Chemical Properties
1-Methylimidazole or N-methylimidazole is an aromatic heterocyclic organic compound with the formula CH3C3H3N2. It is a colorless to yellow liquid, with an amine-like odor. It is miscible with water. N-methylimidazole is an important raw material for the synthesis of pharmaceutical intermediates, used in the preparation of losartan, nizofenone, 1-Methyl-1H-imidazole-5-carbonyl chloride hydrochloride and naphazoline hydrochloride, etc. It is also used as a specialty solvent, a base, and as a precursor to some ionic liquids.
Uses
1-Methylimidazole is an aprotic solvent. It is a derivative of imidazole used in the production of pharmaceuticals, pesticides, ion exchange resins, dye intermediates, textile auxiliaries, photographic chemicals, and corrosion inhibitors. It can also be used as a catalyst for the manufacture of polyurethane and a curing agent for epoxy resins. For example, when 1-methylimidazole is added to an aqueous diethylenetriamine (DETA) solution, high CO2 loading can be achieved through phase separation of the absorbent during CO2 absorption[1].
Preparation
1-Methylimidazole is prepared mainly by two routes industrially. The main one is acid-catalysed methylation of imidazole by methanol. The second method involves the Radziszewski reaction from glyoxal, formaldehyde, and a mixture of ammonia and methylamine.
(CHO)2 + CH2O + CH3NH2 + NH3 → H2C2N(NCH3)CH + 3 H2O
The compound can be synthesized on a laboratory scale by methylation of imidazole at the pyridine-like nitrogen and subsequent deprotonation. Similarly, 1-methylimidazole may be synthesized by first deprotonating imidazole to form a sodium salt followed by methylation.
H2C2N(NH)CH + CH3I → [H2C2(NH)(NCH3)CH]I
[H2C2(NH)(NCH3)CH]I + NaOH → H2C2N(NCH3)CH + H2O + NaI
Definition
ChEBI: 1-methyl-1H-imidazole is a 1H-imidazole having a methyl substituent at the N-1 position. It is a metabolite of 1-methyl-2-thioimidazole (methimazole). It inhibits bone resorption.
General Description
This product has been enhanced for catalysis. 1-Methylimidazole is a derivative of imidazole that is utilized in the manufacture of such classes of items as pharmaceuticals, pesticides, ion-exchange resins, dye intermediates, textile auxiliaries, photographic chemicals, and corrosion inhibitors. It is also used as a catalyst for manufacturing polyurethanes and a curing agent for epoxy resins.
Flammability and Explosibility
Not classified
Purification Methods
Dry it with sodium metal and then distil it. Store it at 0o under dry argon. The picrate has m 159.5-160.5o (from H2O). [Beilstein 23 III/IV 568.]
Toxicity evaluation
Acute toxicity:Harmful if swallowed.
Toxic in contact with skin.
LD50 Oral:1144 mg/kg, LD50 Dermal:400-640 mg/kg.
References
[1] You J, et al. Effect of 1-Methylimidazole on CO2 Absorption by Diethylenetriamine (DETA) Aqueous Solutions. Chemical Engineering & Technology, 2017; 40: 2238-2242.
