2-Mercapto-5-methoxybenzimidazole

Description

2-Mercapto-5-methoxybenzimidazole is used in the preparation of COX-2 inhibitors. It is also employed in the preparation of compounds such as 5-methoxy-2[[(4-methoxy-3, 5-dimethyl-2-pyridinyl) methyl] sulfonyl]-1H-benzimidazole, 5-methoxy-2[[(4-methoxy-3, 5-dimethylpyridin-2-yl-1-oxide) methyl] sulfonyl]-1H-benzimidazole as well as tris[μ-1,2-bis(diphenylphosphino)ethane]-1:2κ2P:P′;1:3κ2P:P′;2:3κ2P:P′-di-μ-bromido-1:2κ4Br:Br-bromido-3κBr-tricopper(I) acetone hemisolvate. Furthermore, it acts as a hetercocyclic building block and serves as an intermediate of drug omeprazole1. Finally, it acts as an intermediate for manufacture of the anti-ulcer drug Omeprazole.

Chemical Properties

off-white to light yellowish-brown powder

Uses

5-Methoxy-2-benzimidazolethiol may be used in the preparation of compounds present as contaminants in omeprazole, such as 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulfonyl]-1H-benzimidazole and 5-methoxy-2-[[(4-methoxy-3,5-dimethylpyridin-2-yl-1-oxide)methyl]sulfonyl]-1H-benzimidazole. It may be used in the synthesis of tris[μ-1,2-bis(diphenylphosphino)ethane]-1:2κ²P:P′;1:3κ²P:P′;2:3κ²P:P′-di-μ-bromido-1:2κ⁴Br:Br-bromido-3κBr-tricopper(I) acetone hemisolvate.

Uses

Reagent used in the synthesis of COX-2 inhibitors

Uses

2-Mercapto-5-methoxybenzimidazole is used in the preparation of COX-2 inhibitors. It is also employed in the preparation of compounds such as 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulfonyl]-1H-benzimidazole and 5-methoxy-2-[[(4-methoxy-3,5-dimethylpyridin-2-yl-1-oxide)methyl]sulfonyl]-1H-benzimidazole. Further, it acts as a hetercocyclic building block and serves as an intermediate of drug omeprazole.

General Description

Pharmaceutical secondary standards for application in quality control provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards

Flammability and Explosibility

Not classified

Synthesis

2-Mercapto-5-methoxybenzimidazole is prepared by starting with p-aminobenzyl ether (2), which is acetylated, nitrated and hydrolysed to give p-acetylaminobenzyl ether (3); this is then hydrogenated using a Ranney nickel catalyst and cyclised with potassium ethyl xanthate. The reaction route is shown below: