6 results about "Isopropenyl acetate" patented technology

The invention belongs to the technical field of organic synthesis, and particularly relates to a preparation method of 1-(2, 4, 6-trichloro-phenyl)-propyl-2-ketone-methoxy oxime ether. Comprising the following steps: (1) chlorination reaction: adding a chlorinating agent into aniline serving as a raw material in a solvent at 0-10 DEG C, and carrying out chlorination reaction to obtain 2, 4, 6-trichloroaniline; (2) coupling reaction: carrying out coupling reaction on 2, 4, 6-trichloroaniline, isopropenyl acetate and a catalyst in a solvent under the initiation of nitroxyl ions to obtain 1-(2, 4, 6-trichloro-phenyl)-propyl-2-ketone; (3) oximation reaction: in a solvent, under the action of alkali, carrying out oximation reaction on the 1-(2, 4, 6-trichloro-phenyl)-propyl-2-ketone and hydroxylamine hydrochloride, so as to obtain 1-(2, 4, 6-trichloro-phenyl)-propyl-2-ketone-oxime; and (4) methylation reaction: carrying out methylation reaction on the 1-(2, 4, 6-trichloro-phenyl)-propyl-2-ketone-oxime and chloromethane in a solvent under the action of alkali to obtain the 1-(2, 4, 6-trichloro-phenyl)-propyl-2-ketone-methoxy oxime ether.

The present invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing 1-(2,4,6-trichloro-phenyl)-propyl-2-ketone-methoxy oxime ether. The method comprises the following steps: (1) chlorination reaction: adding a chlorinating agent into aniline as a raw material in a solvent at 0-10°C, and performing a chlorination reaction to obtain 2,4,6-trichloroaniline; (2) coupling reaction: subjecting 2,4,6-trichloroaniline, isopropenyl acetate and a catalyst to a coupling reaction in a solvent under the initiation of nitroxyl ions, so as to obtain 1-(2,4,6-trichloro-phenyl)-propyl-2-ketone; (3) oximation reaction: subjecting 1-(2,4,6-trichloro-phenyl)-propyl-2-ketone and hydroxylamine hydrochloride to an oximation reaction in a solvent under the action of an alkali, so as to obtain 1-(2,4,6-trichloro-phenyl)-propyl-2-ketone-oxime; and (4) methylation reaction: subjecting 1-(2,4,6-trichloro-phenyl)-propyl-2-ketone-oxime and chloromethane to a methylation reaction in a solvent under the action of an alkali, so as to obtain 1-(2,4,6-trichloro-phenyl)-propyl-2-ketone-methoxy oxime ether.

The invention discloses a synthesis method of a meconazole intermediate 4-(4-chlorophenoxy)-1-(1-methyl vinyl)-2-(trifluoromethyl) benzene, which comprises the following steps of: performing defluorination etherification reaction on 2-bromine-5-fluorobenzotrifluoride (I) serving as a raw material and 4-chlorophenol (II) in the presence of an alkaline reagent to obtain 1-bromine-4-(4-chlorophenoxy)-2-(trifluoromethyl) benzene (III), and reacting the 1-bromine-4-(4-chlorophenoxy)-2-(trifluoromethyl) benzene (III) with 4-chlorophenol (II) to obtain the meconazole intermediate 4-(4-chlorophenoxy)-1-(1-methylvinyl)-2-(trifluoromethyl) benzene (III). The preparation method comprises the following steps: reacting a compound (III) with a Grignard exchange reagent (IV) to prepare an aryl Grignard reagent, and reacting with isopropenyl acetate (V) under the action of an iron catalyst to obtain a meconazole intermediate 4-(4-chlorophenoxy)-1-(1-methylvinyl)-2-(trifluoromethyl) benzene (VI); the method has the advantages of simple reaction system, cheap and easily available raw materials, high raw material conversion rate and high product selectivity, is suitable for industrial production, and has a good application prospect; .

The invention relates to the technical field of organic synthetic chemistry, in particular to a method for synthesizing 7-dehydrocholesterol from cholesterol. Comprising the following steps: dissolving cholesterol in a first solvent, adding cyclohexanone and aluminum isopropoxide, and carrying out an Oppenauer oxidation reaction to obtain an intermediate 1; dissolving the intermediate 1 in a second solvent, sequentially adding isopropenyl acetate and p-toluenesulfonic acid, and carrying out first acetylation reaction to obtain an intermediate 2; dissolving the intermediate 2 in a third solvent, and carrying out an upper debromination reaction to obtain an intermediate 3; and dissolving the intermediate 3 in a fourth solvent, then adding 2, 4, 6-trimethylpyridine and acetyl chloride as reaction accelerators, carrying out a second acetylation reaction to obtain an intermediate 4, and carrying out a reduction reaction and purification on the intermediate 4 to obtain the 7-dehydrocholesterol. The 7-dehydrocholesterol is synthesized by the method, the total synthesis yield exceeds 60%, the product purity is 98% or above, and the method is easy to amplify for industrial synthesis.

The invention belongs to the field of chemical synthesis, and particularly relates to a preparation method of Meldrum's acid. According to the method disclosed by the invention, isopropenyl acetate is used as a synthetic substitute of acetone and reacts with malonic acid under the catalysis of acid to generate only one equivalent amount of acetic acid, so that the reaction efficiency is improved, the precipitation of the generated Meldrum's acid is facilitated, and the yield is improved. The method is simple to operate and stable in process, can be used for large-scale production, and can generate higher economic value. Meanwhile, by screening various acids, the catalytic effect of the trifluoromethanesulfonic acid is the best. In addition, the invention also researches a post-treatment method, and the Meldrum's acid with the purity of more than 99% can be obtained through one-time suction filtration, washing and drying.

The present invention provides a method for preparing 2-(3-acetoxy-2-pentylcyclopent-2-ene-1-yl) methyl acetate, the preparation method comprising the following steps: ordinary methyl dihydrojasmonate and isopropenyl acetate are reacted under a composite catalyst to obtain the 2-(3-acetoxy-2-pentylcyclopent-2-ene-1-yl) methyl acetate, the composite catalyst being composed of a transition metal salt and a layered zirconium phosphate. The method of the present invention has simple operation steps, mild reaction conditions, high yield and easy separation. The environmental protection risks caused by waste salt and waste water generated by quenching and repeated washing due to the use of an acidic catalyst reaction in the prior art are solved, and the problem of equipment corrosion is not only reduced in environmental protection and equipment investment, but also simplified in production process, which is conducive to industrialized mass production of products.