CA2054708A1 - Process for making 2-oxazolines - Google Patents
Process for making 2-oxazolinesInfo
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- CA2054708A1 CA2054708A1 CA002054708A CA2054708A CA2054708A1 CA 2054708 A1 CA2054708 A1 CA 2054708A1 CA 002054708 A CA002054708 A CA 002054708A CA 2054708 A CA2054708 A CA 2054708A CA 2054708 A1 CA2054708 A1 CA 2054708A1
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- reaction
- carbon atoms
- titanium
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- oxazolines
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-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D263/00—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings
- C07D263/02—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings
- C07D263/08—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member
- C07D263/10—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms
- C07D263/14—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms with radicals substituted by oxygen atoms
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D263/00—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings
- C07D263/02—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings
- C07D263/08—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member
- C07D263/10—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms
- C07D263/12—Heterocyclic compounds containing 1,3-oxazole or hydrogenated 1,3-oxazole rings not condensed with other rings having one double bond between ring members or between a ring member and a non-ring member with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms with radicals containing only hydrogen and carbon atoms
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Heterocyclic Carbon Compounds Containing A Hetero Ring Having Nitrogen And Oxygen As The Only Ring Hetero Atoms (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
ABSTRACT
A process for making 2-oxazolines substituted in the 2 position by aryl or aralkyl substituting C4-C6-alkyl groups, hydroxy- or alkoxy-substituted C1-C6-alkyl groups or alkoxy-alkoxy methyl groups, produces the compounds of the title in large quantities if carboxylic acids of the formula R1-COOH, where R1 is one of the above substitutes, or esters or glycerides thereof are caused to react with 2-amino ethanol or ethanol amides of these carboxylic acids in the presence of titanium or zirconium compounds of the M(OR3)4 type (M = Ti or Zr).
A process for making 2-oxazolines substituted in the 2 position by aryl or aralkyl substituting C4-C6-alkyl groups, hydroxy- or alkoxy-substituted C1-C6-alkyl groups or alkoxy-alkoxy methyl groups, produces the compounds of the title in large quantities if carboxylic acids of the formula R1-COOH, where R1 is one of the above substitutes, or esters or glycerides thereof are caused to react with 2-amino ethanol or ethanol amides of these carboxylic acids in the presence of titanium or zirconium compounds of the M(OR3)4 type (M = Ti or Zr).
Description
2 ~ a ~
Wo 90/13546 1 PCT/EP90/00631 A process for the production of 2-oxazolines This invention relates to a process for the production of 2-oxazolines corresponding to g~neral formula I
N ~ I
~ ~ 0 J (~) in which Rl is an aryl or aralkyl radical optionally substituted in the aromatic nucleus, an alkyl group containing 5 to 6 carbon atoms, a hydroxy-substituted alkyl group containing 1 to 6 carbon atoms, an alkoxy-substituted alkyl group containing 1 to 6 carbon atoms in the alkyl group and 1 to 18 carbon atoms in the alkoxy group or a group corresponding to general formula II
R -(OCzHs)p-o-cH2- (II) in which R2 is an alkyl or alkenyl group containing 1 to 18 carbon atoms, more especially a methyl group and p is a number in the range from 1 to 10, more particu-larly 1 to 2, by condensation of carboxylic acid ethanolamides or precur-sors ~hereof in the liquid phase in the presence of cata-lysts, precursors being understood to be carboxylic acids and carboxylic acid esters with lower alkanols or glycerol as the first components and 2-aminoethanol as the second component.
2-Oxazolines substituted in the 2-position are valuable intermediate products which are used inter alia as .
~0~ '8 wo 90/13546 2 PCT/EP90/00631 solvents or plasticizers and, in particular, as polymeriza-tion components.
Numerous processes have been described for the prepar-ation of compounds of this class.
The most simple method is based on the cyclodehydra-tion of N-2-hydroxyethyl carboxylic acid amides (Chem. Rev.
44, 447 et seq (1949), Chem. Rev. 71, 4~5 et ~ (1971)).
However, cyclization of the unsubstituted N-2-hydroxyethyl carboxylic acid amides requires very drastic conditions or the presence of special catalysts. Whereas gas-phase reac-tions in the presence of dehydrating metal oxides, such as Al2O3, SiO~Al2O3, Al2O3/TiO~, Tio2 or MgO, have proved to be suitable for the preparation of readily volatile, short-chain 2-alkyl-2-oxazolines, the more volatile, relatively long-chain 2-alkyl-2-oxazolines are better prepared in the liquid phase. Compounds of manganese, cobalt, molybdenum, tungsten, iron, cadm~um, zinc and tin and also compounds of the rare earth metals have been described as catalysts for the liquid-phase reaction (cf. US-PS 3,562,263, BE-PS 666 829, C.A. 87, 135353, C.A. 87, 135352, US-PS 3,681,329, US-PS 3,681,333, EP-OS O 033 752, US-PS 4,543,414, US-PS
4,354,029, US-PS 4,443,611, EP-OS 0 105 944 and EP-OS 0 164 219). However, the catalysts described in the publications cited above do not lead to good yields in the production of relatively long-chain 2-fatty alkyl-2-oxazolines.
It has now been found that special titanium and zirconium compounds are eminently suitable as catalysts in a process of the type mentioned at the beginning, enabling yields of up to about 90% of the theoretical, based on the starting compound, to be obtained.
Accordingly, the present invention relates to a process of the type mentioned at the beginning in which a) carboxylic acids corresponding to general ~ormula (III) 2~7~8 R1-COOH (III) in which Rl is as defined above, esters of these carboxylic acids with monoalkanols contain-ing l to 4 carbon atoms or glycerides of these carboxylic acids are condensed with 2-aminoethanol or b~ ethanolamides of these carboxylic acids in the presence of titanium or zirconium compounds corre-sponding to general formula IV
M(oR3)4 (IV) in which M represents tetravalent titanium or zirconium and R3 is an alkyl group containing at least 2 and more par-ticularly 2 to 4 carbon atoms, an acyl group containing at least 2 and more particularly 2 to 10 carbon atoms or a 2-aminoethyleneoxy group or a residue of a B-diketone corre-sponding to general formula V
R4-C=CH-Co-R (V) in which R4 and R5 may be the same or different and represent radicals from the group consisting of alkyl groups contain-ing l to 4 carbon atoms and phenyl optionally substituted in the p-position, two of the groups R3 together being formed by the two-bond radical of a dihydric alcohol containing 2 to 4 carbon atoms, in the presence of titanyl acetyl acetonate or in the presence of condensation p~oducts of titanium(IV) or zirconium(lV) tetraalkoxylates corresponding to general 2 ~
lW0 90/13546 4 PCT/EP90/00631 formula IV, in which M and R3 are as defin~d above, with polyfunctional alkanols, more particularly containing 3 to 12 carbon atoms and 2 to 6 hydroxyl groups, and the 2-oxazolines ~hus obtained are isolated with removal of the water and alcohol or glycerol formed.
