an alkoxycarbonyl group, an aryl group, an amino group, a cyano group, a nitro group and a halogen atom at any position on the aromatic ring or heterocyclic ring. No problem (o, m,
including various isomers such as p).

An alkyl group on the aromatic ring or heterocycle,
Alkoxy group, alkoxycarbonyl group, aryl group,
The following are mentioned as an amino group and a halogen atom. That is, as the alkoxy group, a methyl group, an ethyl group, an n- (or i-) propyl group, an n- (or i-,
sec-, tert-) butyl group or the like having 1 to 15 carbon atoms,
Preferred is an alkyl group having 1 to 12 carbon atoms, and the alkoxy group thereof is methoxy group, ethoxy group, n
-(Or i-) propoxy group, n- (or i-, sec
Examples include alkoxy groups having 1 to 15 carbon atoms, such as-, tert-) butoxy group, preferably 1 to 12 carbon atoms, and the alkoxycarbonyl group includes 2 to 12 carbon atoms such as methoxycarbonyl group and ethoxycarbonyl group. And preferably an alkoxycarbonyl group having 2 to 8 carbon atoms, the aryl group includes an aryl group such as phenyl group, and the amino group includes N, N-such as N, N-dimethylamino group. Examples thereof include di-substituted amino groups, and examples of the halogen atom include atoms such as fluorine, chlorine and bromine.

R ¹ , R ² , R ³ and R ⁴ may be the same or different. Examples of such phosphonium salts are those in which all of R ¹ , R ² , R ³ and R ⁴ are aryl groups (tetraarylphosphonium salts).
And R ¹ , R ² , R ³ and R ⁴ are aryl groups and one is another group, R ¹ , R ² and R 4 are
^3, a two are aryl groups of R ^4, two of and what is another group, one of R ^1, R ^2, R ^3, R ⁴
One being an aryl group and three being another group,
An example is one in which none of R ¹ , R ² , R ³ and R ⁴ is an aryl group. Among these phosphonium salts,
It is preferable that all of R ¹ , R ² , R ³ and R ⁴ are aryl groups, and that ^{three of} R ¹ , R ² , R ³ and R ⁴ are aryl groups and one is a heterocyclic group. However, it is preferable that all of R ¹ , R ² , R ³ and R ⁴ are aryl groups.

[0019] The pair of phosphonium salt ion X ^- as is,
Chloride ion, bromine ion, halogen ion such as iodine ion, hydrogen dichloride ion, hydrogen dibromide ion, hydrogen diiodide ion, hydrogen di halide ion such as hydrogen bromide chloride ion, and chlorate ion, Halogenate ions such as bromate ion and iodate ion, perchlorate ions such as perchlorate ion, perbromate ion, and periodate ion, and fats such as acetate ion, trifluoroacetate ion, and propionate ion Aromatic carboxylate ions such as group carboxylate ion, benzoate ion, α- (or β-) naphthalenecarboxylate ion, aromatic hydroxy ion such as phenoxide ion, sulfate ion, hydrogen sulfate ion, phosphate Ion, hydrogen phosphate ion, borate ion Inorganic acid ions such as boron ion, hydrogen borate ion, cyanate ion, thiocyanate ion and fluoroborate ion, and tetraalkyl borate ion having an alkyl group having 1 to 10 carbon atoms such as tetramethyl borate ion and tetraethyl borate ion, , Tetraphenyl borate ion, tetrakis-p-fluorophenyl borate ion and other tetraaryl borate ions, and alkyl having 1 to 16 carbon atoms such as methyl group, ethyl group and n- (or i-) propyl group. Sulfonic acid or alkylsulfinate ion, phenyl group, p-toluyl group, p
Examples thereof include arylsulfonic acid or arylsulfinate ion having an aryl group such as a nitrophenyl group.

[0020] These counterions by X ^- Among, chloride, bromide, and halide ions such as iodide ion,
Hydrogen dichloride ions such as hydrogen dichloride ion, hydrogen dibromide ion, hydrogen diiodide ion and hydrogen bromide chloride ion are preferred, and among them, chloride ion and hydrogen dichloride ion are preferred.

Specific examples of the phosphonium salt include the following compounds. R ¹ , R ² , R ³ ,
Examples of the phosphonium salt in which all of R ⁴ are aryl groups and X ⁻ is a halogen ion include, for example, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetraphenylphosphonium iodide, tetrakis (p-chlorophenyl) phosphonium chloride, Tetrakis (p-fluorophenyl) phosphonium chloride, tetrakis (p-tolyl) phosphonium chloride, p-chlorophenyltriphenylphosphonium chloride, p-chlorophenyltriphenylphosphonium bromide, p-chlorophenyltriphenylphosphonium iodide, and p-tolyltril Phenylphosphonium chloride, p-tolyltriphenylphosphonium bromide, p-tolyltriphenylphosphonium iodide , M-trifluoromethylphenyltriphenylphosphonium chloride, p-biphenyltriphenylphosphonium chloride, m-methoxyphenyltriphenylphosphonium chloride, p-
Methoxyphenyltriphenylphosphonium chloride, p-ethoxyphenyltriphenylphosphonium chloride, p-ethoxyphenyltriphenylphosphonium bromide, p-ethoxyphenyltriphenylphosphonium iodide, p-dimethylaminophenyltriphenylphosphonium chloride, p-ethoxy Carbonyl phenyl triphenyl phosphonium chloride, m-cyanophenyl triphenyl phosphonium chloride, 1-naphthyl triphenyl phosphonium chloride, and 2-thiophene triphenyl phosphonium chloride. Among these phosphonium salts, tetraphenylphosphonium chloride is particularly preferable.

