US3697584A - Pyrolysis of tris(2-carboxyethyl)-isocyanurate - Google Patents
Pyrolysis of tris(2-carboxyethyl)-isocyanurate Download PDFInfo
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- US3697584A US3697584A US885649A US3697584DA US3697584A US 3697584 A US3697584 A US 3697584A US 885649 A US885649 A US 885649A US 3697584D A US3697584D A US 3697584DA US 3697584 A US3697584 A US 3697584A
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- Prior art keywords
- isocyanurate
- tris
- pyrolysis
- carboxyethyl
- acid
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- 238000000197 pyrolysis Methods 0.000 title claims abstract description 28
- HENCHDCLZDQGIQ-UHFFFAOYSA-N 3-[3,5-bis(2-carboxyethyl)-2,4,6-trioxo-1,3,5-triazinan-1-yl]propanoic acid Chemical compound OC(=O)CCN1C(=O)N(CCC(O)=O)C(=O)N(CCC(O)=O)C1=O HENCHDCLZDQGIQ-UHFFFAOYSA-N 0.000 title claims abstract description 14
- ZFSLODLOARCGLH-UHFFFAOYSA-N isocyanuric acid Chemical compound OC1=NC(O)=NC(O)=N1 ZFSLODLOARCGLH-UHFFFAOYSA-N 0.000 claims abstract description 46
- 238000000034 method Methods 0.000 claims abstract description 35
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims abstract description 16
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 claims abstract description 13
- 150000002148 esters Chemical class 0.000 claims abstract description 11
- 239000007983 Tris buffer Substances 0.000 claims description 21
- 238000002360 preparation method Methods 0.000 claims description 14
- 238000010438 heat treatment Methods 0.000 claims description 8
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims description 4
- HFBMWMNUJJDEQZ-UHFFFAOYSA-N acryloyl chloride Chemical compound ClC(=O)C=C HFBMWMNUJJDEQZ-UHFFFAOYSA-N 0.000 claims description 4
- 229910052739 hydrogen Inorganic materials 0.000 claims description 4
- 239000001257 hydrogen Substances 0.000 claims description 4
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 4
- NGNBDVOYPDDBFK-UHFFFAOYSA-N 2-[2,4-di(pentan-2-yl)phenoxy]acetyl chloride Chemical compound CCCC(C)C1=CC=C(OCC(Cl)=O)C(C(C)CCC)=C1 NGNBDVOYPDDBFK-UHFFFAOYSA-N 0.000 claims description 3
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 claims description 3
- JIGUQPWFLRLWPJ-UHFFFAOYSA-N Ethyl acrylate Chemical group CCOC(=O)C=C JIGUQPWFLRLWPJ-UHFFFAOYSA-N 0.000 claims description 3
- 125000005250 alkyl acrylate group Chemical group 0.000 claims description 3
- 125000005907 alkyl ester group Chemical group 0.000 claims description 3
- PNJWIWWMYCMZRO-UHFFFAOYSA-N pent‐4‐en‐2‐one Natural products CC(=O)CC=C PNJWIWWMYCMZRO-UHFFFAOYSA-N 0.000 claims description 3
- 150000001252 acrylic acid derivatives Chemical class 0.000 abstract description 9
- 239000002253 acid Substances 0.000 abstract description 8
- 150000001408 amides Chemical class 0.000 abstract description 7
- 150000008064 anhydrides Chemical class 0.000 abstract description 7
- 150000004820 halides Chemical class 0.000 abstract description 7
- 238000011065 in-situ storage Methods 0.000 abstract description 3
- 238000006243 chemical reaction Methods 0.000 description 28
- -1 CARBOXYETHYL Chemical class 0.000 description 13
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 239000000376 reactant Substances 0.000 description 4
- LENZDBCJOHFCAS-UHFFFAOYSA-N tris Chemical compound OCC(N)(CO)CO LENZDBCJOHFCAS-UHFFFAOYSA-N 0.000 description 4
- JYEUMXHLPRZUAT-UHFFFAOYSA-N 1,2,3-triazine Chemical group C1=CN=NN=C1 JYEUMXHLPRZUAT-UHFFFAOYSA-N 0.000 description 3
- WFDIJRYMOXRFFG-UHFFFAOYSA-N Acetic anhydride Chemical compound CC(=O)OC(C)=O WFDIJRYMOXRFFG-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 3
- 239000011541 reaction mixture Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 125000003118 aryl group Chemical group 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 150000001735 carboxylic acids Chemical class 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000004821 distillation Methods 0.000 description 2
