The present invention provides a compound having the structure: (structurally represented) wherein R1, R2, R3, R4, and R5 are each independently H, halogen, CF3 or C1-C4 alkyl; R6 is alkyl; A is absent or present, and when present is —C(O)— or —C(O)NH—; B is substituted or unsubstituted monocycle, bicycle, heteromonocycle, heterobicycle, benzyl, CO2H or (C1-C4 alkyl)-CO2H, wherein when B is CO2H, then A is present and is —C(O)—, or a pharmaceutically acceptable salt thereof.
本发明提供了一种具有以下结构的化合物:(结构表示)其中R1、R2、R3、R4和R5各自独立地为H、卤素、
CF3或C1-C4烷基;R6为烷基;A不存在或存在,当存在时为—C(O)—或—C(O)NH—;B为取代或未取代的单环、双环、杂单环、杂双环、苄基、CO2H或(C1-C4烷基)-CO2H,其中当B为CO2H时,A存在且为—C(O)—,或其药学上可接受的盐。