5650-44-2

The invention relates to the field of chemistry, in particular to preparation of (S)-(-)-alpha-methylamino propiophenone. The preparation comprises the following steps: reacting (+/-)-alpha-methylamino propiophenone and (2R, 3R)-(-)-tartaric acid derivative in a solvent added with alcohol ether to form salt, crystallizing and filtering to obtain (S)-(-)-alpha-methylamino propiophenone (2R, 3R)-(-)-tartaric acid derivative salt, acidifying, alkalizing, and extracting with a solvent, and distilling to remove the solvent to obtain the product (S)-(-)-alpha-methylamino propiophenone.

The invention discloses a chiral synthesis method of an ephedrine key intermediate (S)-2-methylamino-1-phenyl-1-acetone. The method comprises the following steps: carrying out nucleophilic substitution reaction on dimethyl-(4S, 5S)-2-[(R)-1-bromoethyl]-2-phenyl-1, 3-dioxyethane-4, 5-dicarboxylate (2a) and methylamine in an SN2 reaction environment to finish Walden inversion to generate dimethyl-(4S, 5S)-2-[(S)-1-methylamino]-2-phenyl-1, 3-dioxyethane-4, 5-dicarboxylate(3a); and then removing a chiral auxiliary agent (2S, 3S)-dimethyl tartrate to obtain (S)-2-methylamino-1-phenyl-1-acetone (1a). The compound can be used as a substrate for potassium borohydride reduction in the ephedrine preparation process, so that traditional complicated physical and chemical coexisting splitting operation of dibenzoyl tartaric acid is avoided, and the method has an important industrial application value.

Controllable fabrication of iron vanadate (FeVO4) was achieved by the hydrothermal approach. The excellent catalytic activity of the prepared nanorods of iron vanadate for the oxidation of benzylic alcohols as well as its potential for oxidation of the benzylic sp3 C-Hs in the presence of urea hydrogen peroxide (UHP) as oxidant was reported. The prepared nanorods and nanospheres were fully characterized by FT-IR, XRD, EDAX, ICP-AES, SEM, and TEM. In the presence of the catalyst, alcohols chemoselectively (100%) convert to the corresponding aldehydes/ketones, giving a total turnover number about 380 for 10 consecutive runs.

Mononuclear Cu(II) and Co(II) complexes comprising 2-methyltetrazole-saccharinate bidentate N,N-chelating ligand have been synthesized for the first time and tested as homogeneous catalysts for oxidation of secondary alcohols in a solvent-free and microwave assisted protocol using aqueous tert-butyl hydroperoxide (TBHP) as oxidant. The developed catalytic system exhibits broad functional group compatibility, allowing efficient and selective conversion of a variety of secondary alcohols, including allylic ones, into the corresponding ketones. With typical 0.2 mol% content of the catalyst and under 20–50 W microwave irradiation, most reactions are complete within 10 min, presenting TONs up to 5.5 × 102 and TOFs up to 1.1 × 104 h?1. No additives and co-oxidants have been used, while TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxyl) acts as inhibitor in most cases. A plausible reaction mechanism involving the new catalytic systems is outlined.

The invention discloses a preparation method for an ephedrine or pseudoephedrine intermediate. The preparation method comprises the following steps: with 2-chloropropionyl chloride and benzene as starting materials, carrying out the Friedel-Crafts reaction under the catalysis of Lewis acid so as to produce 2-chloro-1-phenyl-1-acetone; and reacting produced 2-chloro-1-phenyl-1-acetone with methylamine in an aprotic solvent so as to produce 2-methylamino-1-phenyl-1-acetone. The invention also discloses a preparation method for ephedrine or pseudoephedrine. According to the methods, phosphorus trichloride with severe pollution is not used anymore, and dangerous and expensive bromine is not used any longer; the Friedel-Crafts reaction and methylamination are carried out in the same solvent, so cost for public works is saved; and a safe, simple, cheap, green and novel process is provided for synthesis of ephedrine and pseudoephedrine.

Aromatic β-amino ketones/alcohols such as adrenalone play an important role in some stereoselective synthesis of pharmaceuticals. Unfortunately, the transformation of aromatic β-amino ketones to their chiral alcohols has been carried out chemically as no corresponding biocatalyst has been available. Here, a novel carbonyl reductase responsible for the reduction of adrenalone to (R)-(-)-epinephrine was identified and characterized from Kocuria rhizophila. This enzyme was purified to homogeneity by ammonium sulfate precipitation followed by ion-exchange column chromatography, hydrophobic chromatography and gel chromatography. The purified enzyme yielded pure (R)-enantiomer product with high activity and utilized NADH as the cofactor. The enzyme had special significance by showing selectivity for many aromatic β-amino ketones/alcohols such as 2-amino-acetophenone, 2-amino-4′- hydroxyacetophenone, isoproterenol and ephedrine. The maximum reaction rate (Vmax) and apparent Michaelis-Menten constant (Km) for adrenalone and NADH were 14.62 μmol/(min mg) protein and 0.189 mM, 11.66 μmol/(min mg) protein and 0.204 mM respectively. These properties ensure the enzyme a promising future for industrial application as a replacement of chemical synthesis of aromatic β-amino chiral alcohols.

