JPS5838242A - Manufacture of n-substituted methacrylamide 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 The present invention relates to various processes for producing industrially useful amides of acrylic acid and methacrylic acid.

Among the various possible starting compounds, acrylonitrile or methacrylonitrile, for example, are used - especially because they are relatively easy to obtain industrially.

In the simplest case, the unsubstituted amino acids can be obtained by partial hydrolysis of acrylonitrile or methacrylonitrile.

Another method is the so-called Rlter reaction, in which the reaction mechanism is that sufficiently stable carbonium ions react with nitrile to form N-
Produces a replacement statement. In practice, nitriles are reacted with alkenes or alcohols, often in the presence of sulfuric acid.

The Ritter reaction can also be applied to unsaturated nitriles [Plant (H, Plant) and Ritter (J,
J.

Rlter), J, 5m, Ohsm, 8oo
, Vol. 73, p. 4076 (1951)]. Second grade Cal/
In the case of alcohols and olefins that produce nium ions, the Ritter reaction is significantly slower to proceed than in the case of tertiary compounds. When reacting with primary alcohol,
Requires extremely harsh reaction conditions [Hamamoto and Yoshioka,
Japan Chemical Journal vol. 80, ilhsm, Abstr, 55
See Vol. 4349 (1961)].

From US Pat. No. 2,448,991 a method is known for preparing N-isosolpyl-methacrylamide P by mixing isopropyl alcohol with methacrylonitrile at elevated temperature in the presence of an acidic catalyst.

According to 7 Lance Pat. Post-process by extracting.

US Patent! No. 3,161,679 also discloses the reaction of unsaturated nitriles and olefins of 10 to 40 carbon atoms, in which case a 30 to 250% excess of sulfuric acid is added to the mixture of nitrile and olefin. Work-up is carried out by discharging on ice and subsequent neutralization.

Acrylamide and methacrylamide having an α-methyl substituted alkyl group having 5 to 10 carbon atoms or a branched alkyl group having about 6 to 8 carbon atoms on the nitrogen atom are described in Ritter according to Me-Rotsuba Patent Application Publication No. 0004362. Manufactured using a reaction.

N-3-aminoacrylamide r is Canadian Patent No. 9961
According to No. 28, they are obtained by applying the Ritter reaction to the corresponding aminoalkylenes.

These proposed methods are not completely satisfactory. Therefore, methods for synthesizing N-substituted amides of α,β-unsaturated carboxylic acids from unsaturated dicarboxylic acids using other special catalysts have been investigated.

In Japanese Patent Application Publication No. 50-135018, N-
Silicic acid, phosphoric acid, or tungsten molybdenum alcohol is recommended as a catalyst for producing 1it-converted acrylamide. The use of PdO12 as a catalyst in the preparation of N-tart-f tylacrylamide P from acryl di)lyl and tart-butanol or isobutylene is known from US Pat. No. 3,949,989.

However, the proposed implementation of the Ritter reaction is not completely satisfactory.

The present invention provides a process which is as simple as possible and which makes it possible to produce fN-substituted acrylamides or methacrylamides in good yields from as diverse a range of starting compounds as possible to produce acrylonitrile or methacrylonitrile and carmine ions. The challenge is to provide.

By the way, the nitrile of the general formula (■): 1 [in the formula, R1 represents hydrogen or a methyl group] is reacted with at least three carbon atoms which produce calcium ion (B, )e under the action of sulfuric acid. The nitrile of general formula (1) is added to equimolar to 1 molar excess of sulfuric acid together with a slightly insufficient amount or a slight excess of an alkyl compound having an atom (alkyl compound of general formula (U)). After reaction with a compound capable of forming a cation, reaction at 10-100"C, and dilution, the precipitated N-alkylamide of the general formula (R) is separated, preferably without neutralizing the sulfuric acid.
If post-treated by extraction with an inert extractant which is not miscible with dilute sulfuric acid and/or dilute sulfuric acid, the general formula (1): % formula % () [wherein R1 represents hydrogen or methyl group, R2 represents a substituted or unsubstituted cyclic or acyclic alkyl group having a total of at least 3 and up to 40 carbon atoms. It turned out that there was no way to manufacture it.

Generally, the nitrile of general formula (1) is reacted with a compound capable of forming a cation in a ratio of 1:0.9 to 1:1.1 mol. It is advantageous for the concentration of water in the reaction nozzle to be kept as low as possible until after-treatment, for example in the range of catalytic amounts relative to the nitriles of the general formula (m) or the alkyl compounds of the general formula (1)! It turns out that there is something.

