(3-{2-[5-Chloro-3-(4-fluoro-phenylamino)-6-methyl-2-oxo-2H-pyrazin-1-yl]-acetylamino}-benzyl)-carbamic acid tert-butyl ester

(3-{2-[5-Chloro-3-(4-methoxy-benzylamino)-6-methyl-2-oxo-2H-pyrazin-1-yl]-acetylamino}-benzyl)-carbamic acid tert-butyl ester

(4-{4-[(3-Amino-phenylcarbamoyl)-methyl]-6-chloro-5-methyl-3-oxo-3,4-dihydro-pyrazin-2-ylamino}-cyclohexyl)-carbamic acid tert-butyl ester

[4-(6-Chloro-4-{[2-(1H-imidazol-4-yl)-ethylcarbamoyl]-methyl}-5-methyl-3-oxo-3,4-dihydro-pyrazin-2-ylamino)-cyclohexyl]-carbamic acid tert-butyl ester

(4-{4-[(4-Amino-phenylcarbamoyl)-methyl]-6-chloro-5-methyl-3-oxo-3,4-dihydro-pyrazin-2-ylamino}-cyclohexyl)-carbamic acid tert-butyl ester