Iodoethane → methyl 4-(1,1-dioxidotetrahydro-2H-1,2-thiazin-2-yl)-1-ethyl-1H-benzimidazole-6-carboxylate

Participants

Reaction Steps

To a solution of methyl 4-(1,1-dioxidotetrahydro-2H-1,2-thiazin-2-yl)-1H-benzimidazole-6-carboxylate (D253) (230 mg, 0.74 mmol, 1 equiv) in DMF (10 ml) at room temperature was added NaH (60% dispersion in mineral oil, 33 mg, 0.82 mmol, 1.1 equiv) and the resulting mixture was stirred 5 min at this temperature. Ethyl iodide (66 μl, 0.82 mmol, 1.1 equiv) was added and the resulting solution was stirred for 30 min at 60° C. then cooled to room temperature and concentrated in vacuo. The residue was partitioned between AcOEt and a 5% aqueous citric acid solution. The two layers were separated and the aqueous phase saturated with NaCl and extracted twice with AcOEt. The combined organic phases were dried over MgSO4 and concentrated in vacuo to give methyl 4-(1,1-dioxidotetrahydro-2H-1,2-thiazin-2-yl)-1-ethyl-1H-benzimidazole-6-carboxylate (B151) (400 mg, 160%) as a pale yellow viscous oil which was used in the next step without further purification. [M+H]+=338.1, RT=2.43 min.

Provenance & Evidence