JPH09291069A - Production of n-vinyl compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously and safely obtain an N-vinyl compound in a high yield without producing any waste material derived from an auxiliary raw material by subjecting an N-(1-alkoxyalkyl) compound to a dealcoholic reaction in a gas phase and in the presence of a catalyst. SOLUTION: The objective N-vinyl compound expressed by formula II is obtained by subjecting an N-(1-alkoxyalkyl) compound of formula I R1 and R2 are each H or a 1-8C hydrocarbon; (m) and (n) are each 0 or 1; R3 is methyl or ethyl, etc.; R4 is H or a 1-6C hydrocarbon} to a dealcoholic reaction in a gas phase and in the presence of a solid oxide catalyst of the formula Pa Xb Yc Od X is an alkali (alkaline earth) metal; Y is Ti, Zr, Nb or B, etc.; when (a) is 1, (b) is 0.5-5 and (c) is 0-500; (d) is a value defined by the bonding state of the (a) to (c)} at 150-500 deg.C. The compound of the formula II is obtained by a direct one step reaction without using any solvent nor auxiliary raw material. The catalyst has characteristics that the catalytic activity is not lowered even in successively reacting for a long time and the activity is recovered when the air is blown through and coke is burned even after deteriorated by a coking, etc.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an N-vinyl compound by subjecting an N- (1-alkoxyalkyl) compound to a dealcohol reaction in a gas phase in the presence of a catalyst.

N-vinyl compounds can be produced as a variety of functional polymers by homopolymerization or copolymerization with other monomers. They are industrially useful substances used as complexing agents, adhesives, fiber modifiers, dyeing aids, resin additives, flocculants and the like.

[0003]

The following is known as a method for producing an N-vinyl compound by dealcoholizing an N- (1-alkoxyalkyl) compound.

In Japanese Patent Laid-Open No. 6-256306, N
-Alkylpyrrolidone as Group IIb, Group IIIb, IVb
A process for producing N-alkenylpyrrolidone on acidic heterogeneous catalysts other than Group III and Group VIb metal oxides is disclosed. However, this disclosure merely affirmatively excluded from the claims some of the catalytic elements described in other prior art, and there is no specific illustration that all the elements not excluded are effective. None, the range of claimed elements is unduly broad and unclear. As is well known, even if the catalyst contains the same element, this publication discloses that H ₃ PO ₄ and La (H ₂ PO ₄ ) ₃
Only two examples are specifically shown as catalysts. In addition, there is no example of using N- (1-alkoxyalkyl) compound in the reaction in the reaction examples. The catalyst of the present invention is a group Ia (alkali metal element) in this specification.
And the group IIb (alkaline earth metal element) phosphates, the catalyst is N- (1
It has not been shown at all that it is excellent in the production of N-vinyl compounds by dealcoholation reaction of -alkoxyalkyl) compounds.

In Japanese Patent Publication No. 7-49398, a carboxylic acid amide having a leaving group at the α-position is described as MgS or Ca.
Alternatively, a method for producing N-vinylamide by heating in the presence of a porous catalyst composed of Sr oxide or mixed oxide is disclosed.

[0006] Org. Chem. , Vol. Two
3,672-675,1958, a method of dealcoholizing N- (1-methoxyethyl) succinimide to give N-vinylsuccinimide is reported.

In US Pat. No. 4,322,271, an N-α-alkoxyethyl-N-alkyl-carboxylic acid amide is dealcoholized with or without a catalyst to carry out an N-vinyl-N-alkylcarboxylic acid reaction. A method of making an acid amide is disclosed. As a catalyst, Al, B
e, Zr and W weakly acidic oxides or Ca, Al,
The weakly acidic phosphates of Mo, B and W are described.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an N-
Using a (1-alkoxyalkyl) compound as a reaction raw material, N-stage in a gas phase directly without using any auxiliary raw material or solvent.
-To provide a method for producing an N-vinyl compound which can be converted to a vinyl compound at a high conversion rate and with extremely high selectivity, and a catalyst used therefor.

