CN101260045A

CN101260045A - Mono-methylation method for amines compounds

Info

Publication number: CN101260045A
Application number: CNA2007100105342A
Authority: CN
Inventors: 王庆
Original assignee: Fushun Research Inst Of Chem Engineering & Design
Current assignee: Fushun Research Inst Of Chem Engineering & Design
Priority date: 2007-03-07
Filing date: 2007-03-07
Publication date: 2008-09-10

Abstract

The invention relates to the monomethylation of amine-group compounds, in particular to a monomethylation method for amine-group compounds. The method is characterized in that primary amine or secondary amine is used as materials, and methyl carbonate (DMC) is used as a methylation reagent. The method has the advantages that: due to high conversion rate of material amine-group compounds and high selectivity of monomethylation products, target monomethylation products are high in yield. The reaction liquid is kept basic all the time, and compared with other methods, the method can hardly cause the problem of the corrosion of equipments; the toxin of the reagent is light, the reaction condition is mild and the risk is small; the reaction can be completed in one step, the operational path is simple and easy to practice; products are easy to separate, and reaction byproducts of the main reaction are easy to process.

Description

A kind of method of aminated compounds monomethylation

Technical field

The present invention relates to the monomethylation of aminated compounds, specifically be to use methylcarbonate (DMC), on the nitrogen-atoms of this aminated compounds, connect a methyl the most at last as methylating reagent.

Background technology

Aminated compounds is as big class organic compound commonly used, its methylation reaction, and the methods that connect methyl with the methylating reagent reaction that adopt more, also useful formaldehyde, formic acid is by Eschweiler, and the method for W-Clarke reaction connects methyl.But previous methods the methylating reagent that often uses, be meant methyl halide (MeX; X=Cl, Br, I), methyl-sulfate (DMS) and phosphoric acid ester, though be used in nitrogen-atoms on the amine that methylates under the gentle reaction conditions.But there is serious hidden danger in these reagent aspect environment and the processing safety.Such as, methyl-sulfate is a deadly poisonous compound, operational hazards, aftertreatment difficulty.Again such as methyl halide, the halogen-containing by-product after methylating, separation difficulty, and have environmental safety hidden danger.And mostly above-mentioned all methods are to react under slant acidity even strong acidic condition, when equipment corrosion is serious, introduce unnecessary corrosion impurity easily.The more important thing is that above-mentioned reaction method is not easy to grasp for monomethylation and how methylated reaction preference, generally speaking, when monomethylation was had particular requirement, target monomethylation product yield was generally not high.

Methylcarbonate itself is the industrial chemicals of safe, nontoxic and non-environmental-pollution.Problem on direct byproduct behind the methylation reaction, methyl alcohol and carbonic acid gas do not have to handle yet.And in the present invention, be the alkaline condition reaction, reduced the production that brings by corrosion and the cost plus in the treating processes greatly.Most importantly, by control, can obtain the monomethylation target product of high conversion, highly selective to reaction conditions.

Summary of the invention

Methylcarbonate is as a kind of methylating reagent of safety and environmental protection, and along with the rapid raising of production capacity, its practical value is day by day improved.Purpose of the present invention is exactly to be to provide a kind of effective ways that utilize methylcarbonate to make the aminated compounds monomethylation as methylating reagent.

For achieving the above object, the technical solution used in the present invention is:

A kind of method of aminated compounds monomethylation is a raw material with primary amine or secondary amine, uses methylcarbonate (DMC) as methylating reagent; Carry out under the condition of reaction interpolation catalyzer, catalyzer can be: alkali-metal oxyhydroxide, alkali-metal carbonate, diethyl triamine, NaY type molecular sieve; The addition of catalyzer is preferably 0.5～25% for 0.5～40% of the liquid starting material gross weight except that catalyzer.

The present invention is aminated compounds, methylcarbonate, and catalyzer, optionally solvent drops in the reactor, and under normal pressure or pressurized conditions, the temperature reaction certain hour can obtain the monomethylation target product.

The chemical structural formula of described primary amine or secondary amine is R-NH ₂(I) or R ¹-NH-R ²(II);

Wherein, R, R ¹Or R ²For: the saturated or unsaturated alkyl of the straight or branched of C1～C20, contain the single of aromatic nucleus and replace, the group of polysubstituted or non-replacement, contain-OH ,-X (X represents haloid element), Deng the alkyl or the aromatic base of organo-functional group, generate chemical formula by (I) and can use R-NH-CH ₃Express, or generate and to use by (II)

The final product of expressing.

The mole dosage scope of described methylcarbonate is methylcarbonate: amine=0.5～10: 1, be preferably methylcarbonate: amine=1～3: 1; The temperature of reaction is 80～200 ℃, is preferably 90～150 ℃, and the reaction times is 1～24 hour, is preferably 3～15 hours.

