Transformando um AxMapControl em arquivo .MXD

SaveMap.cs

public void saveMap()
        {
            IMapDocument mapDocument = new MapDocumentClass();
            mapDocument.Open("C:\\temp\\Teste.mxd", string.Empty);
            //if (mapDocument.get_IsReadOnly(@"[path to your .mxd]"))
            //{
            //    System.Windows.Forms.MessageBox.Show("Map document \"" + @"[path to your .mxd]" + "\" is read only!");
            //    mapDocument.Close();
            //    return;
            //}
            mapDocument.ReplaceContents((IMxdContents)axMapControlPrincipal.Map);
            mapDocument.SaveAs("C:\\temp\\Teste1.mxd", false, true);
            mapDocument.Close();
        }