Fimasartan Impurity 6

2- (2-butyl-4-methyl-1- ((2'- (1-methyl-1H-tetrazol-5-yl) -[1,1'-biphenyl]-4-yl) methyl) -6-oxo-1,6-dihydropyrimidin-5-yl) -N, N-dimethylethanethioamide--2- (2-butyl-4-methyl-1- ((2'- (2-methyl-2H-tetrazol-5-yl) -[1,1'-biphenyl]-4-yl) methyl) -6-oxo-1,6-dihydropyrimidi