Acetic acid 2-(3-{(R)-(4-{amino[2-methylallyloxycarbonylimino]methyl}phenylamino)-[5-(1-ethylpropoxycarbonyloxymethoxy)-1-pyrimidin-2-yl-1H-[1,2,4]triazol-3-yl]methyl}-2-fluoro-5-methoxyphenoxy)ethyl ester