Back to results
US 6,441,024 B1Granted
Crystal modification of lipoic acid
AssigneeBASF SE
InventorsMartin Jochen Klatt, Markus Niebel, Joachim Paust, Jens Rieger
Life of this patent
Estimating the term…
Abstract
In the 2 Θ diffractogram of an enantiomerically pure crystalline (R)- or (S)-lipoic acid, the most intense reflection line in the range from 13° to 30° is that at 2 Θ=23°.
Claims8
Enantiomerically pure crystalline R- or S-lipoic acid for which the reflection line at 2 Θ=23° is the most intense in the range from 15° to 30° in the 2 Θdiffractogram.
A process for preparing crystalline lipoic acid, which comprises crystallizing the lipoic acid at from 0°C. to −20° C. from a solvent or solvent mixture which has a dielectric constant ε of from 1.95 to 2.4.
Dependencies are inferred from the claim text.