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- ARJOQCYCJMAIFR-UHFFFAOYSA-N prop-2-enoyl prop-2-enoate Chemical class C=CC(=O)OC(=O)C=C ARJOQCYCJMAIFR-UHFFFAOYSA-N 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000005292 vacuum distillation Methods 0.000 description 2
- MHCVCKDNQYMGEX-UHFFFAOYSA-N 1,1'-biphenyl;phenoxybenzene Chemical compound C1=CC=CC=C1C1=CC=CC=C1.C=1C=CC=CC=1OC1=CC=CC=C1 MHCVCKDNQYMGEX-UHFFFAOYSA-N 0.000 description 1
- AYRCKUXVQHNYRW-UHFFFAOYSA-N 1,1,2-triethylguanidine Chemical compound CCN=C(N)N(CC)CC AYRCKUXVQHNYRW-UHFFFAOYSA-N 0.000 description 1
- JIHQDMXYYFUGFV-UHFFFAOYSA-N 1,3,5-triazine Chemical class C1=NC=NC=N1 JIHQDMXYYFUGFV-UHFFFAOYSA-N 0.000 description 1
- KBPLFHHGFOOTCA-UHFFFAOYSA-N 1-Octanol Chemical compound CCCCCCCCO KBPLFHHGFOOTCA-UHFFFAOYSA-N 0.000 description 1
- YKAPOZDXIVTTHG-UHFFFAOYSA-N 1-carbamoyl-1,3,3-triethylurea Chemical compound CCN(CC)C(=O)N(CC)C(N)=O YKAPOZDXIVTTHG-UHFFFAOYSA-N 0.000 description 1
- WHBAYNMEIXUTJV-UHFFFAOYSA-N 2-chloroethyl prop-2-enoate Chemical class ClCCOC(=O)C=C WHBAYNMEIXUTJV-UHFFFAOYSA-N 0.000 description 1
- WDGCBNTXZHJTHJ-UHFFFAOYSA-N 2h-1,3-oxazol-2-id-4-one Chemical class O=C1CO[C-]=N1 WDGCBNTXZHJTHJ-UHFFFAOYSA-N 0.000 description 1
- RKJWJAQVTBECFT-UHFFFAOYSA-N 3,3-dichloropropyl prop-2-enoate Chemical compound ClC(Cl)CCOC(=O)C=C RKJWJAQVTBECFT-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
- 150000008065 acid anhydrides Chemical class 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 150000001253 acrylic acids Chemical class 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000010504 bond cleavage reaction Methods 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 125000002057 carboxymethyl group Chemical group [H]OC(=O)C([H])([H])[*] 0.000 description 1
- 150000007973 cyanuric acids Chemical class 0.000 description 1
- 125000000753 cycloalkyl group Chemical group 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 125000004494 ethyl ester group Chemical group 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical group 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000002734 metacrylic acid derivatives Chemical class 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 229940065472 octyl acrylate Drugs 0.000 description 1
- ANISOHQJBAQUQP-UHFFFAOYSA-N octyl prop-2-enoate Chemical compound CCCCCCCCOC(=O)C=C ANISOHQJBAQUQP-UHFFFAOYSA-N 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 150000003141 primary amines Chemical class 0.000 description 1
- VWQXLMJSFGLQIT-UHFFFAOYSA-N prop-2-enoyl bromide Chemical compound BrC(=O)C=C VWQXLMJSFGLQIT-UHFFFAOYSA-N 0.000 description 1
- QTECDUFMBMSHKR-UHFFFAOYSA-N prop-2-enyl prop-2-enoate Chemical compound C=CCOC(=O)C=C QTECDUFMBMSHKR-UHFFFAOYSA-N 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000007017 scission Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000000859 sublimation Methods 0.000 description 1
- 230000008022 sublimation Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 125000001424 substituent group Chemical group 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/347—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups
- C07C51/377—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/30—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group
- C07C67/317—Preparation of carboxylic acid esters by modifying the acid moiety of the ester, such modification not being an introduction of an ester group by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups
Definitions
- Derivatives of isocyanuric acid are known to react in a variety of ways under pyrolysis conditions, depending upon the substituents pendant from the triazine ring.
