Studies in the synthesis of 2-mercapto-5-methoxybenzimidazole

The compound, 2-mercapto-5-methoxybenzimidazole, is an important intermediate required for the synthesis ofomeprazole. It is a proton pump blocker or an inhibitor of the enzyme, H + /K + -ATPase. In the present work, synthesis of this intermediate by three different routes has been discussed and its yields from all the three routes have been compared.