Depends on how this flight was booked. If booked as a single "direct" flight 842 -- the based mileage credit is 6,156 -- the great circle distance. If booked as two separate segments then it would be 5,252+1,745 = 6,997.
Actually, the flight listing on united.com showed a single flight with the miles value equal to the sum of the segments. The confirmation itinerary looked like this for the outbound, similar for the return:
UNITED 843
Depart: LOS ANGELES 1:30 PM
Arrive: SAO PAULO/GRU 12:02 PM
Seat(s): STOPOVER
Equip: PLANE CHANGE AT ORD
MP miles: 6997
When posted in my MP account, it shows as two separate flights.
There is another inconsistency: When I tried to upgrade only the domestic portion of the outbound (the international leg was F0C0), I could not do it and neither apparently could a couple of agents who told me that they had listed me for an upgrade but in fact had not. I did eventually get an upgrade, but it took four tries:
(1) When I tried to request the upgrade on united.com I found it would only accept a request for the whole journey (LAX-GRU) and would only accept miles or an SWU as the means to pay for it. This makes it seem as if the system viewed the two segments as one indivisible international flight. I called and was told the request was in. There was no indication on united.com that such a request was in fact "in".
(2) When the supposed requested upgrade failed to transition to "waitlisted" at the 1P window, I called again and was told the same thing.
(3) When I did OLCI 24 hours before departure there was again no indication of the upgrade request ever having existed. I called and was told that I had not been on the upgrade list but now was.
(4) I inquired at the check-in desk at LAX and received a DM card showing I was added to the list as of that time. I think this confirms that I was not previously on the upgrade list. I got the upgrade at the gate when a couple decided to decline one upgrade so as to travel together in economy. I got the last seat in F.
Most of this indicates that United views the single flight number/multiple segment international flight as a single international flight, but in this case at least they did list the flight as accruing the miles via ORD and did post my account as two flights.