The starting materials used in the process according to the invention are, in particular, the following car-boxylic acids and esters thereof with lower alkanols or glycerol and ethanolamides thereof benzoic acid which may contain 1 to 3 substituents; typical substituents are C14 alkyl groups, more particularly methyl, C14 alkoxy groups more particularly methoxy, and halogen atoms, such as chlorine and bromine;
phenyl acetic acid or phenyl propionic acid which may be substituted in the aromatic nucleus by 1 to 3 of the substituents mentioned above;
caproic and oenanthic acid;
hydroxycarboxylic acids containing 2 to 7 carbon atoms, more particularly hydroxyacetic acid, (glycolic acid), hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproi~ acid, more particularly the ~-hydroxy-substituted isomers thereof, and optionally lactones there-of;
alkoxy-substituted carboxylic acids which, formally, are alkoxylation products of the above-mentioned hydroxycar-boxylic acids and contain 1 to 18 carbon atoms in the alkoxy group: methoxy-substituted carboxylic acids are preferred;
ether carboxylic acids corresponding to the following formula R2- (OC2H5) p-O-CH2-COOH
in which R2 and p are as defined above; typical examples are the ether carboxylic acids obtained by catalytic oxidation , 2 3~ 8 WO 90/13546 5 PCT/~P90/00631 of adducts of ethylene oxide with primary, saturated or, optionally, even unsaturated alcohols containing 1 to 18 carbon atoms, such as methanol, ethanol, propanol, butanol, pentanol and hexanol, and also saturated or unsaturated fatty alcohols, including technical mixtures thereof, such as caproic, oenanthic, caprylic, capric, undecenyl, lauryl, myristyl, cetyl, stearyl, oleyl, elaidyl, linoleyl and linoleyl alcohol, as described for example in DE-A 26 36 123, EP-B 0 039 111, EP-B 0 018 681 and DE-A 31 35 946.
Particularly preerred ether carboxylic acids are methoxyethoxy acetic acid and methoxyethoxy ethoxy acetic acid.
The carboxylic acid ethanolamides suitable ~or use in the process according to the invention may be obtained by standard methods, ~or example by reaction of the acid chlorides or the C14 alkyl esters of the carboxylic acids with ethanolamine.
The titanium or zirconium compounds suitable for use as catalysts in the process according to the invention are known and, for the most part, are commercially available.
Condensation products of titanium(IV) or zirconium(IV) tetraalkoxylates with polyfunctional alkanols containing 3 to 12 carbon atoms and 2 to 6 hydroxyl groups, such as glycerol, trimethylol propane and pentaerythritol, are esterification and/or transesterification catalysts, which are described for example in US-C 4,705,764, to which reference is hereby made. Another suitable polyalkanol is polyvinyl alcohol. The titanium or zirconium tetra-(2-aminoethoxylates) also suitable as catalysts may be pre-pared from titanium or zirconium tetraal~oxylates and 2-amino-ethanol.
In one pre~erred embodiment of the invention, esters of titanic acid (H4TiO4) or zirconic acid (H4ZrO4) or mixed anhydrides of titanic or zirconic acid with organic acids corresponding to general formula IV, in which M = Ti or Zr .
.
2~7(~
Wo 90/135~6 6 PC~/EP99/006~1 and R3 is an alkyl group containing at least 2 or more than 2 carbon atoms and more particularly 2 to 4 carbon atoms or an acyl group containing 2 or more than 2 carbon atoms, more particularly 2 to 10 carbon atoms, derived from a monocarboxylic acid, are used as catalysts.
In another advantageous embodiment of the invention, catalysts from the group consisting of titanium or zir-conium tetraethylate, tetrapropylate, tetraisopropylate, tetrabutylate and tetraacetate are used.
In another advantageous embodiment of the invention, titanium or zirconium acetyl acetonates corresponding to general formula (VI) (R60) mM (ACA) n (VI ) in which R6 is an alkyl group containing 1 to 4 carbon atoms, ACA is an acetyl acetonate group and m is the number 0 and n is the number 4 or m is the number 2 and n is the number 2, are used as catalysts.
In another advantageous embodiment of the invention, polycondensation products of esters of titanic acid with monoalkanols containing 2 to 10 carbon atoms with penta-erythritol are used as catalysts.
In another advantageous embodiment o~ the inventisn, the catalysts to be used in accordance with the invention are used in a quantity of 0.1 to 10 mol-%, preferably in a quantity of 0.5 to 5 mol-% and more preferably in a quan-tity of 005 to 3 mol-%, based on the carboxylic acid ethanolamide or precursors thereof.
In another advantageous embodiment of the invention, the condensation reaction is carried out at 150 to 270DC, the reaction preferably being carried out in vacuo in an inert gas atmosphere. The water o~ reaction formed may be distilled off together with the 2-oxazolines and separated 2 0 ~ ~ 7 ~ 8 therefrom during the distillation, entrained residual water being removed with typical drying agents, such a~ anhydrous sodium sulfate or molecular sieve (4A). However, the water of reaction may also be removed from the reaction mixture before th~ actual distillation of the 2-oxazolines by azeotropic distillation with high-boiling entraining agents, such as for example tetralin or cumene.
In another preferred embodiment of the invention, the 2-oxazolines may be directly prepared from carboxylic acids or carboxylic acid esters corresponding to general formula VII
Rl-CooR7 (VII) in which R1 is as defined above and R7 is hydrogen or an alkyl group containing 1 to 4 carbon atoms, or from glycerides of caxboxylic acids corresponding to the formula Rl-COOH, more particularly triglycerides, by reaction thereof in the presence of ethanolamine to form the carboxylic acid ethanolamides and leaving the reaction mixture to react in a second step in which the reaction temperature is further increased. Preferred starting materials are the readily obtainable carboxylic acid methyl esters and glycerides. They are reacted in the presence of ethanolamine and the claimed catalysts in a first step at elevated temperature, preferably at atmospheric pressure, with removal of water and alcohol or glycerol to form carboxylic acid ethanolamides and in a second step, the reaction mixture is left to react, preferably in vacuo, with a further increase in the reaction temperature. The ethanolamine is preferably used in a 50 to 400 mol-%
excess, based on the starting material, unreacted or excess ethanolamine being removed ~rom the reaction mixture before the second step. A reaction temperature of 100 to 170~C is preferably applied in the first step, a reaction tempera-2~7~
WO 90/135~6 8 PCT/EP90/00631 ture of 175 to 250C preferably being applied in the second step. The catalysts are preferably used in a quantity o~
0.1 to 10 mol-%, preferably 0.5 to 5 mol-% and moxe prefer-ably 0.5 to 3 mol-~, based on the the starking material used. Titanium tetraalcoholates, more particularly select-ed from the group consisting of titanium tetraethylate, tetrapropylate, tetraisopropylate and tetrabutylate, are again preferably used. Alternatively, mixed anhydrides of titanic acid with monocarboxylic acids, particularly those containing 1 to 4 carbon atoms, preferably titanium tetra-acetate, are used. Other preferred catalysts are titanium or zirconium acetyl acetonates corresponding to general formula VI, the above-mentioned polycondensation products of esters of titanic acid with monoal~anols containing 2 to 10 carbon atoms with pentaerythritol and also titanium(IV) or Zr(IV) tetraaminoethanolates.
