CA1076133A - Process for the preparation of esters - Google Patents
Process for the preparation of estersInfo
- Publication number
- CA1076133A CA1076133A CA261,845A CA261845A CA1076133A CA 1076133 A CA1076133 A CA 1076133A CA 261845 A CA261845 A CA 261845A CA 1076133 A CA1076133 A CA 1076133A
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- substituted
- alkyl
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
- Pyridine Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An improved process for producing an ester from a carboxylic acid and an alcohol which comprises reacting said carboxylic acid with said alcohol by the use of a 1-substituted-2-halopyridinium salt or a 1-substituted-2-haloquinolinium salt as a condensing agent in the presence of a hydrogen halide captor According to this process, various esters, even if they have some steric hindrances, may be obtained in good yields.
An improved process for producing an ester from a carboxylic acid and an alcohol which comprises reacting said carboxylic acid with said alcohol by the use of a 1-substituted-2-halopyridinium salt or a 1-substituted-2-haloquinolinium salt as a condensing agent in the presence of a hydrogen halide captor According to this process, various esters, even if they have some steric hindrances, may be obtained in good yields.
Description
76~33 ~-.', . ~ .
1 The p-resent invention relates to an improved process for producing carboxylic esters. More particularly, .~ .
this invention pertains to a process for producing carboxylic : .
esters by esterification of a carboxylic acid and an ~ ~.
5 alcohol using as a condensing agent a 1-substituted-2- .
halopyridinium salt or l-substituted-2-haloquionolinium . . .
: salt in the presence of a hydrogen halide :captor. . .: .
So far, it has been well known that esterifica- .~... .. .
tion is one of the most important and basic synthetic ;~ -- .
10: methods for the production of esters and that in carrying . .
.
out esterlfication some arrangements such as distillation . of the ester or water as formed, the use of an excess amount of either an alcohol or an acid or removal of ~.
water with a dehydrating agent are needed to obtain the objective ester in high yields. However, these methods are not always satisfactory in view of the equipments or . reaction conditions involved therein.
:: As the result of an intensive study, it has i~ : i ~ been found that by the use of a l-substituted-2-: . ~ 20 halopyridinium salt or 1-substituted-2-haloquinolinium .
salt as a condensing agent in the presence of a hydrogen halide captor: esterification of a carboxylic acid and an alcohol can be carried out under mild reaction conditions and in very high yields. ~ccording to the esterifi.cation : 25 of this invention caxboxylic esters may be obtained in high yields from equi.molar amounts of an alcohol and an acid ~urthermore, this esterification can be appli.ed to such alcohols and acids that were difficult to esterify due to steric hindxance by the conventional proced.ures and ~0 even if this esteri.fication is applied to such acids or . , , ;' .
, . .
.. .
133 j~
alcohols, relatively high yields of esters may be obtained.
The l-substituted-2-halopyridinium salts used in -this invention may be represented by the formula: ;
t~lX ~ ~
y~
R
wherein R is Cl-C6 alkyl, allyl, C3-C6 cycloalkyl-Cl-C2)alkyl, 2-oxo-(Cl-C6)alkyl, aryl-(Cl-C6) alkyl or aryl-substltuted 2-oxo-(Cl-C6j alkyl; X is halogen; Y is halide ion, methylsulfate ion, p-toluenesulfonate ion, ; perchlorate ion or tetrafluoroborate ion; and Z is Cl-C6 alkyl, nitro, halogen or Cl-C6 alkoxy.
The l-substituted-2-haloquinolinium salts may be represented by the~formula: ;~
wherein Rj X, Y and Z are as defined above.
In the significances as described above, "aryl-substitut=d 2-oxo-CCl-C6) alkyl" and "aryl-(Cl-C6)-alkyl"
; may preferably include phenyl-substituted-2-oxo-(Cl-C6) ~ ;
alkyl and phenyl-(Cl-C6) alkyl.
Among the l-substituted-2-halopyridinium salts and the 1-substituted-2-haloquinolinium salts,the followings are particularly preferred: 2-Chloro-l-methyl-pyridinium iodide, 2-iodo-1-methylpyridinium methyl ~,. . .
1 The p-resent invention relates to an improved process for producing carboxylic esters. More particularly, .~ .
this invention pertains to a process for producing carboxylic : .
esters by esterification of a carboxylic acid and an ~ ~.