- US. Pat. No. 3,l08,l l discloses that the tris(Z-hydroxyethyl) derivative undergoes detrimerization upon being subjected to elevated temperatures, especially at reduced pressure, to afford 2-oxazolidones.
- Alkyl esters of isocyanuric acid hydrolyze to carbon dioxide and primary amines upon being heated in the presence of base. Karrer, Organic Chemistry (4th Eng. ed., 1950) p 237.
- tris(2-carboxyethyl)isocyanurate and derivatives thereof undergo pyrolysis to afford acrylic acid and derivatives thereof.
- derivatives of tris(2-carboxyethyl)isocyanurate which undergo analogous pyrolysis include esters, amides, acid halides and anhydrides thereof, thereby affording a synthesis of various acrylate derivatives difficult to obtain otherwise.
- the reaction is useful as a means of providing a high temperature in situ source of a variety of acrylic acid derivatives which are obtained in surprisingly pure form.
- Cyanuric acid, or tautomeric isocyanuric acid is a valuable by-product of the pyrolysis reaction, and can be recycled in the process.
- the formation of cyanuric acid is especially unexpected in that C-N scission in isocyanurate derivatives has never before been observed to leave the triazine ring intact.
- the instant invention involves a pyrolysis reaction unique among isocyanurate derivatives whereby acrylic acid derivatives are obtained and the triazine ring is left intact.
- the process proceeds according to the following sequence: 1
- O o A o nodomcm- N-cHlcmtioH' A (BHzCHzCOH and includes within its scope the various derivatives of carboxylic acids, e.g., esters, amides, acid halides, acid anhydrides and other carboxylic acid derivatives.
- the reaction also includes within its scope the pyrolysis of homologs 'of tris(2-carboxyethyl)isocyanurates, viz., tris(Z-carboxypropyl) and tris(2-carboxybutyl)isocyanurates and the ester, amide, acid halide and anhydride derivatives thereof.
- the reaction provides a method of obtaining acrylic acid, alkyl acrylates, acrylamide, acryloyl chloride, various acrylic acid anhydrides, methacrylates, ethacrylates and other related acrylic acid derivatives from the correspondingly substituted carboxyethyl isocyanurate.
- carboxylic acid derivatives of the isocyanurate or acrylic acids are collectively referred to as carboxylic acid derivatives of the isocyanurate or acrylic acids.
- the reaction is conducted under conditions sufficient to result in the desired pyrolysis of the isocyanurate reactant.
- the reaction requires elevated temperatures, although the required minimum temperatu'reto afford pyrolysis will vary with the particular isocyanurate selected as reactant, desired rate of reaction, reaction pressure, and other considerations disclosed hereinafter.
- the reaction temperature for the instant process will be at leastabout C., preferably within the range of about 250 C.
- the reaction temperature for the instant process will be at leastabout C., preferably within the range of about 250 C.
- temperatures outside this range may be found to be adequate in any particular reaction and the use of such temperatures is within the scope of the instant invention.
- the most advantageous temperature to be employed in any particular instance can be readily determined by simple experimentation.
- reaction is conducted at atmospheric pressure and even at super-atmospheric pressure, it is preferred, in the case of non-volatile acrylic acid products, to employ sub-atmospheric pressure when it is desired to separate the acrylate from the reaction mixture.
- Sub-atmospheric pressure also has the advantage of permitting lower reaction temperatures and faster rate of reaction.