Examples of the phosphonium salt in which all of R ¹ , R ² , R ³ and R ⁴ are aryl groups and X ^- is a hydrogen dihalide ion include, for example, tetraphenylphosphonium hydrogen dichloride and tetraphenylphosphonium. Examples thereof include hydrogen dibromide, tetraphenylphosphonium hydrogen diiodide, and tetraphenylphosphonium hydrogen bromide chloride. Among these phosphonium salts, tetraphenylphosphonium hydrogen dichloride is particularly preferable.

Examples of the phosphonium salt in which all of R ¹ , R ² , R ³ and R ⁴ are aryl groups and X ^- is an aliphatic carboxylate ion include, for example, tetraphenylphosphonium acetate and tetraphenylphosphonium trifluoro. Examples thereof include acetate, p-chlorophenyltriphenylphosphonium acetate, p-ethoxyphenyltriphenylphosphonium acetate, and p-tolyltriphenylphosphonium acetate.

Examples of the phosphonium salt in which all of R ¹ , R ² , R ³ and R ⁴ are aryl groups and X ⁻ is a fluoroborate ion include, for example, tetraphenylphosphonium fluoroborate and p-chlorophenyltriphenylphosphonium. Examples thereof include fluoroborate, p-ethoxyphenyltriphenylphosphonium fluoroborate and p-tolyltriphenylphosphonium fluoroborate. Examples of the phosphonium salt in which all of R ¹ , R ² , R ³ and R ⁴ are aryl groups and X ⁻ is a thiocyanate ion (thiocyanide ion) include:
Tetraphenylphosphonium thiocyanide may be mentioned.

The phosphonium salt in which ^{three of} R ¹ , R ² , R ³ and R ⁴ are aryl groups, one is an alkyl group, and X ⁻ is a halogen ion is, for example, methyltriphenylphosphonium chloride. , Methyltriphenylphosphonium bromide, methyltriphenylphosphonium iodide, ethyltriphenylphosphonium chloride, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium iodide, n
-Propyltriphenylphosphonium chloride, n-
Propyltriphenylphosphonium bromide, n-propyltriphenylphosphonium iodide, i-propyltriphenylphosphonium chloride, i-propyltriphenylphosphonium bromide, n-dodecyltriphenylphosphonium chloride, n-dodecyltriphenylphosphonium bromide, chloromethyltrichloride Phenylphosphonium chloride, methyltris (m-
Examples thereof include chlorophenyl) phosphonium chloride, methyl tris (m-chlorophenyl) phosphonium bromide, ethyl tris (m-chlorophenyl) phosphonium chloride and ethyl tris (m-chlorophenyl) phosphonium bromide.

Further, 3 out of R ¹ , R ² , R ³ and R ⁴
One is an aryl group, one is an aralkyl group, and X ⁻
Examples of the phosphonium salt in which is a halogen ion include benzyltriphenylphosphonium chloride, p
-Fluorobenzyl triphenylphosphonium chloride, p-fluorobenzyl triphenylphosphonium bromide, 2,4-dichlorobenzyl triphenylphosphonium chloride, 2,4-dichlorobenzyl triphenylphosphonium bromide, p-n-butoxybenzyl triphenylphosphonium chloride, pn-butoxybenzyltriphenylphosphonium bromide,
Examples thereof include 2-naphthylmethyltriphenylphosphonium chloride, 2-naphthylmethyltriphenylphosphonium bromide, 9-fluorenyltriphenylphosphonium chloride and 9-fluorenylphenyltriphenylphosphonium bromide.

A phosphonium salt in which ^{three of} R ¹ , R ² , R ³ and R ⁴ are aryl groups, one is a heterocyclic group, and X ⁻ is a halogen ion is, for example, 2-thiophentritril. Phenylphosphonium chloride may be mentioned.

Examples of the phosphonium salt in which ^{three of} R ¹ , R ² , R ³ , and R ⁴ are aryl groups, one is an aryloxy group, and X ⁻ is a halogen ion are:
Phenoxytriphenylphosphonium chloride may be mentioned.

A phosphonium salt in which ^{three of} R ¹ , R ² , R ³ , and R ⁴ are aryl groups, one is an alkyl group, and X ⁻ is an aliphatic carboxylate ion is, for example, methyltril. Examples thereof include phenylphosphonium acetate, ethyltriphenylphosphonium acetate and n-propyltriphenylphosphonium acetate.

A phosphonium salt in which ^{three of} R ¹ , R ² , R ³ and R ⁴ are aryl groups, one is an alkyl group, and X ⁻ is a fluoroborate ion is, for example, methyltriphenylphosphonium. Examples thereof include fluoroborate, ethyltriphenylphosphonium fluoroborate and n-propyltriphenylphosphonium fluoroborate.

