8 results about "Ethyl chloroformate" patented technology

The invention relates to a synthetic method of 2-diphenylmethyl pyrrolidine or an acid salt of 2-diphenylmethyl pyrrolidine. In order to solve the problems of easy ring opening and low yield in the prior art, the invention provides a synthetic method of 2-diphenylmethyl pyrrolidine or an acid salt thereof, which comprises the following steps: in the presence of an alkaline reagent, performing amidation and esterification reaction on a compound pyrrole-2-formic acid as shown in a formula II and ethyl chloroformate in an ROH solvent to obtain a compound as shown in a formula III; r in the ROH solvent is alkyl; performing Grignard reaction with phenyl magnesium bromide to obtain a compound as shown in a formula IV; carrying out reduction reaction on the compound shown in the formula IV under the catalytic action of trifluoroacetic acid and triethyl silane to obtain a compound shown in a formula V; and carrying out hydrolysis reaction on the compound in the formula V under an alkaline condition to obtain the compound 2-diphenylmethylpyrrolidine in the formula I or the acid salt thereof. According to the method, ring-opening impurities can be effectively avoided, the yield is increased to 95% or above, and the purity reaches 99% or above.

The invention discloses a preparation method of L-2, 4-diaminobutyric acid dihydrochloride, which comprises the following steps: (1) taking L-homoserine as an initial raw material, and reacting with concentrated hydrochloric acid in the presence of a zinc chloride / ferrous chloride synergistic catalyst to prepare L-2-amino-4-chlorobutyric acid hydrochloride; (2) after neutralization, carrying out an acylation reaction with ethyl chloroformate to generate N-ethoxycarbonyl-L-4-chlorobutyric acid; (3) carrying out esterification with ethanol so as to obtain N-ethoxycarbonyl-L-4-chlorobutyl amino acid ethyl ester; (4) under the catalysis of sodium iodide, carrying out nucleophilic substitution reaction with phthalimide potassium salt, and cooling, crystallizing and purifying the key intermediate by dropwise adding water to obtain L-2-[(ethoxycarbonyl) amino]-4-phthalimide ethyl butyrate; and (5) finally, hydrolyzing for deprotection, and concentrating and crystallizing to obtain the L-2, 4-diaminobutyric acid dihydrochloride. The method has the advantages of mild reaction conditions, simplicity and convenience in operation, high total yield and the like, and is suitable for large-scale industrial production.

The application discloses a spiromesifen derivative, belongs to the field of crop disease and pest control, and has the structure shown in the following formula 1001, a preparation method thereof is as follows: under the protection of inert gas, 3-(2, 4, 6-trimethylphenyl)-2-oxo-1-oxaspiro[4, 5]-non-3-ene-4-ol and dichloromethane are stirred and cooled to 0-5 DEG C, then triethylamine is added, fluorine ethyl chloroformate is added dropwise, after dropwise addition is completed, the reaction is continued after being raised to room temperature, and then purification is conducted, and the spiromesifen derivative is obtained; the spiromesifen derivative has higher safety for citrus, watermelon and Chinese rose and has better pest control activity than that of spiromesifen.

The application provides a new synthesis method of esacioxin intermediate. The method comprises the following steps: (1) reacting raw material 2-(trifluoromethyl) phenylacetic acid with ethyl chloroformate or isobutyl chloroformate in an inert solvent in the presence of a base to generate a mixed anhydride, and then reacting with ammonia to obtain a corresponding amide compound formula II; (2) preparing an isonitrile compound formula III through a dehydration reaction of the amide compound formula II obtained in the step (1) in the presence of a dehydrating agent and an acid binding agent; (3) cyclizing the isonitrile compound formula III obtained in the step (2) with 2-butynoic acid ethyl ester in the presence of a base and a metal catalyst to form a pyrrole ring compound formula IV; and the reaction formula is shown in the following formula: compared with the prior art, the technical scheme of the application has the advantages of high yield, simple post-treatment, low cost and easy industrialization.