- the reaction is conducted under vacuum distillation conditions, in which event the non-volatile acrylic acid product is obtained in pure form as distillate.
- Volatile acrylic products on the other hand, such as the free acid and ethyl ester, can be easily separated at atmospheric pressure so that reduced pressures are not as preferred in those instances.
- the acrylate product be maintained in the reaction mixture, for example as a source of monomer for in situ polymerization, it will become advantageous to operate at atmospheric or super-atmospheric pressure during the pyrolysis reaction, wherein the cyanu ric acid would sublime out of the reaction mass.
- the pyrolysis reaction can be conducted either in the presence or absence of solvent.
- Suitable solvents will be high boiling materials which are inert under pyrolysis conditions and tripropyl isocyanurate, Dowtherm and the like.
- Reaction time will vary over a large range depending upon other reaction parameters and the extent to which 100 percent conversion is desired. Normally, the reaction must be conducted for at least 30 minutes to achieve an acceptable level of conversion, and it will be continued for up. to several hours or several days until the desired extent of conversion is achieved. In this regard,it is noted. that pyrolysis of the isocyanurates involves substantially. more than mere melting of the reactant.
- acrylic acid derivatives which are prepared by the instant process from the corresponding isocyanurate are the following:
- the reaction is especially advantageous for the preparation of acryloyl chloride, acryloyl bromide,
- the carboxyl-substituted isocyanurate reactants used in the instant invention are readily prepared by procedures taught by the prior art, or by obviousmodifications to procedures taught by the prior art.
- U.S. Pat. No. 3,235,553 disclosed the preparation of tris(Z-carboxyethyl)isocyanurate and alkyl triesters thereof. Further methods for the preparation of the esters are disclosed in U.S. Pat. No. 3,332,945.
- U.S. Pat. No. 3,432,500 discloses the preparation of tris(2-carboxamidoethyl)isocyanurate and various substituted amides.
- isocyanurate derivatives are readily available for pyrolysis to the desired acrylic acid compound.
- the triallyl ester of tris(2-carboxyethyl)isocyanurate can be prepared and chlorinated and then pyrolyzed to afford either the monochloro or dichloropropyl acrylate.
- the tris(2-carboxyethyl)compound can be reacted with any of a variety of other carboxylic acids to afford an appropriate anhydride from which an acrylic acid anhydride can be prepared.
- EXAMPLE 1 Tris(Z-carboxyethyl)isocyanurate (17 g.) was placed in a vacuum distillation apparatus and heated at reduced. pressure to 200 C. Heating was continued until 4 g. of acrylic acid was collected as distillate in a cold trap (71.5 percent yield on 53 percent conversion). Solid cyanuric acid, formed in the distillate by sublimation, was removed by filtration.
- the pyrolysis reaction was also run with 0.1 g. of sodium hydroxide added to the reaction mixture with similar results.
- EXAMPLE 2 Tris(Z-carbethoxyethyl)isocyanurate (60 g.) was heated to l-200 C. in a distillation apparatus at atmospheric pressure until 23 g. of ethyl acrylate was collected as distillate (96 percent yield on 50 percent conversion). Continued heating of-the distillation vessel afforded increased pyrolysis of the isocyanurate.
- EXAMPLE 3 The octyl triester of tris(2-carboxyethyl)isocyanurate was prepared by heating octyl alcohol and the isocyanurate in the presence of 5 weight percent toluene until the theoretical amount of water had been removed. After removal of the toluene, the octyl triester (m.p. 24-26 C.) was then pyrolyzed according to the procedure of Example 1 to afford octyl acrylate and cyanuric acid.
- Tris(2-carbethoxypropyl)isocyanurate Tris(2-carboxamidoethyl)isocyanurate Tris(2-carboxyethyl)isocyanurate acid chloride Tris(2-carboxyethyl)isocyanurate acetic anhydride.
- alkyl acrylate which comprises pyrolyzing a tris(Z-carbalkoxyethyl)isocyanurate.