[0009]

The present inventors have developed N- (1
-Alkoxyalkyl) compounds are being studied intensively for a method and a catalyst capable of directly carrying out a one-step dealcoholization reaction in a gas phase, and a solid oxide containing phosphorus and an alkali metal element and / or an alkaline earth metal element is prepared. When used as a catalyst, it was discovered that an N- (1-alkoxyalkyl) compound can be converted to an N-vinyl compound stably with high conversion and high selectivity over a long time, and has completed the present invention.

That is, according to the present invention, when an N- (1-alkoxyalkyl) compound is subjected to an intramolecular dealcoholization reaction in a gas phase to be converted into an N-vinyl compound, phosphorus, an alkali metal element and / or an alkaline earth metal are used. N using a solid oxide containing a metal element as a catalyst
-A method for producing a vinyl compound.

In another invention of the present invention, an N- (1-alkoxyalkyl) compound is subjected to a dealcohol reaction in a gas phase to give N- (1-alkoxyalkyl) compound.
A dealcohol catalyst for producing a vinyl compound, wherein the catalyst is a solid oxide catalyst containing phosphorus and an alkali metal element and / or an alkaline earth metal element. It relates to a reaction catalyst.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The production method of the present invention is a gas phase intramolecular dealcoholization reaction of an N- (1-alkoxyalkyl) compound represented by the following formula (6) to an N-vinyl compound in the presence of the above catalyst. It is done in the gas phase.

[0014]

[Chemical 6]

(In the formula, m and n are each independently 0.
Or 1. R ₁ and R ₂ are each independently one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 8 carbon atoms. However, when m and n are 0 at the same time, neither R ₁ nor R ₂ is hydrogen. When R ₁ and R ₂ are not hydrogen, R ₁ and R ₂ may combine with each other to form a 5- to 7-membered ring with N. Further, in the ring, the N
In addition to, a hetero atom selected from N, S, and O may be contained, and an unsaturated bond may be contained. R
₃ is one selected from the group consisting of a methyl group, an ethyl group, a propyl group and a butyl group. R ₄ has 1 to 6 carbon atoms
Is a hydrocarbon group. The N- (1-alkoxyalkyl) compound as a reaction raw material used in the production method of the present invention is not particularly limited as long as it is an N- (1-alkoxyalkyl) compound having a vapor pressure which becomes a gas under the reaction conditions. , The following general formula (3):

[0016]

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(In the formula, R ₁ and R ₂ are each independently one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 8 carbon atoms. R ₁ and R ₂ are bonded to each other. A 5- to 7-membered ring may be formed together with N. Further, a hetero atom selected from N, S, and O other than N may be contained in the ring, and R ₃ is a methyl group. , An ethyl group, a propyl group, and a butyl group, and R ₄ is one type selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 6 carbon atoms.). N
-(1-alkoxyalkyl) amides; the following general formula (7):

[0018]

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(In the formula, R ₁ and R ₂ are each independently one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 8 carbon atoms. R ₁ and R ₂ are bonded to each other. A 5- to 7-membered ring may be formed together with N. Further, a hetero atom selected from N, S, and O other than N may be contained in the ring, and R ₃ is a methyl group. , An ethyl group, a propyl group, and a butyl group, and R ₄ is one type selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 6 carbon atoms.). N
-(1-alkoxyalkyl) imides; the following general formula (8):

[0020]

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(In the formula, each of R ₁ and R ₂ is independently selected from the group consisting of hydrocarbon groups having 1 to 8 carbon atoms. R ₁ and R ₂ are bonded to each other with N. 5
A 7-membered ring may be formed. Further, in the ring, a hetero atom selected from N, S, and O other than N may be contained, and an unsaturated bond may be contained. R ₃
Is one selected from the group consisting of a methyl group, an ethyl group, a propyl group and a butyl group. R ₄ is one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 6 carbon atoms. ) N- (1-alkoxyalkyl) amines represented by the formula;

These N- (1-alkoxyalkyl) s
The compound corresponds to each of the raw materials by the production method of the present invention and has the following general formula (4):

[0023]

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(Wherein R ₁ , R ₂ and R ₄ are the same as those in the above general formula (3)); N-vinyl amides; the following general formula (9):

[0025]

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(In the formula, R ₁ , R ₂ and R ₄ are the same as those in the above general formula (7)); N-vinylimides represented by the following general formula (10):

[0027]

[Chemical 12]

(Wherein R ₁ , R ₂ and R ₄ are the same as those in the general formula (8)); and N-vinylamines, etc., respectively.

