Fostamatinib901119-35-5100 % similar 6-[[5-Fluoro-2-[(3,4,5-trimethoxyphenyl)amino]-4-pyrimidinyl]amino]-2,2-dimethyl-2H-pyrido[3,2-b]-1,4-oxazin-3(4H)-one841290-80-061 % similar Fostamatinib disodium914295-16-252 % similar R406841290-81-142 % similar