反应详情

With reference to Example 238 described in Japanese Patent Publication (kokoku) No. 25974/1996, 2,4-bis(methylthio)-3-nitro-6-methylpyridine was obtained, and the thus-obtained nitro compound was dissolved in a mixture of methanol and dioxane, followed by reduction in the presence of Raney nickel in a hydrogen atmosphere. Subsequently, N,N-dimethylaniline (0.85 g, 7 mmol) was added to a suspension of the obtained crude 3-amino-2,4-bis(methylthio)-6-methylpyridine (1.0 g, 5 mmol) in chloroform (15 mL). Under cooling with ice, a solution of bromoacetyl chloride (1.21 g, 6 mmol) in chloroform (3 mL) was added dropwise thereto, and the resultant mixture was stirred at room temperature for 2 hours. Subsequently, TLC was performed to confirm that starting materials had been completely consumed. Thereafter, water (65 mL) was added to the reaction mixture, and the resultant mixture was stirred overnight. The crystals that precipitated were collected through filtration, followed by recrystallization from ethanol and drying through air blow, to thereby yield primary crystals of N-[2,4-bis(methylthio)-6-methylpyridin-3-yl]-2-bromoacetamide (818 mg, yield: 50.9%, HPLC: 97.2%).