33 results about "Diazoacetic ester" patented technology

The invention discloses a method for synthesizing 2-thiabicyclo[3.1.0]-3-hexenyl-6-formate. The method comprises the following steps: adding diazo acetate or a diazo acetate solution to a mixture of a catalyst, thiophene and a solvent in a dropwise mode under stirring at 0-140DEG C, and reacting until a gas is completely discharged; filtering to remove the catalyst, and distilling off excel thiophene and solvent; and finally separating to obtain 2-thiabicyclo[3.1.0]-3-hexenyl-6-formate, wherein the catalyst is a supported Cu catalyst which comprises a Cu active component, an assistant and a carrier. According to the invention, the cheap supported Cu catalyst is adopted, application amounts of reactants are clarified, preparation conditions of the catalyst are regulated, and the assistant is added, so performances of the catalyst are changed, and the reaction selectivity is improved; and the catalyst has the advantages of easy preparation and low cost, cyclopropanation reaction conditions are mild, the reaction selectivity and the product yield are high, and the catalyst is easy to separate after the reaction. The method is suitable for massive synthesis of 2-thiabicyclo[3.1.0]-3-hexenyl-6-formate.

The invention discloses a method for synthesizing pyrazoline nucleoside analogs with a quaternary carbon center, belonging to the technical field of organic chemistry. Starting from 9-alkenyl purine 1 and α-alkyl / aryl diazoacetate 2, DPPB or Pd 2 (dba) 3 As a catalyst, after the reaction, a pyrazoline-like purine nucleoside analog 3 with a quaternary carbon center is obtained, and the reaction yield is moderate to excellent. In the present invention, the diversity and singleness of pyrazoline products can be effectively controlled by changing the catalytic system, and the pyrazoline-like purine nucleoside analog 5 can be obtained after the product is further hydrogenated.

The invention relates to the preparation of cyclopropane carboxylate, in particular to a method for synthesizing 4-thio-bicyclo [3.1.0]-2-hexene-6-formic ether under the mild condition of the catalysis of non-noble metal. The method comprises the following steps of: taking thiophene and ethyl diazoacetate as raw materials, adopting a compound of Cu or Co as a catalyst, adopting a compound which does not contain an alcoholic hydroxyl group, a carboxylic acid group, a primary amino radical and a secondary amino group as a solvent, dripping the ethyl diazoacetate or a solution thereof into the mixture of the catalyst and the thiophene, stirring, reacting for 5-24min at the temperature of 0-120 DEG C until a reaction mixture does not discharge gas any more, then distilling off the solvent andthe excessive thiophene and separating by the methods of column chromatography or reduced pressure distillation and the like to obtain the 4-thio-bicyclo[3.1.0]-2-hexene-6-formic ether, wherein calculated by molar weight, the use quantity of the thiophene in the reaction is 1-200 times that of the ethyl diazoacetate, the use quantity of the catalyst is 0.0001-100mol% of that of the ethyl diazoacetate, and the volume of the solvent is 0-50 times the volume of the thiophene. The invention has low cost, mild condition, better selectivity and higher economic value.

A carried catalyst used for cyclopropanizing 2,5-dimethyl-2,4-hexadiene contains the active component (20-90%) chosen from Fe, Ca, Ni, Ca, Zn, Cr, Mo or Ti, the assistant (0.1-5%) chosen from L, Na or K, and the carrier chosen from alumina silica gel and activated carbon. It is prepared through premodifying carrier, and immersing while adding active component and the organic compound containing hydroxy or carboxyl group and oxygen. Its advantages are low dosage, high output rate, little coking and easy separation.

The invention discloses a continuous synthesis method of diazoacetate, in which glycine ester hydrochloride aqueous solution, sodium nitrite aqueous solution, and organic solvent are subjected to two-stage diazotization synthesis reaction, the product is separated and separated, and the oil layer is deweighted Nitrogen liquid low level tank, water layer to the extraction tank; add extractant to the extraction tank for extraction and continue to stand for stratification, the water layer goes to the acidification reflux tank, and the oil layer goes to the diazo liquid low level tank to combine to obtain a diazoacetate solution . The water layer in the acidification reflux kettle is subjected to acidification reflux, cooling, resin adsorption, negative pressure simple steaming, dehydration and concentration, and centrifugation to obtain the sodium chloride wet base and centrifuged mother liquor. The centrifuged mother liquor is returned to the acidification reflux kettle for use mechanically. The wet base is dried to obtain industrial grade sodium chloride. The method of the invention enables the reaction to be fully carried out so as to obtain a high yield, and at the same time, the high-salt wastewater produced by the reaction is treated to recover sodium chloride; and the continuous production of the whole process is tested. Realize clean production without waste water, waste gas and waste residue discharge.

The invention belongs to the field of the drug synthesis, relating to the novel synthesis method of the natural drug physostigmine preventing the disease of Alzheimer and the derivatives aniline formic ester phenserine. In the invention, the L-tryptophan 3 is used as the raw material; first the chiral oxazolone intermediate 5 is made; then through the three-step and one-pot chute-typed reaction between the molecules of the asymmetric cyproterone, opening of the ring and cyclization, the intermediate 5 reacts with the diazo acetate ester to prepare the optically pure 3-substituted tetrahydropyrrole indole skeleton 6; the skeleton is deoxidized by the tetra-lithium aluminum hydride to get the diol substituted intermediate 7; the intermediate 7 is doffed from the hydroxy-methyl by the Raney-Ni to get the intermediate 8 desoxyeseroline; the intermediate 8 finishes the synthesis of the physostigmine preventing the disease of Alzheimer and derivatives aniline formic ester phenserine, after the bromination, the methyl-etherification, the doffing of the methyl and the carbonylation reactions. The method has the advantages of the high collection rate of the key reactions, the simple operation, and the short reaction steps and so on; and the method has the important practical significance for the solution of the sources of the raw materials of the drug physostigmine and the derivatives aniline formic ester phenserine in the market.

Aldehydes were obtained in excellent yields from ruthenium-porphyrin-catalyzed oxidation of various terminal alkenes with 2,6-dichloropyridine N-oxide under mild conditions. The aldehydes generated from these ruthenium-catalyzed alkene oxidation reactions can be used in-situ for olefination reactions with ethyl diazoacetate in the presence of PPh3, leading to one-pot diazoacetate olefination starting from alkenes.

The invention discloses a chiral sulfonamide derivative, the structural formula is as follows, wherein, R is an aryl group, an alkyl group, a cycloalkyl group, a heterocyclic group, a substituted aryl group, a substituted alkyl group, or a substituted heterocyclic group; Ar 1 Aryl, substituted aryl; Ar 2 Aryl, substituted aryl, heterocyclic aryl; Ar 3 Aryl, substituted aryl, heterocyclic aryl; the present invention uses sulfonamide, aryl diazoacetate, imine as raw material, 4Å molecular sieve as water absorbing agent, rhodium acetate, chiral phosphoric acid to form a catalytic system, In an organic solvent, the chiral sulfonamide derivatives are obtained through one-step reaction. The synthesis method of the invention has the advantages of high atom economy, high selectivity and high yield, and has mild reaction conditions and simple and safe operation. The chiral sulfonamide derivatives with two quaternary carbon centers of the present invention are potential drug active molecules, are widely used in the field of medicine, and have great application prospects.