Tetrahydrofuran → Fmoc-Phe-Lys(Mtr)

Participants

Reaction Steps

A suspension of Lys(Mtr) 2 (4.686 g, 11.20 mmol) and NaHCO3 (941.0 mg, 1 equiv) in water (100 mL) and DME (50 mL) was treated with a solution of Fmoc-Phe-OSu 7a (11.20 mmol) in DME (50 mL). THF (25 mL) was then added to aid solubility. The mixture was stirred at rt for 2 days and then as much DME as possible was removed on the rotovap (bath at 30° C.). The resulting gummy suspension was partitioned between ethyl acetate and pH 5 buffer. The organic phase was washed with water and brine, dried and evaporated to give a pale yellow foam. This was flushed with methylene chloride (100 mL). TLC showed the product to be satisfactorily pure and it was carried on without further purification (8.559 g, 97%). 1H-NMR (CDCl3/CD3OD) δ 1.10-1.93 (m, 6H), 2.31 (t, 2H), 3.00 (m, 2H), 3.71 (s, 3H), 4.02-4.48 (m, 5H), 6.79 (d, 2H), 7.00-7.75 (m, 25H). MS (FAB) 788.2 (MH)+, 810.4 (M+Na)+, 826 (M+K)+. Anal. Calcd for C50H49N3O6—H2O: C-74.51, H-6.38, N-5.21. Found: C-74.17, H-6.57, N-5.41.

Provenance & Evidence