This preparation is based on an adaptation of the method described by Buchwald, et al, J. Am. Chem. Soc., 1996, 118, 7215. To a toluene solution of 2-cyclohexylamino-6-methoxy-7-bromo-quinoxaline (0.1 g, 0.3 mmol) under argon is added morpholine (0.1 g, 0.3 mmol), sodium tert-butoxide (0.04 g, 0.42 mmol), S-(−)-BINAP (cat., 0.001 g), and Pd(dba)2(cat., 0.001 g). The reaction mixture is heated to 80° C. overnight. The mixture is cooled, diluted with Et2O, filtered, concentrated, and chromatographed (50% EtOAc/hexanes). The product is recrystallized from EtOAc/hexanes to provide, in two crops, to provide a yellow solid (m.p. 194-196° C.). Anal. Calcd. for C19H26N4O2: C, 66.64; H, 7.65; N, 16.36; Found: C, 66.60; H, 7.60; N, 16.51.