Examples of the N- (1-alkoxyalkyl) compound include N- (1-methoxyethyl) formamide, N- (1-methoxyethyl) acetamide, N-
N- (1-alkoxyalkyl) amides such as (1-methoxyethyl) -N'-methyl-acetamide and N- (1-ethoxyethyl) -N'-methyl-acetamide; N- (1-methoxyethyl) -2-Pyrrolidone, N
-(1-Methoxyethyl) caprolactam and N-
N-, such as (1-methoxyethyl) -2-morpholinone
(1-alkoxyalkyl) lactams; N- (1-alkoxyalkyl) imides such as N- (1-methoxyethyl) succinimide and N- (1-ethoxyethyl) succinimide; and N- (1-methoxyethyl)
Examples include N- (1-alkoxyalkyl) amines such as pyrrole and N- (1-methoxyethyl) imidazole; however, the present invention is not limited thereto.

The catalyst used in the production method of the present invention is phosphorus,
It is a solid oxide containing an alkali metal element and / or an alkaline earth metal element. Preferably, the following general formula (5):

[0031]

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(Wherein P is phosphorus, X is one or more elements selected from the group consisting of alkali metal elements or alkaline earth metal elements, and Y is from the group consisting of Ti, Zr, Nb, B, Al and Si. One or more elements selected, O is oxygen, and the subscripts a, b and c represent atomic ratios of the respective elements, and when a = 1, range b = 0.5 to 5, c = It ranges from 0 to 500, d is a, b and c.
Is a value determined by the value of and the bonding state of various constituent elements. ) Is a solid oxide.

The method for preparing the catalyst is not particularly limited, and any conventionally known method can be applied. As phosphorus, which is one of the essential components of the catalyst, phosphorus pentachloride, phosphoric acid, phosphates, phosphates, and other organic phosphorus compounds are used as the raw material.

The other essential component, an alkali metal element and / or an alkaline earth metal element, is used as a raw material for oxides, hydroxides, halides, salts (carbonates, nitrates, carboxylates, phosphoric acid). Salts, sulfates, etc.) and metals are used.

As an example of the method for preparing the above-mentioned catalyst, phosphoric acid or phosphates and a source of alkali metal element and / or alkaline earth metal element are added to a suitable molding aid (water, alcohol, etc.), followed by drying, A method of making a catalyst through calcination. A method of impregnating or mixing an aqueous solution of phosphoric acid or phosphate and an alkali metal element and / or alkaline earth metal element source with an oxide of another component element, molding, drying and firing to obtain a catalyst. An aqueous solution of phosphoric acid or phosphate and an alkali metal element and / or alkaline earth metal element source is impregnated into a molded body (a spherical shape, a cylindrical shape, a ring shape, etc.) of an oxide of another component element, followed by drying and firing. A method of using as a catalyst. A method in which a phosphorus source and an alkali metal element and / or alkaline earth metal element source are dissolved or suspended in water together with other component element sources, heated and concentrated under stirring, dried, molded, and calcined to obtain a catalyst. Etc.

The calcination temperature of the catalyst depends on the kind of the catalyst raw material used, but can be set in a wide range of 300 to 1000 ° C, preferably in the range of 400 to 800 ° C.

The activity of the catalyst is hardly reduced even if it reacts continuously for a long time, but if it deteriorates due to coking or the like, the activity can be recovered by passing coke through air.

The reaction according to the production method of the present invention is carried out by using the raw material N-
The (1-alkoxyalkyl) compound is operated under a reaction temperature and a reaction pressure capable of maintaining a gas phase state. The reaction pressure is usually normal pressure or reduced pressure, but pressurization is also possible. The reaction temperature varies depending on other reaction conditions, but is usually 150.
The range of up to 500 ° C, preferably 180 to 450 ° C is suitable. When the reaction temperature is lower than 150 ° C, the raw material N- (1-
The conversion of the alkoxyalkyl) compound decreases,
If the temperature is higher than ° C, the selectivity of the target N-vinyl compound will decrease.

