benzyl 2-[(3S)-1-[2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetyl]-3-(naphthalene-1-carbonylamino)-4-oxo-2,3-dihydro-1,5-benzodiazepin-5-yl]acetate;2-[9H-fluoren-9-ylmethoxycarbonyl(methyl)amino]acetic acid;9H-fluoren-9-ylmethyl N-[2-[(3S)-5-[2-[[(1Z,2S)-1-(carbamoylhydrazinylidene)-4-oxopentan-2-yl]amino]-2-oxoethyl]-3-(naphthalene-1-carbonylamino)-4-oxo-2,3-dihydro-1,5-benzodiazepin-1-yl]-2-oxoethyl]-N-methylcarbamate;9H-fluoren-9-ylmethyl N-(2-chloro-2-oxoethyl)-N-methylcarbamate