Details for Patent: 9,643,929
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Title: | Asymmetric catalytic reduction of oxcarbazepine |
Abstract: | A process for preparing (S)-(+)-10,11-dihydro-10-hydroxy-5H-dibenz/b,f/azepine-5-carboxamide or (R)-(-)-10,11-dihydro-10-hydroxy-5H-dibenz/b,f/azepine-5-carboxamide, by reduction of oxcarbazepine in the presence of a catalyst and a hydride source is disclosed. The catalyst is prepared from a combination of [RuX.sub.2(L)].sub.2 wherein X is chlorine, bromine or iodine, and L is an aryl or aryl-aliphatic ligand, with a ligand of formula (A) or formula (B): ##STR00001## wherein R.sup.1 is chosen from C.sub.1-6 alkoxy and C.sub.1-6 alkyl, n is a number from 0 to 5, and when n is a number from 2 to 5, R.sup.1 can be the same or different, and R.sup.2 is alkyl, substituted alkyl, aryl, substituted aryl, alkaryl or substituted alkaryl. The hydride source is either NR.sup.3R.sup.4R.sup.5 and formic acid, [R.sup.3R.sup.4R.sup.5NH][OOCH] and optionally formic acid, or [M][OOCH].sub.x and formic acid, wherein R.sup.3, R.sup.4 and R.sup.5 are C.sub.1-6 alkyl, M is an alkali metal or alkaline earth metal and x is 1 or 2. A pH from 6.5 to 8 is maintained during the process. |
Inventor(s): | Learmonth; David Alexander (Alfena, PT), Grasa; Gabriela Alexandra (Mantua, NJ), Zanotti-Gerosa; Antonio (Cambridge, GB) |
Assignee: | BIAL--PORTELA & CA, S.A. (S. Mamede do Coronado, PT) |
Filing Date: | Nov 18, 2015 |
Application Number: | 14/944,546 |
Claims: | 1. A pharmaceutical composition comprising (S)-(-)-10-acetoxy-10, 11-dihydro-5H-dibenz/b,f/azepin-5-carboxamide having a chemical purity of at least about 99.96%. 2. A pharmaceutical composition comprising an active pharmaceutical ingredient consisting of (S)-(-)-10-acetoxy-10,11-dihydro-5H-dibenz/b,f/azepin-5-carboxamide having a chemical purity of at least about 99.96%. 3. The composition of claim 2, wherein the amount of (R)-isomer of (S)-(-)-10-acetoxy-10,11-dihydro-5H-dibenz/b,f/azepin-5-carboxamide is below the limit of detection. |