This invention discloses a method for synthesizing and applying propyl 4-{[(1R)-1-phenylethyl]amino}-5-(methoxycarbonyl)-1,2,3,6-tetrahydropyridine-1-carboxylate, belonging to the field of pharmaceutical preparation technology. Specifically, the method involves: removing the tert-butyloxycarbonyl group from 1-tert-butyl 4-oxopiperidinium-1,3-dicarboxylate methyl ester under oxaloyl chloride conditions; reacting the obtained intermediate with ethyl chloroformate in dichloromethane solvent to prepare compound 2; and then reacting compound 2 with the amino group of (R)-(+)-1-phenylethylamine via a nucleophilic substitution reaction to prepare propyl 4-{[(1R)-1-phenylethyl]amino}-5-(methoxycarbonyl)-1,2,3,6-tetrahydropyridine-1-carboxylate. The compound exhibits good lipid-lowering activity and can be used as a potential lipid-lowering drug for the treatment of related diseases. Furthermore, the synthesis method is simple, efficient, and low-cost, and the prepared product has high purity, making it easy to achieve large-scale industrial production.

The application belongs to the technical field of herbicides, and provides a preparation method of the herbicide cycloxaprid, which comprises the following steps: 1, mixing and stirring monocyanamide and ethyl chloroformate, cooling to 0-2 DEG C, adding liquid alkali dropwise, controlling pH and temperature, and carrying out incubation reaction to obtain a product GH520-1; 2, adding dimethyl sulfate and benzyl triethylammonium chloride to the product GH520-1, carrying out warming reaction, and after the reaction is completed, standing and layering to obtain a product GH520-2; 3, adding dimethylamine hydrochloride and liquid alkali to the product GH520-2, supplementing toluene, carrying out warming reaction, cooling to room temperature, standing and layering to obtain a product GH520-3; 4, dissolving the product GH520-3 in toluene, adding cyclohexyl isocyanate, and controlling the reaction temperature to obtain a product GH520-4; and 5, adding sodium methoxide and dimethylamine aqueous solution to the product GH520-4, controlling the reaction temperature, and obtaining a product GH520.

The application discloses a coumarin derivative containing an amide bond and a preparation method and application thereof, and has the characteristics that the specific compound structure of the coumarin derivative is 4-methyl-7-acetylamino coumarin, and the preparation method steps are as follows: 1) 3-hydroxyphenyl ethyl carbamate is prepared by amidation reaction of m-aminophenol and ethyl chloroformate; 2) 4-methyl-7-ethoxycarbonylamino coumarin is prepared by esterification reaction of 3-hydroxyphenyl ethyl carbamate and ethyl acetoacetate; 3) 4-methyl-7-aminocoumarin is prepared by esterolysis reaction of 4-methyl-7-ethoxycarbonylamino coumarin and a mixture of glacial acetic acid and concentrated sulfuric acid; and 4) 4-methyl-7-acetylamino coumarin is prepared by esterification reaction of 4-methyl-7-aminocoumarin, pyridine and acetic anhydride, and the advantages are that the compound has good antiviral and killing effects on white spot syndrome virus, the synthesis method is simple, and the conversion rate is high.

The application discloses a preparation method of L-2,4-diaminobutyric acid dihydrochloride, which comprises the following steps: (1) taking L-homoserine as a starting material, and reacting with concentrated hydrochloric acid in the presence of a zinc chloride / ferrous chloride synergistic catalyst to prepare L-2-amino-4-chlorobutyric acid hydrochloride; (2) after neutralization, acylation reaction is carried out with ethyl chloroformate to generate N-ethoxycarbonyl-L-4-chlorobutyramic acid; (3) esterification is carried out with ethanol to obtain N-ethoxycarbonyl-L-4-chlorobutyramic acid ethyl ester; (4) under the catalysis of sodium iodide, nucleophilic substitution reaction is carried out with phthalimide potassium salt, a key intermediate is purified by dropping water to reduce temperature and crystallize, and L-2-[(ethoxycarbonyl)amino]-4-phthalimidobutyric acid ethyl ester is obtained; and (5) finally, hydrolysis and deprotection are carried out, concentration and crystallization are carried out to obtain L-2,4-diaminobutyric acid dihydrochloride. The application has the advantages of mild reaction condition, simple operation, high total yield and the like, and is suitable for large-scale industrial production.