Acetaldehyde → HCID 131718396, compound

Participants

Reaction Steps

To a stirred solution of the title compound of Example 13 (2.0 g), acetaldehyde (3.0 mL), sodium cyanoborohydride (0.904 g), and water (2.6 mL) in acetonitrile (20 mL) was added glacial acetic acid (0.5 mL) over a period of 6 minutes. The reaction was stirred for 2.5 hours at ambient temperature, and then glacial acetic acid was added (0.5 mL), and the reaction was stirred for an additional 30 minutes. The resulting mixture was evaporated under vacuum, and the residue was partitioned between ethyl acetate and saturated sodium bicarbonate. The layers were separated, and the aqueous layer was extracted once more with ethyl acetate. The combined ethyl acetate extracts were washed with brine, dried over magnesium sulfate, and evaporated under vacuum to a clear, greenish oil. The oil was chromatographed four times: twice through silica gel 60 using 97:3 ethyl acetate:ethanol; next through silica gel 60 using 3:1 chloroform:tetrahydrofuran; and finally through reverse phase silica gel (C18) using 80:20:1 acetonitrile:water:ammonium hydroxide. The product from the last column was co-evaporated three times with ethanol to azeotrope water from the product and dried under vacuum at room temperature to yield the title compound as a white solid containing 1.86% water. HPLC: 99.53% pure.

Provenance & Evidence