1-[(4-{1-[(2,6-difluorophenyl)methyl]-5-[(dimethylamino)methyl]-3-(6-methoxy-1,2-diazin-3-yl)-2,4-dioxothieno[2,3-d]pyrimidin-6-yl}phenyl)amino]-N-{[(4-{1-[(2,6-difluorophenyl)methyl]-5-[(dimethylamino)methyl]-3-(6-methoxy-1,2-diazin-3-yl)-2,4-dioxothieno[2,3-d]pyrimidin-6-yl}phenyl)amino]carbonyl}-N-methoxymethanamide 2,2,2-trifluoroacetic acid