Methyl iodide → Iodide Ion

Participants

Reaction Steps

U.S. Pat. No. 4,176,186 discloses that methylnaltrexone is prepared by reacting naltrexone as raw material with methyl iodide in acetone as solvent in a closed vessel at 70° C. for 4 days to produce an iodide of MNTX after quaternization, and then performing an ion exchange. The two-step reaction has a yield of about 54%. The disadvantages of this method lie in that the raw material would not react completely; the raw material would form a salt and precipitate out during the process of the reaction; a qualified product would not be not ease to be obtained even after refining; moreover; and phenol alkylation byproducts would be generated.

Provenance & Evidence