| abstract |
The present invention relates to a fused aminodihydrothiazine derivative of formula (I): n n n n n n n n n n whereinn X is hydrogen or fluorine; A is CH or N; Y is methyl, ethyl, monofluoromethyl, difluoromethyl, trifluoromethyl, difluoroethyl, methoxy, ethoxy, methoxymethyl or —C≡N;n nand pharmaceutically acceptable salts thereof;n nwhich compound has an Aβ production inhibitory effect or a BACE1 inhibitory effect and is useful as a prophylactic or therapeutic agent for a neurodegenerative disease caused by Aβ and typified by Alzheimer-type dementia. |