- a process for the preparation of acrylic acid and alkyl esters thereof which comprises heating tris(2-carboxyethyl)isocyanurate or a trialkyl ester thereof at a temperature within the range of about l70-250 C. for a time in excess of 30 minutes.
Abstract
Tris(2-carboxyethyl)isocyanurate and esters, amides, anhydrides and acid halides thereof undergo pyrolysis to afford cyanuric acid and acrylic acid or the corresponding ester, amide, anhydride or acid halide thereof. The process provides an in situ source of acrylate derivatives.
Description
United States Patent 1 3,697,584
Little [451 Oct. 10, 1972 [54] PYROLYSIS OF TRIS(2- [58] Field of Search ..260/486 R, 486 D, 153, 526 N,
CARBOXYETHYL) -ISOCYANURATE 260/561 N, 544 Y, 546
[72] Inventor: Edwin D. Little, Convent Station, Primary Examiner Lorraine Aweinberger Assistant ExaminerR. S. Weissberg [73] Assignee: Allied Chemical Corporation, New Attorney-Michael 131052 York, NY. [57] ABS CT 22 Filed: Dec. 16, 1969 r1s -car x e 1800 anurae an e e 1 T (2 b0 y thyl) y t d st rs amdes PP 885,649 anhydrides and acid halides thereof undergo pyrolysis to afford cyanuric acid and acrylic acid or the cording ester, amide, anhydride or acid halide 52 US. ca. .....260/486 R, 260/248 cs, 260/486 1), The Y process provides an in sltu source of 260/526 N, 260/544 Y, 260/546, acrylate derivatives.
[51] Int. Cl. ..C07c 57/04, C07c 69/54 11 Claims, No Drawings PYROLYSIS OF TRIS(2-CARBOXYETHYL) ISOCYANURATE BACKGROUND OF THE INVENTION This invention relates to a method of preparing acrylic acid and derivatives thereof, and in particular, relates to a method of preparation of acrylates from tris(Z-carboxyethyl) isocyanurate and derivatives thereof.
Derivatives of isocyanuric acid are known to react in a variety of ways under pyrolysis conditions, depending upon the substituents pendant from the triazine ring. For example, US. Pat. No. 3,l08,l l discloses that the tris(Z-hydroxyethyl) derivative undergoes detrimerization upon being subjected to elevated temperatures, especially at reduced pressure, to afford 2-oxazolidones. Alkyl esters of isocyanuric acid, on the other hand, hydrolyze to carbon dioxide and primary amines upon being heated in the presence of base. Karrer, Organic Chemistry (4th Eng. ed., 1950) p 237.
However, Smolin et al., s-Triazines (1959) p 406407,
indicates that variation of the base can give other products such as triethylbiuret, ethylene, ethanol, and triethylguanidine, and at page 402 indicates that pyrolysis under acidic conditions affords isocyanates. Carboxyl-substituted isocyanurates, on the other hand, are reported as being relatively stable under conditions which would pyrolyze other isocyanurate derivatives. For example, West German Pat. No. 812,312 of Aug. 27, 1951, discloses that the triethyl esters of tris(3-carboxypropyl)isocyanurate and tris(carboxymethyl)isocyanurate can be subjected to temperatures as high as 250 C. at reduced pressure without decomposition. Similarly, US. Pat. No. 3,230,220 discloses that tris- (carboxymethyl)isocyanurate is substantially more sta ble on heating than is the ethyl homolog.
SUMMARY OF THE INVENTION It has now been found that tris(2-carboxyethyl)isocyanurate and derivatives thereof undergo pyrolysis to afford acrylic acid and derivatives thereof. In addition to the free carboxylic acid, derivatives of tris(2-carboxyethyl)isocyanurate which undergo analogous pyrolysis include esters, amides, acid halides and anhydrides thereof, thereby affording a synthesis of various acrylate derivatives difficult to obtain otherwise.
The reaction is useful as a means of providing a high temperature in situ source of a variety of acrylic acid derivatives which are obtained in surprisingly pure form. Cyanuric acid, or tautomeric isocyanuric acid, is a valuable by-product of the pyrolysis reaction, and can be recycled in the process. The formation of cyanuric acid is especially unexpected in that C-N scission in isocyanurate derivatives has never before been observed to leave the triazine ring intact.