5 alcohol using as a condensing agent a 1-substituted-2- .
halopyridinium salt or l-substituted-2-haloquionolinium . . .
: salt in the presence of a hydrogen halide :captor. . .: .
So far, it has been well known that esterifica- .~... .. .
tion is one of the most important and basic synthetic ;~ -- .
10: methods for the production of esters and that in carrying . .
.
out esterlfication some arrangements such as distillation . of the ester or water as formed, the use of an excess amount of either an alcohol or an acid or removal of ~.
water with a dehydrating agent are needed to obtain the objective ester in high yields. However, these methods are not always satisfactory in view of the equipments or . reaction conditions involved therein.
:: As the result of an intensive study, it has i~ : i ~ been found that by the use of a l-substituted-2-: . ~ 20 halopyridinium salt or 1-substituted-2-haloquinolinium .
salt as a condensing agent in the presence of a hydrogen halide captor: esterification of a carboxylic acid and an alcohol can be carried out under mild reaction conditions and in very high yields. ~ccording to the esterifi.cation : 25 of this invention caxboxylic esters may be obtained in high yields from equi.molar amounts of an alcohol and an acid ~urthermore, this esterification can be appli.ed to such alcohols and acids that were difficult to esterify due to steric hindxance by the conventional proced.ures and ~0 even if this esteri.fication is applied to such acids or . , , ;' .
, . .
.. .
133 j~
alcohols, relatively high yields of esters may be obtained.
The l-substituted-2-halopyridinium salts used in -this invention may be represented by the formula: ;
t~lX ~ ~
y~
R
wherein R is Cl-C6 alkyl, allyl, C3-C6 cycloalkyl-Cl-C2)alkyl, 2-oxo-(Cl-C6)alkyl, aryl-(Cl-C6) alkyl or aryl-substltuted 2-oxo-(Cl-C6j alkyl; X is halogen; Y is halide ion, methylsulfate ion, p-toluenesulfonate ion, ; perchlorate ion or tetrafluoroborate ion; and Z is Cl-C6 alkyl, nitro, halogen or Cl-C6 alkoxy.
The l-substituted-2-haloquinolinium salts may be represented by the~formula: ;~
wherein Rj X, Y and Z are as defined above.
In the significances as described above, "aryl-substitut=d 2-oxo-CCl-C6) alkyl" and "aryl-(Cl-C6)-alkyl"
; may preferably include phenyl-substituted-2-oxo-(Cl-C6) ~ ;
alkyl and phenyl-(Cl-C6) alkyl.
Among the l-substituted-2-halopyridinium salts and the 1-substituted-2-haloquinolinium salts,the followings are particularly preferred: 2-Chloro-l-methyl-pyridinium iodide, 2-iodo-1-methylpyridinium methyl ~,. . .
- 2 - `
; ,.::: :, i,'~:',' ' '' ' ' " ~',~," ` ' ~L~76~33 :
1 sulfate, 2-chloro-1-ethylpyridinium bromide, l-benzyl- ~.
2-chloropyridiniwm bromide, 2-chloro-1-phenacylpyridiniwm chloride, 2-fluoro-1-methylpyridi.niwm p-toluenesulfonate, ,: . .
2-bromo-1-methylpyridiniwm perchlorate, 1-ethyl-2-iodoquinoliniwm iodide, 2-chloro-1-ethyl-4-methoxypyridinium ~etrafluoroborate and 2,6-dichloro-1-ethylpyridinium tetrafluoroborate.
The hydrogen halide --cap~orS; used in this invention may be a tertiary amine of the formula:
wherein Rl, R2 and R3 each are Cl-al5 alkyl, allyl or C3-C6 cycloalkyl-(Cl-C2) alkyl; or betaines which mean ` in this specification compounds having an anion and a cation in their molecule.
; ; The typical examples of said tertiary arnines ; 15 are triethylamine, tri-n-butylamine, N,N-dimethylbutyl- ;
amine, N,N-dimethylcyclohexylamine, lutidine, collidine, N-methylpyrrolidine, N-methylmorpholine, 1,5-diazabicyclo-[4,3,0]nonene-5, 1,4--diazabicyclo[2,2,2]octane and 1,5-diazabicyclo[5,4,0]undecene-5.
