Sodium Carbonate → Boc-His(DNP) 1(S)-cyclohexylmethyl-2(S)-hydroxy-5-(2-pyridyl)-pentylamide

Participants

Reaction Conditions

Reaction Steps

550 μl of pivaloyl chloride are added dropwise, at -5° C., to 1.9 g of Boc-His(DNP)-OH, 360 μl of pyridine and 620 μl of N-ethylpiperidine in 50 ml of CH2Cl2. After 10 minutes at -5° C., the mixture is stirred at +10° C. for 10 minutes. It is again cooled to -5° C. and then 1.3 g of 1(S)-cyclohexylmethyl-2(S)-hydroxy-5-(2-pyridyl)-pentylamine (prepared from 1.7 g of 3-Boc-4(S)-cyclohexylmethyl-2,2-dimethyl-5-(3-(2-pyridyl)propyl)oxazolidine by the process described under b) and subsequent liberation with Na2CO3) in 20 ml of CH2Cl2 are added. After 1 hour at -5° C., the mixture is left to stand at room temperature for 16 hours. 50 ml of saturated Na2CO3 solution are added, and the mixture is extracted 3 times with EA. The combined organic extracts are dried over Na2SO4 and concentrated. Chromatography on silica gel (EA/MeOH 10:1) yields the title compound.

Provenance & Evidence