The present invention provides (S)-N-(2-(4-chlorophenyl)-2-morpholinoethyl)-2- (pyrimidin-2-yl)-4-(trifluoromethyl) thiazole-5- carboxamide as P2X7 inhibitor, its use as a medicament, and a convenient enantiomeric synthesis protocol for the preparation of (S )- N -(2-( 4 -chlorophenyl )-2-morpholinoethyl)-2-(pyrimidin-2-yl )-4-( trifluoromethyl )thiazole-5 -carboxamide.