The illicit drug methylamphetamine is often prepared from the precursor ephedrine or pseudoephedrine, which in turn are obtained by three processes: extraction from the Ephedra plant ("natural"), via fermentation of sugars ("semi-synthetic"), and by a "fully synthetic" route from propiophenone. We report the first method to differentiate between the three industrial routes used to produce the precursors ephedrine and pseudoephedrine by measurement of stable isotope ratios of nitrogen (δ15N), hydrogen (δ2H), and carbon (δ13C). Analysis of 782 samples of seized methylamphetamine allowed classification into three groups using k-means clustering or the expectation-maximization algorithm applied to a Gaussian mixture model. By preparation of 30 samples of ephedrine by the "fully synthetic" industrial process and measuring their δ15N, δ2H, and δ13C values, we observed that 15N becomes significantly depleted compared to the methylamine starting material. Conversion of ten ephedrine samples to methylamphetamine showed that this depletion is maintained in the final drug product, of which the δ15N, δ13C, and δ2H values were distinct from those of ephedrine and methylamphetamine samples of a semi-synthetic (fermentation pathway) origin. Combining modeling analysis with the new experiments and published information on the values of δ2H gave a definitive assignment of the three model groups, and equations to obtain probabilities for the precursor origin of any new sample. A simple rule of thumb is also presented. Making an assignment using delta values is particularly useful when no other chemical profiling information is available.

Cathinone derivatives gained high popularity on the recreational drugs market during the past 10 years. All these compounds are chiral, and the pharmacological potency of the enantiomers of these stimulants is supposed to differ. The goal of this research was to develop a reliable and easy-to-perform high-performance liquid chromatography ultraviolet method for the chiral separation of a set of 24 cathinone derivatives. A commercially available CHIRALPAK AS-H column consisting of amylose tris [(S)-α- methylbenzylcarbamate] coated on 5-μm silica gel was found to be suitable to resolve a majority of the tested compounds. High-performance liquid chromatography measurements were performed in normal phase mode under isocratic conditions with a mobile phase consisting of hexane, isopropanol, and triethylamine at a flowrate of 1 ml/min. The ratio between hexane and isopropanol was optimized by means of three model substances. Under final conditions with a mobile phase of hexane, isopropanol, and triethylamine (97:3:0.1), 19 out of 24 compounds were successfully resolved into their enantiomers and detected at a wavelength of 254 nm. A correlation between the substituents of the nitrogen atom and the separation results are shown. Furthermore, enantiomer separation results of four cathinone derivatives were compared with the results of their amphetamine analogs. Copyright

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Complete asymmetric induction has been achieved during Grignard alkylations/arylations resulting in (1S,2R)- and (1R,2R)-1-phenyl-1-alkyl/aryl-2-(1-pyrrolidinyl)-1-propanols which are isolated as hydrochlorides.

Reduction of N-t-BOC-protected-N-alkyl α-aminoketones with LiEt 3BH or Li(S-Bu)3BH furnishes protected syn-β-aminoalcohols with high selectivities. In contrast, removal of the BOC group followed by reduction of the aminoketone gives anti-β- aminoalcohols with variable selectivities. With aromatic ketones, selectivities are typically high while aliphatic ketones show mediocre to high selectivities depending on steric considerations.

The sale of ephedrine, one of the precursors of methamphetamine, is strictly controlled and monitored in various countries to prevent the production of illicit methamphetamine. There are three kinds of production scheme for ephedrine manufacture, and it is very useful for precursor control to investigate the origin of ephedrine used for the synthesis of illicit methamphetamine. By means of stable isotope ratio mass spectrometry (IR-MS), we investigated the origin of ephedrine based on the δ13C and δ15N values. The various origins of ephedrine (biosynthetic, semisynthetic, or synthetic) could be discriminated clearly by using these values. The δ15N values of synthetic ephedrine were more negative than those of ephedrine from other sources. By the repeated distillation of methylamine in our laboratory, we confirmed that this could be due to isotope separation during distillation for the purification of methylamine used for ephedrine synthesis. The values for ephedrine used as the precursor were well-correlated with those for methamphetamine synthesized from it. This drug characterization analysis should be useful to illuminate the origin of the precursors used for clandestine methamphetamine and to trace the diversion of medicinal ephedrine for illicit manufacture of methamphetamine.

The ultracentennial 10-I-4 iodinane oxide IBX (3; o-iodoxybenzoic acid; 1-hydroxy-1,2-benziodoxol-3(1H)-one 1-oxide) represents a new oxidizing reagent that successfully joins to the large family of known oxidants.IBX, in contrast to other valuable oxidants, is inexpensive to prepare and easy to handle, can tolerate moisture and water, and generally gives very good yields.Furthermore, IBX is mild and chemoselective (primary alcohols are converted into aldehydes with no overoxidation to acids; 1,2-diols are converted to α-ketols or α-diketones without oxidative cleavage; amino alcohols are oxidized to amino carbonyls, without protection of the amino group; sensitive heterocycles are not affected; various other functional groups are compatible with IBX oxidation).IBX is versatile (it works in various solvents and it is highly sensitive to temperature variations), and its solutions in DMSO are stable enough to carry out the oxidation reaction easily.

A series of N1-methyl-1-phenyl-1,2-propanediamines substituted at the nitrogen (N2) by alkyl groups (CH3, C2H5, i-C3H7, t-C4H9) and the corresponding imidazolidines from formaldehyde have been synthesized.The study of their 1H- and 13C-NMR spectra allowed the differentiation of the diastereoisomers in these two series.

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