1-(4-((3'-Chloro-6-Methoxy-[1,1'-biphenyl]-3-yl)Methyl)phenyl)urea

D-159687 is a selective inhibitor of cyclic AMP phosphodiesterase 4D (PDE4D).

D159687 is a brain-penetrant, orally available, highly potent and selective negative allosteric modulator (NAM) against phosphodiesterase 4 (PDE4) subtype PDE4D (hPDE4D7 IC50 = 27 nM; PDE4A1/B1/C1 IC50 = 2.50/1.47/6.80 μM; IC50 ≥29 μM against PDE1/2/3/5/7/8/9/10/11 subtypes). Comparing to Rolipram, D159678 offers similar in vivo efficacy on long-term memory formation by novel object recognition test (MED = 3 μg/kg mouse iv., 1 μg/kg r at p.o.), while being more effective in the scopolamine-impaired Y-maze tests (D159678/Rolipram MED = 0.1/1 μg/kg mouse iv. or 30/100 μg/kg mouse p.o.) and much less emetic in shrews/dog/monkeys (by 100-/3000-/500-fold).