Preferred examples of the betaines are --
; ,.::: :, i,'~:',' ' '' ' ' " ~',~," ` ' ~L~76~33 :
1 sulfate, 2-chloro-1-ethylpyridinium bromide, l-benzyl- ~.
2-chloropyridiniwm bromide, 2-chloro-1-phenacylpyridiniwm chloride, 2-fluoro-1-methylpyridi.niwm p-toluenesulfonate, ,: . .
2-bromo-1-methylpyridiniwm perchlorate, 1-ethyl-2-iodoquinoliniwm iodide, 2-chloro-1-ethyl-4-methoxypyridinium ~etrafluoroborate and 2,6-dichloro-1-ethylpyridinium tetrafluoroborate.
The hydrogen halide --cap~orS; used in this invention may be a tertiary amine of the formula:
wherein Rl, R2 and R3 each are Cl-al5 alkyl, allyl or C3-C6 cycloalkyl-(Cl-C2) alkyl; or betaines which mean ` in this specification compounds having an anion and a cation in their molecule.
; ; The typical examples of said tertiary arnines ; 15 are triethylamine, tri-n-butylamine, N,N-dimethylbutyl- ;
amine, N,N-dimethylcyclohexylamine, lutidine, collidine, N-methylpyrrolidine, N-methylmorpholine, 1,5-diazabicyclo-[4,3,0]nonene-5, 1,4--diazabicyclo[2,2,2]octane and 1,5-diazabicyclo[5,4,0]undecene-5.
Preferred examples of the betaines are --
3,4-dihydro-2H-pyrido~1,2-a]pyrimidin-2-one, triethyl- - :
ammoniwn acetate, l-oxonianaphthalene-7-carboxylate, and (l-methyl-4-pyridini.o) acetate.
In carrying out the esterification of this invention, the amount o~ the 1-substituted-2-halopyridiniwm salt or l-substltuted-2-halo~uinol.iniwm salt used is not particularly limited, but good result~ may be obtained when they are used in an amount of one to -five tirnes as .,; . . .
i076~33 : ~
', ,' .
much as the carboxylic acid by mole. The mixing molar ratio of the hydrogen halide captor to the l-substituted- ~ -2-halopyridinium salt or 1-substituted-2-haloquinolinium salt is not particularly limited, but the preferred ratio -is 2 The esterification of this invention may pre-ferably be carried out in the presence of sn anhydrous organic solvent preferred examples of which are ethyl ether, toluene, tetrahydrofuran, benzene, xylene, ace-10~ ~ tonitrile, 1,2-dimethoxyethane, methylene dlchloride , chloroform or carbon tetrachloride. The reaction of this invention may be carried out at a temperature of 0C to ~: :
the boiling point of the solvent used but the latter is ~ -preferable.
The carboxylic acidg and ~the alcohols used in the present invention are not particularly limited.
The carboxylic acids may be mono-, dl- or poly-carboxylic aclds, oxocarboxylic acids~or amino-carboxylic acids and the alcohols may be mono-, di- or 20~ poly-alcohols, oxoalcohols or aminoaicohols. I- ;
The following examples are given to illustrate the invention more precisely but they should not be ~ -construed to limit the scope of the invention. '` ;
xample 1 -To a suspended CH2CQ2 (2 mYj solution of 2-bromo-l-methylpyridinium iodide (720 mg, 2.4 mmol) was i . ,: .: .
added a mixture of benzyl alcohol (21~ mg, 2.0 mmol), phenylacetic acld ~272 mg, 2.0 mmol) and tri-n-butylamine !.~ ., ~- (888 mg, 4.8 mmol) in CH2CQ2 (2 m~), and the resulting ' : ' '
ammoniwn acetate, l-oxonianaphthalene-7-carboxylate, and (l-methyl-4-pyridini.o) acetate.
In carrying out the esterification of this invention, the amount o~ the 1-substituted-2-halopyridiniwm salt or l-substltuted-2-halo~uinol.iniwm salt used is not particularly limited, but good result~ may be obtained when they are used in an amount of one to -five tirnes as .,; . . .
i076~33 : ~
', ,' .
much as the carboxylic acid by mole. The mixing molar ratio of the hydrogen halide captor to the l-substituted- ~ -2-halopyridinium salt or 1-substituted-2-haloquinolinium salt is not particularly limited, but the preferred ratio -is 2 The esterification of this invention may pre-ferably be carried out in the presence of sn anhydrous organic solvent preferred examples of which are ethyl ether, toluene, tetrahydrofuran, benzene, xylene, ace-10~ ~ tonitrile, 1,2-dimethoxyethane, methylene dlchloride , chloroform or carbon tetrachloride. The reaction of this invention may be carried out at a temperature of 0C to ~: :
the boiling point of the solvent used but the latter is ~ -preferable.
