JP5663964B2 - Method for producing N-vinylamide and apatite used therefor - Google Patents

Description

  The present invention relates to a method for producing N-vinylamide with high yield and high selectivity by dealcoholization of N- (α-alkoxyethyl) amide. N-vinylamide is used in cosmetics, coating agents, ink compositions, petroleum recovery agents, pharmaceutical intermediates and the like.

Regarding the method for producing N-vinylamide, 1) a method of reacting amide and acetylene, 2) a method of reacting vinyl ether and amide, 3) a method of reacting vinyl ester and amide, 4) secondary amine compound and oxirane compound Or a method of reacting alkylene carbonates, 5) a method of performing a thermal decomposition reaction of ethylidenebis (formamide), 6) a method of performing a dehydration reaction of N- (α-hydroxyethyl) -2-pyrrolidone, 7) N- ( A method of carrying out a dealcoholization reaction of (α-alkoxyethyl) amide is known.
As 1), Patent Documents 1 to 4 disclose methods for producing N-vinyl-2-pyrrolidone by reacting 2-pyrrolidone and acetylene in the presence of a strong base catalyst. Patent Documents 5 to 6 disclose a method for producing N-vinyl-ε-caprolactam by reacting ε-caprolactam and acetylene in the presence of a strong base catalyst. In this method, N-vinylamide can be obtained with high selectivity, but (1) there is always a risk of explosion because acetylene is used under pressure. (2) N-vinyl-2-pyrrolidone is converted from 2-pyrrolidone. In the case of production, if the conversion rate is increased, ethylidenebis (2-pyrrolidone) is by-produced and the selectivity is decreased. Therefore, the conversion rate must be suppressed to about 60 to 70%. (3) From ε-caprolactam to When producing vinyl-ε-caprolactam, ring-opening polymerization is likely to occur in the presence of a base compound, and the reaction is preferably carried out at a low temperature. In this case, a high acetylene partial pressure is required to improve the reaction yield. Therefore, there is a problem that it is further disadvantageous in terms of safety.
As 2), Non-Patent Document 1 discloses a method for producing N-vinylamide by reacting vinyl ether and amide in the presence of a palladium catalyst. In this method, N-vinylamide can be obtained in a good yield. However, since the raw material vinyl ether is relatively expensive and 5 mol% of an expensive palladium catalyst is used, Is hard to say.
As 3), Patent Document 7 discloses a method for producing N-vinylformamide by reacting a vinyl ester with formamide in the presence of a base compound. In this method, it cannot be said that the conversion rate of formamide and the selectivity of N-vinylformamide are sufficient. In addition, there is a problem that carboxylic acid derived from vinyl ester is by-produced.
As 4), in Patent Document 8, a secondary amine compound and an oxirane compound or alkylene carbonate are reacted in the presence of an oxide catalyst containing an alkali metal element and / or an alkaline earth metal element and silicon. Discloses a method for producing N-vinylamide, but satisfactory conversion and selectivity are not obtained.
As 5), Patent Documents 9 and 10 include porous materials selected from the group consisting of activated carbon, magnesium oxide, silicon phosphate, strontium pyrophosphate, neutral or basic calcium hydroxyapatite, CuCrO ₂ and La ₂ O _3. Has disclosed a method for producing N-vinylformamide by thermally decomposing ethylidenebis (formamide) in the presence of a neutral catalyst. However, when ethylidenebis (formamide) is thermally decomposed, the by-product formamide and the target compound N-vinylformamide have approximately the same boiling point, which makes it difficult to separate and recover formamide.
6), Patent Document 11 and Non-Patent Documents 2 to 3 describe N- (α-hydroxyethyl) in the presence of an oxide catalyst containing an alkali metal element and / or an alkaline earth metal element and silicon. ) A method for producing N-vinyl-2-pyrrolidone by gas phase intramolecular dehydration reaction of 2-pyrrolidone is disclosed. Patent Document 12 discloses a method for producing N-vinyl-2-pyrrolidone by subjecting N- (β-hydroxyethyl) -2-pyrrolidone to a gas-phase intramolecular dehydration reaction in the presence of a Group 4 element mixture. It is disclosed. However, in these methods, the yield of N-vinyl-2-pyrrolidone is about 90%, and there is still a problem in industrial mass production.
7), Patent Document 9 discloses a porous material selected from the group consisting of activated carbon, magnesium oxide, silicon phosphate, strontium pyrophosphate, neutral or basic calcium hydroxyapatite, CuCrO ₂ and La ₂ O ₃ . A method for producing N-vinylformamide by dealcoholizing N- (α-alkoxyethyl) formamide in the presence of a catalyst is disclosed. However, this method has not achieved results satisfying both the conversion rate of N- (α-alkoxyethyl) formamide and the selectivity of N-vinylformamide. Patent Document 13 discloses that N- (α-alkoxyethyl) -2-pyrrolidone is a gas phase molecule in the presence of an oxide catalyst containing an alkali metal element and / or an alkaline earth metal element and silicon. A method for producing N-vinyl-2-pyrrolidone by an internal dealcoholization reaction is disclosed. However, this method still has problems such as the conversion rate and yield may not reach 95% or more.

