Saxagliptin Dimer Impurity 92

1- ((S) -2- ((1S,3S,5S) -3-cyano-2-azabicyclo[3.1.0]hexan-2-yl) -1- ((1r,3R,5R,7S) -3-hydroxyadamantan-1-yl) -2-oxoethyl) -3- ((S) -2- ((1S,3S,5S) -3-cyano-2-azabicyclo[3.1.0]hexan-2-yl) -1- ((1s,3R,5R,7S) -3-hydroxyadamantan-1-yl) -2-oxoethyl) urea