1-(7-Bromo-4-methyl-3,4-dihydropyrido[2,3-b]-pyrazin-1(2H)-yl)-2,2-dimethylpropan-1-one1-(7-bromo-4-methyl-3,4-dihydropyrido[2,3-b]pyrazin-1(2H)-yl)-2,2-dimethylpropan-1-one1-(7-bromo-4-methyl-3,4-dihydropyrido[2,3-b]pyrazin-1(2H)-yl)-2,2-dimethylpropan-1-one