Certain bis(thio-hydrazide amide) compounds are useful as pharmaceuticals, in particular, as anticancer agents. See, for example Chen, et al., U.S. Pat. No. 6,825,235, U.S. Published Patent Application No. 20040229952; U.S. Pat. Nos. 6,762,204 and 6,800,660 to Koya, et al., and U.S. Published Patent Application Nos. 20050009920, 20040235909, 20040225016, and 20030195258. The entire teachings of these documents are incorporated by reference.
Salts of these bis(thio-hydrazide amide) compounds are believed to be particularly useful at least in part for reasons of solubility. See, for example Koya, et al., U.S. Provisional Patent Application Ser. No. 60/582,596, filed Jun. 23, 2004, and U.S. Provisional Patent Application Ser. No. 60/681,368, filed concurrently herewith. The entire teachings of these applications are incorporated by reference. However, the existing process includes a lyophilization step, which can be energy intensive and poorly suited to scale up to production runs.
Therefore, there is a need for an improved process for preparing salts of bis(thio-hydrazide amide) compounds.