In this variant of the process, the reaction is preferably carried out in vacuo and the water of reaction formed is distilled off together with the 2-oxazolines with further separation during distillation or the water of reaction is removed by azeotropic distillation before distillation of the 2-oxazolines.
It is of particular advantage in this regard to carry out the first and the second stages of the reaction as a one pot reaction in one and the same reactor.
The invention is illustrated by the following Ex-amples.
Example 1.
2-Phenyl-2-oxazoline.
A mixture of 1042 g (7.5 mol) benæoic acid methyl ester (98%), 921 g (15 mol) ethanolamine (99.5%) and 25.5 g (0.075 mol, 1 mol-~) titanium tetrabutylate was introduced into a stirred reactor equipped with a 2(~708 WO 90/13546 9 PCT/EP~0/00~31 fractionating column, descending condenser with distilla-tion receivers, a vacuum source with a cold trap for the water of reaction, a thermometer and an inlet pipe for inert gas.
The reaction mixture was heated under nitrogen; the methanol formed at 128 to 160C was distilled off under normal pressure.
The excess ethanolamine was then distilled off in vacuo at 87C/20 hPa.
The benzoic acid ethanolamide thus obtained was heated in vacuo to 178-226C, the 2-phenyl-2-oxazoline formed and water distilling over simultaneously at 122C/20 hPa. Most of the water was condensed in the cold trap. To free the oxazoline distilled over from any water entrained, a molecular sieve (4A) was introduced as drying agent into the distillation receivers.
2-Phenyl-2-oxazoline, which still contained small quantities of benzoic acid ethanolamide, was obtained in a yield of 836.7 g (75% of the theoretical, based on the benzoic acid methyl ester used).
Pure 2-phenyl-2-oxazoline having the following charac-teristic data was obtained in a yield of 775.3 g (70% of the theoretical) by redistillation using a thin-layer evaporator (Bp. = 120 to 125~C at 19 hPa):
nD20= 1.5672 IR: 1650 (C=N); 1260, 1065 (C-0-C=); 975, 945, 900cm~
(oxazoline).
Example 2.
2-Hydroxymethyl-2-oxazoline. [104]
Glycolic acid methyl ester was reacted with ethanol-amine by the method described in Example 1. The following quantities were used:
135.1 g (1.5 mol) glycolic acid methyl ester WO 90/13546 10 PC~/EP90/00631 184.2 g (300 mol) ethanolamine (99.5%) 5.1 g (0.015 mol, 1 mol-%) titanium tetrabutylate. [340]
Yield = 31.6 g (0.3 mol) - 20% of the theoret.
Sublimation point = 98C ~21 hPa~.
20.7 g pure 2-hydroxymethyl-2-oxazoline were obtained after recrystallization.
Analysis:
C4H7N02 (101.107) calculated: C 47.52 H 6.98 M 13.85 found: C 47.5 H 7.00 N 13.6 IR: 1680 (C=N); 1209, 1099 (C-0-C=3; 981, 956, 922cm (oxazoline);
lH-NNR: delta (in ppm)= 4.76 (lH,s), 4,24 (2H,t,J = 7 Hz), 3.86 (2Ht,J= 7 HZ)o Example 3.
2-(5-Hydroxypentyl)-2-oxazoline. [187~
Caprolactone was reacted with ethanolamine by the method described in Example 1. The following quantities were used:
230.6 g (2.0 mol) caprolactone 245.5 g (4~0 mol) ethanolamine ~99.5~) 6.8 g (0.02 mol, 1 mol-%) titanium tetrabutylate Yield: 249.8 g (approx. 80% purity). (1.06 mol ; 53%) Bp. = 140C (0.03 hPa).
77.2 g of the title compound with a purity of 95% were obtained by redistillation in vacuo (Bp. = 114C at 1.2 hPa).
Example 4.
Methoxymethyl-2-oxazoline. [118]
Methoxyacetic acid was reacted with ethanolamine by the method described in Example 1. The following quanti-ties were used:
180.2 g (2.0 mol) methoxyacetic acid (purity > 95%) .
2~3~08 245.5 g (4.0 mol) ethanolamine 6.8 g (0.02 mol, 1 mol-%) ~itanium tetrabutylate.
Yield: 188.6 g (82% of the theoretical).
Bp. = 130C to 163C (167 hPa).
124.4 g (5~% of the theoretical) of pure 2-methoxy-methyl-2-oxazoline, Bp. 69C/20 hPa, are obtained after redistillation ln vacuo.
Analysis-C5H8N02 (115.134) calculated: C 52.16 H 7.88 N 12.17 found: C 52.0 H 7.94 N 12.3 IR: 1668 (C=N); 1191, 1122 (C-0-C=); 982, 948, 918cm (oxazoline):
lH-NMR: delta (in ppm)= 4.31 (2H,t,J = 7 Hz), 4.12 (2H,s), 3.90 (2H,t,J = 7 Hz), 3.46 (3H,s).
Example 5.
2-(2,5-Dioxahexyl)-2-oxazoline. ~156]
3,6-Dioxaheptanoic acid (methoxyethoxy acetic acid) was reacted with ethanolamine by the method described in Example 1. The following quantities were used:
235 g (1.50 mol) 3,6-dioxaheptanoic acid (purity approx~
80-85%) 215 g (3 mol) ethanolamine (99.5%) 6.0 g (0.0175 mol, 1 mol-%) titanium tetrabutylate.
Yield = 209.1 g (88% of the theoretical).
Bp. = 140 to 180C (0.5 hPa).
129.1 g (61% of the theoretical) of the title compound were obtained after redistillation in vacuo (Bp. = 57 to 66C at 0.01 hPa).
Analysis:
C7Hl3N03 (159.187) calculated: C 52.82 H 8.23 N 8.80 found: C 52.8 H 8.51 N 8.77 n 20= 1.4571 2~7~8 IR: 1669 (C=N); 1199, 1116 (C o-C=); 982, 950, 907cm (oxazoline);
H-NMR: delta (in ppm)= 4.30 (2H,t,J = 7 Hz), 4.24 (2H,s), 3.89 (2H,t,J = 7 Hz), 3.7446 (2H,dd,J = 3.4 Hz), 3.58 (2H,dd,J = 3.4 Hz), 3,38 (3H,s).
Example 6.
2-(2,5,8-Trioxanonyl)-2-oxazoline. [206]
3,6,9-Trioxadecanoic acid (methoxyethoxy ethoxy acetic acid) were reacted with ethanolamine by the method de-scribed in Example 1. The following quantities were used:
231.6 g (1.24 mol) 3,6,9-trioxadecanoic acid (puriky approx. 95~) 159.6 g (2.6 mol) ethanolamine (99.5~) 4.4 g (0.013 mol, 1 mol-%) titanium tetrabutylate.
Yield = 187.0 g (75% of the theoretical).
Bp. = 167 - 182C (0.4 - 2.6 hPa).
149.1 g (59%) of the pure title compound were obtained after redistillation in vacuo (Bp. = 101 - 106C at O.lS
hPa).
