The father-of-two spent almost two days on life support machine before he was pronounced dead after he was knocked to the floor by a single punch outside the Rota Express in Mill Hill Broadway on Saturday, police said.
Police said Mr Patel was working in the shop when a group of teenagers entered the shop and attempted to buy items including cigarette papers but were refused.
The group became aggressive and attacked Mr Patel when a colleague went outside.
The three teenagers then attacked the colleague on the way out before fleeing from the scene.
Mr Patel family said he had moved to the UK from India in 2006 to provide a better life for his children and wife.
Mr Patel worked at the Rota Express Convenience store in The Broadway, Mill Hill where people who knew him described him as “very nice” and “a good natured guy.”
A crowd-funding appeal for Mr Patel’s family raised more than £10,000 in just 12 hours.