70results about "Preparation by halogen elimination" patented technology

The invention relates to fused cyclooctyne compounds, and to a method for their preparation. The invention also relates to a conjugate wherein a fused cyclooctyne compound according to the invention is conjugated to a label, and to the use of these conjugates in bioorthogonal labeling, imaging and / or modification, such as for example surface modification, of a target molecule. The invention further relates to a method for the modification of a target molecule, wherein a conjugate according to the invention is reacted with a compound comprising a 1,3-dipole or a 1,3-(hetero)diene.

The invention belongs to the technical field of fine chemical engineering and provides a method for dechlorinating chlorinated aromatic hydrocarbon through nickel catalysis at room temperature. The dechlorination reaction of the chlorinated aromatic hydrocarbon through nickel catalysis is characterized in that the reaction is carried out in a low-carbon alcoholic solvent in the presence of alkali under the condition of room temperature, and a reaction product is easy to separate and has high yield and good selectivity. The method has the advantages that the method uses low-carbon alcohol with low toxicity, low price and availability as a solvent and a divalent nickel complex with low price as a catalyst to catalyze the dechlorination reaction of the chlorinated aromatic hydrocarbon. The divalent nickel complex has a simple preparation method, high catalytic activity, good selectivity and stability in air.

Disclosed are a method of preparing allyl alcohol and allyl alcohol prepared thereby. The method of preparing allyl alcohol includes adding glycerol with formic acid in an amount of 0.8˜2 equivalents relative to 1 equivalent of glycerol, and increasing a reaction temperature to 220˜260° C. from room temperature at a heating rate of 2.0˜7.0° C. / min so that glycerol and formic acid are reacted.

The invention discloses preparation of a rhodium loaded porous siphonate carbon nitride photocatalyst, and a hydrodechlorination catalytic reaction of parachlorophenol of the rhodium loaded porous siphonate carbon nitride photocatalyst. The preparation method of the photocatalyst comprises the steps of taking melamine as a precursor to prepare carbon nitride by a thermal polymerization method, andthen in a mixed solution of ethyl alcohol and water (v / v 1 to 1), taking sodium borohydride as a reducing agent to prepare the rhodium loaded porous siphonate carbon nitride photocatalyst. The methodof hydrodechlorination of the parachlorophenol by photocatalyzing comprises the steps of putting a certain amount of catalyst and a certain concentration of chlorophenol aqueous solution to a glass reactor with a hydrogen balloon, reacting under illumination, and mainly generating phenol, cyclohexanone, cyclohexanol and other products. According to the preparation, the preparation method of the catalyst is simple, operation is easy, the catalyst can be used for photocatalysis chlorophenol to conduct the efficient hydrodechlorination, reaction conditions are mild, chemical selectivity of the cyclohexanol and the cyclohexanone is high, and the catalyst is easy to recycle.

The present invention relates to a fluorine-containing polymerizable monomer having a structure of the general formula (1),where each of R1 and R2 is independently a methyl group or trifluoromethyl group, andeach of R3 and R4 is independently a hydrogen atom, an alkyl group, a fluorinated alkyl group, a ring structure having an aromatic ring, or an acid-labile protecting group, each of the alkyl group and the fluorinated alkyl group independently having a straight-chain, branched or ring form and having a carbon atom number of 1–25, each of R3 and R4 optionally and independently containing at least one of an oxygen atom and a carbonyl bond.

A fluorine-containing styrene monomer of the formula (2) is produced by a first, second or third process. The first process includes (a) reacting a compound of the formula (1) with a compound of the formula (3), in the presence of a metal catalyst; (b) reacting the product of the step (a) with a base; and (c) reacting the product of the step (b) with hydrogen, in the presence of a metal catalyst and a phosphine or amine, thereby producing the target styrene monomer. The second process includes reacting a compound of the formula (1) with a compound of the formula (12), in the presence of a metal catalyst, thereby producing the target styrene monomer. The third process includes reacting a compound of the formula (13) with a compound of the formula (14) or (15), in the presence of a base, thereby producing the target styrene monomer.

