Dimethylformamide → methyl N-[(1S)-1-[[(1S,2R)-1-benzyl-3-[cyclohexylmethyl-[[(2S)-2-(methoxycarbonylamino)-3-methyl-butanoyl]amino]amino]-2-hydroxy-propyl]carbamoyl]-2-methyl-propyl]carbamate

Participants

Reaction Steps

Under a protective gas atmosphere, 33 mg (0.186 mmol) of N-methoxycarbonyl-(L)-valine (Example 73b) are activated with 82 mg (0.186 mmol) of BOP and 25 mg (0.186 mmol) of HOBT in 1.24 ml of a 0.3M solution of NMM in DMF and, after 15 min, reacted with 25 mg (0.062 mmol) of 1-[2(R)-hydroxy-3(S)-amino-4-phenyl-butyl]-1-[cyclohexylmethyl]-hydrazine (in the form of the hydrochloride salt) for 18 h. The reaction mixture is concentrated by evaporation under HV and the residue is partitioned between 3 portions of methylene chloride, 2 portions of saturated NaHCO3 solution and brine. Column chromatography (Si2, methylene chloride/methanol 99:1→15:1) and precipitation with DIPE from a concentrated solution in DMF yields the pure title compound: tRet (V)=14.7 min; FAB-MS (M+H)+ =606.

Provenance & Evidence