There are provided according to the invention novel compounds of formula (I) and pharmaceutically acceptable salts and solvates thereof,
wherein:
R
1
is phenyl which may be unsubstituted or substituted by one or two substituents selected from fluorine, chlorine, C
1-2
alkoxy-, —CN; phenyl fused to a 5-membered saturated ring containing one oxygen atom; pyridinyl which may be unsubstituted or substituted by one or two substituents selected from fluorine or chlorine; or C-linked pyrazolyl which may be unsubstituted or substituted by the substituent C
1-2
alkyl;
R
2
is C
1-4
alkyl;
R
3
is C
1-2
alkyl; and
n is 0, 1 or 2.
根据本发明提供了公式(I)的新化合物及其药学上可接受的盐和溶剂化物,其中:R1为苯基,可以是未取代的或取代的,所述取代基包括
氟、
氯、C1-2烷氧基、—CN;与含有一个氧原子的5元饱和环融合的苯基;可以是未取代的或取代的
吡啶基,所述取代基包括
氟或
氯;或者是C-连接的
吡唑基,所述取代基可以是未取代的或取代的C1-2烷基;R2为C1-4烷基;R3为C1-2烷基;n为0、1或2。