摘要:
Provided in the present invention is a method for synthesizing 2,7-dimethyl-2,4,6-octatriene-1,8-dialdehyde. The synthesis method comprises the following steps: (1) adding acetaldehyde diethyl acetal and ethyl-(1-propenyl)-ether under the effect of a catalyst to produce 1,1,3-triethoxy-2-methyl-butane; (2) pyrolysis synthesizing 1,1,3-triethoxy-2-methyl-butane under the catalytic effects of isoquinoline and p-Toluenesulfonic acid to produce 1-methoxy-2-methyl-1,3-butadiene; (3) dissolving 1-methoxy-2-methyl-1,3-butadiene in anhydrous ethanol solvent for synthesis with a phase transfer catalyst, cetyl-trimethyl ammonium bromide, and a chlorinating agent, trichloroisocyanuric acid, to generate 4,4-diethoxy-3-methyl-1- chloro-butene; (4) combining 4,4-diethoxy-3-methyl-1-chloro-butene with a triphenylphosphine salt to produce a phosphonium salt; and (5) condensing the phosphonium salt under the effects of hydrogen peroxide in conjunction with sodium carbonate solution to generate 1,1,8,8-tetramethyl-2,7-dimethyl-2,4,6-octatriene; then hydrolyzing under acidic conditions to synthesize 2,7-dimethyl-2,4,6-octatriene-1,8- dialdehyde. The present invention has a simple process route, is easy to operate, and has mild conditions, great yield, and great industrial value.
摘要:
The present invention relates to a method of obtaining radiopharmaceutical precursors, and in particular precursors to protected amino acid derivatives, which are used as precursors for production of radiolabelled amino acids for use in in vivo imaging procedures, such as positron emission tomography (PET).
摘要:
The invention discloses an intermediate 1-methoxyl-2, 6, 10-trimethyl-1, 3, 5, 9-undec-tetraene, and a preparation method and uses thereof. In the synthesis method for the current lycopene intermediate 2-pos double bond C-14 aldehyde (2, 6, 10-trimethyl-2, 5, 9-undecatriene-1-aldehyde), expensive methyl iodide, polluting dimethyl sulphide and dangerous strong base are needed, so that the method is hardly applied to industrial production. The invention provides a new compound 1-methoxyl-2, 6, 10-trimethyl-1, 3, 5, 9-undec-tetraene, and pure 2-pos double bond C-14 aldehyde can be prepared by hydrolyzing and refining the compound. The synthetic route is simplified and the great suitability for industrial production is achieved.
摘要:
The present invention provides a novel method for preparing 4,4,4-trifluorobutane-2-one by providing a fluorobutene selected from the group consisting of 2,4,4,4-tetrafluoro-1-butene, (E)- 1,1,1,3-tetrafluoro-2-butene, (Z)-1,1,1,3-tetrafluoro-2-butene, and mixture thereof; and reacting the fluorobutene(s) with a proton acid and water.
摘要:
Provided is citronellol, which has an elegant rosy fragrance and is extremely useful for fragrance impartation to aromatic articles. A mixture of an alkylamine and isoprene in a molar ratio of from 1:4 to 1:4.5 is subjected to telomerization at 80 to 100°C for 2.5 to 3.5 hours in the presence of an alkyllithium catalyst and/or phenyllithium catalyst to obtain a nerylamine compound containing 2 to 10 wt% α-nerylamine compound represented by general formula (4) From this nerylamine compound, citronellol containing 2 to 10 wt% optically active 3,7-dimethyl-7-octenol is produced through the reaction steps of asymmetric isomerization, hydrolysis, and hydrogenation.
摘要:
A process for producing hinokitiol which comprises obtaining 1-isopropylcyclopentadiene from cyclopentadiene and an isopropylating agent represented by the general formula R-X (wherein R represents isopropyl; and X represents halogeno, etc.) (the step 1); reacting the obtained product with a dihaloketene to give a ketene-adduct (the step 2); and then decomposing this ketene-adduct (the step 3); wherein the above step 1 involves the following three steps: (a) the step of preparing a cyclopentadienyl metal; (b) the step of isopropylating the cyclopentadienyl metal in an aprotic polar solvent to give isopropylcyclopentadiene; and (c) the step of isomerizing 5-isopropylcyclopentadiene contained in the product selectively into 1-isopropylcyclopentadiene under heating.
摘要:
Die Erfindung betrifft Alkyl- oder cycloalkylsubstituierte Cyclohexanon-oxime, wobei das Alkyl- oder Cycloalkyl eine geradkettige oder verzweigte Alkylgruppe mit 1 bis 10 C-Atomen oder eine Cycloalkylgruppe mit 3 bis 10 C-Atomen ist und worin die Bindung des Cyclohexyl-Ringes in Bezug zum Substituenten R sowohl cis- als auch trans-konfiguriert sein kann sowie ihre Weiterverarbeitung zu hochreinen Cyclohexanon-Derivaten und zu hochreinen Cyclohexylamin-Derivaten.
摘要:
La présente invention concerne un procédé de préparation de 4-aryl disubstitué-1-tétralone de formule dans laquelle X représente halogène, alkyle en C₁-C₄ ou alcoxy en C₁-C₄ et Y, situé en position 2′ ou 3′, représente halogène ou alkyle en C₁-C₄, ce procédé se caractérisant en ce qu'il comprend la réaction, en présence d'un agent acide, de l'α-naphtol de formule (II) avec un hydrocarbure aromatique de formule (III) où X représente halogène, alkyle en C₁-C₄ ou alcoxy en C₁-C₄ et Y est situé en position ortho ou méta par rapport à X et représente halogène ou alkyle en C₁-C₄.