Hydrochloric Acid → 4-bromo-2-cyclopropyl-1-(2-methyl-3-(trifluoromethyl)benzyl)-1H-benzo[d]imidazol-6-amine

Participants

Reaction Steps

To a 250 mL round-bottom flask containing MeOH (70 mL) was added crude 4-bromo-2-cyclopropyl-1-(2-methyl-3-(trifluoromethyl)benzyl)-6-nitro-1H-benzo[d]imidazole (5.87 g, 12.92 mmol), tin(II) chloride dihydrate (8.75 g, 38.8 mmol) and hydrochloric acid (5.38 mL, 64.6 mmol). The resultant suspension was heated to 50° C. and monitored by LC/MS. By LC/MS analysis the reaction was complete in 30 minutes. After the reaction had cooled to rt, the majority of the MeOH was removed in-vacuo and sodium carbonate (64.6 mL, 64.6 mmol) was added slowly to adjust the pH to about 10 and the mixture was extracted with Et2O (3×100 mL) and the organic was washed with H2O and brine and dried over MgSO4 and filtered. The solvent was removed in-vacuo leaving the desired compound (3.42 g, 8.06 mmol, 62.4% yield) as crude brown solid that by LC/MS was sufficiently pure to use in the next step. NMR was consistent with desired product. MS (ES+) m/e: 423.1, 423.8 [M+H]+; 1H NMR (400 MHz, METHANOL-d4) δ ppm 7.57 (d, J=7.83 Hz, 1H), 7.19 (t, J=7.83 Hz, 1H), 6.84-6.95 (m, 1H), 6.35-6.58 (m, 2H), 5.51 (s, 1H), 5.42 (s, 1H), 2.57 (s, 3H), 1.84-1.98 (m, 1H), 1.05-1.17 (m, 2H), 0.87-1.05 (m, 2H)

Provenance & Evidence