JPS5916862A - Preparation of n-t-butylformamide - Google Patents

Abstract

PURPOSE:In the reaction between isobutylene and water and/or t-butanol and prussic acid, to obtain the titled compound in high yield, by specifying molar ratios of an acid as a catalyst and prussic acid to isobutylene and/or t-butanol. CONSTITUTION:In the preparation of N-t-butylformamide by reacting isobutylene and water and/or t-butanol with prussic acid in the presence of an acid catalyst (e.g., sulfuric acid), the reaction is carried out under conditions where a molar ratio of the acid to isobutylene and/or t-butanol is 0.05-0.8 and a molar ratio of prussic acid to isobutylene and/or t-butanol is 1.5-10, at 50-120 deg.C, preferably 60-90 deg.C. When the amount of prussic acid used is smaller than the range, side reactions such as isobutylene polymerization, etc. increase. When the reaction temperature exceeds 120 deg.C, the prepared desired compound is decomposed, the acid catalyst is poisoned by the decomposition product, and the yield of the desired compound is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention produces Nt-butylformamide (hereinafter abbreviated as T13F) in high yield by reacting isobutylene and water or/and t-butanol with hydrocyanic acid in the presence of an acid catalyst. Relating to a method of manufacturing.

It is well known that TBF is a useful intermediate for producing t-butylamine, which is a raw material for organic rubber drugs, agricultural chemicals, etc.

Conventionally, the method for producing '1' B F has been carried out using a method in which the molar ratio of sulfuric acid/isobutylene (or (-butanol) is 1 to 2 and the molar ratio of hydrocyanic acid/isobutylene (the father is t-butanol) is 0.8 to 1. 11 by reacting at 20 to 60°C under the conditions of
A method of producing a sulfuric acid adduct of 'BF and then neutralizing it with an alkali such as aqueous ammonia or caustic soda to separate 'l' BF [08P 2,778,097 Ya J, Amer
, Chem, Soe, '10.4048 (194
8)], or a method of obtaining TEF by reacting at 50-250°C in the presence of a 1-20% by weight aqueous acid solution in a molar ratio of hydrocyanic acid/isobutylene of 1 at 50-250°C ( USr 2,457,660) etc. are known.

However, when these known methods were studied, it was found that, for example, the method using 1 to 2 times the molar amount of sulfuric acid to iso-7 tyrene or mono-7 tanol requires a large amount of alkali to separate TBF. There is a problem in the treatment of the neutralized wastewater, and a method using an aqueous solution of 1 to 20% by weight of an acid as a catalyst is described in the Examples of USP 2.457,660, 'l' J31! The yield of ' was less than 10 mol%, and it can be considered that the temperature is extremely unsatisfactory as an industrial production method.

Therefore, the object of the present invention is to overcome the problems of the prior art described above and to obtain TBF in a good yield.

The inventors of the present invention have successfully completed the invention as a result of intensive studies to achieve the object of the present invention.

That is, the present invention provides a method for producing Nt,-butylformamide by reacting isobutylene and water or/and t-butanol with η acid in the presence of an acid catalyst. N-t- characterized in that the reaction is carried out under conditions in which the molar ratio of the acid of the acid catalyst to is 0.05 to 0.8, and the molar ratio of hydrocyanic acid to isobutylene or/and butanol is 1.5 to 10. Method for producing butylformamide.

The present invention will be explained in more detail below.

The reaction temperature of the present invention is 50 to 1,20°C.

In particular, 60 to 90°C is preferable. If the reaction temperature exceeds 120°C, the generated TBF decomposes into t-butylamine and further into isobutylene, and the acid catalyst is poisoned by the generated t-butylamine or ammonia. The yield of TBF tends to decrease.The preferred 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 temperature. When pressurizing above the natural pressure, it is also possible to use a gas inert to the reaction, such as nitrogen.