In the production method of the present invention, the raw material N- (1
The -alkoxyalkyl) compound is usually diluted with a substance inert to the target reaction such as nitrogen, helium, argon, hydrocarbon, and / or reduced pressure to reduce the partial pressure of the N- (1-alkoxyalkyl) compound to 5 to 5. It is supplied to the catalyst layer as 600 mmHg. The space velocity (GHSV) of the raw material N- (1-alkoxyalkyl) compound varies depending on other reaction conditions, but is usually in the range of ¹ to 1000 h ^-1 , preferably 10 to 500 h ^-1 .

In carrying out the present invention, the reactor may be either a fixed bed flow type or a fluidized bed type.

[0041]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.

The conversion, selectivity, and single-flow yield in the examples are defined as follows.

Conversion (mol%) = (consumed N- (1
-Alkoxyalkyl) moles of compound / supplied N-
(Mole number of (1-alkoxyalkyl) compound) × 100 Selectivity (mol%) = (mol number of N-vinyl compound produced / mol number of N- (1-alkoxyalkyl) compound consumed) × 100 Single-flow yield (mol%) = (mol number of N-vinyl compound produced / mol number of N- (1-alkoxyalkyl) compound supplied) × 100 Example 1 (Catalyst preparation) diammonium hydrogen phosphate 13 A solution of 0.2 g in 50 g of water was added to lithium hydroxide (monohydrate).
4.2 g was added to a solution obtained by dissolving 50 g in water, 30.0 g of silicon oxide was added thereto, and water was evaporated while heating and stirring to dry the contents. Then, in air 120 ° C
At 20 ° C. for 20 hours, crushed to 9-16 mesh, and fired in air at 600 ° C. for 2 hours to obtain an atomic ratio of P ₁ L excluding oxygen.
A catalyst having a composition of i ₁ Si ₅ was prepared.

(Reaction) 5 ml of this catalyst was added to an inner diameter of 10 mm.
After being filled in a stainless steel reaction tube of No. 2, it was immersed in a molten salt bath at 220 ° C., and N- (1-methoxyethyl) was placed in the reaction tube.
The 2-pyrrolidone, the raw material gas diluted with nitrogen until its partial pressure is 76 mmHg, was supplied at a space velocity of 200h ^-1 of N-(1-methoxyethyl) -2-pyrrolidone, carrying out the reaction at atmospheric pressure It was The reaction tube outlet gas 1 hour after the start of supply was collected in methanol and analyzed by gas chromatography. As a result, the conversion rate of N- (1-methoxyethyl) -2-pyrrolidone and the selectivity of N-vinyl-2-pyrrolidone were obtained. And single-flow yields are 92.4 mol% and 100, respectively.
It was mol% and 92.4 mol%.

Comparative Example 1 (Reaction) A reaction was carried out in the same manner as in Example 1 except that glass beads having a diameter of about 1 mm were filled instead of the catalyst and the reaction temperature was 250 ° C. N- (1-
The conversion of methoxyethyl) -2-pyrrolidone, the selectivity of N-vinyl-2-pyrrolidone and the single-flow yield were 11.5 mol%, 100 mol% and 11.5 mol%, respectively.

Example 2 (Catalyst preparation) A catalyst having a composition of P ₁ Na ₁ Si _{5 in} terms of atomic ratio excluding oxygen was obtained in the same manner as in Example 1 except that lithium hydroxide was changed to 4.0 g of sodium hydroxide. Was prepared.

(Reaction) The same reaction as in Example 1 was carried out using this catalyst. Conversion rate of N- (1-methoxyethyl) -2-pyrrolidone 1 hour after the start of feeding, N-vinyl-2
-Pyrrolidone selectivity and single-flow yield are respectively 9
The amounts were 1.5 mol%, 98.8 mol% and 90.4 mol%.

Example 3 (Catalyst preparation) A catalyst having a composition of P ₁ K ₁ Si ₅ in terms of atomic ratio excluding oxygen was obtained in the same manner as in Example 1 except that lithium hydroxide was changed to 5.6 g of potassium hydroxide. Was prepared.

(Reaction) The same reaction as in Example 1 was carried out using this catalyst. Conversion rate of N- (1-methoxyethyl) -2-pyrrolidone 1 hour after the start of feeding, N-vinyl-2
-Pyrrolidone selectivity and single-flow yield are respectively 9
It was 1.0 mol%, 98.9 mol%, and 90.0 mol%.

