Macitentan Impurity 4 Catalogue M102659 CAS 556796-88-4 M.W 545.21 M.F C17H15Br2N5O4S Specifications FAQs N-(5-(4-Bromophenyl)-6-(2-(5-bromopyrimidin-2-yloxy)ethoxy)pyrimidin-4-yl)methanesulfonamide