Hydrogenolysis of PNU-100542 (I) removed the benzyloxycarbonyl group and afforded secondary amine (II), which was acylated with (acetoxy)acetyl chloride (III) in the presence of triethylamine to provide amide PNU-142581 (IV). Then, acetate and phthaloyl protecting groups were both removed on treatment with an hydroalcoholic solution of methylamine, and the resulting aminoalcohol PNU-141718 (V) was N-acylated with dichloroacetyl chloride (VI) to yield the desired amide PNU-109230.