Doctor added essence of phenol — it got nowhere (4,3)
I believe the answer is:
dead end
'it got nowhere' is the definition.
The definition suggests a singular noun which matches the answer.
'doctor added essence of phenol' is the wordplay.
'doctor' indicates an anagram.
'essence of' says to take the centre.
The middle letters of 'phenol' are 'en'.
'added'+'en'='addeden'
'addeden' is an anagram of 'DEAD-END'.
Can you help me to learn more?
(Other definitions for dead end that I've seen before include "Where no progress can be made" , "Blind alley, closed passage" , "that's leading nowhere" , "Situation with no way forward" , "Blind alley, cul-de-sac" .)