Process for the preparation of enantiomerically enriched 3-aminopiperidine
The present invention relates to a process for the preparation of enantiomerically enriched 3-aminopiperidine, as in particular of its R-enantiomer (R)-3-aminopiperidine. The invention also relates to an enantiomerically enriched intermediate of said process and to specific acid-addition salts of 3-aminopiperidine (hereinafter also APIP) that are useful for obtaining a single enantiomer of APIP, and to crystalline (R)-3-aminopiperidine-dihydrochloride-monohydrate and crystalline (S)-3-aminopiperidine-dihydrochloride-monohydrate.
1. Crystalline (R)-3-aminopiperidine-dihydrochloride-monohydrate.
2. Crystalline (S)-3-aminopiperidine-dihydrochloride-monohydrate.
3. The crystalline 3-aminopiperidine-dihydrochloride-monohydrate of claim 1 , which in an X-ray powder diffraction diagram at 22° C. and Cu—Kα radiation displays at least 5 of the following reflections, quoted as 2θ values, selected from: 11.0±0.2°, 16.4±0.2°, 17.0±0.2°, 20.9±0.2°, 24.5±0.2°, 25.3±0.2°, 25.9±0.2°, 26.7±0.2°, 27.3±0.2°, 28.4±0.2°, 29.3±0.2°, 30.0±0.2°, 30.7±0.2°, 31.0±0.2° and 31.8±0.2°.
4. The crystalline 3-aminopiperidine-dihydrochloride-monohydrate of claim 2 , which in an X-ray powder diffraction diagram at 22° C. and Cu—Kα radiation displays at least 5 of the following reflections, quoted as 2θ values, selected from: 11.0 0.2°, 16.4±0.2°, 17.0±0.2°, 20.9±0.2°, 24.5±0.2°, 25.3±0.2°, 25.9±0.2°, 26.7±0.2°, 27.3±0.2°, 28.4±0.2°, 29.3±0.2°, 30.0±0.2°, 30.7±0.2°, 31.0±0.2° and 31.8±0.2°.