Convert file .xlsx or .docx to .pdf

public jsonResult Convertfiletopdf(string filename , string filePatgh)

    {
        try
        {

            filePatgh = Path.Combine(Server.MapPath("~/Uploads/"));
            if (filename.Contains(".xlsx"))
            {
                var newfilename = filename.Replace(".xlsx", ".pdf");
                var app = new Application();
                var wkb = app.Workbooks.Open(filePatgh + filename);
                if (!System.IO.File.Exists(filePatgh + newfilename))
                {                      
                    wkb.ExportAsFixedFormat(
                        XlFixedFormatType.xlTypePDF,
                        filePatgh + newfilename,
                        XlFixedFormatQuality.xlQualityStandard,
                        true, true, 1, 10, false);

                }
                wkb.Close();

            }
            if (filename.Contains(".xls"))
            {
                var newfilename = filename.Replace(".xls", ".pdf");
                var app = new Application();
                var wkb = app.Workbooks.Open(filePatgh + filename);

                if (!System.IO.File.Exists(filePatgh + newfilename))
                {
                    wkb.ExportAsFixedFormat(
                        XlFixedFormatType.xlTypePDF,
                        filePatgh + newfilename,
                        XlFixedFormatQuality.xlQualityStandard,
                        true,
                        true,
                        1,
                        10,
                        false);

                    // wkb.ExportAsFixedFormat(XlFixedFormatType.xlTypePDF, filePatgh + newfilename);
                }
                wkb.Close();
            }
            else
            {

                var objWorPdf = new Word2Pdf();
                var fromLocation = filePatgh + "\\" + filename;
                var fileExtension = Path.GetExtension(filename);

                var changeExtension = filename.Replace(fileExtension, ".pdf");
                object toLocation = filePatgh + "\\" + changeExtension;
                objWorPdf.InputLocation = fromLocation;
                objWorPdf.OutputLocation = toLocation;
                if (!System.IO.File.Exists(filePatgh + changeExtension))
                {
                    objWorPdf.Word2PdfCOnversion();
                }



            }
            return Json(filename, JsonRequestBehavior.AllowGet);
        }
        catch (Exception ex)
        {
            throw ;
        }
    }