Sodium Hydroxide → HCID 11949833, compound

Participants

Reaction Steps

Phosphorus pentasulfide (444 mg, 1.0 mmol) was added to a suspension of N-{4-[3-(4-trifluoromethoxybenzyl)-2-oxo-2,3-dihydrobenzimidazol-1-ylmethyl]phenyl}methanesulfonamide (7) (300 mg, 0.61 mmol) in para-xylene (20 mL) under a blanket of argon. The reaction mixture was heated to the boil over a period of 10 h. Following cooling, there was added to the reaction mixture water (1 mL) followed by 2N NaOH solution in water (10 mL), and the mixture was stirred at RT for 30 min. The reaction mixture was extracted with ethyl acetate (4×20 mL). The combined organic phases were dried over Na2SO4 and the solvent removed in vacuo. After purifying the residue by means of column chromatography (SiO2; cyclohexane/EtOAc 2:1), the desired product N-{4-[3-(4-trifluoromethoxybenzyl)-2-thioxo-2,3-dihydrobenzimidazol-1-ylmethyl]phenyl}methanesulfonamide (8) (162 mg, 52% of theory, mp: 167-170° C.) was obtained. After recrystallizing from methanol, there were obtained crystals having a melting point of 175-179° C.

Provenance & Evidence