4-trans-2-carboxy-5,7-dichloro-4-phenylaminocarbonylamino-1,2,3,4-tetrahydroquinoline [ L 689560,L-689,560,L-689560,trans-2-carboxy-5,7-dichloro-4-(((phenylamino)carbonyl)amino)-1,2,3,4-tetrahydroquinoline ] structure given in first source; selective antagonist for the glycine site on the N-methyl-D-aspartate (NMDA) receptor