- Method for preparing lorcaserin
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The invention discloses a method for preparing lorcaserin. Specifically, the method comprises the steps: taking p-chlorophenylacetonitrile as an initial raw material, preparing p-chlorophenylethylamine through reduction; carrying out a reaction with p-toluenesulfonyl chloride to form an amino occupying intermediate; enabling the intermediate to carry out a reaction with monochloroacetone under analkaline condition to form N-(2-(4-chlorphenyl)ethyl)-4-methyl-N-(2-propionyl)benzenesulfonamide, and then carrying out reduction, chlorination, p-toluenesulfonyl removal and intramolecular Friedel-Crafts alkylation to synthesize 8-chloro-1-methyl-2,3,4,5-tetrahydro-1H-3-benzoazepine, carrying out L-(+)-tartaric acid resolution and alkalization on azepine to remove tartaric acid, and acting with hydrogen chloride diethyl ether to salify to prepare lorcaserin. The method has the characteristics of simple synthesis method, good reaction selectivity, high product purity, environmental protectionand low preparation cost.
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Paragraph 0012-0014
(2020/08/22)
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- Synthesis of 3-benzazepines and azepino[4,5-b]heterocyclic ring systems via intramolecular Friedel-Crafts cyclization
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The intramolecular Friedel-Crafts cyclization was found to be effective for the synthesis of 3-benzazepines and azepino[4,5-b]heterocyclic ring systems using simple allylic bromides tethered to activated aromatic nuclei. Amongst the various Lewis acids screened, Bi(OTf)3 was found to be the most effective 'ecofriendly' catalyst for the cyclization.
- Kargbo, Robert B.,Sajjadi-Hashemi, Zohreh,Roy, Sujata,Jin, Xiaomin,Herr, R. Jason
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supporting information
p. 2018 - 2021
(2013/04/10)
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- Instantaneous deprotection of tosylamides and esters with Sml 2/amine/water
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(Chemical Equation Presented) Sml2/amine/water mediates instantaneous cleavage of tosyl amides and tosyl esters. Highly hindered, sensitive and functionalized substrates were successfully deprotected in near quantitative yield.
- Ankner, Tobias,Hilmersson, Goeran
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supporting information; experimental part
p. 503 - 506
(2009/07/11)
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- Pictet-Spengler condensation of N-sulfonyl-β-phenethylamines with α- chloro-α-phenylselenoesters. New synthesis of 1,2,3,4- tetrahydroisoquinoline-1-carboxylates
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The reaction of N-sulfonyl-β-phenethylamines with α-chloro-a- phenylseleno acetate/propionate esters under Lewis acid promotion gives moderate to good yields of the corresponding 1,2,3, 4- tetrahydroisoquinoline-1-carboxylates. Varying degrees of diastereoselection were obtained using chiral sulfonamides and/or esters. Employing this strategy, the achievement of a new total synthesis of Calycotomine is reported.
- Silveira, Claudio C.,Bernardi, Carmem R.,Braga, Antonio L.,Kaufman, Teodoro S.
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p. 4969 - 4972
(2007/10/03)
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- A Convenient Conversion of Primary Amines into the Corresponding Halides Radical Promoted Halodeamination via N-Substituted-N-Tosylhydrazines
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Treatment of 1-substituted-1-tosylhydrazines with 2 equivalents of NCS or NBS in dry THF in presence of light affords the corresponding alkyl halides in good yields.This reaction presumably involves the initial formation of a stabilized hydrazyl radical which is halogenated in a radical chain process.Elimination of p-toluenesulfinic acid and extrusion of nitrogen leads to the corresponding alkyl halide.This route provides an improved method for halodeamination under neutral reaction conditions.
- Collazo, Luis R.,Guziec, Frank S.,Hu, Wei-Xiao Jr.,Pankayatselvan, Ratnadevi
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p. 7911 - 7914
(2007/10/02)
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