DETAILED DESCRIPTION OF THE INVENTION The instant invention involves a pyrolysis reaction unique among isocyanurate derivatives whereby acrylic acid derivatives are obtained and the triazine ring is left intact. The process proceeds according to the following sequence: 1
O o A o nodomcm- N-cHlcmtioH' A (BHzCHzCOH and includes within its scope the various derivatives of carboxylic acids, e.g., esters, amides, acid halides, acid anhydrides and other carboxylic acid derivatives. The reaction also includes within its scope the pyrolysis of homologs 'of tris(2-carboxyethyl)isocyanurates, viz., tris(Z-carboxypropyl) and tris(2-carboxybutyl)isocyanurates and the ester, amide, acid halide and anhydride derivatives thereof. Thus, the reaction provides a method of obtaining acrylic acid, alkyl acrylates, acrylamide, acryloyl chloride, various acrylic acid anhydrides, methacrylates, ethacrylates and other related acrylic acid derivatives from the correspondingly substituted carboxyethyl isocyanurate. Hereinafter these derivatives are collectively referred to as carboxylic acid derivatives of the isocyanurate or acrylic acids. The reaction is conducted under conditions sufficient to result in the desired pyrolysis of the isocyanurate reactant. The reaction requires elevated temperatures, although the required minimum temperatu'reto afford pyrolysis will vary with the particular isocyanurate selected as reactant, desired rate of reaction, reaction pressure, and other considerations disclosed hereinafter. Typically, the reaction temperature for the instant process will be at leastabout C., preferably within the range of about 250 C. Of course,
temperatures outside this range may be found to be adequate in any particular reaction and the use of such temperatures is within the scope of the instant invention. The most advantageous temperature to be employed in any particular instance can be readily determined by simple experimentation.
Although it is possible to conduct the reaction at atmospheric pressure and even at super-atmospheric pressure, it is preferred, in the case of non-volatile acrylic acid products, to employ sub-atmospheric pressure when it is desired to separate the acrylate from the reaction mixture. Sub-atmospheric pressure also has the advantage of permitting lower reaction temperatures and faster rate of reaction. In a more preferred embodiment, the reaction is conducted under vacuum distillation conditions, in which event the non-volatile acrylic acid product is obtained in pure form as distillate. Volatile acrylic products,on the other hand, such as the free acid and ethyl ester, can be easily separated at atmospheric pressure so that reduced pressures are not as preferred in those instances. Also, when it is desired that the acrylate product be maintained in the reaction mixture, for example as a source of monomer for in situ polymerization, it will become advantageous to operate at atmospheric or super-atmospheric pressure during the pyrolysis reaction, wherein the cyanu ric acid would sublime out of the reaction mass.
The pyrolysis reaction can be conducted either in the presence or absence of solvent. Suitable solvents will be high boiling materials which are inert under pyrolysis conditions and tripropyl isocyanurate, Dowtherm and the like.
Reaction time will vary over a large range depending upon other reaction parameters and the extent to which 100 percent conversion is desired. Normally, the reaction must be conducted for at least 30 minutes to achieve an acceptable level of conversion, and it will be continued for up. to several hours or several days until the desired extent of conversion is achieved. In this regard,it is noted. that pyrolysis of the isocyanurates involves substantially. more than mere melting of the reactant. I
When conducting the instant pyrolysis under conditions conducive to separation of the acrylic acid product as it is formed, it will often be found that a quantity of cyanuric acid by-product sublimes over into the distillate receiver. However, the cyanuric acid. is insoluble in the acrylic acid and it can be readily removed therefrom by filtration or other standard separation techniques.
