Here is the solution that worked for me
This code snippet needs any explanation, because it's clear to understand.
using Word = Microsoft.Office.Interop.Word;
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object FileName = @"c:\WordDocument.docx";
object falseValue = false;
object missingValue = Missing.Value;
Word.Application wordApplication = new Word.Application();
Word.Document wordDocument = wordApplication.Documents.Open(ref FileName,
ref missingValue, ref missingValue, ref missingValue, ref missingValue,
ref missingValue, ref missingValue, ref missingValue, ref missingValue,
ref missingValue, ref missingValue, ref missingValue, ref missingValue,
ref missingValue, ref missingValue, ref missingValue);
object EndOfPage = @"\page";
object wdWhat = WdGoToItem.wdGoToPage;
object wdWich = WdGoToDirection.wdGoToNext;
object count = (object)1;
int TotalPages, i;
TotalPages = wordDocument.ComputeStatistics(WdStatistic.wdStatisticPages, ref falseValue);
for (i = 1; i <= TotalPages; i++)
{
Word.Range range = wordDocument.Bookmarks.get_Item(ref EndOfPage).Range;
range.ExportAsFixedFormat(path, Word.WdExportFormat.wdExportFormatPDF);
range = range.GoTo(ref wdWhat, ref wdWich, ref count, ref missingValue);
range.Select();
}