Chromatographic analysis of 1,3-bis(dimethylamino)isopropyl 4-chlorophenoxyacetate dihydrochloride, a new CNS stimulant.

A reversed-phase liquid chromatographic method is developed for the assay of the new CNS stimulant, 1,3-bis(dimethylamino)isopropyl 4-chlorophenoxyacetate dihydrochloride (BCE-001), and its main contaminant, 4-chlorophenoxyacetic acid (PCPA). In the first place the possible reactions of BCE-001 with mobile phase components are investigated and it is found that BCE-001 is readily hydrolysed in water and undergoes transesterification in methanol or ethanol. The methyl ester is formed rapidly and quantitatively so that BCE-001 can be assayed as methyl 4-chlorophenoxyacetate. PCPA is formed as a result of the hydrolysis of BCE-001 during the sample pretreatment and chromatographic separation and this causes an overestimate of the PCPA impurity in the bulk drug. An effective method is developed to prevent the hydrolysis of BCE-001 during sample pretreatment.