[Sproc_of_interest]
in the pattern syntax is interpreted as matching one character that is in the set S,p,r,o,c,_,o,f,_,i,n,t,e,r,e,s,t
.
Three possible ways of solving this are below.
1) Escape [
with square brackets
LIKE '%exec [[]Sproc_of_interest] @parm1=%'
2) Use an escape character
LIKE 'exec \[Sproc_of_interest] @parm1=' ESCAPE '\'
3) Use CHARINDEX
instead of escaping anything
WHERE CHARINDEX('exec [Sproc_of_interest] @parm1=' , TextData) > 0