convert pdf to unformatted txt

#!/usr/bin/bash
#create *sh file and move to /usr/bin
if ls *pdf 1> /dev/null 2>&1; then
for i in *pdf;do pdftotext "$i" "$i".txt;done
for i in *pdf.txt;do tr "\n" " " <"$i">"$i".txt;done
for i in *pdf.txt.txt; do sed -e "s/.\{1000\}/&\n\n/g" <"$i">"$i".txt;done
for i in *pdf.txt.txt.txt; do tr '[:upper:]' '[:lower:]' <"$i">"$i".txt;done
rm *pdf.txt *pdf.txt.txt *pdf.txt.txt.txt #*pdf
rename "s/pdf.txt.txt.txt.txt/txt/" *.pdf.txt.txt.txt.txt
else echo "files do not exist"
fi