Analysis:
CgH17N04 (203.24) calculated: C 53.19 H 8.43 N 6.89 found: C 53.8 H 8.49 N 6.92 25 nD20= 1.4602 IR: 1669 (C=N); 1198, 1109 (C-0-C=); 982, 950, 907cm (oxazoline);
lH-N~R: delta (in ppm)= 4.30 (2H,t,J = 7 Hz), 4.23 (2H,s), 3.88 (2H,t,J = 7 Hz), 3.75 (2H,m), 3.70 (2H,m), 3.65 (2H,m), 3.55 (2H,m), 3.38 (3H,s).
Example 7.
Preparation of a 2-substituted 2-oxazoline from m-tolylic acid . .
:. :
2~7~g ~0 gO/13546 13 PC~/EP9OJ00631 m-Tolylic acid was reacted with ethanolamine by the method described in Example 1 to form 2-(3-methylphenyl)-2-oxazoline. The following quantities were used:
347.3 g (2.5 mol) m-tolylic acid (98%) 307.0 g (5.0 mol) ethanolamine (99.5%) 25.5 g ~0.075 mol, 3 mol-%) titanium tetrabutylate Yield = 241 g (60% of the theoretical) 2-(3-methylphenyl)-2-oxazoline Bp. = 128 - 142C (16 hPa).
IR: 1650 (C=N); 1268, 1067 (C-O-C=); 979, 951, 910cm~
(oxazoline).
H-NMR: delta (in ppm) 7.78 (lH,s); 7.72 (lH,m); 7.29 (2H,m); 4.42 (2H,t,J = 7 Hz); 4.04 (2H,t,J = 7 Hz); 2.37 (3H,s).
Example 8.
Preparation of a 2-substituted 2-oxazoline from m-methoxy-benzoic acid m-Methoxybenzoic acid was reacted with ethanolamine by the method described in Example 1 to form 2-(3-methoxyphen-yl)-2-oxazoline. The following quantities were used:
232.9 g (1.5 mol) m-methoxybenzoic acid (98%) 184.2 g (3.0 mol3 ethanolamine (99.5%) 15.3 g (0.045 mol, 3 mol-%) titanium tetrabutylate Yield = 116 g (44% of the theoretical) 2-(3-methoxyphenyl)-2-oxazoline.
Bp. = 122 - 157C (17-19 hPa) IR: 1650 (C=N); 1270, 1043 (C-O-C=); 930, 951, 910cm (oxazoline).
lH-NMR: delta (in ppm) 7.54 (lH,dt,J = 6; 1 Hz); 7.50 (lH,t,J = 1 Hz); 7.32 (lH,t,J = 6 Hz); 7.03 (lH,dt,J = 6;
1 Hz); 4.43 (2H,t,J = 7 Hz); 4.06 (2H,tJ = 7 Hz); 3.86 (3H,s).
~ ' .
2 ~
WO 90/13546 14 PCT/~P90/00631 Example 9.
Preparation of 2-phenyl-oxazoline from benzoic acid methyl ester in the presence of titaniumtIV) diisopropoxy-bis-acetyl acetonate Benzoic acid methyl ester was reacted with ethanol-amine by the method described in Example 1 to form 2-phenyl-2-oxazoline. The followiny quantities were used:
272.3 g (2.0 mol) benzoic acid methyl ester, 98%
244.3 g (4.0 mol) ethanolamine (99.5%) 7.3 g (0.02 mol, 1 mol-%) titanium(IV) diisopropoxybis-acetyl acetonate.
Yield = 236 g (82% of the theoretical) 2-phenyl-2-oxazo-line.
Bp. = 107 - 120C (20 hPa) Example 10.
Preparation of 2-phenyl-2-oxazoline from benzoic acid ethanolamide in the presence of titanium tetrabutylate.
Benzoic acid ethanolamide was reacted as in Example 1 (second step) to form 2-phenyl-2-oxazoline. The following quantities were used:
330.4 g (1.9 mol) benzoic acid ethanolamide (95%) 7.3 g (0.02 mol, 3 mol-%) titanium tetrabutylate Yield = 216 g (77% of the theoretical) 2-phenyl-2-oxazo-line.
Bp. = 112 - 114UC (19 hPa).
Wo 90/13546 1 PCT/EP90/00631 A process for the production of 2-oxazolines This invention relates to a process for the production of 2-oxazolines corresponding to g~neral formula I
N ~ I
~ ~ 0 J (~) in which Rl is an aryl or aralkyl radical optionally substituted in the aromatic nucleus, an alkyl group containing 5 to 6 carbon atoms, a hydroxy-substituted alkyl group containing 1 to 6 carbon atoms, an alkoxy-substituted alkyl group containing 1 to 6 carbon atoms in the alkyl group and 1 to 18 carbon atoms in the alkoxy group or a group corresponding to general formula II
R -(OCzHs)p-o-cH2- (II) in which R2 is an alkyl or alkenyl group containing 1 to 18 carbon atoms, more especially a methyl group and p is a number in the range from 1 to 10, more particu-larly 1 to 2, by condensation of carboxylic acid ethanolamides or precur-sors ~hereof in the liquid phase in the presence of cata-lysts, precursors being understood to be carboxylic acids and carboxylic acid esters with lower alkanols or glycerol as the first components and 2-aminoethanol as the second component.
2-Oxazolines substituted in the 2-position are valuable intermediate products which are used inter alia as .
~0~ '8 wo 90/13546 2 PCT/EP90/00631 solvents or plasticizers and, in particular, as polymeriza-tion components.
Numerous processes have been described for the prepar-ation of compounds of this class.
The most simple method is based on the cyclodehydra-tion of N-2-hydroxyethyl carboxylic acid amides (Chem. Rev.
44, 447 et seq (1949), Chem. Rev. 71, 4~5 et ~ (1971)).
However, cyclization of the unsubstituted N-2-hydroxyethyl carboxylic acid amides requires very drastic conditions or the presence of special catalysts. Whereas gas-phase reac-tions in the presence of dehydrating metal oxides, such as Al2O3, SiO~Al2O3, Al2O3/TiO~, Tio2 or MgO, have proved to be suitable for the preparation of readily volatile, short-chain 2-alkyl-2-oxazolines, the more volatile, relatively long-chain 2-alkyl-2-oxazolines are better prepared in the liquid phase. Compounds of manganese, cobalt, molybdenum, tungsten, iron, cadm~um, zinc and tin and also compounds of the rare earth metals have been described as catalysts for the liquid-phase reaction (cf. US-PS 3,562,263, BE-PS 666 829, C.A. 87, 135353, C.A. 87, 135352, US-PS 3,681,329, US-PS 3,681,333, EP-OS O 033 752, US-PS 4,543,414, US-PS
4,354,029, US-PS 4,443,611, EP-OS 0 105 944 and EP-OS 0 164 219). However, the catalysts described in the publications cited above do not lead to good yields in the production of relatively long-chain 2-fatty alkyl-2-oxazolines.
It has now been found that special titanium and zirconium compounds are eminently suitable as catalysts in a process of the type mentioned at the beginning, enabling yields of up to about 90% of the theoretical, based on the starting compound, to be obtained.
Accordingly, the present invention relates to a process of the type mentioned at the beginning in which a) carboxylic acids corresponding to general ~ormula (III) 2~7~8 R1-COOH (III) in which Rl is as defined above, esters of these carboxylic acids with monoalkanols contain-ing l to 4 carbon atoms or glycerides of these carboxylic acids are condensed with 2-aminoethanol or b~ ethanolamides of these carboxylic acids in the presence of titanium or zirconium compounds corre-sponding to general formula IV
M(oR3)4 (IV) in which M represents tetravalent titanium or zirconium and R3 is an alkyl group containing at least 2 and more par-ticularly 2 to 4 carbon atoms, an acyl group containing at least 2 and more particularly 2 to 10 carbon atoms or a 2-aminoethyleneoxy group or a residue of a B-diketone corre-sponding to general formula V
R4-C=CH-Co-R (V) in which R4 and R5 may be the same or different and represent radicals from the group consisting of alkyl groups contain-ing l to 4 carbon atoms and phenyl optionally substituted in the p-position, two of the groups R3 together being formed by the two-bond radical of a dihydric alcohol containing 2 to 4 carbon atoms, in the presence of titanyl acetyl acetonate or in the presence of condensation p~oducts of titanium(IV) or zirconium(lV) tetraalkoxylates corresponding to general 2 ~
lW0 90/13546 4 PCT/EP90/00631 formula IV, in which M and R3 are as defin~d above, with polyfunctional alkanols, more particularly containing 3 to 12 carbon atoms and 2 to 6 hydroxyl groups, and the 2-oxazolines ~hus obtained are isolated with removal of the water and alcohol or glycerol formed.
The starting materials used in the process according to the invention are, in particular, the following car-boxylic acids and esters thereof with lower alkanols or glycerol and ethanolamides thereof benzoic acid which may contain 1 to 3 substituents; typical substituents are C14 alkyl groups, more particularly methyl, C14 alkoxy groups more particularly methoxy, and halogen atoms, such as chlorine and bromine;
phenyl acetic acid or phenyl propionic acid which may be substituted in the aromatic nucleus by 1 to 3 of the substituents mentioned above;
caproic and oenanthic acid;
hydroxycarboxylic acids containing 2 to 7 carbon atoms, more particularly hydroxyacetic acid, (glycolic acid), hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproi~ acid, more particularly the ~-hydroxy-substituted isomers thereof, and optionally lactones there-of;
alkoxy-substituted carboxylic acids which, formally, are alkoxylation products of the above-mentioned hydroxycar-boxylic acids and contain 1 to 18 carbon atoms in the alkoxy group: methoxy-substituted carboxylic acids are preferred;
ether carboxylic acids corresponding to the following formula R2- (OC2H5) p-O-CH2-COOH
in which R2 and p are as defined above; typical examples are the ether carboxylic acids obtained by catalytic oxidation , 2 3~ 8 WO 90/13546 5 PCT/~P90/00631 of adducts of ethylene oxide with primary, saturated or, optionally, even unsaturated alcohols containing 1 to 18 carbon atoms, such as methanol, ethanol, propanol, butanol, pentanol and hexanol, and also saturated or unsaturated fatty alcohols, including technical mixtures thereof, such as caproic, oenanthic, caprylic, capric, undecenyl, lauryl, myristyl, cetyl, stearyl, oleyl, elaidyl, linoleyl and linoleyl alcohol, as described for example in DE-A 26 36 123, EP-B 0 039 111, EP-B 0 018 681 and DE-A 31 35 946.
Particularly preerred ether carboxylic acids are methoxyethoxy acetic acid and methoxyethoxy ethoxy acetic acid.
The carboxylic acid ethanolamides suitable ~or use in the process according to the invention may be obtained by standard methods, ~or example by reaction of the acid chlorides or the C14 alkyl esters of the carboxylic acids with ethanolamine.
The titanium or zirconium compounds suitable for use as catalysts in the process according to the invention are known and, for the most part, are commercially available.
Condensation products of titanium(IV) or zirconium(IV) tetraalkoxylates with polyfunctional alkanols containing 3 to 12 carbon atoms and 2 to 6 hydroxyl groups, such as glycerol, trimethylol propane and pentaerythritol, are esterification and/or transesterification catalysts, which are described for example in US-C 4,705,764, to which reference is hereby made. Another suitable polyalkanol is polyvinyl alcohol. The titanium or zirconium tetra-(2-aminoethoxylates) also suitable as catalysts may be pre-pared from titanium or zirconium tetraal~oxylates and 2-amino-ethanol.
In one pre~erred embodiment of the invention, esters of titanic acid (H4TiO4) or zirconic acid (H4ZrO4) or mixed anhydrides of titanic or zirconic acid with organic acids corresponding to general formula IV, in which M = Ti or Zr .
.
2~7(~
Wo 90/135~6 6 PC~/EP99/006~1 and R3 is an alkyl group containing at least 2 or more than 2 carbon atoms and more particularly 2 to 4 carbon atoms or an acyl group containing 2 or more than 2 carbon atoms, more particularly 2 to 10 carbon atoms, derived from a monocarboxylic acid, are used as catalysts.
In another advantageous embodiment of the invention, catalysts from the group consisting of titanium or zir-conium tetraethylate, tetrapropylate, tetraisopropylate, tetrabutylate and tetraacetate are used.
In another advantageous embodiment of the invention, titanium or zirconium acetyl acetonates corresponding to general formula (VI) (R60) mM (ACA) n (VI ) in which R6 is an alkyl group containing 1 to 4 carbon atoms, ACA is an acetyl acetonate group and m is the number 0 and n is the number 4 or m is the number 2 and n is the number 2, are used as catalysts.
In another advantageous embodiment of the invention, polycondensation products of esters of titanic acid with monoalkanols containing 2 to 10 carbon atoms with penta-erythritol are used as catalysts.
In another advantageous embodiment o~ the inventisn, the catalysts to be used in accordance with the invention are used in a quantity of 0.1 to 10 mol-%, preferably in a quantity of 0.5 to 5 mol-% and more preferably in a quan-tity of 005 to 3 mol-%, based on the carboxylic acid ethanolamide or precursors thereof.
In another advantageous embodiment of the invention, the condensation reaction is carried out at 150 to 270DC, the reaction preferably being carried out in vacuo in an inert gas atmosphere. The water o~ reaction formed may be distilled off together with the 2-oxazolines and separated 2 0 ~ ~ 7 ~ 8 therefrom during the distillation, entrained residual water being removed with typical drying agents, such a~ anhydrous sodium sulfate or molecular sieve (4A). However, the water of reaction may also be removed from the reaction mixture before th~ actual distillation of the 2-oxazolines by azeotropic distillation with high-boiling entraining agents, such as for example tetralin or cumene.