The invention belongs to the technical field of insect pheromone synthesis, and discloses a new method for synthesizing (5Z,7E)-dodecane-5,7-diene-1-alcohol as well as acetate and propionate thereof.The method takes propynol as an initial raw material to be subjected to coupling with 1-bromobutane to generate 2-heptyne-1-alcohol, triple bond is reduced to be E-type double bond through LiAlH4, 2-heptyne-1-alcohol is oxidized to be olefine aldehyde through PDC, olefine aldehyde reacts with a Wittig reagent (5-ethyoxyl-5-oxopentyl)triphenyl phosphonium bromide to produce (5Z,7E)-dodecane-5,7-dienoic acid ethyl ester which is reduced by LiAlH4 to obtain (5Z,7E)-dodecane-5,7-diene-1-alcohol, (5Z,7E)-dodecane-5,7-diene-1-alcohol reacts with acetyl chloride and propionyl chloride finally to obtain (5Z,7E)-dodecane-5,7-diene-1-alcohol acetate and (5Z,7E)-dodecane-5,7-diene-1-alcohol propionate. The method utilizes LiAlH4 to reduce the triple bond to be the E-type double bond, and utilizes theWittig reaction of the Wittig reagent with the tail end provided with ester group and aldehyde to directly build the Z-type double bond, the synthesis route is simple, convenient and efficient, and the reaction condition is moderate and environmentally friendly.

The present invention is directed to a new class of thermoplastic elastomers (TPEs) and processes for making them. In some embodiments of the present invention, the end groups of the multi-arm PIB copolymer is a conjugated diene, whereas the other component is a multi-functional dienophile. The components of the TPE of the present invention are chemically connected via the well-known Diels-Alder reaction which is thermally reversible (by the retro-Diels-Alder reaction) at moderately elevated temperatures. The reversibility of the Diels-Alder retro-Diels-Alder reactions allows the recovery of the original components of the TPE and thus its recyclability and also gives the TPE the ability to be reshaped or reformed.

The invention discloses a preparation method of pentafluoropentanol. The preparation method comprises the following steps: firstly, synthetic reaction: carrying out a reaction between propenol and pentafluoroethyliodide under the action of a free radical initiator to generate 4,4,5,5,5-pentafluoro-2-iodo-1-pentanol; secondly, hydrogenated dehalogenation reaction: carrying out the hydrogenated dehalogenation reaction under the action of the 4,4,5,5,5-pentafluoro-2-iodo-1-pentanol to generate a pentafluoropentanol product. The invention provides the preparation method of the pentafluoropentanol. The pentafluoroethyliodide and the propenol serving the raw material undergo free radical reaction to generate the 4,4,5,5,5-pentafluoro-2-iodo-1-pentanol, and the 4,4,5,5,5-pentafluoro-2-iodo-1-pentanol undergoes dehalogenation reaction under the action of a reducing agent to generate the pentafluoropentanol. The method is high in reaction yield and easy for industrial production; in addition, the purity of the product is higher than 99 percent.

The invention provides a method for preparing 4,4'-bis(hydroxymethyl)biphenyl, which comprises the following steps: mixing 4,4'-bis(chloromethyl)biphenyl, a solvent and alkaline liquor according to the mass ratio of 1:4-10:4-10; heating, refluxing and stirring the mixture under the normal pressure and at the temperature of 60 to 100 DEG C; continuously reacting the mixture for at least 4 hours, adding water into the mixture, and filtrating the mixture to obtain a crude product of the 4,4'-bis(hydroxymethyl)biphenyl; and recrystallizing the crude product by an alcoholic solvent to obtain a fine product of the 4,4'-bis(hydroxymethyl)biphenyl. The method has simple operation and short reaction time and is suitable for industrialized production; and the solvent for reaction and the solvent for crystallization can be recycled.