In the present invention, the above-mentioned alkyl compound capable of producing a calsonium ion under the action of sulfuric acid (that is, under the conditions of the Ritter reaction) is defined as the alkyl compound having the general formula (
1 person): [In the formula, R1, R4 and R3 are hydrogen or have 1 to 1 carbon atoms
21 substituted or unsubstituted alkyl groups or aryl groups, R, represents a substituted or unsubstituted alkyl group or substituted or unsubstituted aryl group having 1 to 21 carbon atoms, or a group R,, R4 , R, and R6 together form a ring, and the groups R,, R,, R, and -
Substituted or unsubstituted alkyl compounds with the general formula CMB>: R, -a -oH (厘B) ゝ, 6. [wherein R is an aryl group or Formula: 4, /, R4/ and R6 have the same definition as R3, R4 and -, R6 represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 21 carbon atoms or an aryl group, or The group "1, R4'" is an alcohol in which up to two out of each two of Il+ and R6 represent an aryl group.

[w1 Substituted or unsubstituted -1 alkyl group refers to a substituent that can withstand the conditions of the Ritter reaction without causing any disadvantageous secondary reactions, such as a phenyl group, an acid ano-P group, an alkyl group, or an arynaton group. Represents an optional alkyl group. The aryl group in the present invention is a phenyl group or
It represents a thyl group and may be substituted with inert substituents.

When carrying out the reaction with a starting compound of the general formula (1), an olefin of the general formula (■m) or an alcohol of the general formula When carzenium ions are produced, reaction conditions of 10 to 40°C are generally sufficient.When the reaction proceeds with the formation of secondary carzenium ions, higher temperatures, e.g. ~100° C. is applied. The reaction is generally carried out without applying pressure.

Generally, reaction with acrylonitrile [R in general formula (1)
1-hydrogen] is reacted with methacrylonitrile [general formula (
1) can be carried out at a reaction temperature 10 to 30°C lower than the R1-methyl group].

Particularly preferred is the reaction with an olefin or alcohol of general formula (1) having a low number of carbon atoms, for example, a reaction with an olefin having 3 to 5 carbon atoms WI.

Examples include reactions with propylene, isoprene, pentene-1% m-butene, and the like.

Furthermore, reactions with alcohols having 3 to 5 carbon atoms, such as tert-butanol, tsrt-amyl alcohol, p/zonol-2, butanol-2, etc., are important.

Furthermore, olefins having unsaturated bonds at the terminals, fA etf olefins from henten-1 to heneifusen-1, such as hexene-1, octene-11decene-
1. The reaction with tesiladecene-11 otatadecene-1 and the reaction with cyclic compounds such as cyclopentene, cyclohexene, nor/Ivnene, etc. are important.

Furthermore, the reaction of the invention allows relatively cyclic alcohols or olefins, such as isofrene conductors, such as bicycrene, 2-luneol, norsernene or tricyclic systems,
For example, from adamandole, the corresponding amides of general formula (1) can be prepared manually in a simple manner, and substituted compounds of general formula (m), such as phenyl-substituted compounds, such as styrene,
The corresponding amides of general formula (i) can be easily prepared by reaction with α-methylstyrene, benzyl alcohol, etc.

It is also possible to use higher α-olefin mixtures, for example so-called shop (5HOP) olefins.

Reacting with isozolonon9ol or tsrb-butanol to form N-isozo4pyl methalylamide or N-
terl, -dityl methacrylamide and the corresponding N-
Obtaining acrylamide is of particular industrial importance.

The method according to the invention is particularly suitable, especially under industrial conditions! It is advantageous in that it eliminates the costly neutralization step of sulfuric acid. Particularly in the case of products of general formula (r) with higher alkyl substituents (0 number > 4), the products often separate out as a second phase, crystals or oils.

After separating the formed second phase, it can be extracted with a suitable, mainly inert extractant that is immiscible with aqueous sulfuric acid! Wear.

Suitable extractants are, for example, optionally halogenated hydrocarbons such as toluene, methylene chloride or ethers such as diethyl ether.

It is particularly advantageous to carry out the reaction by adding both components of the general formula (1) and (1) together to sulfuric acid previously placed in a container, the sulfuric acid being already at approximately the reaction temperature. is advantageous. The concentrated sulfuric acid used according to the invention is generally 95 to 100 sulfuric acid, preferably 96 to 98 sulfuric acid.

The reaction time in the process according to the invention is generally 0.5 to 4 hours. The process according to the invention is therefore advantageous in contrast to the current state of the art processes which require significantly longer reaction times. Furthermore, the addition method of the present invention [the components of general formulas (i) and (m) are added as a mixture to sulfuric acid at the reaction temperature] is suitable from the viewpoint of industrial implementation (continuous method or discontinuous method, process control). It turns out that there is a significant advantage in 1, but the state of the art methods of attack are not satisfactory from this point of view.

