Yes, SYNCOPES is a Scrabble word!

Letter values in Scrabble US: S 1, Y 4, N 1, C 3, O 1, P 3, E 1, S 1.

Is it a valid word?

SYNCOPES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a spontaneous loss of consciousness caused by insufficient blood to the brain
(phonology) the loss of sounds from within a word (as in `fo'c'sle' for `forecastle')

Not playable in Scrabble US: DELIQUIUM.