public bool WordToPDF(string sourcePath, string targetPath)
    {
        bool result = false;
        Microsoft.Office.Interop.Word.Application application = new Microsoft.Office.Interop.Word.Application();
        Microsoft.Office.Interop.Word.Document document = null;
        try
        {             
            application.Visible = false;
            document = application.Documents.Open(sourcePath);
            document.ExportAsFixedFormat(targetPath, Microsoft.Office.Interop.Word.WdExportFormat.wdExportFormatPDF);
            result = true;
        }
        catch (Exception e)
        {
            LogHelper.WriteLog(GetType(), e, Level.Error);
            result = false;
        }
        finally
        {
            document.Close();
        }
        return result;
    }