Based on the potent phosphodiesterase 10 A (PDE10A) inhibitor PQ‐10, we synthesized 32 derivatives to determine relationships between their molecular structure and binding properties. Their roles as potential positron emission tomography (PET) ligands were evaluated, as well as their inhibitory potency toward PDE10A and other PDEs, and their metabolic stability was determined in vitro. According to our findings, halo‐alkyl substituents at position 2 of the quinazoline moiety and/or halo‐alkyloxy substituents at positions 6 or 7 affect not only the compounds′ affinity, but also their selectivity toward PDE10A. As a result of substituting the methoxy group for a monofluoroethoxy or difluoroethoxy group at position 6 of the quinazoline ring, the selectivity for PDE10A over PDE3A increased. The same result was obtained by 6,7‐difluoride substitution on the quinoxaline moiety. Finally, fluorinated compounds (R)‐7‐(fluoromethoxy)‐6‐methoxy‐4‐(3‐(quinoxaline‐2‐yloxy)pyrrolidine‐1‐yl)quinazoline (16 a), 19 a–d, (R)‐tert‐butyl‐3‐(6‐fluoroquinoxalin‐2‐yloxy)pyrrolidine‐1‐carboxylate (29), and 35 (IC₅₀ PDE10A 11–65 nM) showed the highest inhibitory potential. Further, fluoroethoxy substitution at position 7 of the quinazoline ring improved metabolic stability over that of the lead structure PQ‐10.

中文翻译：

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含氟6,7-二烷氧基联芳基的磷酸二酯酶10 A抑制剂：抑制力，选择性和代谢的合成和体外评估。

基于有效的磷酸二酯酶10 A（PDE10A）抑制剂PQ-10，我们合成了32种衍生物，以确定其分子结构与结合特性之间的关系。评估了它们作为潜在的正电子发射断层扫描（PET）配体的作用，以及它们对PDE10A和其他PDE的抑制能力，并在体外确定了它们的代谢稳定性。根据我们的发现，喹唑啉部分2位的卤代烷基取代基和/或6位或7位的卤代烷氧基取代基不仅影响化合物的亲和力，而且还影响其对PDE10A的选择性。由于在喹唑啉环的6位上用甲氧基取代了单氟乙氧基或二氟乙氧基，PDE10A相对于PDE3A的选择性增加了。通过6获得相同的结果 喹喔啉部分上的7-二氟取代。最后，氟化物（R）-7-（氟甲氧基）-6-甲氧基-4-（3-（喹喔啉-2-基氧基）吡咯烷-1-基）喹唑啉（16 a），19 a - d，（R）-叔丁基- 3-（6-氟喹喔啉-2-基氧基）吡咯烷-1-羧酸酯（29）和35（IC ₅₀ PDE10A 11-65 n M）表现出最高的抑制潜力。此外，与铅结构PQ-10相比，喹唑啉环7位上的氟乙氧基取代改善了代谢稳定性。