In general, the after-treatment is carried out in an amount of 10 to 40 mol of water per mol of the nitrile of the general formula (i) used! This is done by diluting the reaction mixture with sulfuric acid of approx.
This corresponds to diluting to a content rate of 0 to 50≦. Another advantage of the process of the invention is that the crude product can generally be isolated by filtration, phase separation and/or extraction without neutralization. Another advantage of the present invention is that the sulfuric acid produced can be regenerated, for example, by industrially common methods.

A neutralization step can be added in some cases to increase the yield and/or purity of the product. In such cases, it is advantageous to carry out the neutralization step after isolation of the crude product (unsaturated summer-furkylamide of general formula (4)). It is advantageous to carry out the neutralization with ammonia in gaseous or aqueous form.

The process of the invention, unlike comparable processes of the state of the art, is suitable for implementation on an industrial scale. It is particularly important in this case that the process according to the invention is suitable for continuous operation. The relatively high concentrations of the reaction components and reaction medium and the short residence times also make it possible to apply relatively small equipment in industrial practice. Mild reaction conditions (no pressure,
(up to 100 DEG C.), it is possible to use reaction vessels made of readily available materials such as glass, enamel coating, V4-MU steel, etc.

Next, the present invention will be described in detail based on Examples, but the present invention is not limited thereto.

Example 1-12 Charge 96% sulfuric acid to a reaction vessel and bring to reaction temperature. With stirring and cooling, 1 drop of a mixture of methacrylonitrile and an olefin or alcohol is added within 45 to 90 minutes at reaction temperature 1, followed by further stirring at reaction temperature 1. Methacrylonitrile was previously stabilized with 50 ppm hydroquinone-monomethyl ether and 15 ppm 4-methyl-2,6-di-t@RuzothiA/phenol.

The reaction mixture was placed in ice water (H per mole of nitrile used,
(minimum 10-15 mol), stirred for 30 minutes and the crude product recovered by filtration, phase separation or extraction. If necessary, it can be further purified by fractional vacuum distillation or recrystallization.
F) tart-butano-# 150 mol (11,
219) Methacryloethryl 125 mol (8,4
&? ) Di-tart-butyl-ρ-cresol 19 Apparatus: 12
0j can, stirrer, cooler, peep I lath, overflow pipe, cooling brine Procedure: 96% H, 80425, 6j9 was charged into a 1201 can and the temperature was adjusted to 10°C with cooling brine. 1 g of di-t-butyl-ρ-cresol, methacrylate #8.4
'9 and tert-butanol-1,2J9 was stirred and cooled (cold brine) at 10-18°C.
was added dropwise within 21 hours at a reaction temperature of . Continuing, 1 more
The addition was carried out for 3 hours at 6-21'C, during which a white crystalline precipitate formed.

Add 297% ammonia solution while cooling the reaction notch.
kl town 1-8, and the temperature rose to a maximum of 26°C. The reaction mixture was stirred at room temperature overnight.

The next day, 201 liters of distilled water was added to the reaction mixture, and the product was suction filtered on a suction funnel and washed with 104 distilled water. The suction-filtered white crystals were dried overnight in an oven at 30°C.

Total yield is 15.3639, 87.0% of theory
! be.

Purity by GO: approx. 98.5% Molecular weight: 141.2 Melting point: 60°C Example 14. 6: 96% B, 804 250 mol (2
5,6 kg) methacrylnitrile 125 mol (8
,449) Isopo/e/-At 15
G% Le(9,02'9)Gtert,-Butyl-ρ -Cresol 1g Apparatus: 1
201 can, stirrer, cooler, steam heating device (low pressure steam) Practice: 96% III, So, 25.6 in 1207 can
jlf was charged, and the temperature was adjusted to 90°C using low pressure steam.

A mixture consisting of 1 g of G-t@rt-petitlou-cresol, 8.4 g of methacrylonitrile and 9.02 g of isopropanol is stirred and added dropwise at a temperature of 90 to 103° C. within 45 minutes with cooling (water). added. Continuing, 91 more
Stirred at ~106°C for 21 hours. Distilled water 341 was added at 30-50°C. 25 minutes of ammonia solution was brought to pH 5 with reaction/S latch cooling, and the temperature rose to a maximum of 56°C. The reaction mixture was stirred overnight at room temperature. The product crystallized out during this time. The reaction mixture was filtered the next day with suction using a suction funnel and washed with approx. 357 g of ice water. The suction-filtered pale yellow crystals were dried over a weekend at 30°C in a dry volume (
Crude product 8.5119). The mother liquor and filtrate were stirred with 10/ml of methylene chloride. Separate the organic phase and add Na25o
, filtered and concentrated on a rotary evaporator 1 (crude product 3.2J9). The total crude yield was 11.7J9, which was 73.5≦the theoretical amount.

