Process for preparation of telmisartan
The mixture was diluted with ethyl acetate, washed with water and saturated brine, dried over Na 2 S Ij and filtrated and the solvent was removed under vacuum to obtain 37 mg of compound 3 yield: After completion of the reaction, Isopropanol was evaporated under reduced pressure.
This process comprises the steps of:. Process according to claim 1 for the preparation of telmisartan intermediates of formula 3".
A process according to claim 1, sulphur containing reducing agent used in step a is selected from sodium sulfite, sodium sulfide, sodium dithionite, sodium metabisulfite.
The potassium salt of telmisartan can be further converted to telmisartan by heating the potassium salt of telmisartan in suitable solvents, followed by adjusting the pH using a suitable acid. The granulate is then mixed with at least one other active pharmaceutical ingredient and compressed into tablets.
Filtered the solid and washed with 10 ml of water. Preferably potassium iodide is used. The temperature for conducting the cyclization can be in the range from about 0 about 0 C and particularly at the reflux temperature of the solvents used. In the latter case telmisartan is placed in a solvent together with a corresponding basic agent and mixed together. The reaction mass pH was adjusted to and extracted with ethyl acetate 2x75 ml and the combined organic layer was concentrated under reduced pressure to give methyl methyl propyl-lH-benzimidazolecarboxylate 10 gm, Yield: The temperature for conducting the alkylation can be in the range from about 0 to about.
The reaction time for a process according to the present invention is typically in the range of from about a few minutes to a few hours, depending on the exothermicity of the reaction.
Telmisartan is the INN International Nonproprietary Name for the compound 4'- [2-n-propylmethyl 1 -methylbenzimidazolyl benzimidazol- 1 - ylmethyl]biphenylcarboxylic acid. The reaction mass is heated to reflux till completion. Centrifuged the reaction mass and washed the solid with 14 L of acetone. Even more particularly, the object of the present invention is to provide a process for the preparation of telmisartan nitrile Scheme 5, wherein Z is CN comprising the steps of:.
The invention may also comprise further purification of telmisartan so as to achieve a highly pure compound. The aforementioned process has some disadvantages like lengthy maintenance of the reaction, low purity of the resultant compound and usage of hazardous chemicals like trifluoroacetic acid. EP 0 A and J.
A suitable solvent can be water. Telmisartan, or a pharmaceutically acceptable salt thereof, prepared by a process according to any of claims 1 to The starting compound 8" or 8 4- butyramido methylnitrobenzoic acid can be prepared as disclosed in J.
Date Title Crystalline form of atorvastatin hemi-calcium Process for the preparation of montelukast and its salts Process for the large scale production of rizatriptan benzoate Process for the large scale production of stavudine Top Inventors for class "Organic compounds -- part of the class series" Rank Inventor's name 1 Norbert Lui 2 Gottfried Sedelmeier 3 Nobuharu Ohsawa 4 Michael Keil 5 Sergii Pazenok.
The invention claimed is: The wet solid was charged into a flask and 50 ml of water was added. Accordingly, telmisartan Form A is dissolved in a mixture of solvents consisting of water, formic acid and an organic solvent that is miscible therewith; the solution is heated followed by distillation and telmisartan containing Form A and Form B is precipitated from the mixture by addition of a base.
The molecular structure of telmisartan is represented by Formula I.