Detection method
Fluorescence detection method: Using o-phenylenediamine as the carbon source and phytic acid as the phosphorus source, two P-rich carbon quantum dots RCD and BCD were successfully synthesized by changing the reaction temperature and time of the hydrothermal method. The study found that the red-emitting RCD can achieve sensitive detection of 2-Methylimidazole, while 2-methylimidazole has no obvious quenching effect on the blue-emitting BCD, which makes RCD a sensitive, fast and selective fluorescence sensor for 2-methylimidazole detection. Under the optimal experimental conditions, the fluorescence intensity of RCDs decreases with the increase of 2-methylimidazole concentration; the carbon quantum dot sensor shows a good linear relationship in the detection of 2-methylimidazole concentration in the range of 5 ~ 110 µM, and the minimum detection limit is 0.61 µM (S/N = 3). The sensor can detect 2-methylimidazole in lake water and can be used for the detection of actual samples
[2].
Chemical Properties
2-Methylimidazole is a white to light yellow crystalline powder with an amine-like odor. It is highly soluble in polar organic solvents. Insoluble in ether and cold benzene, easily soluble in water, alcohols and ketones. Irritating to skin and mucous membranes. Mice orally LD50 1400mg/kg.
Chemical Properties
The 2-methylimidazole molecule is approximately planar, and the maximum deviation of all non-H atoms from the plane of the least squares imidazole is 0.006(2)?. N–H··· N hydrogen bonds link molecules together to form infinite chains of hydrogen bond pattern C(4). The crystal of 2-methylimidazole is in orthorhombic crystal system with space group P2
12
12
1 (Z = 4), lattice parameters: a = 5.9957(12) ?, b = 8.1574(16) ? and c = 9.7010(19) ?, V = 474.47(16) ?[1].
Uses
2-Methylimidazole is used as a raw material for the preparation of nitroimidazole antibiotics, which is useful in combat anaerobic bacterial and parasitic infections. It acts as a ligand in coordination chemistry. It is also employed as a hardener or accelerator for epoxy resin and auxiliary agent for textile dyes. Further, it acts as a catalyst for refolding of enhanced colored fluorescent protein. It is also useful as a building block in the synthesis of biologically active compounds. In addition to this, it is used as an active pharmaceutical ingredient intermediate such as metronidazole and dimetridazole.
Uses
2-Methylimidazole is a monomethylated imidazole that can be used as a building block in the preparation of a wide range of biologically active compounds. 2-Methylimidazole as well as other imidazoles
can be use as catalyst for refolding of enhanced coloured fluorescent protein. 2-Methylimidazole has been identified as a byproduct of fermentation and is detected in foods and mainstream and side-str
eam tobacco smoke.
Preparation
2-Methylimidazole is prepared by condensation of glyoxal, ammonia and acetaldehyde, a Radziszewski reaction. It is widely used as a polymeriza tion cross-linking accelerator and a hardener for epoxy resin systems for semiconductor potting compounds and soldering masks.
It is obtained by eliminating dehydrogenation of 2-methylimidazoline. 2-methylimidazoline heated to melt (melting point 107 ℃), carefully add active nickel, raise the temperature to 200-210 ℃ reaction 2h. cool down to below 150 ℃, add water to dissolve, while hot pressure filtration, separation of active nickel, the filter Chemicalbook liquid concentrated to a temperature of 140 ℃ or more, put the material cooling that 2-methylimidazole. Use the method to produce purity of ≥ 98% of the product, 1t product consumption of ethylenediamine (95%) 1095kg, acetonitrile 975kg. better method is to use glyoxal and aldehyde as raw materials.
General Description
It is a white or colorless solid that is highly soluble in polar organic solvents and water. It is a precursor to a range of drugs and is a ligand in coordination chemistry.
Hazard
Possible carcinogen.
Flammability and Explosibility
Not classified
Purification Methods
Recrystallise 2-methylimidazole from *benzene or pet ether. The picrate has m 215o (from H2O). [Beilstein 23 III/IV 594, 23/5 V 35.]
Toxicity evaluation
2-Methylimidazole is harmful if swallowed and may cause severe skin burns and eye damage from exposure. It is also associated with adverse effects such as neurotoxins, reproductive toxins and toxic pneumonia. In vitro studies have shown a mouse LD50: 480 mg/kg (intraperitoneal); 1400 mg/kg (oral).
References
[1] Hachu?a B, et al. Crystal and Molecular Structure Analysis of 2-Methylimidazole. Journal of Chemical Crystallography, 2009; 40: 201–206.
[2] ZHENGYUAN DAI. Synthesis of P-Rich Carbon Quantum Dots for Sensitive Fluorescent Detection of 2-Methylimidazole.[J]. Journal of Fluorescence, 2024. DOI:10.1007/s10895-024-03946-9.
