The invention relates to compounds of formula (I), their enantiomers, diastereoisomers, N-oxides, as well as their pharmaceutically acceptable acid or base addition salts.

• 本发明涉及式(I)化合物、其对映异构体、非对映异构体、N-氧化物以及它们的药学上可接受的酸或碱的加成盐。