In another preferred embodiment of the invention, the 2-oxazolines may be directly prepared from carboxylic acids or carboxylic acid esters corresponding to general formula VII
Rl-CooR7 (VII) in which R1 is as defined above and R7 is hydrogen or an alkyl group containing 1 to 4 carbon atoms, or from glycerides of caxboxylic acids corresponding to the formula Rl-COOH, more particularly triglycerides, by reaction thereof in the presence of ethanolamine to form the carboxylic acid ethanolamides and leaving the reaction mixture to react in a second step in which the reaction temperature is further increased. Preferred starting materials are the readily obtainable carboxylic acid methyl esters and glycerides. They are reacted in the presence of ethanolamine and the claimed catalysts in a first step at elevated temperature, preferably at atmospheric pressure, with removal of water and alcohol or glycerol to form carboxylic acid ethanolamides and in a second step, the reaction mixture is left to react, preferably in vacuo, with a further increase in the reaction temperature. The ethanolamine is preferably used in a 50 to 400 mol-%
excess, based on the starting material, unreacted or excess ethanolamine being removed ~rom the reaction mixture before the second step. A reaction temperature of 100 to 170~C is preferably applied in the first step, a reaction tempera-2~7~
WO 90/135~6 8 PCT/EP90/00631 ture of 175 to 250C preferably being applied in the second step. The catalysts are preferably used in a quantity o~
0.1 to 10 mol-%, preferably 0.5 to 5 mol-% and moxe prefer-ably 0.5 to 3 mol-~, based on the the starking material used. Titanium tetraalcoholates, more particularly select-ed from the group consisting of titanium tetraethylate, tetrapropylate, tetraisopropylate and tetrabutylate, are again preferably used. Alternatively, mixed anhydrides of titanic acid with monocarboxylic acids, particularly those containing 1 to 4 carbon atoms, preferably titanium tetra-acetate, are used. Other preferred catalysts are titanium or zirconium acetyl acetonates corresponding to general formula VI, the above-mentioned polycondensation products of esters of titanic acid with monoal~anols containing 2 to 10 carbon atoms with pentaerythritol and also titanium(IV) or Zr(IV) tetraaminoethanolates.
In this variant of the process, the reaction is preferably carried out in vacuo and the water of reaction formed is distilled off together with the 2-oxazolines with further separation during distillation or the water of reaction is removed by azeotropic distillation before distillation of the 2-oxazolines.
It is of particular advantage in this regard to carry out the first and the second stages of the reaction as a one pot reaction in one and the same reactor.
The invention is illustrated by the following Ex-amples.
Example 1.
2-Phenyl-2-oxazoline.
A mixture of 1042 g (7.5 mol) benæoic acid methyl ester (98%), 921 g (15 mol) ethanolamine (99.5%) and 25.5 g (0.075 mol, 1 mol-~) titanium tetrabutylate was introduced into a stirred reactor equipped with a 2(~708 WO 90/13546 9 PCT/EP~0/00~31 fractionating column, descending condenser with distilla-tion receivers, a vacuum source with a cold trap for the water of reaction, a thermometer and an inlet pipe for inert gas.
The reaction mixture was heated under nitrogen; the methanol formed at 128 to 160C was distilled off under normal pressure.
The excess ethanolamine was then distilled off in vacuo at 87C/20 hPa.
The benzoic acid ethanolamide thus obtained was heated in vacuo to 178-226C, the 2-phenyl-2-oxazoline formed and water distilling over simultaneously at 122C/20 hPa. Most of the water was condensed in the cold trap. To free the oxazoline distilled over from any water entrained, a molecular sieve (4A) was introduced as drying agent into the distillation receivers.
2-Phenyl-2-oxazoline, which still contained small quantities of benzoic acid ethanolamide, was obtained in a yield of 836.7 g (75% of the theoretical, based on the benzoic acid methyl ester used).
Pure 2-phenyl-2-oxazoline having the following charac-teristic data was obtained in a yield of 775.3 g (70% of the theoretical) by redistillation using a thin-layer evaporator (Bp. = 120 to 125~C at 19 hPa):
nD20= 1.5672 IR: 1650 (C=N); 1260, 1065 (C-0-C=); 975, 945, 900cm~
(oxazoline).
Example 2.
2-Hydroxymethyl-2-oxazoline. [104]
Glycolic acid methyl ester was reacted with ethanol-amine by the method described in Example 1. The following quantities were used:
135.1 g (1.5 mol) glycolic acid methyl ester WO 90/13546 10 PC~/EP90/00631 184.2 g (300 mol) ethanolamine (99.5%) 5.1 g (0.015 mol, 1 mol-%) titanium tetrabutylate. [340]
Yield = 31.6 g (0.3 mol) - 20% of the theoret.
Sublimation point = 98C ~21 hPa~.
20.7 g pure 2-hydroxymethyl-2-oxazoline were obtained after recrystallization.
Analysis:
C4H7N02 (101.107) calculated: C 47.52 H 6.98 M 13.85 found: C 47.5 H 7.00 N 13.6 IR: 1680 (C=N); 1209, 1099 (C-0-C=3; 981, 956, 922cm (oxazoline);
lH-NNR: delta (in ppm)= 4.76 (lH,s), 4,24 (2H,t,J = 7 Hz), 3.86 (2Ht,J= 7 HZ)o Example 3.
2-(5-Hydroxypentyl)-2-oxazoline. [187~
Caprolactone was reacted with ethanolamine by the method described in Example 1. The following quantities were used:
230.6 g (2.0 mol) caprolactone 245.5 g (4~0 mol) ethanolamine ~99.5~) 6.8 g (0.02 mol, 1 mol-%) titanium tetrabutylate Yield: 249.8 g (approx. 80% purity). (1.06 mol ; 53%) Bp. = 140C (0.03 hPa).
77.2 g of the title compound with a purity of 95% were obtained by redistillation in vacuo (Bp. = 114C at 1.2 hPa).
Example 4.
Methoxymethyl-2-oxazoline. [118]
Methoxyacetic acid was reacted with ethanolamine by the method described in Example 1. The following quanti-ties were used:
180.2 g (2.0 mol) methoxyacetic acid (purity > 95%) .
2~3~08 245.5 g (4.0 mol) ethanolamine 6.8 g (0.02 mol, 1 mol-%) ~itanium tetrabutylate.
Yield: 188.6 g (82% of the theoretical).
Bp. = 130C to 163C (167 hPa).
124.4 g (5~% of the theoretical) of pure 2-methoxy-methyl-2-oxazoline, Bp. 69C/20 hPa, are obtained after redistillation ln vacuo.
Analysis-C5H8N02 (115.134) calculated: C 52.16 H 7.88 N 12.17 found: C 52.0 H 7.94 N 12.3 IR: 1668 (C=N); 1191, 1122 (C-0-C=); 982, 948, 918cm (oxazoline):
lH-NMR: delta (in ppm)= 4.31 (2H,t,J = 7 Hz), 4.12 (2H,s), 3.90 (2H,t,J = 7 Hz), 3.46 (3H,s).
Example 5.
2-(2,5-Dioxahexyl)-2-oxazoline. ~156]
3,6-Dioxaheptanoic acid (methoxyethoxy acetic acid) was reacted with ethanolamine by the method described in Example 1. The following quantities were used:
235 g (1.50 mol) 3,6-dioxaheptanoic acid (purity approx~
80-85%) 215 g (3 mol) ethanolamine (99.5%) 6.0 g (0.0175 mol, 1 mol-%) titanium tetrabutylate.
Yield = 209.1 g (88% of the theoretical).
Bp. = 140 to 180C (0.5 hPa).