As the acid catalyst used in the present invention, inorganic acids or organic sulfonic acids such as sulfuric acid, aluminum chloride, phosphoric acid, hydrochloric acid, heteropolyacid or p-toluenesulfonic acid are used, but among these, the reaction yield and economy are Sulfuric acid is particularly preferred.

It is necessary to use 0.05 to 0.8 times the mole, and O1 to
Particularly preferred is 0.5 times the mole. If the amount of acid used is less than this range, the conversion rate of isobutylene or t-butanol will be low; conversely, if it is more than this range, there will be no particular disadvantage to the reaction, but the cost of neutralization treatment and wastewater treatment will be high. This is not preferable because it takes too much time and the economy is poor.

It is necessary that the amount is present in moles, and 2 to 4 times the mole is particularly preferable. If the amount of hydrocyanic acid used is less than this range, side reactions such as isobutylene polymerization will increase, resulting in poor TBF selectivity. On the other hand, if the amount of hydrocyanic acid used is greater than this range, there is no particular disadvantage in terms of the reaction, but it is not preferred because it becomes uneconomical. Since most of the excess hydrocyanic acid used in the method of the present invention remains unreacted after the reaction,
After collection, they can be recycled. When carrying out the method of the present invention using isobutylene as a raw material, the equivalent mole of water to isobutylene is theoretically required. The amount of water used in the method of the present invention is not particularly limited, but it is preferable to use 0.8 to 1.5 times the mole of water relative to the isobutylene used, and the amount of water used is 0.8 times the amount of isobutylene used. When the amount is less than mol, the reaction selectivity is good, but the conversion rate of isobutylene becomes poor, which is not preferable. On the other hand, 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 TBF produced, which is preferable. When using t-butanol as a raw material, it is not necessary to add water, but t-butanol is used as a raw material.
There is no disadvantage in the presence of less than 0.5 times the mole of water relative to butanol.If more than 905 times the mole of water is added, the progress of the reaction will not only be slowed down, but also 'I' B
This is not preferable because a hydrolysis reaction of F occurs.

Under acidic conditions such as in the method of the present invention, monobutanol is in an equilibrium relationship with the raw material isobutylene.
Using isobutylene and water as raw materials is equivalent to using monobutanol, and it is of course possible to use a mixture of these as raw materials. '1'BF 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 as a catalyst after the reaction. In addition, when TBF is further subjected to a hydrolysis reaction to obtain t-butylamine, TBF can be isolated by -1 and then subjected to a hydrolysis reaction with an alkali such as caustic soda, or TBF can be isolated. Instead, it is also possible to carry out the hydrolysis reaction by adding an alkali such as caustic soda to the core solution obtained by the method of the present invention. After the reaction, the low-boiling substances such as hydrocyanic acid remaining in the reaction system obtained by the method of the present invention are preferably distilled off by a conventional method such as degassing, and then the above-mentioned treatment is performed (7).

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 4 times according to the method of the present invention, Nt-butylformamide can be obtained in high yield, and the amount of alkali IJ-i required for neutralization can be greatly reduced and the amount of waste water can be reduced. Since the width can be reduced, the method of the present invention is industrially very useful.

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

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

Example 1 11! 98% heavy leaf sulfuric acid 60% in a glass autoclave!
i' (0.6 mol), water 54! V- (8 moles), 24B of hydrocyanic acid! i' (9 mol) and isobutylene 168P (8
mol) and reacted at 80° C. for 2 hours with stirring. After distilling off the hydrocyanic acid remaining in this reaction solution, the reaction solution was neutralized with caustic soda, and after neutralization, the organic layer was separated by gas chromatography (
I got a loaf. TBF was obtained as 288y-(2.85 mol),
The yield was 95% based on isobutylene.

Example 2 The same procedure as in Example 1 was carried out except that monobutanol 2221 (3 moles) was used in place of water 549- (8 moles) and isobutylene 168P (3 moles). TBF is 29IP
(2.88 mol) was obtained with a yield of 96% based on butanol.

