Ethyl Acetate → p-Toluenesulfonic acid

Participants

Reaction Steps

1H-2-[1-Methyl-4-(3-methylthiopropionyl)aminopyrrol-2-yl]benzimidazole-5-[N-[4-[N,N-bis(2-chloroethyl)amino]phenyl]]carboxamide (10.1 g) was dissolved in 35 ml of 98-100% formic acid. To this solution were added 8 ml of methyl p-toluenesulfonic acid and 4.1 g (1.2 equivalents) of p-toluenesulfonic acid monohydrate, and then the mixture was stirred at room temperature for 2 days in darkness. Treatment with ethyl acetate and decantation were repeated 2 times each (700 ml×2), and then sludging was carried out with 300 ml of ethyl acetate to obtain a light yellow powder. This was purified by chromatography on a gel filtration column (Sephadex LH-20, methanol) and was recrystallized from methanol, whereby 8.72 g (53%) of the title compound were obtained.

Provenance & Evidence