Der Pharma Chemica
Journal for Medicinal Chemistry, Pharmaceutical Chemistry, Pharmaceutical Sciences and Computational Chemistry


Identification, Synthesis, and Characterization of Potential Process Related Compounds of Rivastigmine Tartrate

Author(s): Sanjeev R Patil, Bollikonda Satyanarayana, Ketan Amrutia, Maloyesh Biswas, Jaiprakash N Sangshetti, Anil S Bobade, Padi Pratap Reddy, Rajendra Agarwal, Devanand B Shinde

Seven potential process related compounds (impurities) were detected during the impurity profile study of drug substance, rivastigmine tartarate (4). Simple HPLC and MS methods were used for the detection of these process impurities. Based on the spectral data and synthesis the structures of these impurities were characterized as -(S)-3-(1-(Dimethylamino) ethyl) phenyl dimethyl carbamate (6); (S)-3-(1-(dimethylamino) ethyl) phenyl diethyl carbamate (8); (1-Ethyl-3-(1-(3-hydroxyphenyl) ethyl)-1,3-dimethylurea (11); (S)-3-(1-(Dimethylamino) ethyl) phenyl ethylcarbamate (12); 3-Acetyl phenyl ethyl (methyl) carbamate (13); (S)-N,N-dimethyl-1-(3-(4-nitro phenoxy) phenyl) ethanamine (15) and 3- Nitrophenyl ethyl (methyl) carbamate (17). The seven synthesized impurities were co-injected with rivastigmine sample to confirm the retention time in HPLC. The structures of these compounds were established on the basis of spectral data (IR, 1HNMR, 13CMR and MS).