Direct B-alkyl Suzuki-Miyaura cross-coupling of 2-halopurines. Practical synthesis of ST1535, a potent adenosine A2A receptor antagonist.
The scope and limitations of using palladium-catalyzed cross-coupling reactions of diverse butyl metal species with two different 2-halopurines were evaluated. While tributylboranes reacted readily and regioselectively with both 2-chloro-6-dibenzylaminopurines and 2-iodo-6-chloropurines, all the other alkyl metal species were much less reactive and gave very poor yield and/or selectivity of the desired product. This protocol was applied to the synthesis of an important adenosine A(2A) receptor antagonist, ST1535.
Bartoccini
Francesca
F
Department of Drug and Health Sciences, University of Urbino Carlo Bo, P.zza Rinascimento 6, 61029 Urbino (PU), Italy.
Cabri
Walter
W
Celona
Diana
D
Minetti
Patrizia
P
Piersanti
Giovanni
G
Tarzia
Giorgio
G
D000225:Adenine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D011687:Purines / Q000737:chemistry*; D043705:Receptor, Adenosine A2A / Q000378:metabolism*; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry
C506291:2-n-butyl-9-methyl-8-(1,2,3)triazol-2-yl-9H-purin-6-ylamine; D011687:Purines; D043705:Receptor, Adenosine A2A; D014230:Triazoles; D000225:Adenine