Japanese National Patent Publication No. 4-501252 Japanese Patent No. 3545062 International Publication No. 09/150075 pamphlet US Pat. No. 5,656,889 Japanese Patent No. 4026869 Japanese Laid-Open Patent Publication No. 11-60558 JP-A-8-59582 Japanese Laid-Open Patent Publication No. 9-227465 Japanese Patent Publication No. 6-60136 Japanese Patent Publication No. 7-49398 Japanese Patent No. 2939433 Japanese Patent No. 3030846 Japanese Patent No. 2986405

Org. Lett. 2004, 6, 1845. J. Mol. Catal. A: Chemical 2005, 239, 125. Bull. Chem. Soc. Jpn. 2008, 81, 449.

  The present invention provides a method for producing N-vinylamide that achieves extremely high conversion and selectivity in the production of N-vinylamide by dealcoholization reaction of N- (α-alkoxyalkyl) amide, and a catalyst used therefor With the goal.

  As a result of intensive research on catalysts for dealcoholizing N- (α-alkoxyethyl) amide, the present inventors have found that 1) phosphoric acid is used in the dealcoholization reaction of N- (α-alkoxyethyl) amide. Apatite, which is an ordered structure with hydrogen ions as acid sites and regularly arranged acid sites and base sites, is effective because of its high selectivity as a catalyst. 2) The surface of apatite is treated with a phosphoric acid compound. It has been found that the catalytic activity can be remarkably improved by increasing the acid strength of apatite, while the selectivity may decrease. As a result of further research, 3) it was found that when the apatite's Hammett acid strength is in the range of -3.0 to +4.0, it shows extremely high results in both catalytic activity and selectivity, and the present invention was completed. I came to let you.

  That is, in the present invention, N- (α-alkoxyalkyl) amide is subjected to a dealcoholization reaction in the presence of apatite (surface-modified apatite) obtained by surface-modifying apatite represented by the general formula (1) with a phosphoric acid compound. -It relates to a method for producing vinylamide and apatite (surface-modified apatite catalyst) used therein.

(Wherein M is at least one selected from the group consisting of Mg, Ca, Sr, Ba, Pb, Mn and Cd, and Z is at least one selected from the group consisting of P, As and Sb) X is at least one selected from the group consisting of OH, F, Cl, Br, I and At, and 0 ≦ y <1.)

  The present invention uses as a catalyst a novel surface-modified apatite having a Hammett acid strength of −3.0 to +4.0, which is obtained by surface-modifying apatite represented by the general formula (1) with a phosphoric acid compound. Since the production of N-vinylamide by the dealcoholization reaction of-(α-alkoxyalkyl) amide can be carried out with high yield and high selectivity, it greatly contributes to the field of producing N-vinylamide.

  The method for producing N-vinylamide of the present invention is carried out by dealcoholizing N- (α-alkoxyalkyl) amide in the presence of apatite whose surface is modified with a phosphate compound.

  In the production method of the present invention, apatite obtained by surface-modifying apatite represented by the general formula (1), preferably the following general formula (2) with a phosphoric acid compound is used as a catalyst.

(In the formula, M, Z, X and y are as defined above.)

  In the general formulas (1) and (2), the selected M is not particularly limited as long as it belongs to the above-mentioned group, but is preferably Ca. Z that is selected is not particularly limited as long as it belongs to the above-mentioned group, but is preferably P. The selected X is not particularly limited as long as it belongs to the above-mentioned group, but is preferably OH.

