[際「さい」]して/に([際「さい」]し)/に[際「さい」]しての => At the time of A (which starts now).. N2
Time, Situation
中 => Throughout, all over, during the course of N5
Time
[最中「さいちゅう」] => In the middle of A N3
Time, Situation
[中心「ちゅうしん」]に => With A as the center N2
Miscellaneous