The carboxylic acidg and ~the alcohols used in the present invention are not particularly limited.
The carboxylic acids may be mono-, dl- or poly-carboxylic aclds, oxocarboxylic acids~or amino-carboxylic acids and the alcohols may be mono-, di- or 20~ poly-alcohols, oxoalcohols or aminoaicohols. I- ;
The following examples are given to illustrate the invention more precisely but they should not be ~ -construed to limit the scope of the invention. '` ;
xample 1 -To a suspended CH2CQ2 (2 mYj solution of 2-bromo-l-methylpyridinium iodide (720 mg, 2.4 mmol) was i . ,: .: .
added a mixture of benzyl alcohol (21~ mg, 2.0 mmol), phenylacetic acld ~272 mg, 2.0 mmol) and tri-n-butylamine !.~ ., ~- (888 mg, 4.8 mmol) in CH2CQ2 (2 m~), and the resulting ' : ' '
- 4 -`''' ~'"
;. :., .
-. . - .. . . . . . . ..
- .. , , , . . , , . , , , : ~
. :`; 1076~33 ; .
- , 1 mixture was refluxed for 3 hours. After evaporation o*
the solvent, the residue was separated by silica gel column chromatography, and ben~yl phenylacetate was isolated in 97~0 yield.
Example 2 To a CH2CQ 2 ( 2 mQ) solution of 2-chloro~
ethyl-4-methoxypryridinium tetrafluoroborate (296 mg, - 1.2 mmol) was added a mixture of ben~yl alcohol (108 mg, 1.0 mmol)~ phenylacetic acid (136 mg, 1.0 mmol) and triethylamine (243 mg, 2.4 mmol) in CH2a~2 (2 m~) 7 and the resulting mlxture was refluxed for 3 hours. After evaporation of the solvent, the residue was separated by silica gel column chromatography, and benzyl phenylacetate was isolated in 95% yield.
~ ~'; ' " .
15~ Example 3 To a suspended ethyl ether (2 m~) solution of ; 2-chloro-1-methylpyridinium iodide (306 mg, 1.2 mmol) was added a mixture of ben~yl alcohol (108 mg, 1.0 mmol), ~: . , phenylacetic acid (136 mg, 1.0 mmol) and tri-n-butylamine (444 m~, 2.4 mmol) in ethyl ether (2 m~), and the resulting mixture was refluxed for 3 hours. A~ter e~aporation of the soivent, the residue was separated by silica gel column chromatography, and benzyl phenylacetate was isola-ted in 97% yield.
Example 4 To a suspended CH2C~2 ( 2 m~) solution of 2~chloro-1-methylpyridinium iod:ide (306 mg, 1.2 mmol) .
~076133 1 was added a mixture o~ benzyl alcohol (108 mg, 1.0 mmol), phenylacetic acid (136 mg, 1.0 mmol) and 2,6-lutidine (257 mg, 2.4 mmol) in CH2C~2 (2 m~), and the resulting mixture was re-fluxed for 3 hours. After evaporation of the solvent, the residue was separated by silica gel column chromatography, and benzyl phenylacetate was - -isolated in 98% yield. ` -,:; : :
Example 5 To a suspended toluene (2 m~) solution of 2-bromo-1-methylpyridinium iodide (720 mg, 2.4 mmol) was added a mixture of tert-butyl alcohol (148 mg, 2.0 mmol), ~ -phenylacetic acid (272 mg, 2.0 mmol) and tri-n-butylamine (888 mg, 4.8 mmol) in toluene (2 m~), and the resulting -~
;~ mixture was refluxed for 3 hours. After evaporation o-f the solvent, the residue was separated by silica gel column chromatography, and tert-butyl phenylacetate was isolated in 82~o yield. ;~ ~
,..... .. ..
