反应详情

In one aspect of the present invention, the wet bendamustine hydrochloride monohydrate is obtained from a crystallization, recrystallization, trituration or precipitation procedure, wherein the wet bendamustine hydrochloride monohydrate is present in solid, particulate form in admixture with a solvent system comprising water in which the bendamustine hydrochloride monohydrate is substantially insoluble and then separated from the bulk of the solvent system by a method such as filtration, decantation, centrifugation or the like to provide the wet bendamustine hydrochloride monohydrate. For example, a relatively crude portion of bendamustine hydrochloride may be recrystallized from a solvent system comprised of water and collected by one of the aforementioned methods to provide a cake (e.g., a filter cake), which may be washed one or more times with additional solvent (which may be the same as, or different from, the solvent system utilized in the recrystallization). In one embodiment of the invention, the filter cake of bendamustine hydrochloride monohydrate is washed with water and then t-butyl methyl ether to provide the wet bendamustine hydrochloride monohydrate. Generally speaking, it will be preferred to avoid the use of acetone in such a washing step, since the solubility of bendamustine hydrochloride monohydrate in acetone or aqueous acetone tends to result in unacceptably high yield losses.

1. customcollected by one of the aforementioned methods
2. customto provide a cake (e.g.
3. washa filter cake), which may be washed one or more times with additional solvent (which
4. customutilized in the recrystallization)
5. washIn one embodiment of the invention, the filter cake of bendamustine hydrochloride monohydrate is washed with water