JPS5826849A - Manufacture of methacryl- and acrylamide - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION In the production of acrylic acid and methacrylic acid amides, it is particularly important to use starting materials that are easily obtained industrially.

Industrially easily obtainable starting materials are, for example, acrylic or methacrylic acid O nitriles and esters and the acids themselves.

Organic carboxylic acid and alkylamine at a temperature of 100℃ or higher
It was already proposed in US Pat. No. 1,986,854 to obtain alkyl amides of carboxylic acids by reacting at temperatures below 350°C, preferably from 150 to 250°C. In that case, preferably at atmospheric pressure, the gaseous amine is added to the molten acid and the amide formed is removed from the reaction punch by vacuum distillation. The amine must then be fed in a slight excess over the stoichiometrically required amount.

In U.S. Pat. No. 2,719,177, according to the method of the aforementioned U.S. patent, for example, dimethylamine as a gaseous amine component and acrylic acid in a molten state are
- It was shown not to form dimethylacrylamide. The latter patent specifies instead a temperature of 250-55
Continuous gas phase reactions with dehydration catalysts at 0° C. are described. It has been found that reactions with aluminum oxide-containing catalysts and residence times of 1 to 7 seconds are preferred.

The acid to amine ratio is in the range 1:1 to 1:2.5.

In a similar manner, the reaction of acrylic or methacrylic acid with primary or secondary aliphatic or aromatic amines at temperatures above 150° C. in the gas phase is described in DE 10 43 320, in which case , a catalyst containing phosphoric acid or a phosphate salt and capable of eliminating water is used.

In the case of the reaction of N,N-dialkylalkylene diamines with methacrylic acid, the stage of microadducts is known. That is, in the case of N-(dialkylaminoalkyl)-2-methyl-β-alanine, it is included in the reaction (US Pat. No. 3,652,671). Therefore, due to the formation of microadducts, the temperature is then up to 230°C, preferably 18°C.
Methacrylamide P must be obtained by carrying out the removal reaction at 0 to 220° C. while blocking oxygen.

In contrast, reaction with the corresponding acrylic acid gave entirely unsatisfactory results.

The methods of the prior art can be improved in several respects. These processes are either carried out as gas phase reactions at relatively room temperature in the presence of catalysts or are limited to the thermal decomposition of microadducts in certain systems.

Therefore, starting from acrylic acid or methacrylic acid, h+-substituted acrylic-synthetic methacrylamides can be prepared which can be used in general and satisfy the product quality and yield in the most economical way possible. Those who can
When I left, there was a child in section B.

By the way, this stone: In the first step of producing N-directly converted amides of acrylic acid or methacrylic acid, the dk amine is added to the amine at standard pressure, and the amine is slightly grooved, "frame". At the end of the process, the process is carried out in a homogeneous phase at 75-140°C, followed by condensation at 150-250°C while removing water in the second step, followed by post-treatment. It turned out to be quite satisfying.

The present invention is based on the formula (1): [l represents hydrogen or a methyl group, and represents hydrogen or a saturated or unsaturated alkyl group, or a substituted aryl group, Bird represents a saturated or unsaturated optionally substituted cyclic alkyl group or an optionally substituted aryl group or an aralkyl group or an alkylenecarzexamer group, or Bird and Rs are taken together to form a nitrogen-containing heterocyclic ring.
In this case, an acid of the formula ■: OH, = O-000H 1■ 1 (R1 represents the above) is mixed with an amine of the formula I: [8-fold and FLs represent the above] and the standard in the first step. The acid of formula (■) is mixed with the amine of formula (2) in stoichiometric amounts, preferably up to a slight excess of the amine, at a pressure of about 75-14Q°C.
The reaction is carried out under conditions such that the reaction mixture is a homogeneous phase, preferably at 80 to 130°C, and the condensation is carried out at about 150 to 250°C, preferably 160 to 240°C, while removing water produced in the second step.

For post-treatment, the unreacted acid of G' moss, preferably 2, is removed with a suitable base, such as calcium oxide.

After conversion to the salt with calcium carbonate, potassium hydroxide, sodium hydroxide, the amide of formula I is subsequently prepared from the reaction tube, preferably by distillation.

Generally, the desired product of Formula I is a low boiling component, whereas the high boiling component contains a microadduct of an amine to an α,β-unsaturated acid or an α,β-unsaturated amide.

Substituent B2 of the amine of formula (2) is a saturated or unsaturated optionally branched optionally substituted carbon atom 1-18
R represents an alkyl group having
3 is a saturated or unsaturated optionally substituted alkyl or aralkyl group having 1 to 18 cyclic carbon atoms or an optionally polysubstituted aryl group, in particular a phenyl group or represents a thyl group, or R
1 and R3 together form a heterocyclic ring system containing a nitrogen atom and optionally further nitrogen, oxygen, or sulfur atoms.

