Bortezomib Impurity 50

Chemical Name: N,N',N''-((2R,2'R,2''R)-(((1R,1'R,1''R)-(1,3,5,2,4,6-trioxatriborinane-2,4,6-triyl)tris(3-methylbutane-1,1-diyl))tris(azanediyl))tris(1-oxo-3-phenylpropane-1,2-diyl))tris(pyrazine-2-carboxamide)