[6-(4-Carbamimidoyl-phenylethynyl)-1-oxo-3,4-dihydro-1H-isoquinolin-2-yl]-acetic acid tert-butyl ester

{6-[4-(tert-Butoxycarbonylamino-imino-methyl)-phenylethynyl]-1-oxo-3,4-dihydro-1H-isoquinolin-2-yl}-acetic acid tert-butyl ester

6-amino-3,4-dihydro-1-oxo-2(1H)-isoquinolineacetic acid 1,1-dimethylethyl ester

(6-{2-[4-(tert-Butoxycarbonylamino-imino-methyl)-phenyl]-ethyl}-1-oxo-3,4-dihydro-1H-isoquinolin-2-yl)-acetic acid tert-butyl ester

(6-{(Z)-2-[4-(tert-Butoxycarbonylamino-imino-methyl)-phenyl]-vinyl}-1-oxo-3,4-dihydro-1H-isoquinolin-2-yl)-acetic acid tert-butyl ester