Methanesulfonic Acid → 1-ethyl-3-[5-hydroxy-7-[(E)-N-methoxy-C-methylcarbonimidoyl]-1,3-benzothiazol-2-yl]urea

Participants

Reaction Steps

A solution of methanesulfonic acid (6.5 mL) in DCM (32 mL) was added to 1-[5-benzyloxy-7-[(E)-N-methoxy-C-methyl-carbonimidoyl]-1,3-benzothiazol-2-yl]-3-ethyl-urea (718 mg, 1.8 mmol) and the reaction stirred at ambient temperature for 2 h after which time LCMS indicated clean conversion to the desired product. The reaction was diluted with DCM, washed with water and the aqueous layer neutralized with saturated aqueous Na2CO3 solution and extracted with EtOAc. The organic layer was dried (MgSO4), filtered and the solvent was removed in vacuo. The crude material obtained was purified by flash chromatography on silica gel using MeOH:DCM 3:97 as the eluent to give the desired compound as an off white solid, 300 mg, 54% yield.

Provenance & Evidence