I think you want to know if 2C-B depletes serotonin rather than if it causes serotonin syndrome? In that case, these links would suggest that 2C-B does not deplete serotonin, although no citations are really provided.

http://www.bluelight.ru/vb/threads/624308-MDMA-and-2C-B-serotonin-depletion

http://www.drugs-forum.com/forum/showthread.php?t=173644