Potassium Carbonate → 1,3-Dihydro-5-methoxy-2H-benzimidazol-2-one

Participants

Reaction Conditions

Reaction Steps

Intermediate 36 (7.3 g, 30.6 mmol) was dissolved in DMF (70 mL). To this solution was added anhydrous K2CO3 (4.7 g, 33.7 mmol) and the mixture was heated to reflux (130° C.) for 5 h. The solvent was removed under pressure, the residue was poured into ice water, and the aq phase was extracted with EtOAc. The combined organic layers were dried over anhydrous Na2SO4, concentrated under vacuum, and the resulting yellow solid was recrystallized from EtOH to give 5-methoxy-1H-benzo[d]imidazol-2(3H)-one (intermediate 37) (3.6 g, 72%) as a yellow solid. mp: 249-251° C.

Provenance & Evidence