I raised this question before , but it was probably not the apropriate time, so it got deleted.
"At what time can we confirm the last positive action of the crew in the cockpit"?
regards
2:01.
According to sec 1.16.2.1 of the BEA report, AF447 made 3 attempts to connect to Dakar ADS-C: at 1:33, 1:35 and 2:01. (These were rejected because of a flight plan absence or mismatch.)