CN103936625A - Method for synthesizing hexamethylene-1, 6-diamino methyl formate - Google Patents

Abstract

The invention discloses a method for synthesizing methyl hexamethylene-1,6-dicarbamate, which comprises combining 1,6-hexamethylenediamine and dimethyl carbonate under the catalysis of a phenoxy compound under normal pressure Synthesis of methyl hexamethylene‐1,6‐dicarbamate. The method for synthesizing methyl hexamethylene-1,6-dicarbamate of the present invention has the advantages of mild reaction conditions, short reaction time and high HDU yield.

Description

A method for synthesizing hexamethylene-1,6-dicarbamate methyl ester

technical field

The invention belongs to the field of chemical synthesis and relates to a method for synthesizing methyl hexamethylene-1,6-dicarbamate, in particular to 1,6-hexamethylenediamine (HDA for short) and dimethyl carbonate (DMC for short). ) under the catalysis of phenoxy compounds, the method of generating hexamethylene-1,6-dicarbamate methyl ester (abbreviated as HDU). the

Background technique

HDU is an intermediate for the synthesis of hexamethylene-1,6-diisocyanate (referred to as HDI), because the polyurethane material synthesized by HDI has many advantages such as non-yellowing and wear resistance, and its performance is significantly better than that of polyurethane materials containing aromatic rings. , so much favored by the industry. the

At present, the process of industrialized production of HDI is mainly the traditional phosgene method. The disadvantages of this process are: the raw material phosgene is highly toxic and has great harm to the environment; Because the by-product hydrochloric acid contains organic impurities, the market capacity is small, which seriously restricts the development of isocyanate production enterprises. Therefore, the technology of non-phosgene synthesis of HDI has been paid more and more attention. the

The non-phosgene synthetic HDI process includes two key steps: HDU synthesis and thermal cracking. The synthesis of HDU uses HDA and DMC as raw materials, and it is obtained by reaction under the action of a catalyst. The reaction equation is as follows: 

Patent CN1727330 discloses a synthetic method of HDU. The catalyst is lead-containing inorganic and organic salt compounds. The molar ratio of HDA to DMC is 1:2~1:11 and the reaction temperature is 90~180°C. , The yield of HDU can reach up to 98%, but the lead-containing catalyst will cause heavy metal pollution. Patent CN1005901116 discloses a method for synthesizing HDU by catalyzing HDA and DMC with chromium-nickel alloy, but the reaction temperature of this method is preferably 120-150°C, and it needs to be carried out under pressurized conditions, which requires high equipment. Patent CN101565389 reports a method for synthesizing HDU in a polar solvent from HDA and DMC catalyzed by metal oxides such as MoO ₃ , V ₂ O ₅ , Cr ₂ O ₃ , and the highest yield of HDU is 83%. However, this method needs to separate and circulate the polar solvent from the reaction mixture, and the process requires high energy consumption and poor economy. Patent CN102875419 reports a method for synthesizing HDU from HDA and DMC catalyzed by zinc acetate. The reaction time is as long as 4-9 hours, and the yield of HDU is up to 82%. Literature [Wang Huining et al., Industrial Catalysis, 2006, 14(2):52～54] HDA and DMC were used as raw materials to synthesize HDU through sodium methoxide. The molar ratio of HDA to DMC was 1:6, and the reaction time was 2h. Under the condition of temperature 65°C, the yield of HDU is only 58%.

The existing HDU synthesis technology has disadvantages such as high catalyst toxicity, easy pollution of the environment, harsh reaction conditions, and low product yield. The development of efficient catalysts and high HDU yields under mild reaction conditions is a non-phosgene synthesis of HDI. One of the keys to technological development. the

Contents of the invention

The object of the present invention is to provide a kind of HDU synthesis method that obtains higher yield under mild reaction conditions for the above-mentioned deficiency of prior art. the

The purpose of the present invention can be achieved through the following technical solutions:

A synthetic method for methyl hexamethylene-1,6-dicarbamate, using phenoxy compounds as catalysts, using 1,6-hexamethylenediamine and dimethyl carbonate as raw materials to react and synthesize hexamethylene ‐1,6‐Dicarbamate methyl ester. the

The phenoxy compound is preferably phenol or phenoxide, and the phenoxide is one of lithium phenate, sodium phenate, potassium phenate, magnesium phenate, calcium phenate, zinc phenate, and zirconium phenate. the

In the method, the molar ratio of HDA to DMC is preferably 1:2-1:10, more preferably 1:3-1:8. the

In the method, the mass ratio of the catalyst phenoxy compound to HDA is preferably 0.001-0.1:1, more preferably 0.01-0.05:1. the

In said method, the reaction temperature is preferably 30-90°C, more preferably 50-80°C. the

In said method, the reaction time is preferably 0.5-3 hours, more preferably 1-2 hours. the

Beneficial effects: compared with the prior art, the method of the present invention uses phenoxy compounds as catalysts, and has the advantages of mild reaction conditions, short reaction time and high HDU yield. the

Detailed ways

In the following examples, the reaction product is analyzed by high-performance liquid chromatography, and the analytical equipment and conditions are: Agilent1100Series type high-performance liquid chromatography, CZORBAX SB-C18 post, ultraviolet detector, mobile phase is acetonitrile: water=55:45 (volume ratio ), the column temperature is room temperature, the detection wavelength is 200nm, the flow rate is 0.8mL·min ^‐1 , and the injection volume is 20μL.

