HOAt → HCID 66661059, compound

Participants

Reaction Steps

The product from example 34, tert-butyl [(S)-1-(1-cyanocyclopropylcarbamoyl)-3-methylbutyl]carbamate, (1.1 g, 3.72 mmol) was admixed with 20 ml of 1:1 TFA/dichloromethane and stirred at RT for 30 min. Subsequently, the mixture was concentrated by evaporation under reduced pressure and taken up again in dichloromethane and toluene, and solvent and TFA residues were removed under reduced pressure. The resulting N-terminally protected product was reacted further directly. 283 mg (1.5 mmol) thereof were admixed at 0° C. with 136 mg of HOAt (1 mmol, 0.67 eq.), 195 mg of 1,4-dioxaspiro[4.5]decane-8-carboxylic acid from example 33 (1 mmol, 0.67 eq.), 268 mg of EDCl (1.4 mmol, 0.93 eq.) and 0.32 ml of NEM (2.5 mmol) in 2.5 ml of THF and 0.25 ml of DMF, and the mixture was stirred at 0° C. to RT overnight. Subsequently, the solvent was distilled off under reduced pressure, and the residue was taken up in ethyl acetate and extracted by shaking with saturated sodium hydrogencarbonate solution and saturated NaCl solution. Drying over sodium sulfate and evaporating-off the solvent were followed by purification using RP-HPLC (gradient: acetonitrile/water and addition of 0.05% TFA). The product fractions were combined and freeze-dried. Yield: 25 mg (without mixed fractions), corresponds to 7% of theory. 1H NMR: 8.81 (s, 1H); 7.84 (d, 1H); 4.20 (m, 1H); 3.83 (s, 4H); 2.22 (m, 1H); 1.75-0.8 (3 m, about 13H, 1.05 (m, 2H); 0.82 (dd, 6H); MS (ESI+): 364.2.

Provenance & Evidence