Examples of the phosphonium salt in which ^{two of} R ¹ , R ² , R ³ and R ⁴ are aryl groups, two are different groups, and the counter ion X ⁻ is a halogen ion include:
Examples thereof include dimethyldiphenylphosphonium chloride, diethyldiphenylphosphonium chloride, dimethyldiphenylphosphonium bromide, and diethyldiphenylphosphonium bromide.

Examples of the phosphonium salt in which one of R ¹ , R ² , R ³ and R ⁴ is an aryl group, three are different groups, and the counter ion X ⁻ is a halogen ion include:
Examples thereof include diethylmethylphenylphosphonium chloride and diethylmethylphenylphosphonium bromide.

Examples of the phosphonium salt in which none of R ¹ , R ² , R ³ and R ⁴ is an aryl group and the counter ion X ⁻ is a halogen ion include, for example, tetra-n-butylphosphonium chloride and tetra-n- Butylphosphonium bromide may be mentioned.

Of the above phosphonium salts, those which are not commercially available can be easily synthesized according to known methods [Bull. Chem. Soc. Jpn. , 5
6, 2869 (1983), J. Am. Chem. So
c. , 70, 737 (1948)]. For example, tetraarylphosphonium chloride is obtained by reacting a triarylphosphine with a corresponding aryl halide (iodo or bromine compound) in the presence of a palladium acetate catalyst to ionize the resulting tetraarylphosphonium iodide or tetraarylphosphonium bromide. It is synthesized by a method of converting into a tetraarylphosphonium chloride using an exchange resin (chlor type). The obtained tetraarylphosphonium chloride is heat-treated at 80 to 200 ° C. for 0.5 to 5 hours under a flow of a dry inert gas such as dry argon gas, and then in a temperature range of 0. It is preferably treated for 5 to 2 hours. Further, it is preferable to use a commercially available tetraarylphosphonium chloride after performing the same treatment.

The tetraarylphosphonium salt having a counter ion other than the halogen ion is obtained by converting the tetraarylphosphonium chloride obtained as described above into an alkali metal salt (sodium salt, potassium salt, etc.) or ammonium having a corresponding counter ion. Reaction with salt (ion exchange)
It is synthesized by Other phosphonium salts other than the tetraarylphosphonium salt are synthesized by the same method. These phosphonium salts are also preferably treated in the same manner as above.

As the phosphine represented by the general formula (B), R ⁵ , R ⁶ and R ⁷ are the above R ¹ , R ² , R ³ and R ⁴
The same aryl group, alkyl group, aralkyl group or heterocyclic group as those mentioned above can be mentioned. In addition, these groups are
R ⁵ , R ⁶ and R ⁷ are R ⁵ and R ⁶ , R ⁶ and R ⁷ , or R
^It may be bridged between ⁷ and R ⁵ to form a ring containing a phosphorus atom.

R ⁵ , R ⁶ and R ⁷ may be the same or different. As such a phosphine,
For example, R ⁵ , R ⁶ , and R ⁷ are all aryl groups (triarylphosphine), or two of R ⁵ , R ⁶ , and R ⁷ are aryl groups and one is another group. One, one of R ⁵ , R ⁶ and R ⁷ is an aryl group and two are another group, R ⁵ , R ⁶ and R ⁷
None of these include aryl groups. Among these phosphines, those in which all of R ⁵ , R ⁶ and R ⁷ are aryl groups are preferable.

Specific examples of the phosphine include the following compounds. Examples of the compound (triarylphosphine) in which all of R ⁵ , R ⁶ and R ⁷ are aryl groups include, for example, triphenylphosphine and tris (p
-Chlorophenyl) phosphine, tris (p-tolyl)
Examples include phosphine and α-naphthyl (phenyl) -p-methoxyphenylphosphine.

Examples of two of R ⁵ , R ⁶ and R ⁷ which are aryl groups and one of which is another group include, for example, methyldiphenylphosphine and phenyl (p-methoxyphenyl) methylphosphine. To be R ⁵ ,
Examples of one of R ⁶ and R ⁷ being an aryl group and two being another group include dimethyl (phenyl) phosphine and ethyl (phenyl) n-propylphosphine.

Examples of the phosphine in which none of R ⁵ , R ⁶ and R ⁷ is an aryl group include benzyl (n-butyl) methylphosphine and tri-t-butylphosphine. Examples of the crosslinked one of R ⁵ , R ⁶ and R ⁷ include phenylbiphenylenephosphine.

Phosphine dihala represented by the general formula (C)
R as an id⁸, R⁹, R^TenIs the above R¹, R²,
R³, R^FourSimilar to aryl group, alkyl group, aralkyl
Group or heterocyclic group, wherein Y¹, Y²Is a chlorine atom, odor
Examples include halogen atoms such as elementary atoms and iodine atoms.
Can be In addition, these groups are R⁸And R⁹, R⁹When
R ^Ten, Or R^TenAnd R⁸Bridged between and containing a phosphorus atom
It does not matter if it forms a ring.