129.1 g (61% of the theoretical) of the title compound were obtained after redistillation in vacuo (Bp. = 57 to 66C at 0.01 hPa).
Analysis:
C7Hl3N03 (159.187) calculated: C 52.82 H 8.23 N 8.80 found: C 52.8 H 8.51 N 8.77 n 20= 1.4571 2~7~8 IR: 1669 (C=N); 1199, 1116 (C o-C=); 982, 950, 907cm (oxazoline);
H-NMR: delta (in ppm)= 4.30 (2H,t,J = 7 Hz), 4.24 (2H,s), 3.89 (2H,t,J = 7 Hz), 3.7446 (2H,dd,J = 3.4 Hz), 3.58 (2H,dd,J = 3.4 Hz), 3,38 (3H,s).
Example 6.
2-(2,5,8-Trioxanonyl)-2-oxazoline. [206]
3,6,9-Trioxadecanoic acid (methoxyethoxy ethoxy acetic acid) were reacted with ethanolamine by the method de-scribed in Example 1. The following quantities were used:
231.6 g (1.24 mol) 3,6,9-trioxadecanoic acid (puriky approx. 95~) 159.6 g (2.6 mol) ethanolamine (99.5~) 4.4 g (0.013 mol, 1 mol-%) titanium tetrabutylate.
Yield = 187.0 g (75% of the theoretical).
Bp. = 167 - 182C (0.4 - 2.6 hPa).
149.1 g (59%) of the pure title compound were obtained after redistillation in vacuo (Bp. = 101 - 106C at O.lS
hPa).
Analysis:
CgH17N04 (203.24) calculated: C 53.19 H 8.43 N 6.89 found: C 53.8 H 8.49 N 6.92 25 nD20= 1.4602 IR: 1669 (C=N); 1198, 1109 (C-0-C=); 982, 950, 907cm (oxazoline);
lH-N~R: delta (in ppm)= 4.30 (2H,t,J = 7 Hz), 4.23 (2H,s), 3.88 (2H,t,J = 7 Hz), 3.75 (2H,m), 3.70 (2H,m), 3.65 (2H,m), 3.55 (2H,m), 3.38 (3H,s).
Example 7.
Preparation of a 2-substituted 2-oxazoline from m-tolylic acid . .
:. :
2~7~g ~0 gO/13546 13 PC~/EP9OJ00631 m-Tolylic acid was reacted with ethanolamine by the method described in Example 1 to form 2-(3-methylphenyl)-2-oxazoline. The following quantities were used:
347.3 g (2.5 mol) m-tolylic acid (98%) 307.0 g (5.0 mol) ethanolamine (99.5%) 25.5 g ~0.075 mol, 3 mol-%) titanium tetrabutylate Yield = 241 g (60% of the theoretical) 2-(3-methylphenyl)-2-oxazoline Bp. = 128 - 142C (16 hPa).
IR: 1650 (C=N); 1268, 1067 (C-O-C=); 979, 951, 910cm~
(oxazoline).
H-NMR: delta (in ppm) 7.78 (lH,s); 7.72 (lH,m); 7.29 (2H,m); 4.42 (2H,t,J = 7 Hz); 4.04 (2H,t,J = 7 Hz); 2.37 (3H,s).
Example 8.
Preparation of a 2-substituted 2-oxazoline from m-methoxy-benzoic acid m-Methoxybenzoic acid was reacted with ethanolamine by the method described in Example 1 to form 2-(3-methoxyphen-yl)-2-oxazoline. The following quantities were used:
232.9 g (1.5 mol) m-methoxybenzoic acid (98%) 184.2 g (3.0 mol3 ethanolamine (99.5%) 15.3 g (0.045 mol, 3 mol-%) titanium tetrabutylate Yield = 116 g (44% of the theoretical) 2-(3-methoxyphenyl)-2-oxazoline.
Bp. = 122 - 157C (17-19 hPa) IR: 1650 (C=N); 1270, 1043 (C-O-C=); 930, 951, 910cm (oxazoline).
lH-NMR: delta (in ppm) 7.54 (lH,dt,J = 6; 1 Hz); 7.50 (lH,t,J = 1 Hz); 7.32 (lH,t,J = 6 Hz); 7.03 (lH,dt,J = 6;
1 Hz); 4.43 (2H,t,J = 7 Hz); 4.06 (2H,tJ = 7 Hz); 3.86 (3H,s).
~ ' .
2 ~
WO 90/13546 14 PCT/~P90/00631 Example 9.
Preparation of 2-phenyl-oxazoline from benzoic acid methyl ester in the presence of titaniumtIV) diisopropoxy-bis-acetyl acetonate Benzoic acid methyl ester was reacted with ethanol-amine by the method described in Example 1 to form 2-phenyl-2-oxazoline. The followiny quantities were used:
272.3 g (2.0 mol) benzoic acid methyl ester, 98%
244.3 g (4.0 mol) ethanolamine (99.5%) 7.3 g (0.02 mol, 1 mol-%) titanium(IV) diisopropoxybis-acetyl acetonate.
Yield = 236 g (82% of the theoretical) 2-phenyl-2-oxazo-line.
Bp. = 107 - 120C (20 hPa) Example 10.
Preparation of 2-phenyl-2-oxazoline from benzoic acid ethanolamide in the presence of titanium tetrabutylate.
Benzoic acid ethanolamide was reacted as in Example 1 (second step) to form 2-phenyl-2-oxazoline. The following quantities were used:
330.4 g (1.9 mol) benzoic acid ethanolamide (95%) 7.3 g (0.02 mol, 3 mol-%) titanium tetrabutylate Yield = 216 g (77% of the theoretical) 2-phenyl-2-oxazo-line.
Bp. = 112 - 114UC (19 hPa).
Claims (9)
1. A process for the production of 2-oxazolines corre-sponding to general formula I
(I) in which R1 is i) an aryl or aralkyl radical optionally substituted in the aromatic nucleus, ii) an alkyl group containing 4 to 6 carbon atoms, iii) a hydroxy-substituted alkyl group containing 1 to 6 carbon atoms, iv) an alkoxy-substituted alkyl group containing 1 to 6 carbon atoms in the alkyl group and 1 to 18 carbon atoms in the alkoxy group or v) a group corresponding to general formula II
(II) in which R2 is an alkyl or alkenyl group containing 1 to 18 carbon atoms and p is a number in the range from 1 to 10, by condensation of carboxylic acid ethanolamides or precur-sors thereof in the presence of titanium compounds in the liquid phase, characterized in that a1) carboxylic acids corresponding to general formula (III) R1-COOH (III) in which R1 is as defined above, a2) esters of these carboxylic acids with monoalcohols containing 1 to 4 carbon atoms or a3) glycerides of these carboxylic acids are condensed with b) 2-aminoethanol or ethanolamides of these carboxylic acids in a molar ratio of component a) to component b) of 1:1.5 to 1:4 at temperatures of 150 to 270°C in the presence of 0.5 to 3 mol-% - based on carboxylic acid ethanolamide or its precursors - of a titanium compound selected from the group consisting of titanium tetrabutylate, titanium bis-acetyl acetonate and titanium dialkoxy acetyl acetonates and the 2-oxazolines thus obtained are isolated with removal of the water and alcohol or glycerol formed.