  The surface modification of apatite with a phosphoric acid compound is carried out simply by heating and stirring apatite in a solution in which a phosphoric acid compound is dissolved. The solvent for dissolving the phosphate compound is not particularly limited as long as it can dissolve the phosphate compound. Specifically, water, acetone, methanol, ethanol, dioxane, tetrahydrofuran, tetrahydropyran, acetic acid are used. Examples include methyl, ethyl acetate, propyl acetate, ethyl propionate, acetonitrile, propionitrile, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone and the like. Also good.

  The phosphoric acid compound used for the surface modification is not particularly limited, and specific examples include pyrophosphoric acid, phosphoric acid, polyphosphoric acid, and the like, preferably pyrophosphoric acid.

  Surface modification of apatite with a phosphoric acid compound is carried out by the reaction of the hydroxyl group of the hydrogen phosphate ion on the apatite surface and the phosphoric acid compound as shown in the following general formula (3). By this reaction, the surface phosphorus concentration of the apatite after the surface modification becomes larger than that of the raw material apatite, so the Ca / P ratio of the surface modified apatite becomes smaller than that before the modification. Therefore, the progress of surface modification of apatite can be estimated by measuring the Ca / P ratio of the apatite surface before and after the surface modification and examining the degree of decrease after the surface modification.

  The acidity of the surface-modified apatite is derived from the hydroxyl group of hydrogen phosphate ions on the apatite surface. Therefore, as the surface modification of the apatite with the phosphate compound proceeds, that is, the surface Ca / P ratio of the apatite decreases and the acid strength increases.

The acid strength of the surface-modified apatite can be determined by controlling the progress of the surface modification, that is, by defining the reaction conditions such as the reaction temperature, the concentration of the phosphate compound solution to be treated, and the contact time between the apatite and phosphate compound. Can be controlled. From the viewpoint of reaction yield and selectivity, the acid strength of the surface-modified apatite is such that the Hammett acid strength is −3.0 <H ₀ ≦ + 4.0, preferably +1.5 <H ₀ ≦ + 4.0, more preferably It is preferably in the range of +1.5 <H ₀ ≦ + 3.3.

  The acid strength of the surface-modified apatite can be arbitrarily controlled by the reaction temperature, the concentration of the phosphoric acid compound solution to be treated, the reaction time of the apatite and the phosphoric acid compound, and the like. For example, when the reaction temperature is 60 ° C. and the reaction time is 5 hours, the strength of the Hammett acid of the surface-modified apatite can be adjusted to a desired range by setting the concentration of the phosphate compound to 6.0 M to 12.0 M. it can. However, when the reaction is carried out at different reaction temperatures and reaction times, it is possible to adjust the desired Hammett acid strength with different phosphate compound concentrations, and the surface modification of apatite is not limited to the above reaction conditions.

  The surface-modified apatite is obtained as a white powder, and there is no change in the crystal structure or shape of the apatite due to the surface modification.

  When apatite is surface-modified with a phosphoric acid compound, the Ca / P ratio of the surface-modified apatite is smaller than that before the surface modification. The degree of decrease in this Ca / P ratio correlates with the strength of Hammett acid, and as the strength of Hammett acid increases, the Ca / P ratio of the surface-modified apatite becomes smaller than that before modification.

  The N- (α-alkoxyalkyl) amide used in the dealcoholization reaction is not particularly limited as long as it is a compound satisfying the following general formula (4).

(In the formula, R ¹ is one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 6 carbon atoms such as a methyl group and an ethyl group. R ² is a methyl group, an ethyl group, a propyl group, and a butyl group. R ³ and R ⁴ are each independently selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 8 carbon atoms such as a methyl group and an ethyl group. , R ³ and R ⁴ may be bonded to each other to form a 5- to 13-membered ring.)

