Tetrahydrofuran → N-Boc-N'-trityl-L-histidine

Participants

Reaction Steps

2-tert-Butoxycarbonylamino-3-(1-trityl-1H-imidazol-4-yl)-propionic acid benzyl ester (6 g, 10.22 mmol) in MeOH (20 mL) was added potassium hydroxide (1.14 g, 20.44 mmol) in water (10 mL). THF (25 mL) was added to homogenise the solution. The solution was stirred for 1 hour and the solvents removed. Water was added and extracted with Et2O. The aqueous layer was acidified with dilute aqueous HCl and extracted with Et2O. The Et2O was washed with water, brine, dried over MgSO4 and filtered. The solvent was removed to give the title compound (4.792 g, 94%). ESMS 498 (M+H+) Mpt 101.5-103.6° C. 1H NMR (CDCl3) δ 1.35 (9H, s), 3.25 (1H, dd, J=5.37, 14.9), 3.39 (1H, dd, J=4.83, 14.9), 4.46-4.52 (1H, m), 5.66, (1H, d, J=5.91), 6.83 (1H, s), 7.07-7.10 (3H, m), 7.26-7.30 (8H, m), 7.42-7.45 (4H, m), 8.13 (1H, s). 13C NMR (CDCl3) δ 28.26, 29.00, 53.07, 76.14, 78.98, 120.88, 128.21, 128.32, 129.63, 133.68, 137.22, 141.52, 154.90, 173.60.

Provenance & Evidence