Example 6 To a CH2C~2 (2 m~) solution of 2,6-dichloro-l-ethylpyridinium tetrafluoroborate (630 mg, 2.4 mmol) :~
was added a mixture o-f ethyl alcohol (92 mg, 2.0 mmol), phenylacetic acid (272 mg, 2.0 mmol) and tri-n-butylamine (888 mg, 4.~ mmol) in CH2C~2 (2 m~), and the resulting mixture was ref]uxed for 3 hours. A~ter evaporation of the solvent, the residue was separated by silica gel column chromatogxaphy, and ethyl pheny]acctate wa~
isolated in 90% yield. `
.. . . . .
, : , , ' , :,.. . , .,.' ",. ': :
~L076133 . :
.. . . .
1 Example 7 To a suspended CH2C~2 (2 m~) solution of 2-bromo-1-methylpyridinium iodide (720 mg, 2.4 mmol) was added a mixture of cinnamyl alcohol (268 mg, 2.0 mmol), -;
acetic acid (120 mg, 2.0 mmol) and tri-n-butylamine (888 mg, 4.8 mmol) in CH2a~2 (2 m~), and the resulting mixture was refluxed for 3 hours. After evaporation o~
the solvent, the residue was separated by silica gel column chromatography, and cinnamyl acetate was isolated in 82~o yield.
- Example 8 To a CH2C~2 (2 m~) solution of 2-chloro~
~ methylpyridinium p-toluenesulfonate (720 mg, 2.4 rnmol) ; was added a mixture of benzyl alcohol (216 mg, 2.0 mmol), ~ 15 benzoic acid (244 mg, 2.0 mmol) and tri-n-butylamine : .
(888 mg, 4.8 mmol) in CH2CQ2, and the resulting mixture was refluxed ~or 3 hours. After evaporation of the solvent, ~ ~ ~ the residue was separated by silica gel column chromato- ~
;~ graphy, and benzyl benzoate was isolated in 83~o yield. ~-Example 9 ~o a suspended toluene (2 m~) solution of 2-chloro-1-methylpyridinium iodide (306 rmg, 1.2 mmol) was added a mixture of benzyl alcohol (108 mg, 1.0 mmol), pivalic acid (102 mg, 1.0 rnrnol) and tri-n-butylamine (444 mg, 2.4 mMol) in -toluene (2 m~), and the resulting mixture was re~luxed for 3 hours. A-fter evaporation of the solvent, the residue was separated by silica gel column c~lromatography, and benzyl pivala-te was isolated ~ 7 -~:~ . , . , ,, . . . " . . . ....................... .. .. .
, . , , - . , . , . . . ~ .
'`' :., .: ' 1 in 62% yield.
Example 10 - ~ ~o a suspended CH2C~2 ( 2 m~) solution of l-ethyl-2-iodoquinolinium iodide (493 mg, 1.2 mmol) was added a mixture of benzyl alcohol (108 mg, 1.0 mmol), phenylacetic acid (136 mg, 1.0 mmol) and tri-n-butylamine -(444 mg, 2.4 mmol) in CH2C~2 ( 2 m~), and the resulting i~-mixture was refluxed for 3 hours. After evaporation of the solvent, the residue was separated by silica gel column 10 chromatography, and benzyl phenylacetate was isolatéd ~-n 95~o yield. ; -~ ;
~, ,::
-- : : ~ : :, . .
:" ' ' `' '' ~ ' ' ' .
"; ' ' ' '; '' '' " '~ """ ' ~. ',' " '.'.' ' ,' ",'' ' ' " '',' "'1 ., '.' ,, "" " ''"."''."' ''' ' '~; ''. ' . '.' '' ,', ' '' ; ", ,, ,, ., , , , ~, " " , , " ", , .. . ., , , ., , . .. .. ; ! . ', ' ' . .' " ' ' " ' ' '';, . . ' ' "' ' ' ' " ', ' ' . ,', ' . , ~ ' ,', '' ' ., ' " ' ' ~' ' ' ' . ' ' ' ' " ' . ' . ~' .', , ' ' " ". ' ' ' ' , . ' . '
;. :., .
-. . - .. . . . . . . ..
- .. , , , . . , , . , , , : ~
. :`; 1076~33 ; .
- , 1 mixture was refluxed for 3 hours. After evaporation o*
the solvent, the residue was separated by silica gel column chromatography, and ben~yl phenylacetate was isolated in 97~0 yield.
