33817-09-3

The resolution of N-methylamphetamine (MA) was carried out with the resolution agents O,O′-dibenzoyl-(2R,3R)-tartaric acid monohydrate (DBTA) and O,O′-di-p-toluoyl-(2R,3R)-tartaric acid (DPTTA). After partial diastereomeric salt formation, the unreacted enantiomers were extracted by supercritical fluid extraction (SFE). The effects of resolution agent molar ratio to the racemic mixture (mr), extraction pressure (P) and temperature (T) on the resolution efficiency were studied. The best chiral separation was obtained at a quarter of an equivalent resolution agent molar ratio for both resolution agents. Extraction conditions [pressure (100-200bar), temperature (33-63°C)] did not influence the resolution efficiency, which makes the enantiomer separation robust. In one extraction step, both enantiomers can be produced with high enantiomeric excess (ee) and remarkable yield (Y). Using DBTA as a resolution agent eeE=83%, YE=45% for the extract and eeR=82%, YR=42% for the raffinate were obtained.

The invention provides a preparation method of selegiline. The method comprises the steps of carrying out an acyl chlorination reaction on a compound (i), carrying out an acylation reaction on the compound (i) and benzene, and carrying out a propargylation reaction after carbonyl reduction and deacylation to obtain selegiline, wherein in the compound (i), R represents methyl or ethyl or trifluoromethyl or phenyl or benzyl. According to the method, an acyl-D-N-methylalanine compound is used as a raw material and subjected to acylation, carbonyl reduction, the deacylation reaction and the propargylation reaction to obtain the selegiline, not only is the raw material simple and easy to obtain, but also there are few reaction steps, the operation is simple and convenient, and dangerous or high-price reagent raw materials do not need to be used. Meanwhile, according to the method, chiral resolution of an intermediate or a final product is not needed, the ee value of the product is high, theyield is high, and the method is suitable for large-scale and industrial production.

A modified macrocyclic glycopeptide-based chiral stationary phase (CSP), prepared via Edman degradation of vancomycin, was evaluated as a chiral selector for the first time. Its applicability was compared with other macrocyclic glycopeptide-based CSPs: TeicoShell and VancoShell. In addition, another modified macrocyclic glycopeptide-based CSP, NicoShell, was further examined. Initial evaluation was focused on the complementary behavior with these glycopeptides. A screening procedure was used based on previous work for the enantiomeric separation of 50 chiral compounds including amino acids, pesticides, stimulants, and a variety of pharmaceuticals. Fast and efficient chiral separations resulted by using superficially porous (core-shell) particle supports. Overall, the vancomycin Edman degradation product (EDP) resembled TeicoShell with high enantioselectivity for acidic compounds in the polar ionic mode. The simultaneous enantiomeric separation of 5 racemic profens using liquid chromatography-mass spectrometry with EDP was performed in approximately 3?minutes. Other highlights include simultaneous liquid chromatography separations of rac-amphetamine and rac-methamphetamine with VancoShell, rac-pseudoephedrine and rac-ephedrine with NicoShell, and rac-dichlorprop and rac-haloxyfop with TeicoShell.

We report the use of a chiral Cu(II) 3D metal-organic framework (MOF) based on the tripeptide Gly-l-His-Gly (GHG) for the enantioselective separation of metamphetamine and ephedrine. Monte Carlo simulations suggest that chiral recognition is linked to preferential binding of one of the enantiomers as a result of either stronger or additional H-bonds with the framework that lead to energetically more stable diastereomeric adducts. Solid-phase extraction of a racemic mixture by using Cu(GHG) as the extractive phase permits isolating >50% of the (+)-ephedrine enantiomer as target compound in only 4 min. To our knowledge, this represents the first example of a MOF capable of separating chiral polar drugs.

We report the synthesis and reactivity of a chiral aminoborane displaying both rapid and reversible H2 activation. The catalyst shows exceptional reactivity in asymmetric hydrogenation of enamines and unhindered imines with stereoselectivities of up to 99% ee. DFT analysis of the reaction mechanism pointed to the importance of both repulsive steric and stabilizing intermolecular non-covalent forces in the stereodetermining hydride transfer step of the catalytic cycle.

A concise and high yielding enantioselective synthesis of (R)-selegiline, an anti-Parkinson's drug, (S)-benzphetamine, an anti-obesity agent, and (S)-sitagliptin, an anti-diabetic drug has been described starting from commercially available starting materials employing Evans' electrophilic azidation of chiral imide enolates as a key chiral inducing step, which proceeds in a highly diastereoselective manner (>99%).

