Abstract: A process for preparing a procatalyst for polymerization of olefins, comprising contacting a magnesium-containing support with a halogen-containing titanium compound, and an internal electron donor according to Formula (I), said process comprising the steps of: i) contacting a compound R4zMgX42-z with an alkoxy- or aryloxy-containing silane compound to give a first intermediate reaction product, being a solid Mg(OR1)xX12-x, ii) optionally contacting the solid Mg(OR1)xX12-x obtained in step ii) with at least one activating compound selected from the group formed by activating electron donors and metal alkoxide compounds of formula M1(OR2)v-w(OR3)w or M2(OR2)v-w(R3)w, to obtain a second intermediate product; iii) contacting the first or second intermediate reaction product, obtained respectively in step i) or ii), with a halogen-containing Ti-compound and said compound represented Formula (I), as the internal electron donor.

Abstract: The present invention relates to a process for preparing a procatalyst for polymerization of olefins, comprising contacting a magnesium-containing support with a halogen-containing titanium compound, a monoester, a first internal electron donor, wherein the internal electron donor is represented by a compound represented by Formula A, for example a Fischer projection of Formula A, and optionally a second internal electron donor selected from a group consisting of diesters and diethers, Formula A said process comprising the steps of: i) contacting a butyl Grignard compound with an alkoxy- or aryloxy-containing silane compound to give a first intermediate reaction product; ii) optionally activating the first intermediate reaction product with at least one activating compound to give a second intermediate reaction product; iii) contacting the first or second intermediate reaction product, obtained respectively in step i) or ii), with a halogen-containing Ti-compound, the monoester, and said internal electron rep