Example 2 To a CH2CQ 2 ( 2 mQ) solution of 2-chloro~
ethyl-4-methoxypryridinium tetrafluoroborate (296 mg, - 1.2 mmol) was added a mixture of ben~yl alcohol (108 mg, 1.0 mmol)~ phenylacetic acid (136 mg, 1.0 mmol) and triethylamine (243 mg, 2.4 mmol) in CH2a~2 (2 m~) 7 and the resulting mlxture was refluxed for 3 hours. After evaporation of the solvent, the residue was separated by silica gel column chromatography, and benzyl phenylacetate was isolated in 95% yield.
~ ~'; ' " .
15~ Example 3 To a suspended ethyl ether (2 m~) solution of ; 2-chloro-1-methylpyridinium iodide (306 mg, 1.2 mmol) was added a mixture of ben~yl alcohol (108 mg, 1.0 mmol), ~: . , phenylacetic acid (136 mg, 1.0 mmol) and tri-n-butylamine (444 m~, 2.4 mmol) in ethyl ether (2 m~), and the resulting mixture was refluxed for 3 hours. A~ter e~aporation of the soivent, the residue was separated by silica gel column chromatography, and benzyl phenylacetate was isola-ted in 97% yield.
Example 4 To a suspended CH2C~2 ( 2 m~) solution of 2~chloro-1-methylpyridinium iod:ide (306 mg, 1.2 mmol) .
~076133 1 was added a mixture o~ benzyl alcohol (108 mg, 1.0 mmol), phenylacetic acid (136 mg, 1.0 mmol) and 2,6-lutidine (257 mg, 2.4 mmol) in CH2C~2 (2 m~), and the resulting mixture was re-fluxed for 3 hours. After evaporation of the solvent, the residue was separated by silica gel column chromatography, and benzyl phenylacetate was - -isolated in 98% yield. ` -,:; : :
Example 5 To a suspended toluene (2 m~) solution of 2-bromo-1-methylpyridinium iodide (720 mg, 2.4 mmol) was added a mixture of tert-butyl alcohol (148 mg, 2.0 mmol), ~ -phenylacetic acid (272 mg, 2.0 mmol) and tri-n-butylamine (888 mg, 4.8 mmol) in toluene (2 m~), and the resulting -~
;~ mixture was refluxed for 3 hours. After evaporation o-f the solvent, the residue was separated by silica gel column chromatography, and tert-butyl phenylacetate was isolated in 82~o yield. ;~ ~
,..... .. ..
Example 6 To a CH2C~2 (2 m~) solution of 2,6-dichloro-l-ethylpyridinium tetrafluoroborate (630 mg, 2.4 mmol) :~
was added a mixture o-f ethyl alcohol (92 mg, 2.0 mmol), phenylacetic acid (272 mg, 2.0 mmol) and tri-n-butylamine (888 mg, 4.~ mmol) in CH2C~2 (2 m~), and the resulting mixture was ref]uxed for 3 hours. A~ter evaporation of the solvent, the residue was separated by silica gel column chromatogxaphy, and ethyl pheny]acctate wa~
isolated in 90% yield. `
.. . . . .
, : , , ' , :,.. . , .,.' ",. ': :
~L076133 . :
.. . . .
1 Example 7 To a suspended CH2C~2 (2 m~) solution of 2-bromo-1-methylpyridinium iodide (720 mg, 2.4 mmol) was added a mixture of cinnamyl alcohol (268 mg, 2.0 mmol), -;
acetic acid (120 mg, 2.0 mmol) and tri-n-butylamine (888 mg, 4.8 mmol) in CH2a~2 (2 m~), and the resulting mixture was refluxed for 3 hours. After evaporation o~
the solvent, the residue was separated by silica gel column chromatography, and cinnamyl acetate was isolated in 82~o yield.
- Example 8 To a CH2C~2 (2 m~) solution of 2-chloro~
~ methylpyridinium p-toluenesulfonate (720 mg, 2.4 rnmol) ; was added a mixture of benzyl alcohol (216 mg, 2.0 mmol), ~ 15 benzoic acid (244 mg, 2.0 mmol) and tri-n-butylamine : .
