Hydrochloric Acid → 11-Carboxyundecyl 5-amino-4-oxopentanoate hydrochloride

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Reaction Steps

A 1.0 M solution of HCl in diethyl ether (5.0 mL; 5.0 mmol) was added to a stirred solution of the product of 14c (0.95 g; 2.2 mmol) in ethyl acetate (10 mL) at ambient temperature under argon. After 5 days, the mixture was filtered and the residue was triturated with diethyl ether (2×5 mL). The residue was dried overnight at 40° C. and 15 mm Hg to give 0.11 g white solid. The combined ether extracts were evaporated. LC-MS analysis indicated that the product contained ca. 25% 5-amino-4-oxopentanoic acid; the combined crops were purified by flash chromatography on a 150×25 mm silica gel 60 column eluted sequentially with 3% methanol in acetonitrile (1000 mL), 6% methanol in acetonitrile (1000 mL), then 9% methanol in acetonitrile (2000 mL), collecting 56×50 mL fractions. Fractions containing the product were evaporated and the residue was dissolved in water (10 mL). The solution was freeze-dried overnight, and 0.06 g (7.5%) product obtained (white solid, mp 110-115° C. (softens, no sharp mp)).

Provenance & Evidence