JPS6339581B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for producing Nt-alkylamides in high yield by reacting tertiary olefins, water and nitriles in the presence of an acid catalyst. and prussic acid).

It is well known that N-t-alkylamides (hereinafter abbreviated as TAA) are useful intermediates for producing mono-tertiary alkylamines, which are raw materials for organic rubber drugs and pharmaceuticals.

Conventionally, the method for producing TAA is generally carried out in a liquid phase at 20 to 60°C under conditions where the molar ratio of sulfuric acid/tertiary olefins is 1 to 2 and the molar ratio of nitriles/tertiary olefins is 0.5 to 1. A method of reacting to produce a sulfuric acid adduct of TAA and then neutralizing it with an alkali such as ammonium water or caustic soda to separate TAA [USP2773097 and J, Amer・Chem.soc., 70 4048
(1948)], the molar ratio of nitriles/tertiary olefins in the presence of an aqueous solution of 1 to 20 weight acids at 50 to 250 °C.
It is known that there is a method for obtaining TAA by reacting under conditions of 0.6 to 1 (USP 2457660).

However, in these known methods, for example, the method using 1 to 2 times the molar amount of sulfuric acid relative to the tertiary olefin requires an equivalent amount of alkali to separate TAA, and there are problems in the treatment of the neutralized wastewater. The method using an aqueous solution of 1 to 20% by weight of an acid as a catalyst is as described in the examples, TAA
The yield is less than 20 mol%, and it can be said that it is extremely unsatisfactory as an industrial production method.

The present inventors have completed the present invention as a result of intensive studies aimed at improving the problems of these known methods and establishing an excellent industrial production method for TAA.

That is, the present invention relates to a method for producing TAA by reacting tertiary olefins, water, and nitriles in the presence of an acid catalyst (excluding a method for producing N-t-butylformamide from isobutylene, water, and hydrocyanic acid). ), under conditions where the molar ratio of acid to tertiary olefins is 0.05 to 0.8, the molar ratio of water to tertiary olefins is 0.8 to 1.5, and the molar ratio of nitriles to tertiary olefins is 1.5 to 10. This is a method for producing Nt-alkylamides, which involves carrying out a reaction.

Examples of the tertiary olefins used in the method of the present invention include isobutylene, 2-phenylpropane, 2-benzylpropene, 2-methyl-1-butene, 2-methyl-2-butene, and 2-methyl-1-butene.
-Pentene, 2-methyl-2-pentene, 2-methyl-1-hexene, 2-methyl-2-hexene, 2-methyl-1-heptene, 2-methyl-2
-heptene, 2,4,4-trimethyl-1-pentene, 2,4,4-trimethyl-2-pentene and the like. Similarly, examples of nitriles include hydrocyanic acid, acetonitrile, acrylonitrile, and the like.

The reaction temperature is preferably in the range of 50 to 150℃, especially 60 to 100℃.
°C is preferred. At this time, if the reaction temperature is higher than this range, the produced TAA is likely to decompose into mono-t-alkylamines and even tertiary olefins, and the mono-t-alkylamines or ammonia produced at that time may cause acidification. is poisoned
The yield of TAA decreases. Furthermore, if the reaction temperature is lower than this range, the reaction rate will be low and economical efficiency will be poor, which is not preferable.

The reaction pressure is not particularly limited as long as it is equal to or higher than the autogenous pressure of the reaction raw materials and reaction products at the reaction temperatures.
When pressurizing above the autogenous pressure, a gas inert to the reaction, such as nitrogen, may be used.

As the acid catalyst used in the method of the present invention, inorganic acids such as sulfuric acid, aluminum chloride, hydrochloric acid, phosphoric acid, heteropolyacid, P-toluenesulfonic acid, etc., or organic sulfonic acids are used. Sulfuric acid is particularly preferred.

The amount of the acid catalyst used in the method of the present invention needs to be 0.05 to 0.8 times the mole of the tertiary olefin, and is particularly preferably 0.1 to 0.5 times the mole. If the amount of acid used is less than this range, the conversion rate of the reaction will be low, which is not preferred. Further, if the amount of acid used is larger than this range, there is no particular disadvantage in terms of the reaction, but the cost of neutralization treatment and wastewater treatment increases, which is economically disadvantageous, which is not preferable.

The nitrile used in the method of the present invention is suitably used in an amount of 1.5 to 10 times, preferably 2 to 4 times, the amount of the tertiary olefin. If the amount of nitriles used is too small than this range, side reactions such as polymerization of tertiary olefins will increase, resulting in poor TAA selectivity. Further, if the amount of nitriles used is too much than this range, there is no particular disadvantage in terms of the reaction, but it is not preferable because the economical efficiency becomes poor.