R ⁸ , R ⁹ and R ¹⁰ may be the same or different from each other. Examples of such a phosphine dihalide include those in which all of R ⁸ , R ⁹ and R ¹⁰ are aryl groups (triarylphosphine dihalide).
Or two of R ⁸ , R ⁹ , and R ¹⁰ are aryl groups and one is another group, or one of R ⁸ , R ⁹ , and R ¹⁰ is an aryl group, Examples thereof include those in which two are different groups, and those in which none of R ⁸ , R ⁹ and R ¹⁰ is an aryl group. Among these phosphine dihalides, those in which all of R ⁸ , R ⁹ and R ¹⁰ are aryl groups are preferable. Further, Y ¹ and Y ² may be the same or different.

Specific examples of the phosphine dihalide include triphenylphosphine dichloride, triphenylphosphine dibromide and triphenylphosphine diiodide.

As the phosphine oxide represented by the general formula (D), R ¹¹ , R ¹² and R ¹³ are the above R ¹ , R ² and
The same aryl group, alkyl group, aralkyl group or heterocyclic group as R ³ and R ⁴ can be mentioned. Further, these groups may be bridged between R ¹¹ and R ¹² , R ¹² and R ¹³ , or R ¹³ and R ¹¹ to form a ring containing a phosphorus atom.

R ¹¹ , R ¹² and R ¹³ may be the same or different from each other. Examples of such a phosphine oxide are those in which all of R ¹¹ , R ¹² , and R ¹³ are aryl groups (triarylphosphine oxide).
Or two of R ¹¹ , R ¹² , and R ¹³ are aryl groups and one is another group, or one of R ¹¹ , R ¹² , and R ¹³ is an aryl group, Examples thereof include those in which two are different groups, and those in which none of R ¹¹ , R ¹² and R ¹³ is an aryl group. Among these phosphine oxides, those in which all of R ¹¹ , R ¹² and R ¹³ are aryl groups are preferable.

Specific examples of the above-mentioned phosphine oxide include the following compounds in which the phosphorus atom of the compound listed as the phosphine is oxidized.
Examples of the compound (triarylphosphine oxide) in which all of R ¹¹ , R ¹² and R ¹³ are aryl groups include, for example, triphenylphosphine oxide, tris (p-chlorophenyl) phosphine oxide, tris (p-tolyl) phosphine oxide, α-naphthyl (phenyl)
-P-Methoxyphenylphosphine oxide may be mentioned. Examples of two of R ¹¹ , R ¹² , and R ¹³ which are aryl groups and one of which is another group include methyldiphenylphosphine oxide and phenyl (p-methoxyphenyl) methylphosphine oxide. . Examples of one of R ¹¹ , R ¹² , and R ¹³ that is an aryl group and two of which are different groups include dimethylphenylphosphine oxide and ethyl (phenyl) n-propylphosphine oxide.
Examples of those in which none of R ¹¹ , R ¹² and R ¹³ are aryl groups include benzyl (n-butyl) methylphosphine oxide and tri-t-butylphosphine oxide. Examples of the crosslinked one of R ¹¹ , R ¹² and R ¹³ include phenylbiphenylenephosphine oxide.

Among the organophosphorus compounds used in the present invention, tetraarylphosphonium halide, tetraarylphosphonium hydrogen dihalide or triarylphosphine dihalide are preferable, and particularly tetraarylphosphonium chloride and tetraarylphosphonium hydrogen dichloride. Alternatively, triarylphosphine dichloride is preferable.

In the present invention, the organic phosphorus compound may be used alone or in combination of two or more kinds, and may be used by dissolving and / or suspending it in the reaction solution. The organic phosphorus compound is usually 0.001 to 50 mol%, preferably 0.0
1 to 20 mol% is used.

In the decarbonylation reaction of the present invention, a halogen compound may coexist in the reaction system in addition to the organic phosphorus compound. In particular, as an organic phosphorus compound,
When phosphine or phosphine oxide is used, when a phosphonium salt other than halide and hydrogendihalide is used, or when a low concentration of phosphonium halide or phosphonium hydrogendihalide is used, a halogen compound is used. It is preferably present.

Examples of the halogen compound used in the present invention include the following inorganic halogen compounds and / or organic halogen compounds. Of these halogen compounds, chlorine compounds or bromine compounds are preferable, and chlorine compounds are particularly preferable. The halogen compound has a molar ratio (halogen compound / organic phosphorus compound) of 0.01 to 300, preferably 0.1 to 10 with respect to the organic phosphorus compound.
It is added to the reaction system so that it is zero. Further, the halogen compounds may be used alone or in combination of two or more.

Examples of the inorganic halogen compound include aluminum halides such as aluminum chloride and aluminum bromide, platinum group metal halides such as platinum chloride, chloroplatinic acid, ruthenium chloride and palladium chloride, phosphorus trichloride and pentachloride. Phosphorus chlorides such as phosphorus chloride, phosphorus oxychloride, phosphorus tribromide, phosphorus pentabromide, phosphorus oxybromide, hydrogen halides such as hydrogen chloride and hydrogen bromide, and thionyl chloride,
Sulfur chloride, sulfur dichloride, sulfur dichloride, and other sulfur halides, and halogens such as chlorine and bromine are used.

