Reker Ahmed, 17, was beaten up twice over the course of 16 minutes when he and two friends were attacked in Croydon, south London.
The asylum seeker suffered a fractured spine, a bleed on the brain and facial fractures shortly after midnight on 31 March.
Four men, all from Croydon and in their early 20s, were each jailed for four years and two months.
An 18-year-old, Kurt Killick, was sentenced to three years and four months in prison.
They were each found guilty by a jury at trial of two counts of violent disorder.
A sixth man, James Neves, 23, of no fixed address, was given two years and four months for one count of violent disorder.
“This was a cowardly and unprovoked attack by a group of friends on three people who were not known to them,” prosecutor Ben Holt told the court during the trial.
“The precise motive of the attack remains unclear, but there was a racist insult by one defendant at the outset of the attack.”
During the trial, the jury heard that one of the attackers yelled “You are asylum seekers, you are refugees, you have to go back to your country” at Mr Ahmed and his friend.
The attack was so violent that a witness pleaded: “Stop, you’re killing him.”
Mr Ahmed, who has no memory of the attack, said that he has since tried to take his own life, has nightmares and flashbacks and does not sleep properly.
An online campaign to help the teenager inspired donations of more than £59,000 – money which has been placed into a trust fund.
Millie Walder, 18, of Myrtle Road, Croydon, was previously given a community order after pleading guilty to a public order offence.