Synthesis of 4-((1H-benzo[d]imidazol-2-yl)oxy)-3-methylpicolinic acid, a key related substance of Rabeprazole sodium
4-((1H-benzo[d]imidazol-2-yl)oxy)-3-methylpicolinic acid (11) is a key related substance of Rabeprazole sodium. In this article, this key related substance is synthesized by using 3-methylpicolinonitrile as a starting material via a five-step processes. By converting 3-methylpicolinonitrile to 4-hydroxy-3-methylpicolinonitrile (13), the preparation of TM becomes practical. This work provides a guarantee for quality standard establishment of Rabeprazole sodium.