Design and synthesis of trans-N-[4-[2-(6-cyano-1,2,3, 4-tetrahydroisoquinolin-2-yl)ethyl]cyclohexyl]-4-quinolinecarboxamide (SB-277011): A potent and selective dopamine D(3) receptor antagonist with high oral bioavailability and CNS penetration in the rat.
A selective dopamine D(3) receptor antagonist offers the potential for an effective antipsychotic therapy, free of the serious side effects of currently available drugs. Using clearance and brain penetration studies as a screen, a series of 1,2,3, 4-tetrahydroisoquinolines, exemplified by 13, was identified with high D(3) affinity and selectivity against the D(2) receptor. Following examination of molecular models, the flexible butyl linker present in 13 was replaced by a more conformationally constrained cyclohexylethyl linker, leading to compounds with improved oral bioavailability and selectivity over other receptors. Subsequent optimization of this new series to improve the cytochrome P450 inhibitory profile and CNS penetration gave trans-N-[4-[2-(6-cyano-1, 2,3, 4-tetrahydroisoquinolin-2-yl)ethyl]cyclohexyl]-4-quinolinecarbo xamide (24, SB-277011). This compound is a potent and selective dopamine D(3) receptor antagonist with high oral bioavailability and brain penetration in the rat and represents an excellent new chemical tool for the investigation of the role of the dopamine D(3) receptor in the CNS.
Stemp
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Department of Discovery Chemistry, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW, UK. Geoff_Stemp-1@sbphrd.com
Ashmeade
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Branch
C L
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Hadley
M S
MS
Hunter
A J
AJ
Johnson
C N
CN
Nash
D J
DJ
Thewlis
K M
KM
Vong
A K
AK
Austin
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Jeffrey
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Avenell
K Y
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Boyfield
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Hagan
J J
JJ
Middlemiss
D N
DN
Reavill
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Riley
G J
GJ
Routledge
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Wood
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D000818:Animals; D001682:Biological Availability; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D016466:CHO Cells; D002375:Catalepsy / Q000139:chemically induced / Q000523:psychology; D002490:Central Nervous System / Q000187:drug effects / Q000378:metabolism*; D006224:Cricetinae; D018492:Dopamine Antagonists / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology; D006207:Half-Life; D006801:Humans; D008297:Male; D017551:Microdialysis; D009570:Nitriles / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology; D011388:Prolactin / Q000097:blood; D011804:Quinolines / Q000138:chemical synthesis* / Q000493:pharmacokinetics / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000187:drug effects*; D050637:Receptors, Dopamine D3; D044005:Tetrahydroisoquinolines
C493593:DRD3 protein, human; D018492:Dopamine Antagonists; C493595:Drd3 protein, rat; D009570:Nitriles; D011804:Quinolines; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; C409982:SB 277011; D044005:Tetrahydroisoquinolines; D011388:Prolactin