Benzimidazole → ethyl 2-[4-(1H-benzimidazol-1-ylmethyl)phenyl]-1,3-oxazole-4-carboxylate

Participants

Reaction Steps

To a solution of benzimidazole (1.5 eq) in DMF was added portionwise sodium hydride (60% suspension in mineral oil, 1.5 eq) and the reaction mixture was allowed to stir for 45 min at room temperature. The reaction mixture was then added to a solution of ethyl 2-[4-(chloromethyl)phenyl]-1,3-oxazole-4-carboxylate (1 eq) in DMF and the reaction mixture was allowed to stir at room temperature for 2 h. The reaction mixture was poured into ice/water, stirred for 30 min, and the resulting precipitate filtered through a coarse filter without vacuum suction (if the filtration is bad, it is possible to decant the aqueous/DMF layer from the organic precipitate), the precipitate dissolved in methylene chloride, washed with aq. ammonium chloride, water, dried over sodium sulphate, evaporated, triturated with MTBE, filtered, dried in the oven at 40° C. overnight. The product (92.4% yield) was obtained as off-white crystals; m.p. 150-152° C. 1H NMR (300 MHz, DMSO-D6, δ): 8.92 (s, 1H), 8.45 (d, 2H, J=8.5 Hz), 7.99 (d, 2H, J=8.5 Hz), 7.68 (m, 1H), 7.51 (m, 1H), 7.46 (d, 2H, J=8.5 Hz), 7.21 (m, 2H), 5.61 (s, 2H), 4.31 (m, 2H, J=7.2 Hz), 3.32 (s, 2H), 130 (t, 3H, J=7.2 Hz).

Provenance & Evidence