4-Nitrophenol → N-BOC-glvcylproline-4-nitrophenvl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 3.0 g (11.6 mmol) of N-BOC-glycylproline and 1.93 g (13.9 mmol) of 4-nitrophenol in 82 mL of dry THF was cooled to 0° C. and 3.34 g (16.2 mmol) of DCC was added. The mixture was stirred at 0° C. for 1 hour, the ice bath was removed, and the mixture was stirred for 16 hours at room temperature. HOAc (579 μL) was added to the mixture and it was allowed to stir for 30 minutes. The mixture was kept in the freezer for 30 minutes and filtered under vacuum. The filtrate was concentrated and purified by silica gel chromatography (18×150 mm bed, 2.5% EtOAc/97.5% CH2Cl2/1% HOAc). Traces of acetic acid were removed by concentrating from dioxane several times on the rotary evaporator. The concentrate was triturated with 3/1 hexane Et2O and the resulting white solid was collected by filtration to give 4.1 g (90%) of compound 15 as a white solid; TLC Rf 0.09, 40/60/1 EtOAc/hexane/HOAc; 1H NMR(CDCl3) δ 1.09-2.55 (m, 4H), 1.48 (s, 9H), 3.47-3.77 (m, 2H), 4.05 (m, 2H), 4.74 (m, 1H), 5.45 (bd s, 1H), 7.35 (d, 2H), 8.30 (d, 2H).

Provenance & Evidence