5650-44-2Relevant articles and documents
Chiral synthesis method of ephedrine key intermediate (S)-2-methylamino-1-phenyl-1-acetone
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, (2021/04/14)
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.
Nanorods of FeVO4: An efficient heterogeneous catalyst for chemoselective oxidation of benzylic alcohols
Heydari, Akbar,Sheykhan, Mehdi,Sadeghi, Masoud,Radfar, Iman
, p. 248 - 255 (2017/08/10)
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.
Preparation methods for ephedrine or pseudoephedrine and for ephedrine or pseudoephedrine intermediate
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, (2017/04/14)
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.