The organic halogen compound is selected from (1) carbon atom, (2) halogen atom such as chlorine atom and bromine atom, and (3) hydrogen atom, oxygen atom, nitrogen atom, sulfur atom and silicon atom. There may be mentioned compounds composed of at least one atom.

As such an organic halogen compound,
For example, a structure in which a halogen atom is bonded to saturated carbon (C-Hal), a structure in which a halogen atom is bonded to carbonyl carbon (-CO-Hal), a structure in which a halogen atom is bonded to a silicon atom (- C-Si-Hal), or a structure in which a halogen atom is bonded to a sulfur atom (C-
An organic halogen compound having SO ₂ —Hal) is preferably used. However, Hal represents a halogen atom such as a chlorine atom or a bromine atom. These structures are represented by, for example, general formulas (a), (b), (c), and (d), respectively.

[0054]

Embedded image (In the formula, Hal represents a halogen atom such as a chlorine atom and a bromine atom, n ¹ represents an integer of ¹ to 4, and n ² represents an integer of 1 to ^3. )

Specific examples of the organic halogen compound include the following compounds. As the organic halogen compound having a structure in which a halogen atom is bonded to a saturated carbon as represented by the general formula (a),
Chloroform, carbon tetrachloride, 1,2-dichloroethane,
Alkyl halides such as butyl chloride and dodecyl chloride,
Aralkyl halides such as benzyl chloride, benzotrichloride, triphenylmethyl chloride, α-bromo-o-xylene, halogen-substituted aliphatic nitriles such as β-chloropropionitrile and γ-chlorobutyronitrile, and chloroacetic acid. , Halogen-substituted aliphatic carboxylic acids such as bromoacetic acid and chloropropionic acid.

Examples of the organic halogen compound having a structure in which a halogen atom is bonded to a carbonyl carbon as represented by the general formula (b) include acetyl chloride, oxalyl chloride, propionyl chloride, stearoyl chloride, benzoyl chloride and 2 -Acid halides such as naphthalenecarboxylic acid chloride and 2-thionephenecarboxylic acid chloride,
Examples thereof include aryl halogenoglyoxylates such as phenyl chloroglyoxylate, aryl halides such as phenyl chloroformate, and the like.

Examples of the organohalogen compound represented by the general formula (c) having at least one structure in which a halogen atom is bonded to a silicon atom include halogenated silanes such as diphenyldichlorosilane and triphenylchlorosilane. Is mentioned.

Examples of the organic halogen compound having a structure in which a halogen atom is bonded to a sulfur atom as represented by the general formula (d) include halogen such as p-toluenesulfonic acid chloride and 2-naphthalenesulfonic acid chloride. Sulfonyl chloride and the like.

In the decarbonylation reaction of diaryl oxalate, the diaryl oxalate and the organophosphorus compound are put in a reactor, and the halogen compound is further put in the reactor if necessary, and the temperature is 100 to 450 ° C., preferably 160 to 450.
° C, more preferably 180-400 ° C, especially 180-
By heating at 350 ° C., a batch or continuous liquid phase reaction is performed. At this time, according to the above reaction formula, diaryl carbonate is produced from diaryl oxalate and carbon monoxide is produced. The reaction pressure is
When the reaction temperature exceeds the boiling point of the diaryl oxalate, it is pressurized, but it is usually atmospheric pressure or reduced pressure. In addition,
The material of the reactor is not particularly limited, and for example,
A glass or stainless steel (SUS) reactor can be used.

A solvent is not particularly required for the reaction, but if necessary, diphenyl ether, sulfolane, N-methylpyrrolidone, dimethylimidazolidone, 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H A solvent such as) -pyrimidinone can be appropriately used. After the reaction, the produced diaryl carbonate is separated and purified by distillation or the like.

[0061]

EXAMPLES Next, the present invention will be specifically described with reference to Examples and Comparative Examples. The conversion of diaryl oxalate (ratio of consumed diaryl oxalate to charged diaryl oxalate), selectivity of diaryl carbonate (ratio of produced diaryl carbonate to consumed diaryl oxalate) and yield (charged diaryl oxalate) The ratio of the produced diaryl carbonate to oxalate) was determined on a molar basis (mol%).

Reference Example 1 [Synthesis of p-chlorophenyltriphenylphosphonium iodide] [Bull. Chem. Soc. Jpn. , 56, 28
69 (1983)] In a 100 ml eggplant-shaped flask, 3.30 g of triphenylphosphine (11.4
mmol) and 3.00 g of p-chloroiodobenzene (1
2.6 mmol) was dissolved in 40 ml of xylene. 30.0 mg of palladium acetate (0.134 mmo) was added to this solution.
1) was added, and the mixture was stirred at 150 ° C. for 9.5 hours in an argon atmosphere. After completion of stirring, the reaction solution was cooled to room temperature and the precipitated solid was collected by suction filtration. This was washed with xylene and further dried under reduced pressure at 130 ° C. for 3 hours to give p-chlorophenyltriphenylphosphonium iodide 5.4.
8g was obtained (yield: 87%, melting point: 219-222).
° C). The elemental analysis values are C: 57.84%, H: 3.
It was 74% (theoretical value is C: 57.57%, H: 3.
82%).

