39 results about "3-buten-2-one" patented technology

Procedure for preparation of compounds with the general formula 1, which include the racemic mixtures (±)-1, and the enantiomerically pure compounds (−)-1 and (+)-1, wherein R1 and R3, like or different, represent an atom of hydrogen, chlorine, fluorine, a methyl, trifluoromethyl or methoxy group; R2 represents an atom of hydrogen, chlorine, fluorine, a methyl, trifluoromethyl, methoxy, trifluoromethoxy, methylsulphonyl or aminosulphonyl group; R4 represents an atom of hydrogen, chlorine, fluorine, a methyl, trifluoromethyl, methoxy, trifluoromethoxy, methylsulphonyl or aminosulphonyl group, with the condition that one of the substituents R2 or R4 is a methylsulphonyl or aminosulphonyl group; which involves obtaining the racemic mixture with the general formula (±)-1 by reacting an (E)-1,1,1-trifluoro-4-aryl-3-buten-2-one with a phenylhydrazine, followed by a treatment with chlorosulphonic acid, or by reacting with chlorosulphonic acid followed by a reaction with sodium hydroxide and, finally, with thionyl chloride. The product obtained by either of these methods is made to react with ammonium carbonate or ammonia, or with sodium sulphite and methyl iodide or methyl sulphate. In addition, to obtain the enantiomerically pure compounds with the general formula 1 by resolving the racemic mixture with the general formula (±)-1, a reaction is effected with optically active ephedrine, followed by formation of the sodium salt of each enantiomer, reaction with thionyl chloride and ammonium carbonate or ammonia, or instead with thionyl chloride followed by sodium sulphite and methyl iodide or methyl sulphate to thereby obtain separately the enantiomerically pure compounds with the general formulae (−)-1 and (+)-1.

The invention addresses the problem of providing a method for producing 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione that is suited to industrial production. The invention provides a method for producing 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione by reacting 3-bromo-3-buten-2-one and 2-hydroxy-1,4-naphthoquinone in the presence of a solvent, then obtaining crystals of 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione by adding an alcohol-based solvent and / or water to the reaction system, and treating the crystals by using a specific adsorbent in the presence of a solvent.

4-Chloro-4-alkoxy-1,1,1-trifluoro-2-butanones, prepared by reacting alkyl vinyl ethers with trifluoroacetyl chloride, are useful for preparing 4-alkoxy-1,1,1-trifluoro-3-buten-2-ones.

The invention discloses preparation methods of 3,4-dimethyl pyrazole and 3,4-dimethyl pyrazole phosphate. The preparation method of the 3,4-dimethyl pyrazole comprises the following steps of: (1) reacting 2-butanone and paraformaldehyde at the temperature of 30-60 DEG C under the action of protonic acid for 4-20 hours in an organic solvent A, adjusting pH (Potential of Hydrogen) to be 7-8 after the reaction is finished, and performing atmospheric distillation to obtain 3-methyl-3-butylene-2-ketone; and (2) thermally reacting the 3-methyl-3-butylene-2-ketone prepared by the step (1) with hydrazine hydrate at the temperature of 40-50 DEG C for 2-8 hours, cooling reaction solution to 25-30 DEG C, adding an alkaline compound and hydrogen peroxide aqueous solution, and performing thermal reaction at the temperature of 30-60 DEG C for 3-10 hours after the addition is finished, wherein the obtained reaction solution is post-treated to obtain the 3,4-dimethyl pyrazole. The 3,4-dimethyl pyrazole is then reacted with phosphoric acid to form a salt so as to obtain the 3,4-dimethyl pyrazole phosphate. The method has the advantages of cheap and readily available raw materials, easiness in operation, high reaction yield, high product purity, capabilities of removing a large amount of concentrated sulfuric acid in a technological process and thus reducing the production of three wastes and high suitability for industrial large-scale production.

The invention discloses a method for synthesizing 4-alkoxy-1,1,1-trifluoro-3-butane-2-ketone by taking trifluoroacetic acid, vinyl alkyl ether and phosgene as raw materials in the presence of a solvent and an acid-binding agent. A chemical reaction formula is as shown in the specification, wherein R is methyl, ethyl, n-propyl, isopropyl and normal-butyl. The preparation method disclosed by the invention is simple and convenient in process and simple to operate, has reaction yield of 85.6% (in terms of trifluoroacetic acid), and product purity of 98%, and is low in production cost and suitable for industrial production.

Procedure for preparation of compounds with the general formula 1, which include the racemic mixtures (±)-1, and the enantiomerically pure compounds (−)-1 and (+)-1, wherein R1 and R3, like or different, represent an atom of hydrogen, chlorine, fluorine, a methyl, trifluoromethyl or methoxy group; R2 represents an atom of hydrogen, chlorine, fluorine, a methyl, trifluoromethyl, methoxy, trifluoromethoxy, methylsulphonyl or aminosulphonyl group; R4 represents an atom of hydrogen, chlorine, fluorine, a methyl, trifluoromethyl, methoxy, trifluoromethoxy, methylsulphonyl or aminosulphonyl group, with the condition that one of the substituents R2 or R4 is a methylsulphonyl or aminosulphonyl group; which involves obtaining the racemic mixture with the general formula (±)-1 by reacting an (E)-1,1,1-trifluoro-4-aryl-3-buten-2-one with a phenylhydrazine, followed by a treatment with chlorosulphonic acid, or by reacting with chlorosulphonic acid followed by a reaction with sodium hydroxide and, finally, with thionyl chloride. The product obtained by either of these methods is made to react with ammonium carbonate or ammonia, or with sodium sulphite and methyl iodide or methyl sulphate. In addition, to obtain the enantiomerically pure compounds with the general formula 1 by resolving the racemic mixture with the general formula (±)-1, a reaction is effected with optically active ephedrine, followed by formation of the sodium salt of each enantiomer, reaction with thionyl chloride and ammonium carbonate or ammonia, or instead with thionyl chloride followed by sodium sulphite and methyl iodide or methyl sulphate to thereby obtain separately the enantiomerically pure compounds with the general formulae (−)-1 and (+)-1.