Dalbavancin Impurity 19

(3S,15R,18R,34R,35S,38S,48R,50aR) -5,55-dichloro-56- (((2S,3R,4R,5S,6S) -4,5-dihydroxy-6- (methoxycarbonyl) -3- (10-methylundecanamido) tetrahydro-2H-pyran-2-yl) oxy) -15- (dimethylamino) -6,11,34,40,44-pentahydroxy-2,16,36,50,51,59-hexaoxo-42- (((2R,3S,4S,5S,6R) -3,4,5-trihydroxy-6- (hydroxymethyl) tetrahydro-2H-pyran-2-yl) oxy) -2,3,16,17,18,19,35,36,37,38,48,49,50,50a-tetradecahydro-1H,15H,34H-3,18:35,48-bis (epiminomethano) -20,23:30,33-dietheno-4,8:10,14:25,28:43,47-tetra (metheno) benzo[14,15][1]oxa[7,17]diazacyclotetracosino[4,5-d][1,14]dioxa[6,22]diazacyclooctacosine-38-carboxylic acid