Compounds of formula I are disclosed:
in which X is a 5-membered heteroaryl ring and R is as defined herein. The compounds are inhibitors of the processing of APP by gamma-secretase, and hence are useful in the treatment or prevention of Alzheimer's disease.
                            公开了式子I的化合物:其中X是5-成员的杂环芳基环,R如此定义。这些化合物是γ-分泌酶处理APP的
抑制剂,因此在治疗或预防阿尔茨海默病方面是有用的。