  Specifically, N- (α-methoxyethyl) -2-pyrrolidone, N- (α-ethoxyethyl) -2-pyrrolidone, N- (α-normalpropoxyethyl) -2-pyrrolidone, N- (α- Isopropoxyethyl) -2-pyrrolidone, N- (α-normalbutoxyethyl) -2-pyrrolidone, N- (α-isobutoxyethyl) -2-pyrrolidone, N- (α-tertiarybutoxyethyl) -2- Pyrrolidone, N- (α-methoxyethyl) -ε-caprolactam, N- (α-ethoxyethyl) -ε-caprolactam, N- (α-normalpropoxyethyl) -ε-caprolactam, N- (α-isopropoxyethyl ) -Ε-caprolactam, N- (α-normal butoxyethyl) -ε-caprolactam, N- (α-isobutoxyethyl) -ε-caprolactam, N- (α-tertiarybutoxyethyl) -ε-caprolactam, N -(α-Methoxyethyl) formamide, N- (α-Ethoxyethyl) formamide , N- (α-normalpropoxyethyl) formamide, N- (α-isopropoxyethyl) formamide, N- (α-normalbutoxyethyl) formamide, N- (α-isobutoxyethyl) formamide, N- (α- Tertiary butoxyethyl) formamide, N- (α-methoxyethyl) acetamide, N- (α-ethoxyethyl) acetamide, N- (α-normalpropoxyethyl) acetamide, N- (α-isopropoxyethyl) acetamide, N -(α-normal butoxyethyl) acetamide, N- (α-isobutoxyethyl) acetamide, N- (α-tertiarybutoxyethyl) acetamide and the like.

  For example, the N- (α-alkoxyalkyl) amide may be prepared by reacting an acetal with an amide in the presence of a sulfuric acid catalyst (Chem. Ber. 1965, 99, 2127.) or in the presence of a phosphoric acid catalyst in the presence of an acetaldehyde and an alcohol or amide. Can be produced by a method (for example, JP-A-5-97799).

  The reaction according to the production method of the present invention should satisfy both the conversion rate of N- (α-alkoxyalkyl) amide and the selectivity of N-vinylamide regardless of whether the reaction is performed in a batch reactor or a fixed bed continuous reactor. A grade is obtained.

  When the production method of the present invention is carried out in a batch reactor, the catalyst is used in the range of 0.1 to 10 wt%, preferably 1 to 5 wt% with respect to N- (α-alkoxyalkyl) amide. If the amount is less than 0.1 wt%, the reaction rate decreases, and thus productivity decreases. Moreover, it cannot be said that it is economical if a catalyst is used exceeding 10 wt%.

  When the production method of the present invention is carried out in a batch reaction apparatus, it is preferable to continuously remove alcohol produced by the reaction by distillation because this reaction is an equilibrium reaction.

  When the production method of the present invention is carried out in a fixed bed continuous reaction apparatus, the surface-modified apatite powder is used after being molded. At this time, the molding method is not particularly limited, and methods such as rolling molding, extrusion molding, and compression molding using a tableting machine are possible. The reaction can be carried out at normal pressure, reduced pressure, or increased pressure. The shape of the fixed bed reactor may be either vertical or horizontal.

Although the reaction temperature concerning the manufacturing method of this invention changes also with other reaction conditions, it is 150-400 degreeC normally, Preferably the range of 180-300 degreeC is preferable. When the reaction temperature is lower than 150 ° C., the conversion rate of N- (α-alkoxyalkyl) amide is lowered, and when it is higher than 400 ° C., side reactions such as polymerization occur simultaneously, and the selectivity for N-vinylamide is lowered.
When the production method of the present invention is carried out by a batch reaction, a solvent-free method is preferred.

(Surface Ca / P ratio)
The surface atom concentration of the catalyst was estimated by ESCA measurement and calculated by taking the ratio of the surface atom concentration of Ca and P.

Hammett acid strength was measured according to the literature (Catalyst Course (separate volume) Catalyst Experiment Handbook, Catalysis Society of Japan, Kodansha Scientific, page 170).
The indicators used for measuring the strength of Hammett acid are shown below.

(Measurement of Hammett acid strength)
About 10 mL of benzene was added to a 25 mL Erlenmeyer flask, and a small amount of sample powder was quickly added thereto. Subsequently, about 0.1 mL of the indicator solution was added in order from the smallest pKa, and the acid strength was determined from the pKa of the indicator that first displayed an acidic color. For example, when there was no coloration with 4-benzeneazodiphenylamine and coloration with p-dimethylaminoazobenzene, the strength of Hammett acid was assumed to be +1.5 <H ₀ ≦ + 3.3.

  EXAMPLES Next, although an Example demonstrates this invention in detail, this invention is not limited to a following example.