Substituents which may have a radical R2 or R3 -as defined above are in particular carboxy-, alkoxycarzenyl-, (alkyl)-carnomoyl-, sulfo-
, sulfonami-P- and especially (alkyl)-amino- groups.

When the substituent has an alkyl group, it is preferably an alkyl group having 1 to 6 carbon atoms. In a narrow sense, the amine in 2) may be a compound of the following formula 2': [Rs represents the above, and A is a group -(OR4R5)
n also represents a hacyclohexyl group, a phenyl group or a hanaphthyl group, in which R4 is hydrogen or an alkyl group having 1 to 6 carbon atoms or a feral group;

is hydrogen or an alkyl group having 1 to 6 carbon atoms; Lx is hydrogen or a group -000H, -0ONR6B, -
000 Hatake, -80s H, -80, NR11R? or NRJR4 (in which case R6 and R7 and R'6 and R/
, each representing hydrogen or an alkyl group having 1 to 6 carbon atoms), and n is an integer from 1 to 18 (provided that if X does not represent -N RhfL+, n is simply l), or A together with X forms an allyl group or an alkenylcarzexami P group].

Compounds of formula (2) include, for example, amino acids, their esters and amino acids, such as glycine, alanine, and alkylene diamines, such as ethylene diamine, propylene diamine, hexamethylene diamine, phenylene diamine,
Includes neopentanediamine and dimethylaminoneopentanamine and sarcosine. In the case of using a compound of formula (1) having two 1st or 27th mino groups, such as alkylene diamine, in the present invention, α, β of formula (2)
- Reaction with two unsaturated acid molecules is possible. This system of reactions to obtain bis-amide compounds is included in the claimed protection.

Particularly preferred are reactions starting from methacrylic acid compounds (R1 = methyl) and compounds of the formula 2 in which R is not hydrogen, and reactions starting from acrylic acid (Rs = hydrogen) and amines of the formula This is a reaction between the two raw materials in (1) and the unsaturated amine (2), especially allylamine and diallylamine.

These reactions have proven particularly favorable. This is because the target products of the formula I can only be prepared with difficulty and with insufficient purity or in low yields or generally at a disadvantage in terms of cost using alternative processes. It is.

Of further particular importance is the reaction of the latter with branched alkylamines, such as isopropylamine. The reaction of the components of formulas (1) and (2) is preferably carried out in a ratio of 1 mole of acid to 1 to 1.2 moles of amine.

In order to avoid polymerization losses, the reaction and the post-treatment of the reaction products should be carried out using polymerization inhibitors, such as phenolthiazine, hydroquinone, aromatic diamines, e.g. ttfN, N'-
Preference is given to working in the presence of diphenyl-p-phenylenediamine, iron compounds such as iron acetylacetonate (■), copper compounds such as copper oleate and others (see DE 2809102).

In the reaction proceeding under standard pressure according to the present invention, the reaction can be carried out in two reaction steps each having a different temperature level. In that case, generally 75-140°C, preferably 80-140°C
In the first step, which proceeds at 130 DEG C., the addition of a portion of the amine to the α,β-unsaturated acid of 2) is envisaged. It is then important that the reaction takes place in the first step in a homogeneous phase; no lumpy crystalline gruel should form.

Reaction line solvents, such as quidyrole, mesitylene.

It may be carried out in the presence of isobutylpenzole, di-isoamyl ether, dichlorpentole, tecarin, cresol, x-7'rom-4-chloro-penzole, nitrope/so/l/, resorcin-diethyl ether,
Preferably, it can be carried out without using a solvent. In principle (7) in the first reaction the amine is added to the acid, preferably in the presence of a stabilizer; the time of course depends on the size of the reaction. Approximate time and temperature of the second reaction step in the transition phase,
This means that the 0 reaction involves heating to about 165°C and preferably introducing a weak gas stream, for example a nitrogen stream, in order to remove the water that forms during condensation. Continue at process temperature.

At that time, for example, for several hours or more, for example, for three hours or more, 160-1
It can be left in the temperature IL range of 80°C, especially at about 165°C. In the second reaction step, the water formed is preferably removed by distillation.

Finally, heating can be carried out at even higher temperatures, for example at about 230° C., in order to bring about the reaction.

Alternatively, the amine can be heated gradually after polymerization, i.e. within a few hours (for example 3 hours), from about 165 DEG C. to the upper working temperature, ie in the range of 210 DEG to 230 DEG C.

Of course, too long a treatment at temperatures above 210° C. must be permeable.

To begin the work-up, it is advisable to combine any acid still present, for example by adding a suitable base, such as calcium oxide, calcium hydroxide, potassium hydroxide or the like.

Isolation of the desired amide of formula I is preferably carried out by fractional distillation, especially vacuum distillation. Work-up by flash vacuum distillation or work-up by thin-layer evaporator has also proven advantageous.

Generally, the low-boiling component is the desired amide and the high-boiling component is a microadduct to an optionally present unsaturated acid or unsaturated amide F'I of formula (2).

The invention will now be explained with reference to examples.

