1. Methyl 1-methyl-4-nitro-1H-imidazole-2-carboxylate (3.3 g, 17.8 mmol) was dissolved in a 1:1 solvent mixture of methanol/ethyl acetate (100 mL) and Pd/C catalyst (400 mg) was added. The reaction was shaken at 70 psi hydrogen pressure for 14 hours.
2. Upon completion of the reaction, the reaction mixture was filtered through a bed of diatomite and the diatomite was washed with methanol. The filtrate was concentrated under reduced pressure to give the crude product methyl 4-amino-1-methyl-1H-imidazole-2-carboxylate as a black oil.
3. The crude product was dissolved in benzene and concentrated again under reduced pressure to obtain a black solid. It was filtered and washed with ether to give purified amine (2.5 g, 88%).
4. The purified amine (14.7 mmol) was dissolved in acetonitrile (50 mL) and N,N-diisopropylethylamine (DIEA, 2.3 mL, 18 mmol) was added. An acetonitrile solution (50 mL) of 1-methyl-2-trichloroacetylimidazole (3.6 g, 14.7 mmol) was added slowly at 0 °C. The reaction mixture was allowed to stand for 5 minutes at room temperature.
5. The reaction mixture was stirred at room temperature for 10 hours. After completion of the reaction, the solvent was removed under reduced pressure and the residue was dissolved in methanol and the product was precipitated by the addition of ether to afford the target compound, methyl 4-amino-1-methyl-1H-imidazole-2-carboxylate (2.13 g, 68%). 6. The structure of the product was confirmed by the presence of 1H-imidazole (3.6 g, 14.7 mmol).
6. The structure of the product was confirmed by 1H-NMR, 13C-NMR and EI-HRMS.
