Lopinavir EP Impurity D 

Chemical Name: (1R,3R)-1-[(1R)-1-[[2-(2,6-Dimethylphenoxy)acetyl]amino]-2-phenylethyl]-3-[[(2R)-3-methyl-2-[2-oxotetrahydropyrimidin-1(2H)-yl]butanoyl]amino]-4-phenylbutyl hydrogen sulfate (as per EP);

Synonym: (6S,8R,9S,10R,13S,14S,17R)-17-acetyl-17-hydroxy-10,13-dimethyl-6-(methyl-d3)-1,2,6,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-3H-cyclopenta[a]phenanthren-3-one