Sunday, November 23, 2014


Common name: Lansoprazole, AG-1749, ABT-006, CG-4801, A-65006
Trademarks: Ogast, Lanzor, Lanzo, Agopton, Opiren, Bamalite, Takepron, Lansox, Lansox, Ogastro, Monolitum, Prevacid, Zoton
Molecular Formula: C16H14F3N3O2S
CAS Registry Number: 103577-45-3
Molecular Weight: 369.368
InChI: InChI=1S/C16H14F3N3O2S/c1-10-13(20-7-6-14(10)24-9-16(17,18)19)8-25(23)15-21-11-4-2-3-5-12(11)22-15/h2-7H,8-9H2,1H3,(H,21,22)
CAS Name: 2-[3-Methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-ylmethylsulfinyl]-1H-benzimidazole; 2-(2-Benzimidazolylsulfinylmethyl)-3-methyl-4-(2,2,2-trifluoroethoxy)pyridine
Activity: Agents for Gastritis, Anti-Helicobacter Pylori Agents, Antiulcer Drugs, Esophageal Diseases, Treatment of, Gastric Antisecretory Drugs, Gastroesophageal Reflux Disease, Agents for, GASTROINTESTINAL DRUGS, Non-Ulcer Dyspepsia, Agents for, H+/K+-ATPase Inhibitors
Intermediates:4-Nitro-2,3-lutidine-N-oxide (37699-43-7)
2-Hydroxymethyl-3-methyl-4-(2,2,2-trifluoroethoxy)pyridine hydrochloride (103577-66-8)
2-Chloromethyl-3-methyl-4-(2,2,2-trifluoroethoxy)pyridine hydrochloride (127337-60-4)
2-[3-Methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinyl]methylthio-1H-benzimidazole (103577-40-8)

Lansoprazole as Medicine:

Lansoprazole belongs to a group of drugs called proton pump inhibitors (PPIs). It decreases the amount of acid produced in the stomach.  It is a racemic 1:1 mixture of the enantiomers dexlansoprazole (Dexilant, formerly named Kapidex) and levolansoprazole.

Dexlansoprazole is an enantiomerically pure active ingredient of a commercial drug as a result of the 'enantiomeric shift'.

Lansoprazole as Chemical Compound:

It is an organic heterocyclic compound having a Benzimidazole moiety. More specifically, it is a sulfinylbenzimidazoles - a polycyclic aromatic compounds containing a sulfinyl group attached at the position 2 of a benzimidazole moiety. Other important chemical classifications are:
1. Organoflourine compound
2. Alkyl aryl ethers 
3. Pyridines and derivatives 
4. Heteroaromatic compounds 
5. Sulfoxides 
6. Sulfinyl compounds 
7. Azacyclic compounds 
8. Alkyl fluorides
9. Triflouromethane compounds

Lansoprazole synthesis: US4628098; US4689333 (same in Ref. 3)

Lansoprazole synthesis: Der Chemica Sinica 2013, 4(2), 122-126 (Green Chemistry, Appel's Reaction used instead of thionyl chloride)

Lansoprazole synthesis: Bull Korean Chem Soc 200223(4), 626-628
Important chemistry involved in Lansoprazole synthesis:

1. Flourine Chemistry
2. Cyanation Chemistry
3. Reduction Process
4. Oxidation Process

1. Nohara, A.; et. al. Pyridine derivatives and their production. US4628098; US4689333
2. Makino, T.; et. al. Stabilized pharmaceutical composition comprising a benzimidazole compound, its production and its use as an antiulcer agent. JP87277322
3. Kubo, K.; et. al. Synthesis of 2-[[(4-fluoroalkoxy-2-pyridyl)methyl]sulfinyl]-1H- benzimidazoles as antiulcer agents. Chem Pharm Bull 1990, 38(10), 2853-2858. (synthesis and selection of Lansoprazole as clinical candidate)
4. Pai, N. R.; et. al. Green chemical route for process development of lansoprazole intermediate. Der Chemica Sinica 2013, 4(2), 122-126.
5. Ahn, K.-W.; et. al. A New Synthetic Process of Lansoprazole. Bull Korean Chem Soc 2002, 23(4), 626-628.
6. Harrington, P. J. (Eds) Lansoprazole in Pharmaceutical Process Chemistry for Synthesis: Rethinking the Routes to Scale-Up. 2011, Wiley Publications. (reports synthesis and analysis of various routes wrt yields and sustainability.)

For more drugs and their synthesis: Synayurajan database