A process for producing a polypropylene composition, wherein a propylene random copolymer is polymerized in a multistage polymerization process in the presence of a solid catalyst component comprising a magnesium halide, a titanium halide and an internal electron donor; and a cocatalyst comprising an aluminium alkyl and optionally an external electron donor, and an optional nucleating agent; the multistage process comprising the steps of (a) continuously polymerizing propylene together with a comonomer selected from alpha-olefins with 2 or 4 to 8 carbon atoms, in a first polymerization stage by introducing streams of propylene, hydrogen and said comonomer into the first polymerization stage at a temperature of 60 to 80°C and a pressure of 3000 to 6500 kPa to produce a first propylene random copolymer, wherein said first propylene random copolymer has a melt flow rate MFR 2 (2.16 kg; 230°C; ISO 1133) of from 0.2 to 3.0 g/min; (b) withdrawing from the first polymerization stage a stream comprising said first propylene random copolymer and transferring said stream into a second polymerization stage; (c) polymerizing propylene together with a comonomer selected from alpha-olefins with 2 or 4 to 8 carbon atoms, in said second polymerization stage by introducing streams of propylene, said comonomer and optionally hydrogen into said second polymerization stage at a temperature of 70 to 90°C and a pressure of 1000 to 3000 kPa to produce a propylene random copolymer of said first propylene random copolymer and a second propylene random copolymer, wherein the comonomer content of the propylene random copolymer is in the range of 4.5 to 9.5 mol%, based on the total molar content of the propylene random copolymer; (d) continuously withdrawing a stream comprising said propylene random copolymer from the second polymerization stage and optionally mixing said propylene random copolymer with additives; and (e) extruding said propylene random copolymer mixture into pellets, which have a melt flow rate MFR 2 (2.16 kg; 230°C; ISO 1133) of from 0.05 to 1.0 g/min, wherein the first propylene random copolymer preferably has a higher MFR 2 than the second propylene random copolymer, and wherein the polypropylene composition comprises a nucleating agent that is introduced to the propylene random copolymer during the polymerization process of the propylene random copolymer or in form of a masterbatch together with e.g. a carrier polymer; and wherein the polypropylene composition has a polydispersity index of from 2.0 to 7.0, a melt flow rate MFR 2 (2.16 kg, 230°C) of from 0.05 to 1.0 g/10 min, determined according to ISO 1133, and a Charpy Notched Impact Strength at 0°C of at least 6.0 kJ/m 2, determined according to ISO 179/1eA:2000 using notched injection moulded specimens. a solid catalyst component comprising a magnesium halide, a titanium halide and an internal electron donor; and a cocatalyst comprising an aluminium alkyl and optionally an external electron donor, and an optional nucleating agent; (a) continuously polymerizing propylene together with a comonomer selected from alpha-olefins with 2 or 4 to 8 carbon atoms, in a first polymerization stage by introducing streams of propylene, hydrogen and said comonomer into the first polymerization stage at a temperature of 60 to 80°C and a pressure of 3000 to 6500 kPa to produce a first propylene random copolymer, wherein said first propylene random copolymer has a melt flow rate MFR 2 (2.16 kg; 230°C; ISO 1133) of from 0.2 to 3.0 g/min; (b) withdrawing from the first polymerization stage a stream comprising said first propylene random copolymer and transferring said stream into a second polymerization stage; (c) polymerizing propylene together with a comonomer selected from alpha-olefins with 2 or 4 to 8 carbon atoms, in said second polymerization stage by introducing streams of propylene, said comonomer and optionally hydrogen into said second polymerization stage at a temperature of 70 to 90°C and a pressure of 1000 to 3000 kPa to produce a propylene random copolymer of said first propylene random copolymer and a second propylene random copolymer, wherein the comonomer content of the propylene random copolymer is in the range of 4.5 to 9.5 mol%, based on the total molar content of the propylene random copolymer; (d) continuously withdrawing a stream comprising said propylene random copolymer from the second polymerization stage and optionally mixing said propylene random copolymer with additives; and (e) extruding said propylene random copolymer mixture into pellets, which have a melt flow rate MFR 2 (2.16 kg; 230°C; ISO 1133) of from 0.05 to 1.0 g/min,