Ask for money from hoodlum exchanging grand for cocaine (5)
I believe the answer is:
touch
'ask for money from' is the definition.
(touch can mean to pressure someone for money)
I don't understand how the remainder of the clue works.
(Other definitions for touch that I've seen before include "Manner of playing piano, say" , "Hint" , "Pinch" , "spot" , "Move" .)