1: 5-[(3AS,4S,6AR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl]pentanoic acid With tributyl-amine; isobutyl chloroformate in N,N-dimethyl-formamide T=20°C; 0.166667 h; 2: 6-amino-hexanoic acid in N,N-dimethyl-formamide T=5°C; 2 h;

sodium hydroxide in 1,4-dioxane; water T=0 - 20°C; pH=8 - 8.5; Inert atmosphere;

in 1-methyl-pyrrolidin-2-one T=50 - 100°C;

1: triethylamine / 1-methyl-pyrrolidin-2-one / 2 h / 60 °C 2: 1-methyl-pyrrolidin-2-one / 50 - 100 °C View Scheme

1: 74 percent / Et3N / dimethylformamide 2: 85 percent / 1 M NaOH / methanol; H2O / 20 °C View Scheme

1: 74 percent / Et3N / dimethylformamide 2: 85 percent / 1 M NaOH / methanol; H2O / 20 °C View Scheme

1: 6-[5-(2-oxohexahydrothieno[3,4-d]imidazol-6-yl)pentanoylamino]hexanoic acid With N,N,N',N'-tetramethyl-O-(N-succinimidyl)uronium tetrafluoroborate; N-ethyl-N,N-diisopropylamine in water; N,N-dimethyl-formamide T=20°C; 0.333333 h; 2: 6-amino-hexanoic acid in water; N,N-dimethyl-formamide 1 h; 3: With hydrogenchloride in ethanol; water T=4°C; 20 h;

1: 6-[5-(2-oxo-hexahydro-thieno[3,4-d]imidazol-4-yl)-pentanoylamino]-hexanoic acid With pyridine; dicyclohexyl-carbodiimide in N,N-dimethyl-formamide T=20°C; 0.0833333 h; 2: 1-hydroxy-pyrrolidine-2,5-dione in N,N-dimethyl-formamide 18 h;