1 - methyl imidazole is one of the important intermediate of imidazoles, which has extensive application in Ionic liquid epoxy resin and curing agent. The traditional synthetic methods of 1 - methyl imidazole  are two-step and one-step process, wherein, two-step method is firstly condensing glyoxal and formaldehyde, ammonia water to generate imidazole, then going on a methylation reaction with the dimethyl sulfate  finally get 1 - methyl imidazole, however, this process is using the highly toxic raw material of dimethyl sulfate, which will also higher the cost; the one-step method is taking glyoxal, formaldehyde, methylamine and ammonia water as raw materials, but this process exists the shortcomings of low yield, many more by-products and has more troublesome in separating and purifying. 

 

One research has pointed out a new kind of synthesis methods of 1 - methyl imidazole, which is introducing the ammonium metatungstate column brace hydrotalcite as catalyst, using imidazole as raw material, and methanol as the methylation reagent, and through the fixed bed continuous method to directly synthesize 1 - methyl imidazole. The reaction equation is showing as the picture below: 

The properties of this method to prepare 1 - methyl imidazole are as follows: 

1. The molar ratio of imidazole and the methanol is optimized of 1:4 ~ 6;

2. The reaction conditions are: the pressure in the fixed bed is 0.4 ~ 0.6 MPa, the temperature shall be in 320 ~ 350°C, the reaction liquid feed quality airspeed is 0.3 ~ 0.4 / h;

3. The advantages of simple operation, less pollution and high yield, and is easy to be industrialized production;

4. Ammonium metatungstate (AMT) catalyst has high catalytic activity, small pollution to the environment, long life and other advantages;

5. The methanol used as methylation reagent will lower the cost of raw materials, and also has lower toxicity. 

 

Ammonium metatungstate catalyst is a new kind of catalyst with better property. When methyl alcohol transfers to hydrocarbon, it shows great catalytic ability and unique selectivity. And thus, ammonium metatungstate is widely used in petroleum, electronic, national defense, aviation, metallurgy, anticorrosion and antiflaming, etc. It now becomes new catalytic material, and its application and consumption is increased day by day.