# US 9,751,855 B2 · Process for the preparation of chiral 8-(3-aminopiperidin-1-yl)-xanthines

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- Number: US 9,751,855 B2
- Document ID: US9751855B2
- Status: Granted
- Kind: B2
- Application number: 15/414,694
- Filed: 2017-01-25
- Published: 2017-05-11
- Granted: 2017-09-05
- Earliest claimed: 2004-11-05
- Assignees: Boehringer Ingelheim International GmbH
- Applicants: Boehringer Ingelheim International GmbH
- Inventors: Waldemar Pfrengle; Thorsten Pachur; Thomas Nicola; Adil Duran
- Web page: https://patentgrep.com/patent/US9751855B2

## CPC

- C07D 401/04: directly linked by a ring-member-to-ring-member bond
- A61P 3/00: Drugs for disorders of the metabolism (of the blood or the extracellular fluid A61P7/00)
- A61P 3/04: Anorexiants; Antiobesity agents
- A61P 3/08: for glucose homeostasis (pancreatic hormones A61P5/48)
- A61P 3/10: for hyperglycaemia, e.g. antidiabetics
- A61P 19/00: Drugs for skeletal disorders
- A61P 19/02: for joint disorders, e.g. arthritis, arthrosis
- A61P 19/10: for osteoporosis
- A61P 29/00: Non-central analgesic, antipyretic or antiinflammatory agents, e.g. antirheumatic agents; Non-steroidal antiinflammatory drugs [NSAID]
- A61P 37/06: Immunosuppressants, e.g. drugs for graft rejection
- A61P 43/00: Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
- C07D 473/04: two oxygen atoms
- C07D 473/06: with radicals containing only hydrogen and carbon atoms, attached in position 1 or 3
- C07B 2200/07: Optical isomers
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- C07B: GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR (preparation of carboxylic acid esters by telomerisation C07C67/47; telomerisation C08F)

## Abstract

The invention relates to an improved process for preparing enantiomerically pure 8-(3-aminopiperidin-1-yl)-xanthines.

## Claims

### Claim 1

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.

### Claim 2

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.

### Claim 3

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.