Reference Example 2 [Synthesis of p-chlorophenyltriphenylphosphonium chloride] (J. Am. Chem. Soc., 70, 737 (19)
48)) In a 50 ml eggplant type flask, p-chlorophenyltriphenylphosphonium iodide (1.00 g, 2.00 mmol) obtained in Reference Example 1 and Amberlite IRA-400 (organic strong basic ion) were used. 10 ml (14 mg equivalent) of the exchange resin, chloro type) was stirred with 20 ml of ion-exchanged water at room temperature for 1 hour.
After completion of stirring, the ion exchange resin was removed by filtration, and the ion exchange resin was washed with a small amount of ion exchange water. The obtained filtrate and washings were combined to make 25 ml, and 6.50 g of sodium chloride was added thereto to precipitate crystals. The precipitated crystals were collected by suction filtration, dissolved in 50 ml of methylene chloride, insoluble materials were removed by filtration, and ether 3 was added to the filtrate.
0 ml was added to precipitate crystals.

The crystals were washed with ether, and then dried at 120 ° C. for 1 hour and at 150 ° C. for 1 hour under a flow of dry argon gas.
The heat treatment was performed at 180 ° C. for 1 hour, and then at 180 ° C. for 30 minutes under a flow of dry hydrogen chloride gas. The treated product was heat-treated at 180 ° C. for 1 hour under a flow of dry argon gas and then cooled to room temperature to obtain 0.63 g of p-chlorophenyltriphenylphosphonium chloride (yield: 77%, melting point: 158-). 160 ° C). Other non-commercially available phosphonium chlorides were similarly synthesized from the corresponding iodide or bromide and subjected to heat treatment and hydrogen chloride treatment. Table 1 shows the yields and physical properties of these phosphonium chlorides.

Reference Example 3 [Synthesis of tetraphenylphosphonium thiocyanide]
In a 50 ml eggplant-shaped flask, 1 g of tetraphenylphosphonium chloride was dissolved in 10 ml of water, 10 ml of water in which a theoretical amount of ammonium thiocyanate was dissolved was added, and the mixture was stirred at room temperature for 0.5 hours. The formed precipitate was filtered, washed with water three times, and then reprecipitated from a methylene chloride-ether mixed solvent (volume ratio 1: 2). The precipitate was washed with methylene chloride and then washed with dry argon under a stream of 1
Heat treatment was performed at 60 to 200 ° C. to obtain 0.88 g of tetraphenylphosphonium thiocyanide (yield: 83
%, Melting point: 300 ° C. or higher). Note that tetraphenylphosphonium trifluoroacetate was subjected to heat treatment at 160 to 200 ° C. under a flow of argon without washing with water after forming a precipitate and filtering in the same manner as above. The results are shown in Table 1.

[0066]

[Table 1]

Example 1 6.0 g (2) of diphenyl oxalate was placed in a 50 ml glass flask equipped with a thermometer, a stirrer and a reflux condenser.
4.8 mmol) and tetraphenylphosphonium chloride 0.093 g (0.25 mmo) as a catalyst.
(l: 1 mol% relative to diphenyl oxalate) and heated to 255 ° C., and then, under normal pressure, the generated carbon monoxide was removed to the outside of the system, and a decarbonylation reaction was carried out at this temperature for 3 hours. . The tetraphenylphosphonium chloride was used after being treated in the same manner as in Reference Example 2. After completion of the reaction, the reaction solution was cooled to room temperature and analyzed by gas chromatography. As a result, the conversion of diphenyl oxalate was 96.2%, and 5.05 g (23.6 mmol) of diphenyl carbonate was produced (selection). Rate: 99.0%, yield: 95.2%).

Examples 2 to 4 The decarbonylation reaction was carried out in the same manner as in Example 1 except that the amount of catalyst, the amount of diphenyl oxalate, the reaction temperature and the reaction time were changed as shown in Table 2. . The results are shown in Table 2.

Examples 5 to 9 In Example 1, except that the kind and amount of the catalyst were changed as shown in Table 2, and the amount of diphenyl oxalate, the reaction temperature and the reaction time were changed as shown in Table 2. The decarbonylation reaction was carried out in the same manner as in Example 1. However, for tetraphenylphosphonium bromide, use the commercially available product as it is,
As tetraphenylphosphonium hydrogen dichloride, one synthesized by a known method was used as it is [Z. anorg. allg. Chem. , 551 (1
987), 179]. The results are shown in Table 2.

[0070]

[Table 2]

Comparative Example 1 In Example 1, 3.97 g of diphenyl oxalate
(16.4 mmol) was used, and the decarbonylation reaction was carried out in the same manner as in Example 1 except that the catalyst (tetraphenylphosphonium chloride) was not added. As a result, the conversion of diphenyl oxalate was 0%, and formation of diphenyl carbonate was not observed.

