Cesium carbonate → HCID 131719568, compound

Participants

Reaction Steps

A mixture of 52 mg of N-tert-butoxycarbonyl-2(R)-methyl-4(S)-hydroxy-5(S)-amino-7(S)-isopropyl-8-(3-hydroxy-4-tert-butyl-phenyl)-octanoic acid (N-butyl)amide (Example 5a), 47.5 mg of caesium carbonate, 0.012 ml of iodoacetic acid ethyl ester and 5 ml of acetone is stirred for 3 hours under reflux and then concentrated by evaporation. The residue is partitioned between diethyl ether and water. The organic phases are dried and combined and then concentrated by evaporation, yielding the title compound in the form of the crude product: Rf (dichloromethane/diethyl ether=8:2)=0.28.

Provenance & Evidence