2,4,6-Trimethylpyridine → HCID 178502496, compound

Participants

Reaction Steps

To a cold (0-4° C.) stirred solution of 4-iodobenzene-1,2-diamine (1.3 g, 5.3 mmol) and (2S,5S)-1-[(2S)-2-(methoxycarbonylamino)-3-methyl-butanoyl]-5-methyl-pyrrolidine-2-carboxylic acid (1.52 g, 4.99 mmol) in DMF (23.8 ml) is sequentially added HATU (2.321 g, 6.103 mmol) and 2,4,6-collidine (1.052 ml, 7.964 mmol). The reaction mixture is stirred at rt overnight, diluted with water, extracted with ethyl acetate. Combined extracts are washed with water, saturated bicarbonate solution, brine, dried (Na2SO4), concentrated and dried under high vacuum to afford crude amide. The resulting residue dissolved in acetic acid (28 ml) is heated at 60° C. for 8 hours. Acetic acid is removed, the residue neutralized with sat. NaHCO3 solution, and diluted with ethyl acetate (20 ml). The aqueous solution is extracted with ethyl acetate, combined organic extracts are washed with aq. NaHCO3 solution, brine, dried (Na2SO4), and concentrated. The concentrate is purified by flash column chromatography on silica gel using ethyl acetate-hexanes (1:1 to 7:3) as eluent afforded methyl N-[(1S)-1-[(2S,5S)-2-(5-iodo-1H-benzimidazol-2-yl)-5-methyl-pyrrolidine-1-carbonyl]-2-methyl-propyl]carbamate (2.3 g, 2.28 mmol, 92%).

Provenance & Evidence