Acetonitrile → Ammonium hydroxide methanol

Participants

Reaction Steps

Prepared according to the method described in Example 6(d) above from (R)-N5 -(Cbz)-N2 -(diphenylacetyl)-(R)-N-[1-(4-bromophenyl)ethyl]ornithine amide (1.00 g; 1.56 mmol; from step (c) above), acetonitrile (30 mL), CH2Cl2 (10 mL) and trimethylsilyl iodide (0.34 g, 1.70 mmol), 1.5 hours reaction time, followed by additional trimethylsilyl iodide (0.14 g; 0.70 mmol), 0.5 hours reaction time. Work up using triethylamine (10 mL) gave the crude product as an oil (1.00 g). The product was chromatographed on silica gel eluting with MeOH, then with MeOH:ammonium hydroxide (30:1) to give pure sub-title compound (free base) as an off-white crushable foam (0.57 g).

Provenance & Evidence