Claims for Patent: 8,883,805

Summary for Patent: 8,883,805

Title:	Process for the preparation of chiral 8-(3-aminopiperidin-1-yl)-xanthines
Abstract:	The invention relates to an improved process for preparing enantiomerically pure 8-(3-aminopiperidin-1-yl)-xanthines.
Inventor(s):	Pfrengle; Waldemar (Biberach an der Riss, DE), Pachur; Thorsten (Biberach an der Riss, DE), Nicola; Thomas (Ingelheim am Rhein, DE), Duran; Adil (Biberach an der Riss, DE)
Assignee:	Boehringer Ingelheim International GmbH (Ingelheim am Rhein, DE)
Application Number:	13/782,149
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,883,805
Patent Claims:	1. A compound of formula (II) ##STR00015## or an enantiomer thereof, wherein R.sup.1 is a phenylcarbonylmethyl, benzyl, naphthylmethyl, pyridinylmethyl, pyrimidinyl-methyl, quinolinylmethyl, isoquinolinylmethyl, quinazolinylmethyl, quinoxalinylmethyl, naphthyridinylmethyl or phenanthridinylmethyl group wherein the aromatic or heteroaromatic moiety is in each case mono- or disubstituted by R.sub.a, where the substituents may be the same or different and R.sub.a is a hydrogen, fluorine, chlorine or bromine atom or a cyano, methyl, trifluoromethyl, ethyl, phenyl, methoxy, difluoromethoxy, trifluoromethoxy or ethoxy group, or two R.sub.a radicals, when they are bonded to adjacent carbon atoms, may also be an --O--CH.sub.2--O-- or --O--CH.sub.2--CH.sub.2--O-- group, R.sup.2 is a methyl, ethyl, propyl, isopropyl, cyclopropyl or phenyl group, and R.sup.3 is a 2-buten-1-yl, 3-methyl-2-buten-1-yl, 2-butyn-1-yl, 2-fluorobenzyl, 2-chlorobenzyl, 2-bromobenzyl, 2-iodobenzyl, 2-methylbenzyl, 2-(trifluoromethyl)benzyl or 2-cyanobenzyl group. 2. The compound of formula (II) according to claim 1, wherein R.sup.1 is a phenylcarbonylmethyl, benzyl, naphthylmethyl, pyridinylmethyl, pyrimidinyl-methyl, quinolinylmethyl, isoquinolinylmethyl, quinazolinylmethyl, quinoxalinylmethyl or naphthyridinylmethyl group wherein the aromatic or heteroaromatic moiety is in each case mono- or disubstituted by R.sub.a, where the substituents may be the same or different, and R.sub.a is a hydrogen, fluorine or chlorine atom or a cyano, methyl, ethyl, methoxy or ethoxy group, R.sup.2 is a methyl, ethyl, propyl, isopropyl, cyclopropyl or phenyl group, and R.sup.3 is a 2-buten-1-yl, 3-methyl-2-buten-1-yl, 2-butyn-1-yl, 2-fluorobenzyl, 2-chlorobenzyl, 2-bromobenzyl, 2-iodobenzyl, 2-methylbenzyl, 2-(trifluoromethyl)benzyl or 2-cyanobenzyl group. 3. The compound of formula (II) according to claim 2, wherein R.sup.1 is a cyanobenzyl, (cyanopyridinyl)methyl, quinolinylmethyl, (methylquinolinyl)methyl, isoquinolinylmethyl, (methylisoquinolinyl)methyl, quinazolinylmethyl, (methylquinazolinyl)methyl, quinoxazinylmethyl, (methylquinoxalinyl)methyl, (dimethylquinoxalinyl)methyl or naphthyridinylmethyl group, R.sup.2 is a methyl, cyclopropyl or phenyl group, and R.sup.3 is a 2-buten-1-yl, 3-methyl-2-buten-1-yl, 2-butyn-1-yl, 2-chlorobenzyl, 2-bromobenzyl or 2-cyanobenzyl group. 4. The compound of formula (II) according to claim 3, wherein R.sup.1 is a (4-methylquinazolin-2-yl)methyl, (3-methylisoquinolin-1-yl)methyl or (3-cyanopyridin-2-yl)methyl group, R.sup.2 is a methyl group, and R.sup.3 is a 2-butyn-1-yl group. 5. The compound according to claim 4 of formula ##STR00016## wherein R.sup.1 is a (4-methylquinazolin-2-yl)methyl, (3-methylisoquinolin-1-yl)methyl or (3-cyanopyridin-2-yl)methyl group, R.sup.2 is a methyl group, and R.sup.3 is a 2-butyn-1-yl group. 6. A compound of formula ##STR00017## wherein R.sup.1 is a (4-methylquinazolin-2-yl)methyl group, R.sup.2 is a methyl group, and R.sup.3 is a 2-butyn-1-yl group. 7. A method of preparing a compound of formula ##STR00018## or a physiologically tolerated salt thereof, said method comprising deprotecting a compound of formula ##STR00019## wherein R.sup.1 is a (4-methylquinazolin-2-yl)methyl, (3-methylisoquinolin-1-yl)methyl or (3-cyanopyridin-2-yl)methyl group, R.sup.2 is a methyl group and R.sup.3 is a 2-butyn-1-yl group. 8. The method of claim 6, wherein the phthalyl protecting group of the compound of formula ##STR00020## is detached; wherein R.sup.1 is a (4-methylquinazolin-2-yl)methyl group, R.sup.2 is a methyl group, and R.sup.3 is a 2-butyn-1-yl group. 9. The method according to claim 8, wherein the phthalyl protecting group is detached in the presence of ethanolamine. 10. The method according to claim 8, wherein the phthalyl protecting group is detached in the presence of i) ethanolamine and ii) in the presence of toluene or a mixture of tetrahydrofuran and water. 11. The method according to claim 8, further comprising crystallizing the deprotected compound from ethanol or methanol. 12. The method according to claim 8, wherein the deprotected compound is crystallized from ethanol. 13. Medicament comprising a compound obtained by the method according to claim 8, and optionally one or more inert carriers and/or diluents. 14. Medicament comprising a compound obtained by the method according to claim 12, and optionally one or more inert carriers and/or diluents.