Example 1

HDA116g, DMC630g, catalyst phenol5.8g were added into the normal pressure reactor, the reaction temperature was 85°C and the reaction was stirred for 2h. The reaction product was analyzed by high performance liquid chromatography, and the yield of HDU was 98.5%. the

Example 2

116g of HDA, 720g of DMC, and 11.6g of catalyst calcium phenate were added into the reactor at normal pressure, and the reaction temperature was 90°C and the reaction was stirred for 1h. The reaction product was analyzed by high performance liquid chromatography, and the yield of HDU was 98.7%. the

Example 3

116g of HDA, 270g of DMC, and 11.6g of catalyst potassium phenate were added into the reactor at normal pressure, and the reaction temperature was 80°C and the reaction was stirred for 2.5h. The reaction product was analyzed by high-performance liquid chromatography, and the yield of HDU was 99.2%. the

Example 4

116g HDA, 180g DMC and 1.16g magnesium phenate catalyst were added into the reactor at normal pressure, and the reaction temperature was 90°C and the reaction was stirred for 3 hours. The reaction product was analyzed by high performance liquid chromatography, and the yield of HDU was 98.3%. the

Example 5

HDA116g, DMC630g, catalyst sodium phenate 3.48g were added into the normal pressure reactor, the reaction temperature was 90°C and the reaction was stirred for 3h. The reaction product was analyzed by high performance liquid chromatography, and the yield of HDU was 99.7%. the

Example 6

HDA116g, DMC450g, catalyst phenol0.116g were added into the normal pressure reactor, the reaction temperature was 90°C and the reaction was stirred for 3h. The reaction product was analyzed by high performance liquid chromatography, and the yield of HDU was 98.1%. the

Example 7

116g HDA, 360g DMC and 3.48g catalyst zinc phenate were added into the reactor at normal pressure, and the reaction temperature was 50°C and the reaction was stirred for 3h. The reaction product was analyzed by high performance liquid chromatography, and the yield of HDU was 98.0%. the

Example 8

116g of HDA, 720g of DMC and 11.6g of catalyst sodium phenate were added into the reactor at normal pressure, and the reaction temperature was 30°C and the reaction was stirred for 0.5h. The reaction product was analyzed by high performance liquid chromatography, and the yield of HDU was 99.5%. the

Example 9

Add HDA116g, DMC900g, catalyst magnesium phenate 3.48g in the atmospheric pressure reactor, reaction temperature is 90 ℃ Under stirring reaction 1.5h, reaction product is analyzed by high performance liquid chromatography, and the productive rate of HDU is 99.1%. the

Example 10

116g of HDA, 720g of DMC and 3.48g of catalyst zirconium phenate were added into the normal pressure reactor, and the reaction temperature was 90°C and the reaction was stirred for 1.5h. The reaction product was analyzed by high performance liquid chromatography, and the yield of HDU was 98.4%. the

Example 11

116g of HDA, 720g of DMC, and 3.48g of catalyst magnesium phenate were added into the reactor at normal pressure, and the reaction temperature was 90°C and the reaction was stirred for 1.5h. The reaction product was analyzed by high-performance liquid chromatography, and the yield of HDU was 99.1%. the

Claims (10)

1. a synthetic method of hexamethylene-1,6-dicarbamate methyl ester is characterized in that adopting phenoxy compound as catalyst, taking 1,6-hexamethylenediamine and dimethyl carbonate as raw material, reaction Synthesis of methyl hexamethylene‐1,6‐dicarbamate. 2. according to the synthetic method of the described hexamethylene-1,6-dicarbamate of claim 1, it is characterized in that described phenoxy compound is a kind of of phenol or phenoxide. 3. according to claim 2 described hexamethylene-1, the synthetic method of 6-dicarbamate methyl ester is characterized in that phenate is lithium phenate, sodium phenate, potassium phenate, magnesium phenate, calcium phenate, zinc phenate or One of the zirconium phenoxides. 4. according to the synthetic method of the described hexamethylene-1,6-dicarbamate methyl ester of claim 1, it is characterized in that the mol ratio of 1,6-hexamethylenediamine and dimethyl carbonate is 1:2～1 :10. 5. according to the synthetic method of hexamethylene-1,6-dicarbamate methyl described in claim 4, it is characterized in that the mol ratio of 1,6-hexamethylenediamine and dimethyl carbonate is 1:3～1 :8. 6. according to the synthetic method of the described hexamethylene-1,6-dicarbamate methyl ester of claim 1, it is characterized in that the mass ratio of phenoxy compound and 1,6-hexamethylenediamine is 0.001～0.1:1 . 7. according to claim 6 described hexamethylene-1, the synthetic method of 6-dicarbamate methyl ester, it is characterized in that the mass ratio of phenoxy compound and 1,6-hexamethylenediamine is 0.01～0.05:1 . 8. according to the synthetic method of the described hexamethylene-1,6-dicarbamate methyl ester of claim 1, it is characterized in that reaction temperature is 30～90 ℃, preferably 50～80 ℃. 9. according to the synthetic method of the described hexamethylene-1,6-dicarbamate methyl ester of claim 1, it is characterized in that the reaction time is 0.5～3h, preferably 1～2h. 10. the synthetic method of hexamethylene-1,6-dicarbamate methyl ester according to claim 1 is characterized in that reaction pressure is normal pressure.