Example 4 (Catalyst preparation) Magnesium hydrogen phosphate (trihydrate) 1
50 g of water was added to 7.4 g and 30.0 g of silicon oxide, and they were kneaded in a mortar. Then 20 at 120 ℃ in air
After drying for 5 hours and crushing to 9-16 mesh, 500 in air
After firing for 2 hours at ℃, the atomic ratio excluding oxygen is P ₁ Mg ₁ Si
A catalyst having a composition of ₅ was prepared.

(Reaction) Using this catalyst, the reaction temperature was set to 2
The reaction was performed in the same manner as in Example 1 except that the temperature was changed to 00 ° C. 1 hour after the start of feeding, N- (1-methoxyethyl)-
The conversion of 2-pyrrolidone, the selectivity of N-vinyl-2-pyrrolidone, and the single-flow yield were 99.1 mol% and
They were 99.2 mol% and 98.3 mol%.

Example 5 (Catalyst preparation) In the same manner as in Example 4, except that the magnesium hydrogen phosphate was changed to 8.6 g of calcium hydrogen phosphate (dihydrate), P _{1 was used in the} atomic ratio excluding oxygen. Ca ₁ Si ₁₀
A catalyst having the following composition was prepared.

(Reaction) Using this catalyst, the reaction temperature was set to 2
The reaction was performed in the same manner as in Example 1 except that the temperature was changed to 00 ° C. 1 hour after the start of feeding, N- (1-methoxyethyl)-
The conversion of 2-pyrrolidone, the selectivity of N-vinyl-2-pyrrolidone, and the single-flow yield were 100 mol% and 1%, respectively.
They were 00 mol% and 100 mol%.

Example 6 (Catalyst preparation) 13.2 g of diammonium hydrogen phosphate was dissolved in 40 g of water, and lithium hydroxide (monohydrate) was added to the solution.
After adding 5.2 g to a solution prepared by dissolving 50 g in water, 30.0 g of silicon oxide was added, and water was evaporated while heating and stirring to dry the contents. Then 2 at 120 ° C in air
Dry for 0 hours, crush to 9-16 mesh, then in air 70
After firing at 0 ° C. for 2 hours, the atomic ratio excluding oxygen is P ₁ Li
A catalyst having a composition of _1.25 Si ₅ was prepared.

(Reaction) Using this catalyst, a reaction was carried out in the same manner as in Example 1 except that the reaction raw material was changed to N- (1-ethoxyethyl) -2-pyrrolidone. The conversion rate of N- (1-ethoxyethyl) -2-pyrrolidone, the selectivity of N-vinyl-2-pyrrolidone, and the single-flow yield 1 hour after the start of feeding were 93.0 mol% and 100 mol%, respectively. 9
It was 3.0 mol%.

Example 7 (Reaction) Using the catalyst of Example 6, the reaction raw material was converted into N- (1
-Ethoxyethyl) -N-methylacetamide was used, and the reaction was performed in the same manner as in Example 1 except that the reaction temperature was 200 ° C. The conversion rate of N- (1-ethoxyethyl) -N-methylacetamide, the selectivity of N-vinyl-N-methylacetamide, and the single-flow yield 1 hour after the start of feeding are 98.7 mol% and 100 mol, respectively. %, 98.7
Mole%.

Example 8 (Reaction) Using the catalyst of Example 6, the reaction raw material was converted into N- (1
-Isopropoxyethyl) acetamide was used, and the reaction was performed in the same manner as in Example 1 except that the reaction temperature was 200 ° C. The conversion rate of N- (1-isopropoxyethyl) acetamide, the selectivity of N- (1-isopropoxyethyl) acetamide, and the single-flow yield after 1 hour from the start of feeding were
They were 94.5 mol%, 100 mol% and 94.5 mol%, respectively.

Example 9 (Reaction) Using the catalyst of Example 6, the reaction raw material was converted into N- (1
-Ethoxyethyl) succinimide, 210 ℃
The reaction was carried out in the same manner as in Example 1 except that The conversion rate of N- (1-ethoxyethyl) succinimide, the selectivity of N- (1-ethoxyethyl) succinimide, and the single-flow yield one hour after the start of feeding were 93.6 mol% and 99.2 mol%, respectively. , 92.9 mol%.

