The invention relates to novel processes for the preparation of high-purity roflumilast. The process involves reacting the anion of 4 - armino -3,5 dichloropyridine (I), with an activated derivative of 3-cyclopropylmethoxy-4-difluoromethoxybenzoic acid (II), characterized in that the molar ratio of the employed anion of 4-amino-3,5 dichloropyridine to the activated derivative of 3-cyclopropylmethoxy-4-difluoromethoxybenzoic acid is at least 1.5 and at most 3, preferably at least 1.8 and at most 2.7 particularly preferably at least 2 and at most 2.5 and very particularly preferably 2.2
这项发明涉及一种制备高纯度
罗氟司特的新工艺。该工艺涉及将4-
氨基-3,5-二
氯吡啶(I)的阴离子与3-环丙基甲氧基-4-
二氟甲氧基苯甲酸(II)的活化衍
生物反应,其特征在于所使用的4-
氨基-3,5-二
氯吡啶的阴离子与3-环丙基甲氧基-4-
二氟甲氧基苯甲酸的活化衍
生物的摩尔比至少为1.5且最多为3,最好至少为1.8且最多为2.7,特别好至少为2且最多为2.5,非常特别好至少为2.2。