Since most of the excess nitriles used in the method of the present invention remain unreacted after the reaction, they can be recycled and used after recovery. When carrying out the method of the present invention using tertiary olefins as a raw material, theoretically, equimolar amounts of water are required relative to the tertiary olefins. When using tertiary olefins as raw materials in the method of the present invention, the amount of water used is relative to the tertiary olefins.
It is preferably 0.8 to 0.5 times the molar amount. If the amount of water used is less than 0.8 moles, the conversion rate of the reaction will be poor, which is not preferable. If the amount of water used exceeds 1.5 times the mole, the concentration of the catalyst acid becomes too low, which not only slows down the progress of the reaction, but also causes a hydrolysis reaction of the TAA produced, which is not preferable.

TAA obtained by the method of the present invention can be extracted by a conventional method such as liquid separation or extraction after neutralizing the acid that is the catalyst after the reaction.
In addition, when TAA is to be further subjected to a hydrolysis reaction to obtain a mono-tertiary alkylamine, TAA can be once isolated and then subjected to a hydrolysis reaction with an alkali such as caustic soda by a known method, It is also possible to carry out the hydrolysis reaction by adding an alkali to the reaction solution obtained by the method of the present invention without isolation. Excess nitriles remaining in the reaction system obtained by the method of the present invention are preferably distilled off by a conventional method such as degassing or distillation after the reaction, and then the above treatment is performed. .

The purpose of the reaction in the present invention can be achieved using either a batch method or a continuous method.

As described above, by carrying out the reaction according to the method of the present invention, Nt-alkylamides can be obtained in high yield, and the amount of alkali required for neutralization can be greatly reduced and waste water can be greatly reduced. Therefore, the method of the present invention is industrially very useful.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

Note that the percentages shown in the examples are mol% unless otherwise specified.

Example 1 In a 0.5 glass autoclave, 60 g (0.6 moles) of 98 wt% sulfuric acid, 54 g (3 moles) of water, 369 g (9 moles) of acetonitrile, and 168 g of isobutylene were added.
(3 mol) and reacted at 80° C. for 2 hours while stirring with a magnetic stirrer.

After neutralizing this reaction solution, the organic layer was subjected to gas chromatography analysis. 324 g (2.82 mol) of Nt-butylacetamide was obtained, and the yield was 94% based on isobutylene.

Example 2 The same procedure as in Example 1 was carried out except that 58.8 g (0.6 mol) of phosphoric acid was used instead of 60 g (0.6 mol) of 98 wt% sulfuric acid.

299 g (2.6 mol) of Nt-butylacetamide was obtained, and the yield was 87% based on isobutylene.

Example 3 Instead of 60 g (0.6 mol) of 98 wt% sulfuric acid, P-
The same procedure as in Example 1 was carried out except that 103.2 g (0.6 mol) of toluenesulfonic acid was used. 311 g (2.7 mol) of N-t-butylacetamide was obtained, and the yield was 90% based on isobutylene.

Example 4 Instead of 60 g (0.6 mol) of 98 wt% sulfuric acid, 12-
In addition to using 274 g (0.15 mol) of molybdophosphoric acid,
The same procedure as in Example 1 was carried out. 290 g (2.52 mol) of Nt-butylacetamide was obtained, and the yield was 84% based on isobutylene.

Example 5 20g of 98wt% sulfuric acid instead of 60g (0.6mol)
The same procedure as in Example 1 was carried out except that the amount was changed to (0.2 mol).

283 g (2.46 mol) of Nt-butylacetamide was obtained, and the yield was 82% based on isobutylene.

Comparative example 1 6g instead of 60g (0.6 mol) of 98wt% sulfuric acid
The same procedure as in Example 1 was conducted except that (0.06 mol) was used.

138 g (1.2 mol) of Nt-butylacetamide was obtained, and the yield was 40% based on isobutylene.

Example 6 210 g instead of 60 g (0.6 mol) of 98 wt% sulfuric acid
The same procedure as in Example 1 was conducted except that (2.1 mol) was used. N-t-butylacetamide is 327g (2.84
mol) was obtained, and the yield was 95% based on isobutylene.

Example 7 185 instead of 369 g (9 moles) of acetonitrile
The same procedure as in Example 1 was carried out except that 4.5 mol of 1.0 g (4.5 mol) was used.

224 g (1.95 mol) of N-t-butylacetamide was obtained, and the yield was 65% based on isobutylene.

Comparative Example 2 Instead of 369g (9 mol) of acetonitrile,
The same procedure as in Example 1 was carried out except that 123 g (3 mol) was used.

