Hydrochloric Acid → 2,7-Diaminoheptanoic acid monohydrochloride

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Reaction Steps

A mixture of 14.63 g (0.34 mole) the compound 5 and 6N HCl (200 ml) was heated at reflux for five hours then cooled to precipitate the phthalic acid which was removed by filtration. The filtrate was concentrated in vacuo to remove the excess HCl, and the residue was precipitated from absolute ethanol in acetone, as an oil. The oil was dissolved in 40 ml water and charged to the top of a strong acid cation exchange column, Bio Rad AG50W-X8 (3.75 cm W×48 cm L). Following a water wash of two column volumes an ammonium hydroxide gradient (0.3-0.5N) was used to elute the product. Concentration of the column effluent, pH adjustment to pH 5.8 and crystallization from water/ethanol afforded the monohydrochloride of DL-homolysine 7. Yield: 10.2 g (94%). Mp 263° C. (lit. mp 264° C. for monohydrochloride, lit mp 176° C. for monohydrochloride monohydrate). TLC: Rf =0.11 (C), 0.30 (D). MW calc 160.12, found 160. Anal. calc. for C7H16N2O2.HCl: C, 42.74; H, 8.20; N, 14.24; Cl, 18.02. Found: C, 42.90; H, 8.65; N, 14.17; Cl, 18.35. HPLC 96%. 1H NMR (D2O) 1.45 (4H, m), 1.70 (2H, m), 1.88 (2H, m), 3.00 (2H, m), 3.75 (1H, t, 7 Hz). Spinco analysis: single peak with elution time equivalent to ammonia.

Provenance & Evidence