| abstract |
The invention relates to a method for the synthesis of the losartan potassium salt of the formula, in particular the potassium salt of 2-n-butyl-4-chloro-1 [(2'- (tetrazol-5-yl) -1,1'-biphenyl) -4-yl) methyl] imidazole-5-methanol. The yield of the finished product is increased. The process is run with starting compound 2-n-butyl-4-chloro-1 [(2'- (2-triphenylmethyl-2H-tetrazol-5-yl) -1,1'-biphenyl-4-yl) -methyl ] -1H-imidazole-4-methanol of formula (N) which is reacted in an alcohol of formula (N) in which R is a straight chain C 1 -C 4 alkyl group having 0.1-1 equivalent of potassium hydroxide. The final product of formula I is isolated after crystallization of the solution, the solvent being replaced with aprotic or slightly proton. |