The invention discloses a method for synthesizing propargyl alcohol. The method includes hydrolyzing 1, 3-dichloropropene in saturated alkali metal carbonate solution to obtain 3-chloropropene alcohol; removing hydrogen chloride from the 3-chloropropene alcohol under the condition of the presence of a polar solvent dimethyl sulfoxide and hydroxide of alkali metal so as to obtain the propargyl alcohol. The method has the advantages that the 1, 3-dichloropropene is used as a raw material, the raw material can come from wide sources, is inexpensive and is easily available, the propargyl alcohol is easy to dehydrate, energy can be saved, and environments can be protected; the propargyl alcohol obtained by the aid of the method is high in yield and purity.

The invention relates to a preparation method of 1, 1-cyclopropane dimethanol. The method comprises the steps of conducting ring-closure reaction on organic dihalide and a reducing agent in an alcohol solvent under a certain condition to obtain a solution of 1, 1-cyclopropane dimethanol and halide salt, introducing ammonia under certain conditions so as to conduct solid-liquid separation, filter and rectify to obtain 1, 1-cyclopropane dimethanol. Due to the adoption of the preparation method, the process of 1, 1-cyclopropane dimethanol is simple and concise, the safety is high, and meanwhile, the yield reaches to more than 90%, the purity of 1, 1-cyclopropane dimethanol is more than 98%, and the quality of 1, 1-cyclopropane dimethanol is improved effectively.

The present invention provides processes and intermediates for preparing cinacalcet base and pharmaceutically acceptable salts thereof.

The invention discloses a synthetic method for 2-butyne-1-ol. Innovation points of the invention are as follows: a waste liquid containing 1,3-dichloro-2-butylene and produced in rubber production is used as a starting raw material and undergoes hydrolysis so as to obtain 3-chloro-2-butenyl-1-ol, then elimination is carried out so as to obtain 2-butyne-1-ol, and finally high-purity 2-butyne-1-ol is prepared. According to the synthetic method for 2-butyne-1-ol, the raw material is the waste liquid produced in rubber production and is cheap and widely available, so utilization of the waste, greenness and environmental protection are realized. The synthetic method is simple and is safe and easy to operate; and consumed labor force and resources by the method are substantially reduced. Product yield reaches more than 88%, and product purity reaches 96 to 98%.

The invention relates to a new method for synthesizing 4-pentyne-1-alcohol. In the method, 2-chloromethyl tetrahydrofuran is used as a raw material, in the presence of a lower temperature, tetrahydrofuran is used as a solvent, and n-butyllithium is used as a strong base for eliminating to obtain the 4-pentyne-1-alcohol, wherein the productivity can reach 91 percent. In the invention, the low-price raw material and a simple and convenient condition are used, and the method has higher productivity compared with the traditional method.

Processes are provided for producing propargyl alcohol in an industrially advantageous manner. One of the processes comprises reaction of 1,2,3-trichloropropane with 3 equivalents or more of an alkali compound to produce propargyl alcohol. The other process comprises (1) a first step of reaction of 2,3-dichloro-1-propanol with an amine to produce chloroallyl alcohol, and (2) a second step of reaction of the chloroallyl alcohol obtained in the above step (1) with an alkali compound to produce propargyl alcohol.

The invention provides a method for preparing difluoroethanol through catalytic hydrogenation. The method has the beneficial effects that hydrogenation reduction reaction is carried out by using ethyl chlorodifluoroacetate as the raw material, a Pd / C as a catalyst, triethylanmine as an acid-binding agent and ethanol as a solvent; the atom F has higher electronegativity and HF can not be generated in the ethyl chlorodifluoroacetate hydrogenation process, but the C-Cl bond is easy to hydrogenate and HCl is easy to generate, thus neutralizing generated HCl by adding the acid-binding agent triethylanmine, propelling reaction to be carried out positively and increasing the conversion rate of ethyl chlorodifluoroacetate; on the other side, used in ester hydrogenation reaction, the Pd / C catalyst has good characteristics of low hydrogen-ester ratio, high raw material conversion rate, high alcohol selectivity, stable catalyst, and the like; and therefore, the method has the effect of solving the problems that the reaction process in the traditional ester hydrogenation process is complex, is high in investment and is not suitable for small-scale production in the fine chemical industry field.