Among the acrylic acid derivatives which are prepared by the instant process from the corresponding isocyanurate are the following:
Acrylic acid Methyl acrylate Ethyl acrylate Propyl acrylate i-Propyl acrylate Amyl acrylate Z-Ethylhexylacrylate n-Octyl acrylate n-Decyl acrylate Allyl acrylate Benzyl acrylate Cyclohexyl acrylate 2-Chloropropyl acrylate 2,3-Dichloroprpyl acrylate Acrylamide N-Methyl acrylamide N-Ethyl acrylamide N-Isopropylacrylamide N-Benzylacrylamide N,N-Dimethyl acrylamide N,N-Diethylacrylamide Acryloyl chloride Acryloyl bromide Acrylic anhydride Acrylic acetic anhydride Acrylic propionic anhydride Acrylic benzoic anhydride Methacrylic acid Methyl methacrylate.
The reaction is especially advantageous for the preparation of acryloyl chloride, acryloyl bromide,
include N-methylpyrrolidone,
chloroethyl acrylates and other acrylate derivatives difficult to prepare otherwise due to the unsaturation of the material.
The carboxyl-substituted isocyanurate reactants used in the instant invention are readily prepared by procedures taught by the prior art, or by obviousmodifications to procedures taught by the prior art. For example, U.S. Pat. No. 3,235,553 disclosed the preparation of tris(Z-carboxyethyl)isocyanurate and alkyl triesters thereof. Further methods for the preparation of the esters are disclosed in U.S. Pat. No. 3,332,945. Also, U.S. Pat. No. 3,432,500 discloses the preparation of tris(2-carboxamidoethyl)isocyanurate and various substituted amides. By further reaction on these derivatives or modification of these procedures according to methods well known to those with ordinary skill in the art, other isocyanurate derivatives are readily available for pyrolysis to the desired acrylic acid compound. For example, the triallyl ester of tris(2-carboxyethyl)isocyanurate can be prepared and chlorinated and then pyrolyzed to afford either the monochloro or dichloropropyl acrylate. Additionally the tris(2-carboxyethyl)compound can be reacted with any of a variety of other carboxylic acids to afford an appropriate anhydride from which an acrylic acid anhydride can be prepared.
The following examples are provided to illustrate the instant invention more fully. They are provided for illustrative purposes only and are not to be construed as limiting the invention, which is defined in the appended claims. Variations and modifications in the procedures of the examples may be made by those with skill in the art without departing from the scope of the invention.
EXAMPLE 1 Tris(Z-carboxyethyl)isocyanurate (17 g.) was placed in a vacuum distillation apparatus and heated at reduced. pressure to 200 C. Heating was continued until 4 g. of acrylic acid was collected as distillate in a cold trap (71.5 percent yield on 53 percent conversion). Solid cyanuric acid, formed in the distillate by sublimation, was removed by filtration.
The pyrolysis reaction was also run with 0.1 g. of sodium hydroxide added to the reaction mixture with similar results.
EXAMPLE 2 Tris(Z-carbethoxyethyl)isocyanurate (60 g.) was heated to l-200 C. in a distillation apparatus at atmospheric pressure until 23 g. of ethyl acrylate was collected as distillate (96 percent yield on 50 percent conversion). Continued heating of-the distillation vessel afforded increased pyrolysis of the isocyanurate.
EXAMPLE 3 The octyl triester of tris(2-carboxyethyl)isocyanurate was prepared by heating octyl alcohol and the isocyanurate in the presence of 5 weight percent toluene until the theoretical amount of water had been removed. After removal of the toluene, the octyl triester (m.p. 24-26 C.) was then pyrolyzed according to the procedure of Example 1 to afford octyl acrylate and cyanuric acid.
EXAMPLE 4 The procedure of Example I ,is repeated using the following isocyanurates to afford cyanuric acid and the corresponding derivative of acrylic acid:
Tris(2-carbethoxypropyl)isocyanurate Tris(2-carboxamidoethyl)isocyanurate Tris(2-carboxyethyl)isocyanurate acid chloride Tris(2-carboxyethyl)isocyanurate acetic anhydride.
