Patent ID: 7683170

Claim:
A method for preparing 7-ethyl-10-[4-(1-piperidino)-1-piperidino]-carbonyloxy-camptothecin comprising reacting a reactants mixture of 1-chlorocarbonyl-4-piperidinopiperidine hydrochloride and 7-ethyl-10-hydroxycamptothecin in a polar aprotic solvent with diisopropylethylamine in the presence of a catalytic amount of a N-containing cyclic organic compound, and optionally in the presence of a water binding agent in an amount which effectively binds any water present in the above reactants and solvent, wherein said polar aprotic solvent is selected from the group consisting of DMF, DMSO, 1,4-dioxane, THF, methylene chloride, chloroform, acetonitrile and mixture thereof, and said N-containing cyclic organic compound is selected from the group consisting of 4-dimethylaminopyridine, lutidine, pyrrole, imidazole, N-methylimidazole, 4-pyrrolidinopyridine, 4′,6′-diamidini-2-phenylindole and 1,4-diazabicyclo[2,2,2]octane (DABCO).