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

The invention relates to a method for simultaneously determining residual quantities of sixteen sensitized aldehyde and ketone perfumes in a toy, and firstly discloses a method for simultaneously determining the residual quantities of the sixteen sensitized aldehyde and ketone perfumes consisting of 5-methyl-2,3-hexanedione, trans-2-heptenal, trans-2-hexenaldimethylacetal, citral, cinnaldehyde, hydroxycitronellal, benzalacetone, 2,4-dihydroxy-3-methylbenzaldehyde, alpha-isomethylionone, lilial, 6,10-dimethyl-3,5,9-undecatrien-2-one, 4-(4-methoxyphenyl)-3-butylene-2-one, alpha-amyl cinnamic aldehyde, lyral, 1-(4-methoxyphenyl)-1-pentene-3-one, and hexylcinnamaldehyde in the toy to fill the technological blank. The method which allows cloth toys, paster toys, and plastic toys (the ABS material, the PVC material and the PS material) to be detected has the advantages of wide coverage and strong applicability. The method which adopts the ion trap-mass spectrum in a qualitative and quantitative secondary mass spectrum MS / MS mode has a good qualitative and quantitative capability to complex matrix toy samples.

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 provides a solid base catalyst and a preparation process for preparing 4-(2-furyl)-3-buten-2-one. The catalyst comprises an alkaline carrier, an activated auxiliary agent and a water-resistant auxiliary agent. The catalyst has the characteristics of easy preparation and low preparation cost. The continuous production process is particularly suitable for condensation of furfural withacetone to prepare 4-(2-furyl)-3-buten-2-one, can effectively inhibit occurrence of multi-condensation side reactions, and has a high product yield. At the same time, the catalyst under the process has the characteristics of high activity, high product selectivity, good water resistance and uneasiness to deactivate.

The invention relates to a benzofuran [2, 3-c] pyridine compound and a synthetic method thereof. The benzofuran [2, 3-c] pyridine compound has a general formula shown in the specification, wherein R1 is phenyl, 3-bromo-phenyl, 4-bromo-phenyl, 4-chloro-phenyl, 4-methoxy-phenyl, 3-methyl-phenyl or 4-methyl-phenyl; R2 is hydrogen or 5-chlorine, 5-bromine, 5-tert-butyl, 3,5-ditert-butyl, 4-methoxy, 5-methoxy, 5-methyl, 3,5-dimethyl and 4,5-dimethyl; R3 is methyl or phenyl, 4-bromo-phenyl, 3-bromo-phenyl, 2-chloro-phenyl, 4-chloro-phenyl, 4-methoxy-phenyl and 4-methyl-phenyl. According to the synthetic method disclosed by the invention, alpha-bromoacetophenone or a derivative thereof as well as 4-(2-hydroxyphenyl)-3-butylene-2-ketone or a derivative thereof are used as reactants, and a one-pot method is adopted to synthesize the benzofuran [2, 3-c] pyridine compound. The synthetic method is simple and convenient in step, mild in condition and high in yield.

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.

The invention discloses a synthesis method for piperitone. The synthesis method comprises the following steps: A: taking methyl isobutyl ketone as a raw material to react with formaldehyde under the catalysis of hydrogen chloride to obtain 3-isopropyl-3-butene-2-ketone; B: carrying out Michael addition on the 3-isopropyl-3-butene-2-ketone and acetyl acetate under the effect of an alkaline catalyst to obtain a 2-acetyl-4-isopropyl-5-oxo-methyl caproate intermediate; C: carrying out intramolecular aldol condensation on the 2-acetyl-4-isopropyl-5-oxo-methyl caproate intermediate under an alkaline condition to obtain a carboxylic ester of the piperitone; D: carrying out hydrolysis and acidification decarboxylation on the carboxylic ester of the piperitone under the alkaline condition to obtain the piperitone. According to the synthesis method, a synthesis route uses conventional chemical raw materials and a reaction condition is moderate; related synthesis steps are classic methods. The three-waste condition and the operation condition are greatly improved so that the synthesis method is a novel synthesis route.

The invention provides a one-pot synthesis method of conjugate eneyne thioether based on 1-hydrocarbon sulfenyl-4-aryl-butene-2-ketone substrate. The method includes feeding Lithium Hexamethyldisilazide (LiHMDS) to a tetrahydrofuran (THF) solution of 1-hydrocarbon sulfenyl-4-aryl-butene-2-ketone under protection of low-temperature nitrogen; stirring; adding [C1P(O) (OEt)2] dropwisely to the reaction system, increasing the temperature to a room temperature after the addition and continuing to stir; after the reaction system cools again to a low temperature, dripping the LiHMDS to the reaction system and stirring for reaction under the temperature; and obtaining the conjugate eneyne thioether from the reaction mixture after normal aftertreatment and column chromatographic separation. The method is a convenient and economical processing method for the conjugate eneyne thioether.