[0059]

EFFECT OF THE INVENTION By using the production method of the present invention, an N-vinyl compound can be continuously produced directly from an N- (1-alkoxyalkyl) compound by a one-step reaction without using any solvent or auxiliary raw material. It is possible to easily and safely produce an N-vinyl compound in a good yield without the generation of a waste product.

By using the catalyst of the present invention, it is possible to continuously produce an N-vinyl compound directly from an N- (1-alkoxyalkyl) compound by a one-step reaction without using any solvent or auxiliary raw material. It is possible to easily and safely produce an N-vinyl compound in good yield without generation of a substance.

The catalyst of the present invention is excellent in that the catalytic activity is hardly reduced even if it reacts continuously for a long time, and even if it is deteriorated by coking, etc., the activity is recovered by burning air and burning coke. It has excellent characteristics.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07D 233/60 103 C07D 233/60 103 265/10 265/10 // C07B 61/00 300 C07B 61 / 00 300

Claims (5)

[Claims] 1. An N- (1-alkoxyalkyl) compound is subjected to dealcoholization reaction in the gas phase in the presence of a solid oxide catalyst containing phosphorus and an alkali metal element and / or an alkaline earth metal element. A method for producing an N-vinyl compound, which comprises converting to an N-vinyl compound. 2. The N- (1-alkoxyalkyl) compound has the following general formula (1): (In the formula, m and n are each independently 0 or 1. R ₁ and R ₂ are each independently one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 8 carbon atoms. However, when 0 m and n are simultaneously, R ₁ and R ₂ are not both hydrogen. also, when R ₁ and R ₂ is not hydrogen, with R ₁ and R ₂ are bonded to each other n 5 to 7 A member ring may be formed, and, in addition to the above-mentioned N in the ring,
It may contain a heteroatom selected from N, S, and O, and may contain an unsaturated bond. R ₃ is one selected from the group consisting of a methyl group, an ethyl group, a propyl group and a butyl group. R ₄ is hydrogen and has 1 to 6 carbon atoms
Is one selected from the group consisting of hydrocarbon groups of ), Wherein the N-vinyl compound is represented by the following general formula (2): The production method according to claim 1, which is a compound represented by the formula (wherein R ₁ , R ₂ , R ₄ , m and n are the same as those in the general formula (1)). 3. The N- (1-alkoxyalkyl) compound has the following general formula (3): (In the formula, R ₁ and R ₂ are each independently one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 8 carbon atoms. Further, R ₁ and R ₂ are bonded to each other to form 5 with N. ~
A 7-membered ring may be formed. Further, in the ring, a hetero atom selected from N, S, and O other than N may be included. R ₃ is one selected from the group consisting of a methyl group, an ethyl group, a propyl group and a butyl group. R
₄ is one selected from the group consisting of hydrogen and a hydrocarbon group having 1 to 6 carbon atoms. ) Are N- (1-alkoxyalkyl) amides represented by the following general formula (4): The method according to claim 1, wherein the N-vinyl amide is represented by the formula (wherein R ₁ , R ₂ and R ₄ are the same as those in the general formula (3)). 4. The catalyst has the following general formula (5): (In the formula, P is phosphorus, X is one or more elements selected from the group consisting of alkali metal elements or alkaline earth metal elements, and Y is one selected from the group consisting of Ti, Zr, Nb, B, Al and Si. The above element, O is oxygen, and the subscripts a, b and c represent atomic ratios of the respective elements, and when a = 1, range b = 0.5 to 5 and c = 0.
The range is up to 500, and d is a numerical value determined by the values of a, b and c and the bonding state of various constituent elements. The manufacturing method of any one of Claim 1 to 3 which is a solid oxide represented by these. 5. A catalyst for producing an N-vinyl compound by subjecting an N- (1-alkoxyalkyl) compound to a dealcohol reaction in a gas phase, wherein the catalyst comprises phosphorus, an alkali metal element and / or A catalyst for dealcoholization reaction, which is a solid oxide catalyst containing an alkaline earth metal element.