Dimethyl oxalate

Physical property data

1. Properties: colorless monoclinic crystal[1]

2. Melting point (°C) : 54[2]

3. Boiling point (°C): 163.5[3]

4. Relative density (water = 1) : 1.15[4]

5. Saturation vapor pressure (kPa) : 0.13 (20°C) [5]

6. Heat of combustion(kJ/mol): -1672.8[6]

7. Octanol/Water partition coefficient: -0.17[7]

8. Flash Point(°C): 75[8]

9. Solubility: slightly soluble in cold water, soluble in ethanol, ether, etc. [9]

Storage method

Storage Precautions [15] Store in a cool, ventilated warehouse. Keep away from fire and heat sources. The package is sealed. It should be stored separately from oxidants, reducing agents, acids, alkalis, and edible chemicals, and should not be mixed. Equipped with the corresponding variety and quantity of fire-fighting equipment. The storage area should be equipped with suitable materials to contain the spill.

Synthesis method

1. It is obtained by esterification of oxalic acid and methanol in the presence of sulfuric acid.

2. Preparation method:

In the reaction bottle equipped with stirrer and water separator, 2.4kg (15.87mol) of oxalic acid (2), 2.4kg (75mol) of anhydrous methanol, 4kg of benzene and 20mL of concentrated sulfuric acid were added. Heating and reflux azeotropic dehydration under stirring. The reflux liquid is stratified, and the benzene layer flows back to the reaction flask, and the methanol is evaporated after the water is basically distilled. Washed with water, the organic layer is washed with 10% sodium carbonate solution, and dried with anhydrous calcium chloride. Filtration, crystallization occurs after the filtrate is frozen. Filtration, drying, dimethyl oxalate (1) 1.59kg, yield 85%. [17]

Main uses:

1. Used in organic synthesis, as an intermediate of vitamin B13, and can also be used as a solvent and plasticizer. 2. It is used to prepare high-purity methanol.