(S)-ethyl 2-((3R,11aS)-3-methyl-1,4-dioxo-3,4,11,11a-tetrahydro-1H-pyrazino[1,2-b]isoquinolin-2(6H)-yl)-4-phenylbutanoate; Quinapril Diketopiperazine; (?S,3S,11aS)-1,3,4,6,11,11a-Hexahydro-3-methyl-1,4-dioxo-?-(2-phenylethyl)-2H-pyrazino[1,2-b]isoquinoline-2-acetic Acid; PD 109488; USP Quinapril Related Compound A