Comparative Example 2 In Example 1, 5.0 g of diphenyl oxalate
(20.7 mmol) was used, the reaction temperature was changed to 330 ° C., and the catalyst (tetraphenylphosphonium chloride) was used.
The decarbonylation reaction was carried out in the same manner as in Example 1 except that was not added. As a result, the conversion of diphenyl oxalate was 10.8% and diphenyl carbonate was 0.1%.
8 g (0.84 mmol) had been produced (selectivity: 3
(7.7%, yield: 4.1%)

Comparative Example 3 5.0 g of diphenyl oxalate (2 g was added to a closed reactor made of stainless steel having an internal volume of 90 ml equipped with a thermometer and a stirrer.
0.7 mmol) and 5.0 g of tetrahydrofuran, and 0.5 g (3.8 g) of potassium phenolate as a catalyst.
mmol) was added and the temperature was raised to 100 ° C., at which temperature 3
The decarbonylation reaction was carried out for an hour. As a result, the conversion of diphenyl oxalate was 0%, and formation of diphenyl carbonate was not observed. The results of Comparative Examples 1 to 3 are shown in Table 3.

[0074]

[Table 3]

Examples 10 to 18 Example 1 was repeated except that the kind and amount of the catalyst were changed as shown in Table 4 and the amount of diphenyl oxalate and the reaction temperature were changed as shown in Table 4. The decarbonylation reaction was carried out in the same manner as in. The results are shown in Table 4.

[0076]

[Table 4]

Examples 19-24 Example 1 was repeated except that the kind and amount of the catalyst were changed as shown in Table 5 and the amount of diphenyl oxalate and the reaction temperature were changed as shown in Table 5. The decarbonylation reaction was carried out in the same manner as in. As the phenoxytriphenylphosphonium chloride, one synthesized by a known method was used as it was [Liebigs Ann. Che
m. , 1975, 406]. The results are shown in Table 5.

Example 25 The decarbonylation reaction was performed in the same manner as in Example 1 except that tris (p-chlorophenyl) phosphophine (1.24 mmol) was used as the catalyst (tetraphenylphosphonium chloride). As a result, the conversion of diphenyl oxalate was 99.4%, the selectivity of diphenyl carbonate was 81.6%, and the yield was 81.1%.

Example 26 The decarbonylation reaction was performed in the same manner as in Example 1 except that the catalyst (tetraphenylphosphonium chloride) was replaced with triphenylphosphine dichloride (1.24 mmol). As a result, the conversion of diphenyl oxalate was 98.7%, the selectivity of diphenyl carbonate was 93.0%, and the yield was 91.8%.

Example 27 The decarbonylation reaction was carried out in the same manner as in Example 1 except that the catalyst (tetraphenylphosphonium chloride) was replaced with triphenylphosphine oxide (1.24 mmol). The diphenyl oxalate used at this time contained 3000 pp of chlorine ions.
m was contained. As a result, the conversion of diphenyl oxalate was 11.6%, the selectivity of diphenyl carbonate was 94.0%, and the yield was 10.9%.

[0081]

[Table 5]

Example 28 In Example 1, the catalyst (tetraphenylphosphonium chloride) was added to triphenylphosphine (1.24 mm).
ol) instead of aluminum chloride (0.25 mmol)
Was added, and the decarbonylation reaction was carried out in the same manner as in Example 1 except that the reaction temperature was changed as shown in Table 6. As a result, the conversion rate of diphenyl oxalate was 91.7%.
The selectivity of diphenyl carbonate was 93.0% and the yield was 85.3%.

Examples 29 to 33 Example 2 was repeated except that aluminum chloride was replaced by the inorganic halogen compound shown in Table 6 and the amount of diphenyl oxalate and the reaction temperature were changed as shown in Table 6.
The decarbonylation reaction was performed as in 8. The results are shown in Table 6
Shown in

[0084]

[Table 6]

Examples 34 to 47 Example 2 was repeated except that aluminum chloride was replaced by the organohalogen compound shown in Table 7 and the amount of diphenyl oxalate and the reaction temperature were changed as shown in Table 7.
The decarbonylation reaction was performed as in 8. However, Example 4
In Nos. 1, 43 and 44, the amount of catalyst (triphenylphosphine) was changed as shown in Table 7. The results are shown in Table 7.

[0086]

[Table 7]

Example 48 In Example 1, the catalyst (tetraphenylphosphonium chloride) was replaced with triphenylphosphine oxide (1.24 mmol), and aluminum chloride (0.
50 mmol) was added, and the decarbonylation reaction was carried out in the same manner as in Example 1 except that the reaction temperature was changed as shown in Table 8. As a result, the conversion of diphenyl oxalate was 53.5% and the selectivity of diphenyl carbonate was 9%.
The yield was 4.0% and the yield was 50.3%.

Examples 49 to 56 In the same manner as in Example 48, except that aluminum chloride was replaced by the halogen compound shown in Table 8 and the amount of diphenyl oxalate and the reaction temperature were changed as shown in Table 8. A decarbonylation reaction was performed. However, in Example 51, the amount of catalyst (triphenylphosphine oxide) is shown in Table 8.
Changed as shown in. Table 8 shows the results.

