ignoring variable containing and multiple spaces usnig sed command

I have two variables,

first= new pool ser/@10.25.89.322 
second=ESX_10.2.3.4@10.52.33.21

i want to replace ESX_10.2.3.4@10.52.33.21 with new pool ser/@10.25.89.322 and also want to remove space before new word.

i have tried like,

sed -i -e "s/${second}/"${first//\/\\}"/g"

and

sed -i -e "s/${second}/"${first//\[ ]*/\\}"/g"
sed -i -e "s/${second}/"${first//\ */ *\\}"/g"

I don’t want to delete space ,just want to replace as it is(except space before “new”).

Answer

Give a try to this:

sed -i "/${second}/ {s:${second}:${first//\/\\}:g ; s/ new /new /}"

It is removing the space in the first occurrence of new in the line after replacement.

Also, in the test below, double-quote were added:

$ first=" new pool ser/@10.25.89.322" 
$ second=ESX_10.2.3.4@10.52.33.21
$ sed -i "/${second}/ {s:${second}:${first//\/\\}:g ; s/ new /new /}" mytestfile.txt