The invention discloses a preparation method of 2,3,5,6-tetrafluorohydrazine-1,4-benzene dimethanol, and belongs to the technical field of fine chemical synthesis. The preparation method is characterized by comprising the following reaction steps that (1) chlorine is led into paraxylene under catalyzing of a catalyst and irradiation of visible light to achieve chlorination, then nitrogen is led in to expel residual hydrogen chloride gas, and 1,4-dual(trichloromethyl)-2,3,5,6-tetrachlorobenzene is obtained; (2) the 1,4-dual(trichloromethyl)-2,3,5,6-tetrachlorobenzene and potassium fluoride are subject to fluorization and alcoholysis in an alcohol solvent, the solvent is recycled through reduced pressure distillation, washing is carried out the neutral state is obtained, drying is carried out, and 1,4-dual(silane oxygen methyl chloride)-2,3,5,6-tetrachlorobenzene is obtained; and (3) hydrogen is led into the 1,4-dual(silane oxygen methyl chloride)-2,3,5,6-tetrachlorobenzene in a solvent containing a metal catalyst and an acid-binding agent to be subject to catalytic hydrogenation reduction, an upper-layer organic phase is subject to cooling, suction filtration and drying to obtain the2,3,5,6-tetrafluorohydrazine-1,4-benzene dimethanol. The preparation method has the beneficial effects that the raw materials are low in price and easy to obtain, the synthetic route is short, operation is easy and convenient, and the product cost is low.

The invention discloses a side fluorine-containing diphenyl acetylene diluent for liquid crystals with high birefringence and a synthesis method of the side fluorine-containing diphenyl acetylene diluent. The structural formula of the diluent is shown in the description, wherein X represents O or CH2 and R represents C1-C6 alkyl; the diluent is synthesized by industrially mature Sonogashira coupling and Witting reaction. The method is simple and efficient and is suitable for industrialized production. The diluent structurally contains a side fluorine substituent and a terminal alkene substituent, the low-temperature performance of the liquid crystals with high birefringence can be effectively improved, the birefringence of the diluent is higher than that of a commercial 3HHV diluent by 13-15 times, and the high birefringence of a liquid crystal material can be guaranteed while rotational viscosity of the liquid crystals with high birefringence is reduced.

Methods for preparation of olefins, including 8- and 11-unsaturated monoenes and polyenes, via transition metathesis-based synthetic routes are described. Metathesis reactions in the methods are catalyzed by transition metal catalysts including tungsten-, molybdenum-, and ruthenium-based catalysts. The olefins include insect pheromones useful in a number of agricultural applications.

The invention belongs to the technical field of isotope labeling chemical synthesis, and discloses a method for synthesizing a deuterated compound in an aqueous phase solvent. The method is based on the following chemical reaction equation: a halide, diazonium salt or Xanthate shown in a formula (I), a material containing a phosphorus-deuterium bond shown in a formula (II), an initiator, alkali and a solvent are mixed and react to obtain a reduced deuterated product shown in a formula (III), wherein the solvent is water (1H2O) or a mixed solvent consisting of water and an organic solvent. By researching and improving the types of raw materials for constructing a reaction system and adopting the material containing the phosphorus-deuterium bond shown in the formula (II) as a deuterium source, compared with the prior art, the method can effectively solve the problems that the reaction conditions are strict, the adopted deuterium source is seriously excessive, strict anhydrous (1H2O) is needed and / or the reaction needs to be carried out in a deuterated solvent in the preparation process of the deuterated compound.