The present invention provides a compound of formula I having BACE1 inhibitory activity, their manufacture, pharmaceutical compositions containing them and their use as therapeutically active substances. The active compounds of the present invention are useful in the therapeutic and/or prophylactic treatment of e.g. Alzheimer's disease.COMPUESTOS DERIVADOS DE N-(3-(5-AMINO-3,6-DIHIDRO-2H-1,4-TIAZIN-3-IL)FENIL)AMIDA COMO INHIBIDORES DE BACE 1; COMPOSICIÓN FARMACÉUTICA; Y USO DEL COMPUESTO CONTRA LA ENFERMEDAD DE ALZHEIMER.