JPH07247244A - Production of tertiary amines substituted with alkyl group at alpha-position - Google Patents

Abstract

PURPOSE:To obtain a tertiary amine substituted with an akyl group at alpha-position readily and in high yield by reacting an N-oxide of a tertiary amine with an alkane in the presence of a metal complex and a strong acid. CONSTITUTION:An N-oxide of a tertiary amine (e.g. trimethylamine N-oxide) is reacted with an alkane (e.g. cyclohexane) in the presence of a metal complex and/or a metal oxide (e.g. palladium acetate) and a strong acid (e.g. trifluoroacetic acid) in a solvent at 0 to 250 deg.C for 1-100 hours to give a tertiary amine substituted with an alkyl group at alpha-position. The used amount of the metal complex and/or the metal oxide can be reduced by adding a salt of a peroxy acid. The used amount of the N-oxide of a tertiary amine is 1X10<-5> to 1X10<2>mols based on the alkane, that of the metal complex is 1X10<-5> to 1X10<2>mols and that of the strong acid is >=1X10<-3>mol.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a tertiary amine having an α-position substituted with an alkyl group. The present invention relates to a method for producing a tertiary amine having an α-position substituted with an alkyl group, which comprises reacting an N oxide with an alkane.

[0002]

PRIOR ART, PROBLEMS TO BE SOLVED BY THE INVENTION As a method for producing a tertiary amine having an α-substituted alkyl group,
For example, a method in which formalin and formic acid are allowed to act on primary amines having an alkyl group substituted at the α-position (J. Am. Chem. Soc., 79
3145 (1957)), a method of reacting dimethylformamide on an aldehyde substituted with an alkyl group at the α-position (JP-A-49-1
No. 9071), a method of reacting an alkene with carbon monoxide and a secondary amine in the presence of a rhodium complex (J.Org.Chem.,
47 445 (1982)) and the like are known. However, nothing is known about the production of tertiary amines in which an alkyl group is substituted at the α-position from alkanes and N-oxides of tertiary amines.

The present inventors have found that alkanes and tertiary amines N
As a result of extensive studies on the reaction with oxides,
It has been found that, in the presence of a metal complex and / or a metal oxide and a strong acid, the alkane reacts with the N oxides of a tertiary amine to obtain a tertiary amine having an α-substituted alkyl group. At the same time, various studies were further added to complete the present invention.

[0004]

That is, the present invention provides a tertiary amine N in the presence of a metal complex and / or a metal oxide and a strong acid.
The present invention provides a method for producing a tertiary amine having an α-position substituted with an alkyl group, which comprises reacting an oxide with an alkane.

The present invention will be described in detail below. Examples of the metal complex include palladium-based, copper-based, nickel-based, silver-based, manganese-based, iron-based, and transition metal-based complexes such as a mixture of these metals. Specific compounds include, for example, carboxylic acid salts thereof, acetylacetonate salts, halides, ammonium salts, sulfate salts, nitrate salts and the like, and coordination compounds thereof.

As a specific compound of the palladium-based metal complex
Is, for example, Pd (NH₃)₂(N0₂)₂, Pd (NH₃)₂Br₂, Pd (NH₃)₂Cl
₂, PdCl₂(CH₃CN), PdCl₂(PhCN), PdCl₂(1,5-C₈H₁₂),
Pd (O ₂CCH₃)₂, Pd (O₂CC₃H₇)₂, Pd (CH₃COCHCOCH₃)₂ , Pd
Br₂, PdCl₂ , PdI₂, Pd (CN) ₂ , Pd (NO₃)₂・ XH₂O, Pd (O
COC₂H_Five)₂, PdSO_Four・ 2H₂O, Pd (O₂CCF₃)₂, [Pd (NH₃)_Four] (N
0₃)₂, [Pd (NH₃)_Four] [PdCl_Four], Pd (CH₃CN) (BF_Four)₂, PdCl
₂[(Ph)₃P]₂, Pd [(Ph)₃P] _FourEtc. are illustrated. Above all, Pd
(O₂CCH₃)₂, Pd (O₂CC₃H₇)₂, PdCl₂Etc. are preferably used
Be done.