[Example 1]
(Catalyst preparation)
Pyrophosphate (428 mg, 2.40 mmol) was dissolved in 200 mL of acetone to prepare a 12.0 M pyrophosphate-acetone solution. Hydroxyapatite (manufactured by Aldrich, 3.06 g) that had been dried under reduced pressure at 80 ° C. and a 12.0 M pyrophosphoric acid-acetone solution were added to a 300 mL eggplant flask and stirred at reflux for 5 hours.
After the refluxing, hydroxyapatite was filtered off and further washed with 300 mL of acetone. It dried under reduced pressure at 80 degreeC and obtained the surface modification apatite with a yield of 3.04g. The obtained surface-modified hydroxyapatite was measured for ESCA and Hammett acid strength. As a result, the Ca / P ratio of the surface-modified hydroxyapatite surface was 0.834, and the Hammett acid strength was +1.5 <H ₀ ≦ + 3.3. I found out that

[Example 2]
N- (α-ethoxyethyl) -2-pyrrolidone (8.50 g, 54.1 mmol) and the surface-modified hydroxyapatite catalyst (451 mg) prepared in Example 1 were added to a 30 mL eggplant flask. The mixture was heated and stirred at a temperature of 220 ° C., and ethanol produced by the reaction was continuously removed from the reaction system by distillation. When the reaction solution after 20 minutes of reaction was analyzed by ¹ H NMR, the conversion of N- (α-ethoxyethyl) -2-pyrrolidone was> 99%, and the yield and selectivity of N-vinyl-2-pyrrolidone were 99% and> 99% respectively.

[Example 3]
(Catalyst preparation)
Surface-modified hydroxyapatite was prepared in the same manner as in Example 1 except that the concentration of the pyrophosphate-acetone solution was changed to 6.00M. When the ESCA and Hammett acid strengths were measured, it was found that the Ca / P ratio of the surface-modified hydroxyapatite surface was 0.980, and the Hammett acid strength was +3.3 <H ₀ ≦ + 4.0.

[Example 4]
The reaction was carried out in the same manner as in Example 2 except that the catalyst was changed to the surface-modified hydroxyapatite prepared in Example 3. After 20 minutes of reaction, the conversion of N- (α-ethoxyethyl) -2-pyrrolidone was 97%, and the yield and selectivity of N-vinyl-2-pyrrolidone were 97% and> 99%, respectively.

[Example 5]
(Catalyst preparation)
Surface-modified hydroxyapatite was prepared in the same manner as in Example 1 except that the concentration of the pyrophosphate-acetone solution was changed to 18.0M. When the ESCA and Hammett acid strengths were measured, it was found that the Ca / P ratio of the surface-modified hydroxyapatite surface was 0.660, and the Hammett acid strength was -3.0 <H ₀ ≦ + 1.5.

[Example 6]
The reaction was performed in the same manner as in Example 1 except that the catalyst was changed to the surface-modified hydroxyapatite prepared in Example 5. After 20 minutes of reaction, the conversion of N- (α-ethoxyethyl) -2-pyrrolidone was> 99%, and the yield and selectivity of N-vinyl-2-pyrrolidone were 91% and 90%, respectively.

[Comparative Example 1]
Except that hydroxyapatite (made by Aldrich, surface Ca / P = 1.25, Hammett acid strength + _4.0 <H ₀ ≦ + 4.8) was used as the catalyst, which was not subjected to surface modification, in the same manner as in Example 1. Reaction was performed. After 60 minutes of reaction, the conversion of N- (α-ethoxyethyl) -2-pyrrolidone was 51%, and the yield and selectivity of N-vinyl-2-pyrrolidone were 51% and> 99%, respectively.

[Comparative Example 2]
According to Example 6 of Patent Document 11, a catalyst Li—P—O / SiO ₂ having a composition of P ₁ Li _1.25 Si _{5 at} an element ratio excluding oxygen was prepared. The reaction was carried out in the same manner as in Example 1 except that Li—P—O / SiO ₂ prepared here was used as a catalyst. After 20 minutes of the reaction, the conversion rate of N- (α-ethoxyethyl) -2-pyrrolidone was 95%, and the yield and selectivity of N-vinyl-2-pyrrolidone were 92% and 97%, respectively.

[Example 7]
The reaction was performed in the same manner as in Example 2 except that the raw material was changed to N- (α-ethoxyethyl) -ε-caprolactam. After 60 minutes of reaction, the conversion of N- (α-ethoxyethyl) -ε-caprolactam was 95%, and the yield and selectivity of N-vinyl-ε-caprolactam were 95% and> 99%, respectively.