Described reaction can be carried out under the condition of adding or not adding solvent; When adding solvent, solvent can be: methyl alcohol, N, dinethylformamide (DMF), triglyme etc.; 0～100% of the liquid starting material gross weight of the add-on scope of solvent outside desolventizing is preferably 10～40%;

Described reaction can be carried out under normal pressure or pressurized conditions; If carry out under pressurized conditions, reaction pressure is 0.1～5MPa, is preferably 0.1～1MPa.

Compare with other synthetic methods, the present invention has following characteristics:

1, raw material aminated compounds reaction conversion ratio height, monomethylation selectivity of product height.Thus, target monomethylation product yield height.

2, reaction solution remains alkalescence, than in additive method, almost can ignore the equipment corrosion problem.

3, reagent toxicity is little, and the reaction conditions gentleness is dangerous little.

4, one step of reaction finishes, and operational path is simple, and is easy to implement.

5, product is easy to separate, and the reaction by-product of main reaction is easy to handle.

Embodiment

In order to help understanding, some preferably synthetic examples have below been enumerated to content implementation process of the present invention.Can not be interpreted as that this example is the restriction to claim scope of the present invention.

Embodiment 1 is by the synthetic methylphenylamine of aniline

With aniline 93g and 90g DMC, the 37g Diethylenetriamine is put in the autoclave, behind the nitrogen replacement, is warmed up to 100 ℃, reacts 12 hours.Low-boiling point material is removed in distillation then, collects 194～196 ℃ of cuts, can obtain the 99g methylphenylamine, yield 92.5%.

Embodiment 2 is by the synthetic N-methyl formyl aniline of formanilide

With formanilide 121g and 108g DMC, 4.6g salt of wormwood is put in the reaction flask, is warmed up to 90 ℃, under the reflux conditions, reacts 6 hours.Low-boiling point material is removed in distillation then, and product is collected the cut of 130-133 ℃/2.1kPa through underpressure distillation, obtains 130g N-methyl formyl aniline, yield 96.3%.

Embodiment 3 is by the synthetic N-methyl stearylamine of stearylamine

With stearylamine 269g and 270g DMC, 162g methyl alcohol, the 3.5gNaY molecular sieve is put in the autoclave, is warmed up to 100 ℃, under the condition of boosting naturally, reacts 3 hours.Then product is filtered the back distillation, remove low-boiling point material, through overcooling, drying, obtain the 269g methylphenylamine, yield 95%.

Embodiment 4 is by the synthetic p-methylaminophenol of p-aminophenol

With p-aminophenol 109g and 135g DMC, 3.5g potassium hydroxide is put in the autoclave, is warmed up to 120 ℃, under the condition of boosting naturally, reacts 8 hours.Product obtains the 116g p-methylaminophenol, yield 94.3% through crystallization and recrystallization, drying then.

Claims

1. the method for an aminated compounds monomethylation, it is characterized in that: with primary amine or secondary amine is raw material, uses methylcarbonate as methylating reagent; Be reflected under the condition of adding catalyzer and carry out, catalyzer can be: alkali-metal oxyhydroxide, alkali-metal carbonate, diethyl triamine, NaY type molecular sieve; The addition of catalyzer is 0.5～40% of the liquid starting material gross weight except that catalyzer.

2. in accordance with the method for claim 1, it is characterized in that: the chemical structural formula of described primary amine or secondary amine is R-NH ₂(I) or R ¹-NH-R ²(II);

Wherein, R, R ¹Or R ²Be the saturated or unsaturated alkyl of the straight or branched of C1～C20, contain aromatic nucleus singly replace, the group of polysubstituted or non-replacement, contain-OH ,-X (X represents haloid element),

The alkyl of organo-functional group or aromatic base.Generate chemical formula by (I) and can use R-NH-CH ₃Express, or generate and to use by (II)

The final product of expressing.

3. in accordance with the method for claim 1, it is characterized in that: the mole dosage scope of described methylcarbonate is methylcarbonate: amine=0.5～10: 1; The temperature of reaction is 80～200 ℃, and the reaction times is 1～24 hour.

4. in accordance with the method for claim 1, it is characterized in that: the mole dosage scope of described methylcarbonate is methylcarbonate: amine=1～3: 1; The temperature of reaction is 90～150 ℃, and the reaction times is 3～15 hours.

5. it is characterized in that in accordance with the method for claim 1: described reaction can be carried out under the condition of adding or not adding solvent; When adding solvent, solvent can be: methyl alcohol, N, dinethylformamide, triglyme; 0～100% of the liquid starting material gross weight of the add-on scope of solvent outside desolventizing.

6. it is characterized in that in accordance with the method for claim 5: 10～40% of the liquid starting material gross weight of the add-on scope of described solvent outside desolventizing.

7. it is characterized in that in accordance with the method for claim 1: the addition of described catalyzer is 0.5～25% of the liquid starting material gross weight except that catalyzer.

8. it is characterized in that in accordance with the method for claim 1: described reaction can be carried out under normal pressure or pressurized conditions; If carry out under pressurized conditions, reaction pressure is 0.1～5MPa.

9. it is characterized in that in accordance with the method for claim 8: described reaction pressure is 01～1MPa.