Triphenylmethane → 3H-benzoimidazole-5-carboxylic acid N-tert-butyl-N'-(2-ethyl-3-methoxy-benzoyl)-hydrazide

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Reaction Steps

About 120 mg of 3-trityl-3H-benzoimidazole-5-carboxylic acid N-tert-butyl-N′-(2-ethyl-3-methoxy-benzoyl)-hydrazide were dissolved in 35 mL of CH3OH and added into a hydrogenation bottle, together with 2 drops of glacial acid and 0.20 g Pd/C. Hydrogenation was conducted by shaking the bottle for 6 hours and then remaining under H2 pressure for 16 hours. The Pd/C was removed by filtration and the methanol removed by an evaporator. The residue was stirred with CH2Cl2 and the CH2Cl2 was decanted. Evaporation of the CH2Cl2 yielded a solid product identified by NMR, as triphenylmethane. The residue was stirred with dilute KOH/H2O and extracted with ethyl acetate. The ethyl acetate was dried and concentrated on a rotary evaporator to yield the product 3H-benzoimidazole-5-carboxylic acid N-tert-butyl-N′-(2-ethyl-3-methoxy-benzoyl)-hydrazide. NMR analysis of the product indicated the absorbances for the methoxy and t-Butyl groups occurred at 3.69 and 1.61 vs. 3.77 and 1.59 for the starting material.

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