(888 mg, 4.8 mmol) in CH2CQ2, and the resulting mixture was refluxed ~or 3 hours. After evaporation of the solvent, ~ ~ ~ the residue was separated by silica gel column chromato- ~
;~ graphy, and benzyl benzoate was isolated in 83~o yield. ~-Example 9 ~o a suspended toluene (2 m~) solution of 2-chloro-1-methylpyridinium iodide (306 rmg, 1.2 mmol) was added a mixture of benzyl alcohol (108 mg, 1.0 mmol), pivalic acid (102 mg, 1.0 rnrnol) and tri-n-butylamine (444 mg, 2.4 mMol) in -toluene (2 m~), and the resulting mixture was re~luxed for 3 hours. A-fter evaporation of the solvent, the residue was separated by silica gel column c~lromatography, and benzyl pivala-te was isolated ~ 7 -~:~ . , . , ,, . . . " . . . ....................... .. .. .
, . , , - . , . , . . . ~ .
'`' :., .: ' 1 in 62% yield.
Example 10 - ~ ~o a suspended CH2C~2 ( 2 m~) solution of l-ethyl-2-iodoquinolinium iodide (493 mg, 1.2 mmol) was added a mixture of benzyl alcohol (108 mg, 1.0 mmol), phenylacetic acid (136 mg, 1.0 mmol) and tri-n-butylamine -(444 mg, 2.4 mmol) in CH2C~2 ( 2 m~), and the resulting i~-mixture was refluxed for 3 hours. After evaporation of the solvent, the residue was separated by silica gel column 10 chromatography, and benzyl phenylacetate was isolatéd ~-n 95~o yield. ; -~ ;
~, ,::
-- : : ~ : :, . .
:" ' ' `' '' ~ ' ' ' .
"; ' ' ' '; '' '' " '~ """ ' ~. ',' " '.'.' ' ,' ",'' ' ' " '',' "'1 ., '.' ,, "" " ''"."''."' ''' ' '~; ''. ' . '.' '' ,', ' '' ; ", ,, ,, ., , , , ~, " " , , " ", , .. . ., , , ., , . .. .. ; ! . ', ' ' . .' " ' ' " ' ' '';, . . ' ' "' ' ' ' " ', ' ' . ,', ' . , ~ ' ,', '' ' ., ' " ' ' ~' ' ' ' . ' ' ' ' " ' . ' . ~' .', , ' ' " ". ' ' ' ' , . ' . '
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for producing an ester by esterification of a carboxylic acid and an alcohol which comprises carrying out the esterification by the use of a 1-substituted-2-halo-pyridinium salt of the formula:
wherein R is C1-C6 alkyl, allyl, C3-C6 cycloalkyl-(C1-C2)-alkyl, 2-oxo-(C1-C6)alkyl, aryl-(C1-C6) alkyl or aryl-substituted 2-oxo-(C1-C6)alkyl; X is halogen; Y- is halide ion, methylsulfate ion, p-toluenesulfonate ion, perchlorate ion or tetrafluoroborate ion; and Z is C1-C6 alkyl, nitro, halogen or C1-C6 alkoxy, or a 1-substituted-2-haloquinolinium salt of the formula:
wherein R, X, Y- and Z are as defined above, as a condensing agent in the presence of a hydrogen halide captor in an anhydrous organic solvent at a temperature from 0°C to the boiling point of the solvent used.
wherein R is C1-C6 alkyl, allyl, C3-C6 cycloalkyl-(C1-C2)-alkyl, 2-oxo-(C1-C6)alkyl, aryl-(C1-C6) alkyl or aryl-substituted 2-oxo-(C1-C6)alkyl; X is halogen; Y- is halide ion, methylsulfate ion, p-toluenesulfonate ion, perchlorate ion or tetrafluoroborate ion; and Z is C1-C6 alkyl, nitro, halogen or C1-C6 alkoxy, or a 1-substituted-2-haloquinolinium salt of the formula:
wherein R, X, Y- and Z are as defined above, as a condensing agent in the presence of a hydrogen halide captor in an anhydrous organic solvent at a temperature from 0°C to the boiling point of the solvent used.
2. A process according to Claim 1, wherein the hydro-gen halide captor is a tertiary amine or a betaine.
3. A process according to Claim 1, wherein the 1-substituted-2-halopyridinium salt or the 1-substituted-2-haloquinolinium salt is selected from the group consisting of 2-chloro-1-methylpyridinium iodide, 2-iodo-1-methyl-pyridinium methyl sulfate, 2-chloro-1-ethylpyridinium bromide, 1-benzyl-2-chloropyridinium bromide, 2-chloro-1-phenacylpyridinium chloride, 2-fluoro-1-methylpyridinium p-toluenesulfonate, 2-bromo-1-methylpyridinium perchlorate, 1-ethyl-2-iodoquinolinium iodide, 2-chloro-1-ethyl-4-methoxypyridinium tetrafluoroborate and 2,6-dichloro-1-ethylpyridinium tetrafluoroborate.