[0089]

[Table 8]

Example 57 Example 57 was repeated except that the amount of the catalyst (tetraphenylphosphonium chloride) was changed to 0.02 mmol and the amount of diphenyloxalate, the reaction temperature and the reaction time were changed as shown in Table 9 in Example 1. The decarbonylation reaction was carried out in the same manner as in 1. As a result, the conversion of diphenyl oxalate was 84.4% and the selectivity of diphenyl carbonate was 9%.
The yield was 9.0% and the yield was 83.6%.

Examples 58 to 60 The decarbonylation reaction was carried out in the same manner as in Example 57 except that the halogen compounds shown in Table 9 were added. The results are shown in Table 9.

Examples 61 to 68 In Example 1, the kind and amount of the catalyst were changed as shown in Table 9, the halogen compound shown in Table 9 was added if necessary, and the amount of diphenyl oxalate, reaction temperature and The decarbonylation reaction was performed in the same manner as in Example 1 except that the reaction time was changed as shown in Table 9. The results are shown in Table 9.

[0093]

[Table 9]

Example 69 In Example 1, 1.30 g of bis (4-chlorophenyl) oxalate in place of diphenyloxalate
(4.18 mmol) was used, the catalyst (tetraphenylphosphonium chloride) was added at 5 mol% with respect to bis (4-chlorophenyl) oxalate, and the reaction time was 2
The decarbonylation reaction was carried out in the same manner as in Example 1 except that the time was changed to 0 minutes. As a result, the conversion rate of bis (4-chlorophenyl) oxalate was 96.5%, and bis (4-chlorophenyl) carbonate was 1.13 g (3.99 mmo).
l) was produced (selectivity: 99.0%, yield: 95.
5%).

[0095]

INDUSTRIAL APPLICABILITY According to the present invention, a diaryl carbonate useful as a raw material for a polycarbonate can be produced from diaryl oxalate with a high selectivity, and a high yield can be produced by selecting a catalyst. Further, by using the excellent catalyst of the present invention, as compared with a known method of boiling a diaryl oxalate to carry out a decarbonylation reaction, the diaryl carbonate can be produced with a high selectivity and a high yield at an industrially suitable low reaction temperature. It can be manufactured. Furthermore, since phosgene, which is a highly toxic compound, is not used in the present invention, the diaryl carbonate can be produced safely and easily. The present invention is the first method capable of industrially producing a diaryl carbonate from a diaryl oxalate and is very useful.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoichi Inobe 5 1978, Ogushi, Ube, Yamaguchi Prefecture 5 1978, Ube Research Co., Ltd. (72) Inventor Toshihiko Sumita 5 1978, Ogushi, Ube, Yamaguchi Prefecture 5 Ube Kosan Co., Ltd.Ube Institute (72) Inventor Keigo Nishidaira 10 1978, Kobeshi, Ube City, Yamaguchi Prefecture Ube 10) Ube Kosan Co., Ltd. Kosan Co., Ltd.Ube Integrated Works (72) Inventor Satoru Fujitsu 10 1978, Kogushi, Ube City, Yamaguchi Prefecture Ube Ube Integrated Works Co., Ltd.

Claims (10)

[Claims] 1. A method for producing a diaryl carbonate, which comprises heating a diaryl oxalate in the presence of an organic phosphorus compound to carry out a decarbonylation reaction. 2. The valence of the phosphorus atom of the organic phosphorus compound is 3
The method for producing a diaryl carbonate according to claim 1, wherein the diaryl carbonate has a valence of 5 or a valence of 5. 3. The method for producing a diaryl carbonate according to claim 1, wherein the organic phosphorus compound is an organic phosphorus compound having at least one carbon-phosphorus (CP) bond. 4. The method for producing a diaryl carbonate according to claim 1, wherein the organic phosphorus compound is a phosphonium salt, phosphine, phosphine dihalide or phosphine oxide. 5. The method for producing a diaryl carbonate according to claim 1, wherein the organic phosphorus compound is a tetraarylphosphonium salt, triarylphosphine, triarylphosphine dihalide or triarylphosphine oxide. 6. The method for producing a diaryl carbonate according to claim 1, wherein the organic phosphorus compound is a tetraarylphosphonium halide, a tetraarylphosphonium hydrogen dihalide or a triarylphosphine dihalide. 7. The method for producing a diaryl carbonate according to claim 1, wherein a decarbonylation reaction is carried out in the presence of a halogen compound. 8. The halogen compound is at least one inorganic halogen compound selected from aluminum halides, platinum group metal halides, phosphorus halides, sulfur halides, hydrogen halides and simple halogens. The method for producing a diaryl carbonate according to claim 7, which is characterized in that. 9. A halogen compound having a structure in which a halogen atom is bonded to saturated carbon (C—Hal) and a structure in which a halogen atom is bonded to carbonyl carbon (—CO—Ha).
l), an organohalogen compound having a structure in which a halogen atom is bonded to a silicon atom (C-Si-Hal) or a structure in which a halogen atom is bonded to a sulfur atom (C-SO ₂ -Hal). The method for producing a diaryl carbonate according to claim 7, wherein Hal represents a halogen atom. 10. The method for producing a diaryl carbonate according to claim 7, wherein the halogen is chlorine.