You can check solutions in this link: http://www.codeproject.com/Questions/346784/How-to-convert-word-document-to-pdf-in-Csharp
I recommend using this among solutions as first:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Microsoft.Office.Interop.Word;
public partial class Default2 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Microsoft.Office.Interop.Word.Application appWord = new Microsoft.Office.Interop.Word.Application();
wordDocument = appWord.Documents.Open(@"D:\desktop\xxxxxx.docx");
wordDocument.ExportAsFixedFormat(@"D:\desktop\DocTo.pdf", WdExportFormat.wdExportFormatPDF);
}
public Microsoft.Office.Interop.Word.Document wordDocument { get; set; }
}
