METHOD FOR PRODUCING PURE CRYSTALLINE FORM OF 2-N-BUTYL-3-((2-(1H-TETRAZOLE-5-YL) (1,1'-BIPHENYL)-4-METHYL)-1,3-DIAZAPSPIRO (4,4') NON -1- EN-4-ONE

摘要

Method for producing pure 2-n-Butyl-3-(2-(1H-tetrazole-5yl) (1,1'-biphenyl)-4-yl) methyl)-1,3-diazaspiro(4,4')non-1-en-4-one that is known as Irbesartan, in crystalline form A starting from crude Irbesartan, by controlling the cooling rate of the purification step.