4. A process according to Claim 1, wherein the anhydrous organic solvent is selected from the group con-sisting of ethyl ether, toluene, tetrahydrofuran, benzene, xylene, acetonitrile, 1,2-dimethoxyethane, methylene dichlorlde, chloroform and carbon tetrachloride.
5. A process according to Claim 1, wherein the hydrogen halide captor is selected from the group consist-ing of triethylamine, tri-n-butylamine, N,N-dimethylbutyl-amine, N,N-dimethylcyclohexylamine, lutidine, collidine, N-methylpyrrolidine, N-methylmorpholine, 1,5-diazabicyclo [4,3,0]nonene-5, 1,4-diazabicyclo[2,2,2]octane, 1,5-diaza-bicyclo[5,4,0]undecene-5, 3,4-dihydro-2H-pyrido-[1,2-a]
pyrimidin-2-one, triethylammonium acetate, 1-oxonianaphtha-lene-7-carboxylate and (1-methyl-4-pyridino)-acetate.
pyrimidin-2-one, triethylammonium acetate, 1-oxonianaphtha-lene-7-carboxylate and (1-methyl-4-pyridino)-acetate.
6. A process according to Claim 1, wherein the 1-substituted-2-halopyridinium salt or the 1-substituted-2-halo-quinolinium salt is used in an amount of 1 to 5 moles per mole of the carboxylic acid.
7. A process for producing an ester by esterification of a carboxylic acid and an alcohol in equimolar amounts which comprises carrying out the esterification by the use of at least one mole per mole of the carboxylic acid of 1-substituted-2-halopyridinium salt of the formula wherein R is C1-C6 alkyl, allyl, C3-C6 cycloalkyl-(C1-C2)-alkyl, 2-oxo-(C3-C6)alkyl, phenyl-(C1-C6)alkyl or phenyl-substituted 2-oxo-(C2-C6)alkyl, X is halogen, and Y- is halide ion, methyl-sulfate ion, p-toluenesulfonate ion, perchlorate ion or tetra-fluoroborate ion, or 1-substituted-2-haloquinolinium salt of the formula wherein R, X and Y- are as defined above, as a condensing agent, in the presence of at least 2 equimolar amounts per mole of the 1-substituted-2-halopyridinium salt or the 1-substituted-2-haloquinolinium salt of a tertiary amine of the formula wherein R1, R2 and R3 each are C1-C15 alkyl, allyl or C3-C6 cycloalkyl, or an amine selected from the group consisting of lutidine, N-methylmorpholine, 1,5-diazabicyclo[4,3,0]nonene-5, 1,4-diazabicyclo[2,2,2]-octane and 1,5-diazabicyclo[5,4,0]-undecene-5 in an anhydrous organic solvent at a temperature of 0°C to the boiling point of the solvent used.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50117038A JPS5242815A (en) | 1975-09-27 | 1975-09-27 | Process for preparation of carboxylic acid esters |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1076133A true CA1076133A (en) | 1980-04-22 |
Family
ID=14701887
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA261,845A Expired CA1076133A (en) | 1975-09-27 | 1976-09-22 | Process for the preparation of esters |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS5242815A (en) |
| CA (1) | CA1076133A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5696764A (en) * | 1979-12-27 | 1981-08-05 | Rateikureeto Intern Inc | Improved hydraulic cement adhesive composition |
| JPS56164050A (en) * | 1980-05-22 | 1981-12-16 | Denki Kagaku Kogyo Kk | Formation aid and manufacture of formed body therewith |
| JPS58153768U (en) * | 1982-04-09 | 1983-10-14 | 株式会社東芝 | non-return valve |
| JPS58195161U (en) * | 1982-06-23 | 1983-12-26 | 日産自動車株式会社 | check valve |
-
1975
- 1975-09-27 JP JP50117038A patent/JPS5242815A/en active Granted
-
1976
- 1976-09-22 CA CA261,845A patent/CA1076133A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5545059B2 (en) | 1980-11-15 |
| JPS5242815A (en) | 1977-04-04 |
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