Diisopropylcarbodiimide → Fmoc-Gly-Allyl

Participants

Reaction Steps

0.848 g Fmoc-Nle (2.4 mmol) was coupled to 2.0 g MBHA resin (1.6 mmol) with 0.367 g HOBt (2.4 mmol) and 0.373 mL DIPCDI (2.4 mmol) in 20 mL DCM-DMF (1:1) for 2.3 h. The resin was washed 3 times with DMF, deprotected with 20 mL piperidine-DMF (1:1) for 30 min, and washed 3 times with DMF. 1.82 g allyl linker (3.2 mmol) was coupled to the resin with 0.489 g HOBt (3.2 mmol) and 0.497 mL DIPCDI (3.2 mmol) in 20 mL DMF for 18.5 h. The resin was washed 1 time with DMF and 2 times with DCM, deprotected twice with 20 mL TFA-DCM (9:1), first for 20 min, then for 10 min, washed 3 times with DCM, neutralized with 20 mL DIEA-DCM (1:9) for 15 min, and washed 1 time with DCM and 2 times with DMF. 1.43 g Fmoc-Gly (4.8 mmol) was esterified to the allyl resin with 0.735 g HOBt (4.8 mmol), 0.746 mL DIPCDI (4.8 mmol), and 0.059 g DMAP (0.48 mmol) in 20 mL DMF for 6.5 h. The resin was washed 1 time with DMF and 2 times with DCM and stored under vacuum overnight.

Provenance & Evidence