3-[(N-tert-butoxycarbonylamino)acetylaminoj-4-methylaminobenzoic acid-N-(2-pyridyl)-N-(2-ethoxycarbonylethyl)amide → 1-Methyl-2-(n-tert-butoxycarbonylaminomethyl)benzimidazol-5-yl-carboxylic acid-n-(2-pyridyl)-n-(2-ethoxycarbonylethyl)amide

Participants

Reaction Steps

10.0 g (0.02 mol) of 3-[(N-tert-butoxycarbonylamino)acetylamino]-4-methylaminobenzoic acid-N-(2-pyridyl)-N-(2-ethoxycarbonylethyl)amide were dissolved in 50 mL of glacial acetic acid and refluxed for one hour. Then the solvent was distilled off, the residue was mixed with ice water and adjusted to pH 8 by the addition of 2N ammonia. After extraction three times with ethyl acetate, the combined organic phases were washed with saline solution and dried over sodium sulfate. After evaporation of the solvent, the crude product was chromatographed on silica gel, eluting first with methylene chloride, then with methylene chloride/ethanol (50:1) and (25:1). The desired fractions were combined and evaporated down. Yield: 5.85 g (61% of theory), C25H31N5O5 (481.6); Rf value: 0.70 (silica gel; methylene chloride/ethanol=9:1).

Provenance & Evidence