Sequential palladium-catalysed C- and N-arylation reactions as a practical and general protocol for the synthesis of the first series of oxcarbazepine analogues

The first series of oxcarbazepine analogues, starting from readily-available materials and through a high-yielding five-step sequence based on palladium catalysis, is reported. The so-obtained compounds incorporate not only a variety of substituents in both of the aryl rings comprising the framework of an oxcarbazepine, but also involve the more challenging palladium-catalysed coupling of a number of heteroaromatic substrates. The addition of small amounts of water in some of the metal-catalysed processes showed a beneficial effect, highly increasing the selectivity of such reactions.     

Synthesis and characterization of potential impurities of Oxcarbazepine drug substance: An antiepileptic agent

Oxcarbazepine is a drug substance used to treat epilepsy. During its bulk synthesis of various impurities formation will be observed. Herein we describe the formation, synthesis and characterization of four potential impurities, namely, N-acetyl Oxcarbazepine, N-formyl Oxcarbazepine, N-carbamoyl Oxcarbazepine, and Oxcarbazepine dimer. These impurities are listed in several Pharmacopoeias and the control of these impurities below the threshold level is essential. Our study will be a guide for making these reference standards.     

Synthesis by precipitation polymerisation of molecularly imprinted polymer microspheres for the selective extraction of carbamazepine and oxcarbazepine from human urine

Two molecularly imprinted polymers (MIPs), in the physical form of well-defined polymer microspheres, were synthesised via precipitation polymerisation (PP) using an antiepileptic drug, carbamazepine (CBZ), as template molecule, methacrylic acid as functional monomer and either divinylbenzene 80 (DVB-80) or a mixture of DVB-80 and ethylene glycol dimethacrylate (EGDMA) as crosslinking agents. The MIP obtained using DVB-80 alone as crosslinking agent (MIP A) had a narrow particle size distribution (9.5 ± 0.5 μm) and a well-developed permanent pore structure (specific surface area in the dry state = 758 m² g⁻¹), whereas when a mixture of DVB-80 and EGDMA (MIP B) were used as crosslinking agents, the polymer obtained had a broader particle size distribution (6.4 ± 1.8 μm) and a relatively low specific surface area (23 m² g⁻¹). The molecular recognition character of both polymers was evaluated by means of LC and then a molecularly imprinted solid-phase extraction (MISPE) protocol; CBZ was recognised by both polymers, and useful cross-selectivity for oxcarbazepine (OCBZ), which is the main metabolite of CBZ, also observed. In a detailed bioanalytical study, MIP A was selected in preference to MIP B since MIP A enabled a high volume of sample to be extracted such that lower limits of detection were achievable using this polymer. High recoveries of CBZ and OCBZ were obtained in a MISPE protocol when 50 mL of human urine spiked at 0.2 mg L⁻¹ were percolated through MIP A (90% and 83%, respectively).     

A new synthesis of oxcarbazepine using a Friedel-Crafts cyclization strategy

A novel, simple, and straightforward process for the large-scale synthesis of oxcarbazepine, the active ingredient of Trileptal^®, a medicine for the treatment of epilepsy, has been developed. Starting from readily available 1,3-dihydro-1-phenyl-2H-indol-2-one, a Friedel-Crafts cyclization strategy provides a direct route to the tricyclic framework of the target molecule. Crucial to the success of the strategy was the choice of the proper nitrogen-protecting group.     

Isocratic Reversed-Phase HPLC for Simultaneous Separation and Determination of Seven Antiepileptic Drugs and Two of their Active Metabolites in Human Plasma

A simple reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination of the antiepileptic drugs (AEDs) zonisamide (ZNS), primidone (PRI), lamotrigine (LTG), phenobarbital (PB), phenytoin (PHT), oxcarbazepine (OXC), and carbamazepine (CBZ) and two of their active metabolites, monohydroxycarbamazepine (MHD) and carbamazepine 10,11-epoxide (CBZE) in human plasma. Plasma (100 μL) was pretreated by deproteinization with 300 μL methanol containing 20 μg mL⁻¹ propranolol hydrochloride as internal standard. HPLC was performed on a C₈ column (4.6 mm × 250 mm; particle size 5 μm) with methanol–acetonitrile–0.1% trifluoroacetic acid, 235:120:645 (v/v), as mobile phase at a flow rate of 1.5 mL min⁻¹. ZNS, OXC, and CBZ were monitored by UV detection at 235 nm, and PRI, LTG, MHD, PB, PHT, and CBZE by UV detection at 215 nm. Relationships between response and concentration were linear over the concentration ranges 1–80 μg mL⁻¹ for ZNS, 5–50 μg mL⁻¹ for PRI, 1–25 μg mL⁻¹ for LTG, 1–50 μg mL⁻¹ for MHD, 5–100 μg mL⁻¹ for PB, 1–10 μg mL⁻¹ for CBZE, 0.5–25 μg mL⁻¹ for OXC, 1–50 μg mL⁻¹ for PHT, and 1–25 μg mL⁻¹ for CBZ. Intra-day and inter-day reproducibility were adequate (coefficients of variation were ≤11.6%) and absolute recovery ranged from 95.2 ± 6.13 to 107.7 ± 7.76% for all the analytes; for the IS recovery was 98.69 ± 1.12%. The method was proved to be accurate, reproducible, convenient, and suitable for therapeutic monitoring of the nine analytes.     

抗癫痫新药奥卡西平的合成进展

综述了抗癫痫药奥卡西平的各种合成方法,并评价了其优缺点。参考文献37篇