Tulathromycin Impurity 7

(2R,3R,4S,5R,8R,10R,11R,12S,13R,14R) -11- (((2S,3R,4S,6R) -4- (dimethylamino) -3-hydroxy-6-methyltetrahydro-2H-pyran-2-yl) oxy) -2-ethyl-4,10-dihydroxy-13- (((2R,4R,5S,6S) -5-hydroxy-4-methoxy-4,6-dimethyl-5- ((propylamino) methyl) tetrahydro-2H-pyran-2-yl) oxy) -3,5,8,10,12,14-hexamethyl-1-oxa-6-azacyclopentadecan-15-one