how to replace text which has ' using sed

Question

It' s easy to find and replace text in sed using

sed 's/text/replace_text/g'

But how to use this if we have ' in text or replace_text? I want to replace { by '{ for an awk script.

I tried different ways:

• sed 's/{/'{/g' 22 > 23

  results in Unmatched '.

• sed 's/{/"'"{/g' 22 > 23

  result in Unmatched ".

Can anyone tell how to do it?