Navigator pop Until

 72

Instead of:

          Navigator.of(context).push(
            MaterialPageRoute(
              builder: (context) => Page1(),
            ),
          );

use:

          Navigator.of(context).push(
            MaterialPageRoute(
              settings: RouteSettings(name: "/Page1"),
              builder: (context) => Page1(),
            ),
          );

and then you can use :

Navigator.of(context)
              .popUntil(ModalRoute.withName("/Page1"));