Acetyl chloride → 5-Bromo-2-methyl-1-(tetrahydropyran-4-yl)benzimidazole hydrochloride

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Reaction Steps

A 2-neck flask was charged with 5-bromo-2-(tetrahydropyran-4-yl)aminoaniline (see Synthesis Example 18-2) (2.72 g, 10.0 mmol) and anhydrous toluene (20 mL) and this was refluxed. To this was added dropwise over approx. 15 m acetyl chloride (1.57 g, 20.0 mmol) in toluene solution (approx. 2.5 mL), and this was stirred under these conditions for 2 hours. After being allowed to cool to room temperature, this was concentrated under reduced pressure and the residue was reslurried in hexane (20 mL). The precipitated crystals were filtered off and washed with hexane. The crystals obtained were dried at reduced pressure with heating to yield the title compound (3.14 g, 94.7% yield) as a light purple solid.

Provenance & Evidence