PROCESS FOR THE SYNTHESIS OF A TETRAZOL DERIVATIVE

摘要

The invention relates to a process for the synthesis of losartan potassium of formula in particular potassium salt of 2-n-butyl-4-chloro-1[(2'-(tetrazol-5-yl)-1,1'-biphenyl-4-yl)-methyl]imidazol-5-methanol. The yield of the end product is increased. According to the process initial compound is used of 2-n-butyl-4-chloro-1[2'-(2-triphenylmethyl-2H-tetrazol-5-yl)-1,1'-biphenyl-4-yl)-methyl]-1H-imidazol-4-methonol with the formula which reacts in alcohol with formula wherein R means C1-C4 alkyl group with a strain chain, with 0.1-1 equivalent of potassium hydroxide. The final product with formula (I) is isolated after crystallizing out by changing the solvent to an aprotic or weakly protic solvent.