In the last years the identification of new legal and illegal highs has become a huge challenge for the police and prosecution authorities. In an analytical context, only a few analytical methods are available to identify these new substances. Moreover, many of these recreational drugs are chiral and it is supposed that the enantiomers differ in their pharmacological potency. Since nonenantioselective synthesis is easier and cheaper, they are mainly sold as racemic mixtures. The goal of this research work was to develop an inexpensive method for the chiral separation of cathinones and amphetamines. This should help to discover if the substances are sold as racemic mixtures and give further information about their quality as well as their origin. Chiral separation of a set of 6 amphetamine and 25 cathinone derivatives, mainly purchased from various Internet shops, is presented. A LiChrospher 100 RP-18e, 250 x 4 mm, 5 μm served as the stationary phase. The chiral mobile phase consisted of methanol, water, and sulfated β-cyclodextrin. Measurements were performed under isocratic conditions in reversed phase mode using UV detection. Four model compounds of the two substance classes were used to optimize the mobile phase. Under final conditions (methanol:water 2.5:97.5 + 2% sulfated β-cyclodextrin) enantiomers of amphetamine and five derivatives were baseline separated within 23 min. In all, 17 cathinones were completely or partially chirally separated. However, as only 3 of 25 cathinones were baseline resolved, the application of this method is limited for cathinone analogs. Additionally, the results were compared with an RP-8e column. Copyright

A short and enantioselective formal synthesis of (R)-selegiline has been achieved using Jacobsen's hydrolytic kinetic resolution (HKR) of phenyl propylene oxide.

The invention is directed to 6-(4-pyι?midinyl)-1 H-indazole derivatives. Specifically, the invention is directed to compounds according to Formula (I) wherein R1 - R4 are defined herein. The compounds of the invention are inhibitors of PDK1 and can be useful in the treatment of immune and metabolic diseases and disorders characterized by constitutively activated ACG kinases such as cancer and more specifically cancers of the breast, colon, and lung. Accordingly, the invention is further directed to pharmaceutical compositions comprising a compound of the invention. The invention is still further directed to methods of inhibiting PDK1 activity and treatment of disorders associated therewith using a compound of the invention or a pharmaceutical composition comprising a compound of the invention.

Conjugation of the phenol derived from rivastigmine with amphetamines gave access to novel carbamate cholinesterase inhibitors. All compounds possessed increased affinity and selectivity for AChE compared to rivastigmine and were orally bioavailable. Comp

An efficient enantioselective synthesis of (R)-selegiline has been achieved by two routes, via proline-catalyzed α-aminooxylation as well as α-amination of phenylpropanaldehyde as the key step.

A process for synthesis of R-(-)-N, α -Dimethylphenethylamine (Levmetamfetamine, formula I), or S-(+)-N, α - Dimethyl phenethylamine (Methamphetamine, formula II ), from d-ephedrine of formula III or l-ephedrine formula IV, the process comprising the steps of (a) acylating the d- or l-ephedrine base of formula III or formula IV with an acylating agent to make a reaction mixture containing a N- acylated ephedrines of formula V or formula VI ; (b) deoxygenation of N-acylated ephedrines to make the compound of the formula VII or Formula VIII by using Raney Nickel catalyst ; and (c) acid hydrolysis of the above deoxygenated products to get the levmetamfetamine or methamphetamine.

A simple and effective procedure for the enantioselective synthesis of two important neurotransmitter drugs, that is, (S)-3,4-dihydroxyphenylalanine (l-DOPA) and (R)-N,α-dimethyl-N-2-propynylbenzeneethaneamine [(R)-selegiline], is described by employing the Sharpless asymmetric dihydroxylation (AD) as a key step to introduce chirality.

A number of tertiary N-allyl- and N-propargyl-substituted amines have been prepared by alkylation of secondary amines under solid-liquid phase-transfer catalysis conditions.

On reacting racemic amine bases with half equivalent amount of sodium-hydrogen-tartrate in a water-benzene solvent system, the mixed-neutral tartrate accumulates in the aqueous phase, while the free base concentrates in the organic phase, resulting in enantiomer separation without crystallization.

(S)-N-methyl-α-methyl-phenethylamines 5a-d were obtained in 56-62 percent e.e. from chiral synthon (-)-N-cyanomethyl-4-phenyl-1,3-oxazolidine-1.

Determination of the stereochemical makeup of forensic samples can provide information about the source of the sample and a basis for intersample comparisons.The clandestine synthesis of methamphetamine and related amines continues to be a major source of these drugs of abuse.Most synthetic methods employ carbon-nitrogen bond formation and produce a racemic mixture; however, the individual enantiomers of ephedrine and pseudoephedrine contain the structural components of methamphetamine in chiral form.This paper will focus on the stereochemical course of the synthesis of methamphetamine via hydrogenolysis of the benzylic hydroxyl group in ephedrine and pseudoephedrine.The configurations of these amines were determined by liquid chromatography on an achiral C18 stationary phase following precolumn derivatization with 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl isothiocyanate.

-