Example 3 Replacement of 98% sulfuric acid GOF-(0.6 mol) Lini 1
1-t-rux:/sujl/phonic acid 108.25
The procedure was carried out in the same manner as in Example 1 using 4 (0.6 mol), except that 27 fM (2.7 mol) of TBF was obtained, and the yield was 90% based on isobutylene. child.

Example 4 98% by weight sulfuric acid was added to 2
The same procedure as in Example 1 was carried out except that 0P (0.2 mol) was used. 'l'BF was obtained in an amount of 242 y-(2.4 mol), and the yield was 80% based on isobutylene.

Comparative Example 1 6f instead of 98 wt% sulfuric acid 60y-(0.6 mol)
The same procedure as in Example 1 was carried out except that i' (0.06 mol) was used. TBF was obtained as 118P (1.17 mol), and the yield was 89 qh based on isobutylene.

Example 5 98N amount % 210 instead of sulfuric acid 60P (0.6 mol)
The same procedure as in Example 1 was conducted except that P (2.1 mol) was used. 287F (284 mol) of TBF was obtained, and the yield was 95 gruel based on isobutylene.

Example 6 Instead of 24B5L (9 mol) of hydrocyanic acid, 122! i-(
The same procedure as in Example 1 was carried out except that 4.5 mol) was used.

TBF was obtained as 192P (1.9 mol), with a yield of 63% based on isobutylene.

Comparative Example 2 Hydrocyanic acid 24B! ? (9 moles) was replaced by 81 g (3 moles).

814 (0.8 mol) of i' B F were obtained, the yield was 27% based on isobutylene.

Example 7 W drunk/24B! 8152 (1 mol) instead of i' (9 mol)
The procedure was carried out in the same manner as in Example 1 except that 5 mol) was used.

'l'BF is 291! The yield of V(2,88-El) was 96% based on isobutylene.

Example 8 The same procedure as in Example 1 was carried out except that 5041 (24 moles) was used instead of 248 g (9 moles) of hydrocyanic acid.

TBF (298F<2.9 mol) was obtained, and the yield was 97% based on isobutylene.

Example 9 Water 54! 72. instead of i' (8 moles). P (4 moles)
The same procedure as in Example 1 was carried out except for the use.

TBF was obtained as 212y (2.1 mol), with a yield of 70% based on isobutylene.

Comparative Example 8 Instead of water 54P (8 mol), 108y- (6 mol)
The procedure was carried out in the same manner as in Example except that the following procedure was used.

TBF was obtained as 9]4 (0.9 mol), with a yield of 30% based on isobutylene.

Example 1O The same procedure as in Example 1 was carried out except that the reaction temperature was 60°C instead of 80°C.

242 M' (2.4 mol) of TBF was obtained, the yield was 80% based on isobutylene.

Example 11 The same procedure as in Example 1 was carried out except that the reaction temperature was 100°C instead of 80°C.

1''B F was obtained in an amount of 245* (2.43 mol), with a yield of 81% based on 1 sovnarene.

Comparative Example 4 The reaction temperature was 130°C instead of 80°C.
Row j (ivy) as in Example 1.

TBF was obtained in the amount of 106y-(1.05 mol), with a yield of 35% based on isobutylene.

Claims (3)

[Claims] (1) In the production 1/1 method, isobutylene and water or/and t-phthanol are reacted with hydrocyanic acid in the presence of a nitrogen catalyst. The molar ratio of acid to isobutylene is 0.05 to 0.08, and isobutylene is 1;1. /
and the molar ratio of ¥1' acid to phthanol is 1.5.
N-t-, which is customary to carry out the reaction under conditions of ~10
A method for producing butylformamide, (2) Reaction temperature is 50-120°C, preferably 60-90°C
゛0 is Ff N-Ice range The method described in paragraph 1 (3) The method according to claim 1, wherein the acid is sulfuric acid, phosphoric acid, or ll-1-luenesulfonic acid.