Hydrochloric Acid → 5-Bromo-1-methyl-1,3-dihydro-2H-benzo[d]imidazol-2-one

Participants

Reaction Conditions

Reaction Steps

A solution of 4-bromo-N1-methylbenzene-1,2-diamine (581 mg, 2.89 mmol) in methylene chloride (50 mL) was cooled to 0° C. in an ice/water bath and treated dropwise with a solution of 20% phosgene in toluene (1.52 mL). When the addition was complete, triethylamine (585 mg, 5.78 mmol) was added and the reaction stirred at 0° C. for 30 min. After this time, the reaction was poured into 1 M hydrochloric acid (80 mL) and extracted with methylene chloride. The combined organic layers were washed with water and dried over sodium sulfate. The drying agent was removed by filtration and the filtrate concentrated under reduced pressure. The resulting residue was purified by trituration with ethyl acetate to afford 5-bromo-1-methyl-1H-benzo[d]imidazol-2(3H)-one. 1H NMR (400 MHz, DMSO-d6) δ 10.98 (bs, 1H), 7.17 (dd, J=8.4, 1.6 Hz, 1H), 7.10 (d, J=1.6 Hz, 1H), 7.05 (d, J=8.4 Hz, 1H), 3.26 (s, 3H).

Provenance & Evidence