112928-27-5Relevant articles and documents
From simple quinoxalines to potent oxazolo[5,4-: F] quinoxaline inhibitors of glycogen-synthase kinase 3 (GSK3)
Lassagne, Frédéric,Duguépéroux, Camille,Roca, Carlos,Perez, Concepcion,Martinez, Ana,Baratte, Blandine,Robert, Thomas,Ruchaud, Sandrine,Bach, Stéphane,Erb, William,Roisnel, Thierry,Mongin, Florence
, p. 154 - 162 (2019)
2,7-Disubstituted oxazolo[5,4-f]quinoxalines were synthesized from 6-amino-2-chloroquinoxaline in four steps (iodination at C5, substitution of the chloro group, amidation and copper-catalysed cyclization) affording 28 to 44% overall yields. 2,8-Disubstituted oxazolo[5,4-f]quinoxaline was similarly obtained from 6-amino-3-chloroquinoxaline (39% overall yield). For the synthesis of other oxazolo[5,4-f]quinoxalines, amidation was rather performed before substitution; moreover, time-consuming purification steps were avoided between the amines and the final products (38 to 54% overall yields). Finally, a more efficient method involving merging of the last two steps in a sequential process was developed to access more derivatives (37 to 65% overall yields). Most of the oxazolo[5,4-f]quinoxalines were evaluated for their activity on a panel of protein kinases, and a few 2,8-disubstituted derivatives proved to inhibit GSK3 kinase. While experiments showed an ATP-competitive inhibition on GSK3β, structure-activity relationships allowed us to identify 2-(3-pyridyl)-8-(thiomorpholino)oxazolo[5,4-f]quinoxaline as the most potent inhibitor with an IC50 value of about 5 nM on GSK3α.