Specific examples of the copper-based metal complex include cuprous chloride, cupric chloride, cuprous bromide, cupric bromide,
Cuprous iodide, cupric iodide, copper hydroxide, copper acetate, copper oxalate, copper formate, copper naphthenate, copper stearate, copper sulfate,
Examples include copper nitrate and copper carbonate. Of these, copper acetate, copper sulfate and the like are preferably used.

Examples of metal oxides include oxides of niobium, molybdenum, ruthenium, manganese, tungsten, iron, osmium, cobalt, palladium, zinc and the like. The amount of the metal complex and / or the metal oxide used is
It is usually about 1 × 10 ⁻⁵ to 1 × 10 ² mol times that of the alkane.

In the present invention, the amount of the metal complex and / or the metal oxide used can be reduced by coexisting a salt of peroxy acid. Examples of the salt of peroxy acid include salts of peroxysulfate and salts of peroxyhydrochloric acid. Examples of specific compounds include ammonium peroxydisulfate, sodium peroxydisulfate, potassium peroxydisulfate, potassium peroxydiphosphate, and the like. When a salt of peroxy acid is used, it is usually 1 × 10 ⁻⁵ to 1 × 10 ^{2 with} respect to the alkane.
It is used in molar times.

Examples of strong acids include halogen-substituted carboxylic acids and halogen-substituted alkyl sulfonic acids. Specific compounds include, for example, trifluoroacetic acid, difluoroacetic acid, trichloroacetic acid, monochloroacetic acid, dichloroacetic acid, pentafluoropropionic acid, trifluoromethanesulfonic acid, and the like. Of these, trifluoroacetic acid is preferably used. The strong acid is usually used in an amount of 1 × 10 ⁻³ mol or more with respect to the alkane, and can also be used as a solvent.

Examples of the alkane include linear alkanes such as methane, ethane, propane and butane, branched alkanes such as 2-methylpropane, 2-methylbutane, 2,2-dimethylpropane and 2,2-dimethylbutane, and cyclopentane. And cycloalkanes such as cyclohexane and cycloheptane.

Further, as N oxides of tertiary amines,
Examples thereof include trimethylamine N oxide, triethylamine N oxide, methyldiethylamine N oxide, dimethylethylamine N oxide, isopropyldimethylamine N oxide, dimethylaniline N oxide, and dimethylbenzylamine N oxide. The amount used is usually about 1 × 10 ⁻⁵ to 1 × 10 ² mol times the alkane.

The reaction is usually carried out in the presence of a solvent.
As such a solvent, for example, a halogen-substituted carboxylic acid such as trifluoroacetic acid, trichloroacetic acid, monochloroacetic acid or dichloroacetic acid is usually used. The amount used is usually approximately equal to 10 times the volume of the alkane.

When the N oxides of the tertiary amine are reacted with the alkane, the reaction temperature is usually about 0 to 250 ° C, preferably 100 to 200 ° C. Reaction time is normal
It is about 1 to 100 hours.

Thus, 3 substituted with an alkyl group at the α-position
Although a primary amine is produced, after the reaction, the metal complex and the strong acid are removed by a conventional method, and then the intended tertiary amine can be taken out by a means such as distillation.

[0016]

Industrial Applicability According to the method of the present invention, tertiary amines having an alkyl group substituted at the α-position can be easily and efficiently produced from alkanes and N-oxides of tertiary amines.

[0017]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. The yield was calculated by the following formula. Yield (%) = tertiary amines (mol) / alkyl metal complex (mol) formed at the α-position formed × 100

Example 1 Palladium acetate (Pd (OCOCH ₃ ) ₂ ) 5 mmol (1.25 g)), anhydrous trimethylamine N-oxide (1.88 g, 25 mmol) and cyclohexane (5
ml, 42.85 mmol) and trifluoroacetic acid (15 ml) were added, the mixture was heated to 150 ° C. with stirring, and the stirring was continued at the same temperature for 20 hours. After cooling to room temperature, the reaction solution was slowly poured into 2N sodium hydroxide aqueous solution, and after confirming that the solution was alkaline, it was extracted with dichloromethane, dried and concentrated to give 0.706 g of N, N-dimethyl-cyclohexylmethylamine. Got Almost no by-products were observed. The yield is
It was 101% (Pd metal standard).

