The NYPD says the 38-year-old woman walked into the lobby of the building when the man slapped her backside.
It happened Sunday at 3:30 a.m. near 190 Street and Woodhull Avenue in Hollis.
The man followed her into the elevator and began punching and kicking her.
The attacker said he was going to rape the victim and then forcibly removed her shirt and bra.
He then grabbed her iPhone and fled.
The woman suffered bruising and swelling to her face. She was taken to Jamaica Hospital in stable condition.
Anyone with information in regard to this incident is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).
RELATED | Bronx DA Darcel Clark to man who shot baby girl: 'You're not going to get away with it'
* More Queens news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube