- Preparation method of dopamine hydrochloride
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The invention provides a method which comprises the following steps: taking veratraldehyde as a starting raw material, firstly carrying out condensation reaction with nitromethane to generate 3, 4-dimethoxy-beta-nitrostyrolene, carrying out catalytic reduction to obtain 3, 4-dimethoxy phenylethylamine, carrying out reaction with hydrobromic acid to remove methoxy, and finally salifying with hydrochloric acid to obtain dopamine hydrochloride. The preparation method has the advantages of cheap and easily available initial raw materials, simple process, no high-temperature and high-pressure steps, low cost, high purity and high yield, and is suitable for industrial production.
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- Synthetic method of high-purity dopamine hydrochloride
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The invention provides a synthetic method of dopamine hydrochloride, and belongs to the field of drug synthesis. The preparation method comprises the following steps: taking 3,4-dimethoxyphenylethylamine as an initial raw material, firstly reacting with an acid to form a salt, re-crystallizing and refining to obtain 3,4-dimethoxyphenylethylamine salt, reacting with hydrobromic acid to remove methyl to generate dopamine hydrobromide, and finally reacting with hydrochloric acid to form a salt so as to obtain dopamine hydrochloride. The preparation method provided by the invention has the advantages of cheap and easily available initial raw materials, simple process, no high-temperature and high-pressure hydrogenation step, low cost, high purity and high yield, and is suitable for industrialproduction.
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Paragraph 0034; 0037-0038; 0041-0042; 0045-0046; 0049
(2020/11/23)
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- Method for efficiently preparing 5,6-dihydroxyindole (by machine translation)
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The preparation method 5,6 - of the compound,dihydroxyindole comprises the following steps :(1): dissolving 3,4 - dialkoxybenzylethylamine and a catalyst in an organic solvent, in an organic solvent, carrying out reflux reaction, in the heated stirring state ;(2) and then further purifying to obtain (1)-hydroxyindole solid powder, which is suitable for industrial production, and has a high, product purity, stability, and easy long-term storage after the operation steps, are short ;(3) reaction steps, through an oxidation reaction, and then further purifying the intermediate compound I, and then purifying the compound I by the oxidizing agent, and then purifying the intermediate compound. I by using a, reducing agent, and then, purifying the intermediate compound I by the, oxidation reaction step 5,6 - and further, purifying the obtained dopamine white solid, powder . by oxidation reaction . The method comprises the following steps. (by machine translation)
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Paragraph 0031-0035
(2020/04/29)
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- Catalytic Strategy for Regioselective Arylethylamine Synthesis
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A mild, modular, and practical catalytic system for the synthesis of the highly privileged phenethylamine pharmacophore is reported. Using a unique combination of organic catalysts to promote the transfer of electrons and hydrogen atoms, this system performs direct hydroarylation of vinyl amine derivatives with a wide range of aryl halides (including aryl chlorides). This general and highly chemoselective protocol delivers a broad range of arylethylamine products with complete regiocontrol. The utility of this process is highlighted by its scalability and the modular synthesis of an array of bioactive small molecules.
- Boyington, Allyson J.,Seath, Ciaran P.,Zearfoss, Avery M.,Xu, Zihao,Jui, Nathan T.
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supporting information
p. 4147 - 4153
(2019/03/07)
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- Palladium-catalyzed cyanomethylation of aryl halides through domino Suzuki coupling-isoxazole fragmentation
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A one-pot protocol for the cyanomethylation of aryl halides through a palladium-catalyzed reaction with isoxazole-4-boronic acid pinacol ester was developed. Mechanistically, the reaction proceeds through (1) Suzuki coupling, (2) base-induced fragmentation, and (3) deformylation as shown by characterization of all postulated intermediates. Under optimized conditions (PdCl2dppf, KF, DMSO/H2O, 130 °C) a broad spectrum of aryl bromides could be converted into arylacetonitriles with up to 88% yield.
- Velcicky, Juraj,Soicke, Arne,Steiner, Roland,Schmalz, Hans-Guenther
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supporting information; experimental part
p. 6948 - 6951
(2011/06/19)
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- A new and efficient route for the synthesis of naturally occurring catecholamines
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Catecholamines, sympathomimetic drugs and adrenergic receptor antagonists, have been prepared by a regioselective oxidation of the corresponding 4-hydroxyphenethylamine derivatives by 2-iodoxybenzoic acid (IBX) in homogeneous as well as in heterogeneous conditions and followed by cleavage of the amino protective group. By using polymer-supported IBX, after the first oxidation, the oxidant can be recovered, regenerated, and efficiently reused for several additional times. An efficient, easy and green procedure for the synthesis of N-(methoxycarbonyl)dopamine, key component of many pharmaceuticals, has also been reported. Georg Thieme Verlag Stuttgart.
- Bernini, Roberta,Crisante, Fernanda,Barontini, Maurizio,Fabrizi, Giancarlo
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experimental part
p. 3838 - 3842
(2010/03/30)
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- Towards synthetic adrenaline receptors - Shape-selective adrenaline recognition in water
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A new rationally designed receptor molecule binds adrenaline derivatives in water. Its binding pattern (see picture) imitates the interplay of noncovalent interactions operating in the natural receptor. High shape selectivity is achieved for the slim dopamine skeleton, and leads to rejection of substrates with an a-substituent, such as amino acid derivatives.
- Herm, Michael,Molt, Oliver,Schrader, Thomas
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p. 3148 - 3151
(2007/10/03)
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- Synthesis of Dopamines Labelled with 13C in the α- or β-Side Chain Position and Their Application to Structural Studies on Melanins by Solid-State NMR Spectroscopy
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Solid-state NMR spectroscopy was applied to the analysis of melanins prepared by peroxidase-H2O2 oxidation of dopamines specifically 13C labelled in the α- or β-side chain positions.A surprisingly diverse pattern of signals indicated the presence of uncyclized dopamine and noradrenaline-derived units, in addition to indole and carbonyl carbon atoms.These structural features, coupled with the results obtained from elemental analysis of dopamine melanin samples prepared under different conditions, point to a pigment formation process more complex than previously believed. - Key Words: CP-MAS NMR Spectroscopy / Melanin / Oxidative phenolic coupling / Quinone methides / Labelled compounds, 13C / Dopamines / Enzymes
- Crescenzi, Orlando,Kroesche, Christoph,Hoffbauer, Wilfried,Jansen, Martin,Napolitano, Alessandra,et al.
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p. 563 - 568
(2007/10/02)
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- Bioavailability and pharmacokinetics of an oral dopamine prodrug in dogs.
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The bioavailability and pharmacokinetics of an oral dopamine prodrug, N-(N-acetyl-L-methionyl)O,O-bis(ethoxycarbonyl)dopamine (1), were examined in dogs, and the mechanism of its absorption and bioactivation was discussed. Compound 1 showed a plasma dopamine concentration that was several times higher than that of dopamine (DA) following oral administration to dogs, while the plasma concentrations of dopamine-30-sulfate (DA-SO4) and 3,4-dihydroxyphenylacetic acid (DOPAC) are lower in comparison with that of DA. The conversion of 1 to DA occurred in proportion to the dose administered. Compound 1 also showed a plasma DA concentration that was several times higher than that of other DA prodrugs reported hitherto. In dog plasma, in vitro, 1 was converted to its deethoxycarbonylated form, N-(N-acetyl-L-methionyl)dopamine (2), while other related compounds, N-(L-methionyl)dopamine (3), N-(L-methionyl)O,O-bis(ethoxycarbonyl)-dopamine (4), and O,O-bis(ethoxycarbonyl)dopamine (5), were rapidly converted to DA (however, 2 was stable in plasma). Bioavailability, based on the AUC of DA, 1, 2, and 5 following oral administration to dogs, increased in the following order: 1, 2, 5, and DA. Thus, it was shown that the two protective groups introduced in 1 served to reduce the first-pass metabolism of the DA moiety in the absorption process. It was also confirmed that 1 is converted to 2 or DA in blood, liver, and intestine.
- Murata,Noda,Kohno,Samejima
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p. 812 - 814
(2007/10/02)
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