86 g (0.75 mol) of N-t-butylacetamide was obtained, and the yield was 25% based on isobutylene.

Example 8 615 instead of 369 g (9 moles) of acetonitrile
The same procedure as in Example 1 was carried out except that g (15 mol) was used.

N-t-butylacetamide 331g (2.88mol)
The yield was 96% based on isobutylene.

Example 9 984 instead of 369 g (9 mol) of acetonitrile
The same procedure as in Example 1 was carried out except that g (24 mol) was used.

334 g (2.9 mol) of Nt-butylacetamide was obtained, and the yield was 97% based on isobutylene.

Example 10 The same procedure as in Example 1 was carried out except that 72 g (4 moles) of water was used instead of 54 g (3 moles) of water.

N-t-butylacetamide 242g (2.1mol)
The yield was 70% based on isobutylene.

Comparative example 3 108g (6 moles) instead of 54g (3 moles) of water
The same procedure as in Example 1 was carried out except for the use.

104 g (0.9 mol) of Nt-butylacetamide was obtained, and the yield was 30% based on isobutylene.

Example 11 The reaction temperature was 60°C instead of 80°C.
The same procedure as in Example 1 was carried out.

N-t-butylacetamide 282g (2.45mol)
The yield was 82% based on isobutylene.

Example 12 The reaction temperature was 100°C instead of 80°C.
The same procedure as in Example 1 was carried out.

N-t-butylacetamide is 293g (2.55
The yield obtained was 85% based on isobutylene.

Example 13 The reaction temperature was 140°C instead of 80°C.
The same procedure as in Example 1 was carried out.

242 g (2.10 mol) of Nt-butylacetamide was obtained, and the yield was 70% based on isobutylene.

Comparative Example 4 The same procedure as in Example 1 was carried out except that the reaction temperature was 160°C instead of 80°C.

127 g (1.1 mol) of Nt-butylacetamide was obtained, and the yield was 37% based on isobutylene.

Example 14 Example 1 except that 336 g (3 moles) of 2,4,4-trimethyl-1-pentene and 243 g (9 moles) of hydrocyanic acid were used instead of 168 g (3 moles) of isobutylene and 369 g (9 moles) of acetonitrile. I did the same thing.

424 g (2.7 mol) of Nt-octylformamide was obtained, with a yield of 2,4,4-trimethyl-1
- It was 90% based on Penten standards.

Example 15 Instead of 369 g (9 mol) of acetonitrile,
In addition to using 477 g (9 mol) of acrylonitrile,
The same procedure as in Example 1 was carried out.

335 g (2.64 mol) of N-t-butyl acrylamide was obtained, and the yield was 88% based on isobutylene.

Example 16 336 g of 2,4,4-trimethyl-1-pentene
(3 moles) instead of 2-phenylpropene 354 g
The same procedure as in Example 14 was carried out except that (3 mol) was used.

340 g (2.1 mol) of N-1-methyl-1-phenylethylformamide was obtained, and the yield was 70% based on 2-phenylpropene.

Example 17 336 g of 2,4,4-trimethyl-1-pentene
(3 mol) instead of 2-methyl-2-butene 210
The same procedure as in Example 14 was carried out except that g (3 mol) was used.

316 g (2.75 mol) of N-(1,1-dimethylpropyl)-formamide was obtained, and 2-methyl-2
-Yield based on butene was 92%.

Example 18 336 g of 2,4,4-trimethyl-1-pentene
The same procedure as in Example 14 was carried out except that 294 g (3 moles) of 2-methyl-2-hexene was used instead of (3 moles).

386 g (2.70 mol) of N-(1,1-dimethylpentyl)-formamide was obtained, and 2-methyl-2
-The yield based on hexene was 90%.

Claims (1)

[Claims] 1. A method for producing N-t-alkylamides by reacting tertiary olefins, water and nitriles in the presence of an acid catalyst (provided that N-t-alkylamides are produced from isobutylene, water and hydrocyanic acid). (excluding methods for producing t-butylformamide), the molar ratio of acid to tertiary olefins is 0.05 to 0.8, the molar ratio of water to tertiary olefins is 0.8 to 1.5, and the molar ratio of nitriles to tertiary olefins is 0.05 to 0.8. ratio is 1.5
1. A method for producing N-t-alkylamides, characterized by carrying out the reaction under conditions of -10. 2. The method for producing Nt-alkylamides according to claim 1, wherein the reaction temperature is 50 to 150°C. 3 Claim 1 in which the acid is sulfuric acid or phosphoric acid
Method for producing Nt-alkylamides described in Section 1.