Hydrochloric Acid → 1-methyl-2,3-dihydro-1H-1,3-benzodiazol-2-one

Participants

Reaction Conditions

Reaction Steps

A solution of 1-isopropenyl-1,3-dihydro-2H-benzimidazol-2-one (30 g, 0.172 moles) in DMF (180 ml) was added dropwise over 30 minutes to a suspension of 80% sodium hydride (5.42 g, 0.181 moles) in DMF (60 ml). The reaction mixture was heated at 45° C. for 45 minutes then a solution of methyl iodide (16.1 ml, 0.258 moles) in DMF (50 ml) was added dropwise. The reaction mixture was heated at 80° C. to 90° C. for 45 minutes, cooled at room temperature and adjusted to pH 3 to 4 with 37% HCl and heated at 80° C. for 30 minutes. The reaction mixture was cooled at room temperature and poured into ice/water. The solid residue separated was filtered and dried to give 19 g of the title compound, m.p. 188° C.-190° C.

Provenance & Evidence