[Example 8]
The reaction was conducted in the same manner as in Example 2 except that the reaction temperature was changed to 180 ° C. and the raw material was changed to N- (α-ethoxyethyl) formamide. After 90 minutes of the reaction, the conversion of N- (α-ethoxyethyl) formamide was 88%, and the yield and selectivity of N-vinylformamide were 66% and 75%, respectively.

[Comparative Example 3]
The reaction was performed in the same manner as in Example 7 except that the catalyst was changed to activated carbon (Darco Japan Norit Co., Ltd.). After 60 minutes of reaction, the conversion of N- (α-ethoxyethyl) formamide was 89%, and the yield and selectivity of N-vinylformamide were 1.2% and 1.4%, respectively.

[Example 10]
The surface-modified apatite prepared in Example 9 was pressure-molded under the conditions of 20 MPa for 2 to 3 minutes and sized to a particle size of 0.5 to 1.0 mm. After 2 mL of the surface apatite catalyst formed in a glass reaction tube (diameter 12 mm) was filled, it was heated to 220 ° C. with a mantle heater. A raw material gas diluted with argon until the partial pressure of N- (α-ethoxyethyl) -2-pyrrolidone is 76 mmHg is supplied at a space velocity of 200 h ⁻¹ of N- (α-ethoxyethyl) -2-pyrrolidone, The reaction was performed at normal pressure. The liquid aggregated from the outlet of the reaction tube 1 hour after the start of the supply was collected and analyzed by ¹ H-NMR and HPLC. The conversion of N- (α-ethoxyethyl) -2-pyrrolidone was> 99%, N The yield and selectivity of -vinyl-2-pyrrolidone were> 99% and> 99%, respectively.

[Example 11]
The reaction was conducted in the same manner as in Example 10 except that the source gas N- (α-ethoxyethyl) -2-pyrrolidone was changed to N- (α-ethoxyethyl) -ε-caprolactam. The aggregated product was collected from the reaction tube outlet 1 hour after the start of the feed, and analyzed by ¹ H-NMR and HPLC. As a result, the conversion of N- (α-ethoxyethyl) -ε-caprolactam was> 99%. The yield and selectivity of N-vinyl-ε-caprolactam were> 99% and> 99%, respectively.

[Example 12]
The reaction was conducted in the same manner as in Example 10 except that the source gas N- (α-ethoxyethyl) -2-pyrrolidone was changed to N- (α-ethoxyethyl) formamide. The aggregated product was collected from the outlet of the reaction tube 1 hour after the start of the supply, and analyzed by ¹ H-NMR and HPLC. As a result, the conversion of N- (α-ethoxyethyl) formamide was 93%, N-vinylformamide The yield and selectivity were 92% and 99%, respectively.

Claims (3)

The apatite represented by the following general formula (1) is surface-modified with pyrophosphoric acid, and N- (α-alkoxy is present in the presence of apatite whose Hammett acid strength (Ho) is adjusted to a range of −3.0 to +4.0. A process for producing N-vinylamide, which comprises subjecting an alkyl) amide to a dealcoholization reaction.

(Wherein M is at least one selected from the group consisting of Mg, Ca, Sr, Ba, Pb, Mn and Cd, and Z is at least one selected from the group consisting of P, As and Sb) X is at least one selected from the group consisting of OH, F, Cl, Br, I and At, and 0 ≦ y <1.) The method for producing N-vinylamide according to claim 1, wherein the apatite represented by the general formula (1) is a phosphate apatite represented by the following general formula (2).

(Wherein M is at least one selected from the group consisting of Mg, Ca, Sr, Ba, Pb, Mn and Cd, and X is selected from the group consisting of OH, F, Cl, Br, I and At) At least one selected from 0 ≦ y <1.) The method for producing N-vinylamide according to claim 1 or 2, wherein N- (α-alkoxyalkyl) amide is a compound represented by the following general formula (3).

(In the formula, R ¹ is one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 6 carbon atoms. R ² is selected from the group consisting of a methyl group, an ethyl group, a propyl group, and a butyl group. R ³ and R ⁴ are each independently one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 8 carbon atoms, and R ³ and R ⁴ are bonded to each other, and 5 to 13 A member ring may be formed.)