What is claimed is:
l. A process for the preparation of compounds of the wherein R is hydrogen, methyl 'or ethyl and X is selected from the group consisting of halogen, OR wherein R is hydrogen, alkyl, cycloalkyl, aryl or halogen-substituted alkyl, and NR -,R wherein R and R are independently selected from the group consisting of hydrogen, alkyl or aryl which comprises pyrolyzing an isocyanurate compound of the formula:
' alkyl acrylate which comprises pyrolyzing a tris(Z-carbalkoxyethyl)isocyanurate.
5'. The process of claim 4 wherein said acrylate is ethyl acrylate and said isocyanurate is tris( 2-carbethoxyethyl)isocyanurate.
6. The process of claim 1 for the preparation of an acrylamide which comprises pyrolyzing a tris(2-carboxamidoethyl)isocyanurate.
7. The process of claim 1 for the preparation of acryloyl chloride which comprises pyrolyzing the acid chloride of tris(2-carboxyethyl)isocyanurate.
8. The process of claim 1 wherein said pyrolysis comprises heating said isocyanurate at a temperature in excess of about 150 C. for a time in excess of about 30 minutes.
9. The process of claim 8 wherein the temperature of said pyrolysis is within the range of about l-250 C.
10. The process of claim 1 wherein said pyrolysis is conducted at sub-atmospheric pressure.
11. A process for the preparation of acrylic acid and alkyl esters thereof which comprises heating tris(2-carboxyethyl)isocyanurate or a trialkyl ester thereof at a temperature within the range of about l70-250 C. for a time in excess of 30 minutes.
Claims (10)
- 2. A process according to claim 1 wherein R1 is hydrogen.
- 3. The process of claim 1 for the preparation of acrylic acid which comprises pyrolyzing tris(2-carboxyethyl)isocyanurate.
- 4. The process of claim 1 for the preparation of an alkyl acrylate which comprises pyrolyzing a tris(2-carbalkoxyethyl)isocyanurate.
- 5. The process of claim 4 wherein said acrylate is ethyl acrylate and said isocyanurate is tris(2-carbethoxyethyl)isocyanurate.
- 6. The process of claim 1 for the preparation of an acrylamide which comprises pyrolyzing a tris(2-carboxamidoethyl)isocyanurate.
- 7. The process of claim 1 for the preparation of acryloyl chloride which comprises pyrolyzing the acid chloride of tris(2-carboxyethyl)isocyanurate.
- 8. The process of claim 1 wherein said pyrolysis comprises heating said isocyanurate at a temperature in excess of about 150* C. for a time in excess of about 30 minutes.
- 9. The process of claim 8 wherein the temperature of said pyrolysis is within the range of about 170*-250* C.
- 10. The process of claim 1 wherein said pyrolysis is conducted at sub-atmospheric pressure.
- 11. A process for the preparation of acrylic acid and alkyl esters thereof which comprises heating tris(2-carboxyethyl)isocyanurate or a trialkyl ester thereof at a temperature within the range of about 170*-250* C. for a time in excess of 30 minutes.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US88564969A | 1969-12-16 | 1969-12-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3697584A true US3697584A (en) | 1972-10-10 |
Family
ID=25387390
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US885649A Expired - Lifetime US3697584A (en) | 1969-12-16 | 1969-12-16 | Pyrolysis of tris(2-carboxyethyl)-isocyanurate |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3697584A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4085269A (en) * | 1976-07-27 | 1978-04-18 | Basf Aktiengesellschaft | 1,3,5 Tris-(2-chloroformyl-oxyethyl)-isocyanurate |
| EP0465302B1 (en) * | 1990-07-02 | 1994-12-28 | Elf Atochem S.A. | Precursors of isocyanurate polymers having hydroxyl, urethane, isocyanate or acrylate groups, and process for their preparation |
-
1969
- 1969-12-16 US US885649A patent/US3697584A/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4085269A (en) * | 1976-07-27 | 1978-04-18 | Basf Aktiengesellschaft | 1,3,5 Tris-(2-chloroformyl-oxyethyl)-isocyanurate |
| EP0465302B1 (en) * | 1990-07-02 | 1994-12-28 | Elf Atochem S.A. | Precursors of isocyanurate polymers having hydroxyl, urethane, isocyanate or acrylate groups, and process for their preparation |
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