54 results about "Ethyl diazoacetate" patented technology

The invention discloses a preparation method of chiral dimethyl cyclopropyl carboxamide. The method comprises a step of asymmetric cyclopropyl alkylation and a step of catalytic amidation of cyclopropyl formic ether, wherein in the step of asymmetric cyclopropyl alkylation, a cyclopropyl alkylation reaction is carried out on ethyl diazoacetate and isobutene under the catalysis of a chiral ligand complex of a cuprous salt so as to obtain (S)-dimethyl cyclopropyl formate; and in the step of catalytic amidation of cyclopropyl formic ether, an ammonolysis reaction is carried out on the (S)-dimethyl cyclopropyl formate by one step so as to directly obtain (S)-2,2-dimethyl cyclopropyl carboxamide, and refining the carboxamide with an alcohol so as to obtain the chiral dimethyl cyclopropyl carboxamide with chemical purity being greater than 99.5% and an e.e. value being greater than 99.5%. Thus, the method used for synthesizing the (S)-2,2-dimethyl cyclopropyl carboxamide is environment-friendly, simple, rapid and efficient.

The invention discloses a method for preparing N-sulfonimide: using ferric sulfate as a catalyst or no catalyst, and potassium hydrogen sulfate as an auxiliary agent to realize the three-component reaction of amide, sulfonamide and ethyl diazoacetate to prepare N ‑Sulfonimide has the following advantages: cheap and green catalyst, more economical reaction, wide substrate versatility, readily available raw materials, can be carried out in the air, and simple post-processing, which is conducive to the synthesis of drug molecules and large-scale industrialization applications in . At the same time, the reactants, catalysts, assistants and the like used in the present invention are cheap and easy to obtain, the reaction composition is reasonable, no ligands and toxic metal catalysts are required, the atom economy is high, the reaction steps are few, and a higher reaction can be obtained only in one step. Yield, in line with the requirements and directions of contemporary green chemistry and medicinal chemistry.

The invention discloses a preparation method of a key intermediate of amlodipine, and relates to the field of pharmaceutical synthesis. The specific steps are as follows: compound 3 (2-(2-(2-hydroxyethoxy)ethyl)isoindoline-1,3-dione) is obtained by reacting with DMSO (dimethyl sulfoxide) and oxalyl chloride Compound 2 (2-(2-(1,3-dioxaisoindolin-2-yl)ethoxy)acetaldehyde); then compound 2 and ethyl diazoacetate, catalyzed by Lewis (Lewis) acid A C-H bond insertion reaction occurs under the following conditions to obtain compound 1 ((2-(1,3-dioxaisoindolin-2-yl)ethoxy)-3-oxabutyric acid ethyl ester). The preparation method of the present invention avoids the NaH route commonly used in current production, the total yield is equivalent to the NaH route, and the raw materials are cheaper and easier to obtain, thereby greatly improving the safety and production efficiency, and reducing the total cost by about 30%. Suitable for industrial production.

The invention discloses a method for preparing 4-aminobutyrate derivatives, and relates to a method for preparing the 4-aminobutyrate derivatives. The purpose of the invention is to solve the problemsof complicated steps, a low yield, and environmental pollution in the synthesis of the 4-aminobutyrate derivatives by using conventional methods. The method comprises the following steps: a diarylamine derivative, an olefin derivative and ethyl diazoacetate are dissolved into an organic solvent under a nitrogen atmosphere and room temperature, then a photocatalyst is added, mixing is performed uniformly, the mixed material is placed below a blue LED lamp, an illumination reaction is performed, rotary evaporation is performed to remove the solvent, chromatography separation purification is performed by using a silica gel column, and therefore the product, one 4-aminobutyrate derivative, is obtained. The reaction in the method provided by the invention can be performed under a normal temperature and normal pressure, the reaction conditions are mild, the yield can reach 80%, and the method has the advantages of simple operation, no pollution, safety, environmental friendliness and low costs, and is applied to the field of organic synthesis.

The invention belongs to the technical field of chemical medicines, and specifically relates to a synthesis method of (1R,2R)-1-p-thiamphenylphenyl-2-amino-1,3-propanediol (I). The method comprises: 1. Compound (III) is prepared by condensing p-thymphenylbenzaldehyde (II) with primary amine. 2. Under the action of a catalyst, compound (III) undergoes acridinization reaction with ethyl diazoacetate to generate compound (IV). 3. Compound (IV) is reduced to obtain compound (V). 4. Under the action of acid, compound (V) undergoes a one-pot ring-opening reaction and deprotection reaction to obtain (1R,2R)-1-p-thiamphenylphenyl-2-amino-1,3-propanediol ( I). The method of the invention has the advantages of novel design, short route, mild conditions, simple operation, good enantioselectivity, high yield and good industrialized production prospect.

Disclosed is a new method for synthesizing 2-fluorocyclopropanecarboxylic acid comprising: 1) performing reaction of 1,1-dichloro-1-fluoroethane with thiophenol in the presence of an alkali, to produce a phenyl sulfide intermediate; 2) performing oxidation reaction of the phenyl sulfide intermediate with Oxone; 3) performing elimination reaction of the product of Step 2) in the presence of an alkali, to obtain 1-fluoro-1-benzenesulfonyl ethylene; 4) performing addition reaction of the 1-fluoro-benzenesulfonyl ethylene with ethyl diazoacetate in the presence of a catalyst, to obtain a cyclopropane intermediate; 5) performing elimination reaction of the cyclopropane intermediate in the presence of an alkali before acidification, to obtain 2-fluorocyclopropanecarboxylic acid. Herein, the synthetic route is short, used materials are bulk commodities, and raw materials are inexpensive and readily available. The process can be safely scaled up by replacing commonly used mCPBA reagents with Oxone. Further, reaction yield is improved, production cost is greatly reduced, and operation is simplified.