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US 9,751,855 B2Granted
Process for the preparation of chiral 8-(3-aminopiperidin-1-yl)-xanthines
AssigneeBoehringer Ingelheim International GmbH
InventorsWaldemar Pfrengle, Thorsten Pachur, Thomas Nicola, Adil Duran
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Abstract
The invention relates to an improved process for preparing enantiomerically pure 8-(3-aminopiperidin-1-yl)-xanthines.
Claims3
A process for preparing (R)-3-(phthalimido)piperidine, comprising:
- reacting rac-3-aminopiperidine with phthalic anhydride;
- and
- precipitating (R)-3-(phthalimido)piperidine by adding D-tartaric acid.
A process for preparing (S)-3-(phthalimido)piperidine, comprising:
- reacting rac-3-aminopiperidine with phthalic anhydride;
- precipitating (S)-3-(phthalimido)piperidine by adding L-tartaric acid.
A process for preparing (R)-3-(phthalimido)piperidine and (S)-3-(phthalimido)piperidine, comprising:
- reacting rac-3-aminopiperidine with phthalic anhydride;
- and
- precipitating (R)-3-(phthalimido)piperidine by adding D-tartaric acid;
- and
- precipitating (S)-3-(phthalimido)piperidine by adding L-tartaric acid.
2 more elements
Dependencies are inferred from the claim text.