(I) in which R1 is i) an aryl or aralkyl radical optionally substituted in the aromatic nucleus, ii) an alkyl group containing 4 to 6 carbon atoms, iii) a hydroxy-substituted alkyl group containing 1 to 6 carbon atoms, iv) an alkoxy-substituted alkyl group containing 1 to 6 carbon atoms in the alkyl group and 1 to 18 carbon atoms in the alkoxy group or v) a group corresponding to general formula II
(II) in which R2 is an alkyl or alkenyl group containing 1 to 18 carbon atoms and p is a number in the range from 1 to 10, by condensation of carboxylic acid ethanolamides or precur-sors thereof in the presence of titanium compounds in the liquid phase, characterized in that a1) carboxylic acids corresponding to general formula (III) R1-COOH (III) in which R1 is as defined above, a2) esters of these carboxylic acids with monoalcohols containing 1 to 4 carbon atoms or a3) glycerides of these carboxylic acids are condensed with b) 2-aminoethanol or ethanolamides of these carboxylic acids in a molar ratio of component a) to component b) of 1:1.5 to 1:4 at temperatures of 150 to 270°C in the presence of 0.5 to 3 mol-% - based on carboxylic acid ethanolamide or its precursors - of a titanium compound selected from the group consisting of titanium tetrabutylate, titanium bis-acetyl acetonate and titanium dialkoxy acetyl acetonates and the 2-oxazolines thus obtained are isolated with removal of the water and alcohol or glycerol formed.
2. A process as claimed in claim 1, characterized in that the condensation is carried out in the presence of titanium diisopropoxy acetyl acetonate.
3. A process as claimed in claims 1 and 2, characterized in that the reaction is carried out in vacuo.
4. A process as claimed in any of claims 1 to 3, charac-terized in that the water or alcohol of reaction formed is distilled off together with the 2-oxazolines and is subse-quently or simultaneously separated therefrom or is removed by azeotropic distillation before the distillation of the 2-oxazolines.
5. A process as claimed in any of claims 1 to 4, charac-terized in that, in a first reaction stage, carboxylic acids or carboxylic acid esters corresponding to general formula VII
R1-COOR3 (VII) in which R1 is as defined above and R3 is hydrogen or an alkyl group containing 1 to 4 carbon atoms, or carboxylic acid glycerides are reacted in the presence of ethanolamine at elevated temperature and at atmospheric pressure to form the fatty acid ethanolamides, water and alcohol or glycerol formed are removed and, in a second reaction stage, the reaction mixture is left to react in vacuo while the reaction temperature is further increased.
R1-COOR3 (VII) in which R1 is as defined above and R3 is hydrogen or an alkyl group containing 1 to 4 carbon atoms, or carboxylic acid glycerides are reacted in the presence of ethanolamine at elevated temperature and at atmospheric pressure to form the fatty acid ethanolamides, water and alcohol or glycerol formed are removed and, in a second reaction stage, the reaction mixture is left to react in vacuo while the reaction temperature is further increased.
6. A process as claimed in claims 1 to 5, characterized in that unreacted or excess ethanolamine is removed from the reaction mixture before the second reaction stage.
7. A process as claimed in claims 1 to 6, characterized in that the first stage of the reaction is carried out at a temperature of 100 to 170°C.
8. A process as claimed in claims 1 to 7, characterized in that the second stage of the reaction is carried out at a temperature of 175 to 270°C.
9. A process as claimed in claims 1 to 8, characterized in that the first and second stages of the reaction are carried out as a one-pot reaction.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19893914133 DE3914133A1 (en) | 1989-04-28 | 1989-04-28 | METHOD FOR PRODUCING 2-OXAZOLINES |
| DEP3914133.0 | 1989-04-28 | ||
| PCT/EP1990/000631 WO1990013546A1 (en) | 1989-04-28 | 1990-04-19 | A process for making 2-oxazolines |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2054708A1 true CA2054708A1 (en) | 1990-10-29 |
Family
ID=6379724
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002054708A Abandoned CA2054708A1 (en) | 1989-04-28 | 1990-04-19 | Process for making 2-oxazolines |
Country Status (6)
| Country | Link |
|---|---|
| EP (2) | EP0394849A1 (en) |
| JP (1) | JPH04504854A (en) |
| BR (1) | BR9007335A (en) |
| CA (1) | CA2054708A1 (en) |
| DE (1) | DE3914133A1 (en) |
| WO (1) | WO1990013546A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4226805A1 (en) * | 1992-08-13 | 1994-02-17 | Henkel Kgaa | Binder mixtures for stoving enamels |
| DE4313511A1 (en) * | 1993-04-24 | 1994-10-27 | Henkel Kgaa | Batch process for the preparation of oxazolines and oxazines |
| DE19603304C2 (en) * | 1996-01-25 | 1999-09-09 | Inventa Ag | Use of oxazoline compounds as an activator for triggering the anionic lactam polymerization |
| NL1012572C2 (en) * | 1999-07-12 | 2001-01-15 | Dsm Nv | Preparation of an aromatic oxazoline. |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1067437B (en) * | 1956-05-11 | 1959-10-22 | Rohm & Haas Company, Philadelphia, Pa. (V. St. A.) | Process for the preparation of 4,4-dialkyl-2vinyl- and 4,4-dialkyl-2-isopropenylsu'bstituierten oxazolines and 5,6-dihydro-4H! -1,3-oχ3zinen and their spirans |
| US3681329A (en) * | 1970-05-04 | 1972-08-01 | Allied Chem | Process for the preparation of cyclic iminoethers |
| DE3824982A1 (en) * | 1987-11-10 | 1989-05-18 | Henkel Kgaa | 2- (11-HYDROXY-8-HEPTADECENYL- OR 11,8- AND 11,9-HEPTADECADIENYL) OXAZOLIN, AND METHOD FOR THE MANUFACTURE, IF SUCH, OF SUBSTITUTED HOEHERER 2- (ALKYL- AND ALKENYL) -OXAZOLINES |
-
1989
- 1989-04-28 DE DE19893914133 patent/DE3914133A1/en not_active Withdrawn
-
1990
- 1990-04-19 BR BR909007335A patent/BR9007335A/en not_active Application Discontinuation
- 1990-04-19 JP JP50597990A patent/JPH04504854A/en active Pending
- 1990-04-19 EP EP90107480A patent/EP0394849A1/en not_active Withdrawn
- 1990-04-19 WO PCT/EP1990/000631 patent/WO1990013546A1/en not_active Application Discontinuation
- 1990-04-19 EP EP19900906187 patent/EP0470104A1/en not_active Withdrawn
- 1990-04-19 CA CA002054708A patent/CA2054708A1/en not_active Abandoned
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| Publication number | Publication date |
|---|---|
| EP0470104A1 (en) | 1992-02-12 |
| DE3914133A1 (en) | 1990-10-31 |
| BR9007335A (en) | 1992-04-21 |
| WO1990013546A1 (en) | 1990-11-15 |
| JPH04504854A (en) | 1992-08-27 |
| EP0394849A1 (en) | 1990-10-31 |
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