Example 2 In Example 1, copper acetate (C
u (OCOCH _{3) 2)} except for using 0.25mmol was performed in conformity with Example 1. Almost no by-products were observed. N, N-
The yield of dimethyl-cyclohexylmethylamine is 3000
% (Based on Cu metal).

Example 3 The procedure of Example 1 was repeated, except that nickel acetate (Ni (OCOCH ₃ ) ₂ ) 5 mmol was used instead of palladium acetate. By-products such as cyclohexanol and cyclohexyl trifluoroacetate were observed. N, N-
The yield of dimethyl-cyclohexylmethylamine is 39%.
(Ni metal standard).

Example 4 In Example 1, silver acetate (A
g (OCOCH ₃ )) 5 mmol was used, and the procedure of Example 1 was repeated. By-products such as cyclohexanol and cyclohexyl trifluoroacetate were observed. The yield of N, N-dimethyl-cyclohexylmethylamine was 24% (based on Ag metal).

Example 5 The procedure of Example 1 was repeated, except that manganese acetate (Mn (OCOCH ₃ ) ₂ ) 5 mmol was used instead of palladium acetate in Example 1. A by-product of cyclohexanol was observed. The yield of N, N-dimethyl-cyclohexylmethylamine was 35% (based on Mg metal).

Example 6 In Example 1, instead of palladium acetate, iron chloride (F
eCl ₃₎ except for using 5mmol was performed in conformity with Example 1. Almost no by-products were observed. N, N-dimethyl-
The yield of cyclohexylmethylamine was 7.5% (based on Fe metal).

Example 7 The procedure of Example 1 was repeated, except that 0.5 mmol of palladium acetate was used. By-products such as cyclohexyl trifluoroacetate were observed. The yield of N, N-dimethyl-cyclohexylmethylamine was 149% (P
d Metal standard).

Example 8 Instead of using 5 mmol of palladium acetate in Example 1, 0.5 mmol of palladium acetate and osmium oxide (OsO ₄ ) were used.
Was carried out according to Example 1 except that 0.05 mmol was used. By-products such as cyclohexanol and cyclohexyl trifluoroacetate were observed. N, N- dimethyl-
The yield of cyclohexylmethylamine was 528% (based on Pd metal).

Example 9 The procedure of Example 1 was repeated, except that 0.05 mmol of osmium oxide (OsO ₄ ) was used instead of 5 mmol of palladium acetate. By-products such as cyclohexanol were found. The yield of N, N-dimethyl-cyclohexylmethylamine was 213% (based on Pd metal (Pd metal was 0.
It was assumed that 5 mmol was used)).

Example 10 In a 100 ml autoclave under an argon atmosphere, trifluoroacetic acid (5 ml) and anhydrous trimethylamine N-oxide (5 mm
ol), potassium peroxydisulfate (9 mmol), palladium acetate (0.05 mmol), and copper acetate (Cu (OCOCH ₃ ) ₂ 0.05 mmol), and then propane is injected at 10 atm from a valve with a pressure-holding valve, and the mixture is stirred. The mixture was heated to 150 ° C. and stirred at the same temperature for 20 hours. After cooling to room temperature, the reaction solution was slowly poured into a 2N sodium hydroxide aqueous solution, and after confirming that the solution was alkaline, extraction with dichloromethane, drying and concentration were carried out to obtain 0.0354 g of N, N-dimethyl- (2- Methylpropyl) amine was obtained. No by-product of n-butyldimethylamine was observed. The yield was 350% (based on Pd metal).

Example 11 Example 10 was repeated except that copper acetate was not used.
It was carried out in accordance with. No by-product of n-butyldimethylamine was observed. N, N-dimethyl- (2-methylpropyl)
The yield of amine was 116% (based on Pd metal).

Example 12 The procedure of Example 10 was repeated, except that palladium acetate was not used. No by-product of n-butyldimethylamine was observed. The yield of N, N-dimethyl- (2-methylpropyl) amine was 400% (based on Cu metal).

Claims (2)

[Claims] 1. An α-substituted alkyl group at the α-position characterized by reacting an N-oxide of a tertiary amine with an alkane in the presence of a metal complex and / or a metal oxide and a strong acid.
For producing primary amines. 2. The method according to claim 1, which is carried out in the presence of a salt of peroxy acid.