Example l 4 moles of methacrylic acid in a four-necked flask.

Phenothiazine 2f, hydroquinone 0.52 at 90°C
Then, 4 mol of n-hexylamine was added to 45 ml. It was heated to 165° C. under a weak stream of nitrogen (water scavenger) and the reaction mixture was kept at this temperature for 3 hr, during which time the reaction water formed was distilled off.

Subsequently, the temperature of the can was increased to 230° C. by simultaneously drawing out more water. %N by fractional distillation of the reaction mixture in vacuo
-hexyl methacrylic acid amide was obtained in a yield of 72X.

Examples 2 to 5 Analogously to Example 1, methacrylic acid was reacted with various amines in the presence of 50 ppm of hydroquinone and 500 ppm of iron (In) acetylacetonate or copper oleate as stabilizers. The yield of the N-substituted methacrylamide obtained is reported in the table.

Unreacted methacrylic acid can be easily combined as a salt (e.g. CaO or KOH) before work-up by distillation.
), the methacrylamide thus formed can be isolated very easily in high purity by distillation.

Example 6 To 9 moles of acrylic acid, a, iron cetyl acetonate (III
)24. and 2. each of hydroquinone monomethyl ether, phenothiazine and N,N'-diphenyl-p-phenylenediamine. At the same time, 9 mol of dimethylaminopropylamine was added at 110-130°C. After addition (
2hr), heated from 165℃ to 215℃ 1c3hr,
The resulting water was distilled off. The reaction mixture was fractionally distilled in vacuo.

Yield of N-(dimethylaminopropyl)-acrylic acid amide: 53% of theory.

Examples 7 to 9 2 moles of acrylic acid was added to iron acetylacetonate (T[I)
5. and phenothiazine 0.5. and heated to 80℃, 8
2 moles of aniline were added during 30 min at 0-120°C. Subsequently, the reaction mixture was heated from 160°C to 240°C for 4 hours, and the reaction water produced was distilled off. Acrylic anilide was isolated in 42% yield. The same reaction in the presence of 0.1 mole of lithium hydroxide gave a yield of 46% of theory, and the reaction in the presence of 1 mole of aluminum isopropylate gave a yield of 44% of theory. .

Example 10 4 moles of methacrylic acid, 5 moles of copper oleate. and Hydrokino 70
．． 5 was placed in mesitylene lt and heated at 75°C for 10 m
74 mol of allyl amine was added to 1N. The water of reaction formed at boiling temperature (can part: 160 DEG -165 DEG C.) was then removed azeotropically (in a mixture of methacrylic acid and some amine).

After a reaction time S hr, 40% of the theoretical amount of N-allyl methacrylamide was formed.

Example 11 Methacrylic acid was reacted with methylamine in the same manner as in Example 2, and by work-up by flash vacuum distillation, N
-Methyl methacrylic acid amide P was obtained in a yield of 65%.

Sub-agent Patent Attorney Toshio Yano

Claims (1)

[Claims] 1 Formula I: R,0 (Rt represents hydrogen or a methyl group, and the islands represent hydrogen or a saturated or unsaturated optionally polysubstituted alkyl group or an optionally polysubstituted alkyl group) b represents an aryl group b R8
represents a saturated or unsaturated optionally polysubstituted cyclic alkyl group or an optionally polysubstituted aryl group or an aralkyl group or an alkylenecardexamide group; and which together contain nitrogen to form a heterocyclic ring], the method for producing an acid amide of the formula ■: OH! = O-000H 1M k. The acid of the formula (R1 represents the above) is mixed with the amine of the formula (R1 and R3 are the above) and the acid of the formula (1) is mixed with the amine of the formula Condensation is carried out at about 150-250° C. with removal of water produced in the second step, with a stoichiometric amount of up to a slight excess of 2. In order to post-process the unreacted acid of the formula (■), it is converted into a salt with a base, and then the acid amide (R) of the formula (■) is reacted from the reaction patch. The method according to claim 1, which is produced by distillation. 3. The method according to claim 1, wherein at least one of the substituents aX and R3 of the amine of formula (1) is an unsaturated alkyl group. 4. The method according to any one of claims 1 to 3, wherein at least R1 of the amine (2) is an allyl group. 5. The method according to any one of claims 1 to 3, wherein R2 and R3 are allyl groups. 4. The method according to claim 1. 6. The method according to claim 1, wherein at least one of the substituents R- or 3 of the amine of formula (1) is a branched alkyl group. 7. The substituent The method according to claim 6, wherein at least one of R or R3 is an inpropyl group. R2 of the amine in 8.2) is hydrogen, and R3 has 1 to 6 carbon atoms. Claim 1 which is an alkyl group having
The method described in section. 9. The method according to claim 8, wherein FL2 of the amine of formula (1) is hydrogen and R3 is a methyl group. 2. The method according to claim 1, wherein the IO reaction and post-treatment are carried out in the presence of a polymerization inhibitor.