Example 15 1M sulfuric acid was charged, the temperature was raised to 40°C, and the mixture was stirred.
0.5 mol of acrylonitrile, an olefin having 8 to 12 carbon atoms (5HELL) within 35 minutes while cooling
709 and di-tart-butyl-ρ-cresol 5
1v of the mixture was added. (At that time, the reaction temperature is up to 45
).

The reaction mixture was further stirred at 40°C for 3 hours, and then poured into ice water for 4 hours.
00IL1. After 15 minutes, the aqueous mixture was extracted twice with methylene chloride, the organic phases were combined and the methylene chloride was distilled off. The desired product was obtained in 99% crude yield.

Example 16 The same procedure as Example 15 was carried out except that the reaction temperature was 20 to 24°C, and the yield was 96% of the theoretical amount.

Examples 17-25 Preparation of N-decyl-acrylamide An isolyl mixture of decene-1 and acrylonitrile was placed at reaction temperature in a pre-contained sulfuric acid solution. (96%),
Stirred. The reaction mixture was added to ice water, the product was extracted with an extractant, and the extractant was distilled off to obtain the product.

Claims (1)

[Claims] 1. General formula (1): % formula % (1) [In the formula, R1 represents hydrogen or a methyl group, and R. substituted or unsubstituted cyclic or acyclic alkyl radicals having a total of at least 3 and up to 40 carbon atoms.
General formula (1): % Formula % () [In the formula, R1 represents hydrogen or a methyl group] Nitriles are combined to form carminiram ion (R2) ■ under the action of sulfuric acid, and a total of at least three a substituted or unsubstituted cyclic or acyclic alkyl compound having up to 40 carbon atoms (alkyl compound of general formula (I)) in equimolar to twice molar amounts at a predetermined temperature. Nonitrile of general formula (1) is reacted with sulfuric acid together with an alkyl compound of general formula (I) by adding it to concentrated sulfuric acid, and then further reaction at a reaction temperature of 10 to xoo'e, and diluting with water. N-substituted methacrylamide and A method for producing acrylamide P. 2. As a compound of the general formula (m) capable of producing car-nium ion (R2)Φ under the action of sulfuric acid, the compound of the general formula (mA
) : [In the formula, R1, R4 and R6 are hydrogen or have 1 to 1 carbon atoms
21 substituted or unsubstituted alkyl groups or aryl groups, R6 represents a substituted or unsubstituted alkyl group having 1 to 21 carbon atoms or a substituted or unsubstituted aryl group; R1 and I! , together form a ring, and the groups also include R4, R, and R6
2. The process according to claim 1, wherein at most two of the olefins represent monol groups. 3. Under the action of sulfuric acid, carzenium io> (R2)■ is produced as a compound of the general formula (it)
: R, -0-0■ (1B)ゝ,・ [In the formula, R7 is an aryl group or the formula: R' °\ , OR-(F) group 1 table f''・4 R,, R4 and R5 are R1, and R11: have the same definition, and represent hydrogen, a substituted or unsubstituted alkyl group or aryl group having 11 to 21 carbon atoms;
or a patent using an alcohol in which two of the groups R, , R4, R, and R6 together form an aliphatic ring, and at most two of the groups R3' to R6 and R2 represent an aryl group. The method according to claim 1. 4. Any one of claims 1 to 3, wherein the nitrile of general formula (m) and the alkyl compound of general formula (i) are present in a molar ratio of 1:0.9 to 1:1.1. The method described in Section 1. 5. The method according to any one of claims 1 to 4, wherein the reaction time is 5 minutes to 4.5 hours. 6. The method according to claim 2, wherein R4, R6 and - in the general formula (A) represent hydrogen, and R1 represents an alkyl group having 1 to 12 carbon atoms. 7. Isosili/ as the alkyl compound of general formula (1)
2. A process as claimed in claim 1, in which alcohol, tart-butanol, cyclohexanol, benzyl alcohol or isozotylene or cyclohexane is used. 8. The method according to claim 1, which is carried out continuously. 9. A method according to any one of claims 1 to 8, wherein the concentration of water in the reaction patch is maintained in the catalytic range until after-treatment.