Citric Acid → DTAF lysine

Participants

Reaction Steps

α-t-BOC-lysine (1.39 g, 5.64 mmol) was dissolved in 50 ml of 9:1 water-triethylamine, and the solution was cooled to 0° with an ice-water bath. A single portion (1.00 g, 1.88 mmol) of DTAF was added, and the reaction mixture was allowed to stir at 0° for 1.0 hr. The solution was poured into 200 ml of EtOAc, and aqueous citric acid solution was added until the pH of the aqueous phase was approximately 4. The layers were separated, and the aqueous layer was extracted with 100 ml of EtOAc. The combined organic layers were washed with 100 ml of water, dried (MgSO4) and evaporated affording 1.22 g of the DTAF-lysine derivative as an orange foam. The crude product was dissolved in a small volume of MeOH and precipitated by the addition of ether-hexane.

Provenance & Evidence