32results about How to "Avoid ultra-low temperature reactions" patented technology

The invention relates to a preparation method of a 5-HT1F agonist compound. The preparation method of the 5-HT1F agonist compound comprises the steps that 2,3-butanedione and 2-halogenated acrylonitrile are subjected to 1,4-addition reaction to obtain 2-halogenated-5,6-dioxo n-heptanoic nitrile, then the 2-halogenated-5,6-dioxo n-heptanoic nitrile and ammonia are subjected to pyridine cyclizationand amino protection to obtain 2-disubstituted methylamino-6-acetyl pyridine, then 2-disubstituted methylamino-6-(1-methyl piperidine-4-base)formyl group piperidine is prepared through hydroxyethylation, sulfonic acid esterification and methylamine condensation reaction, and then the 5-HT1F agonist compound Lasmiditan is obtained through deprotection reaction and 2,4,6-trifluoro-benzoyl chloride amidation. The raw materials of the preparation method of the 5-HT1F agonist compound are easy to get, ultralow temperature reaction is avoided, the operation is simple and convenient, the cost is low,and industrial production of Lasmiditan is easy.

The invention relates to the field of pharmaceutical chemistry, in particular to a synthesis method of a minodronate midbody and synthesis of minodronate. The preparation method of minodronate includes the following steps: using organic solvent to dissolve 2-aminopyridine, adding 4-acetyl chloride ethyl acetoacetate for reaction, monitoring the reaction solution by TLC(Thin-Layer Chromatography) until spots of 4-acetyl chloride ethyl acetoacetate disappear, concentrating to a dry state, dissolving concentrate in water, washing a water layer to remove impurities, extracting the water layer with the organic solvent, washing extract liquor, separating out an organic layer, conducting filtration, and concentrating the concentrate to be in a dry state, thereby obtaining A1.

The invention discloses a boron amine compound synthesis technology and product application. Halogenate RX, halogenate BrBY2 and solvent are mixed and added into initiator and magnesium metal in a dropwise mode, and the temperature is kept within the range from 0 DEG C to 80 DEG C in the dropping process; after a reaction occurs, the rest is added, then the temperature is kept within the range from 20 DEG C to 80 DEG C for the reaction, saturation ammonium chloride is added for quenching, and after reduced pressure distillation, RBY2 is obtained. The technology is simple in operation, ultrlow temperature conditions, Grignard reagent concentration and the self-coupling problem are avoided, the reaction yield is high, the product stability is good, and the technology is suitable for being popularized in an industrialization mode. After the product is subjected to a derivatization reaction with KHF2 and MIDA, RBF3K and RB (MIDA) can be obtained.

The invention discloses a novel synthesis method for 2,5-dibromo-iodobenzene and belongs to the field of organic chemistry synthesis.The synthesis method includes the steps that with 1,4-dibromo-benzene being a starting raw material, trifluoroacetic acid and iodine are subjected to an iodination reaction to synthesize the target product 2,5-dibromo-iodobenzene.The method avoids low-temperature reaction, is easy to implement, generates a small number of by-products, is suitable for industrialized production and has good application prospects.2,5- dibromo-iodobenzene is an important fine chemical intermediate and is widely applied to the fields of synthesis medicine, pesticide, dye, plastics, functional polymer materials and others.

The invention discloses a method for synthesizing 3-aminobenzeneboronic acid, and belongs to the field of organic synthesis. The method comprises the following steps: performing coupling reaction on 3-nitrobromobenzene and catechol diboron under action of a palladium catalyst; adding water for quenching; adding an acid for salifying a product and entering a water layer; adding alkali into the separated water layer to adjust to near neutral; and extracting and desolventizing to obtain the 3-aminobenzeneboronic acid. The method is simple in operation, high in purity of the obtained product and suitable for industrialized scale-up production.

The invention discloses salt of tulathromycin, particularly oxalate, a preparation method of tulathromycin oxalate and application of tulathromycin oxalate to preparation of tulathromycin.

The invention discloses a salt for preparing a tulathromycin intermediate, and particularly relates to oxalate and a preparation method thereof as well as application of the oxalate in a method for preparing tulathromycin.

A method of preparing 2-aminopyrimidine-5-boronic acid pinacol ester is disclosed. The method includes subjecting 2-chloropyrimidine that is a raw material and NBS to bromization under catalysis of BF3-Et2O to obtain 2-chloro-5-bromopyrimidine; reacting the 2-chloro-5-bromopyrimidine with n-Bu3MgLi at a temperature ranging from -20 DEG C to -10 DEG C; adding methoxyboronic acid pinacol ester or isopropoxyboronic acid pinacol ester; performing boronization to obtain 2-chloropyrimidine-5-boronic acid pinacol ester; adding into ammonia water or a methanol-ammonia solution; and reacting at 80-100 DEG C in a sealed manner to obtain the 2-chloropyrimidine-5-boronic acid pinacol ester. Synthetic process conditions of the method are mild. An ultralow-temperature reaction is avoided. Reactions can be performed continuously. A pure product can be obtained only by simple recrystallization of the final product.

The invention discloses a preparation method of Draxxin. The method comprises the following steps: enabling a reaction between an intermediate TA04 and benzyl chloroformate, so as to obtain TA05; oxidizing the TA05 with DMSO and IBX at the temperature of 20-30 DEG C, so as to obtain TA06; dissociating and performing aftertreatment after the TA06 becomes oxalate TA06-OX, so as to obtain purified TA06; oxidizing the TA06 with trimethylsulfonium bromide and potassium tert-butoxide, so as to obtain TA07; hydrogenating the TA07 to remove a protection group, so as to obtain TA08; enabling a reactionbetween the TA08 and n-propylamine, so as to obtain TA; dissociating and performing aftertreatment after the TA becomes oxalate TA-OX, so as to obtain purified end-product Draxxin. The total yield ofthe Draxxin prepared with the method is increased by above 20%.

The present invention belongs to the field of medicine and chemical industry, relates to a bacterial protein synthesis inhibitor preparation method, and specifically relates to a tedizolid phosphate preparation method. According to the method, intermediates of every steps and a final product are high in purity. Further, by the use of diisopropylamine dibenzyl phosphite as a phosphorylating agent, a dimerization product can be avoided, and the preparation method has a higher yield. The preparation method is shorter in route and mild in reaction conditions, avoids the use of toxic, irritating and strongly-corrosive reagents, is green and environmentally-friendly, meanwhile avoids the use of ultra-low temperature reaction, and is simple and easy in preparation and high in production efficiency. Therefore, the preparation method is particularly adapted to industrial production.

The invention discloses a new method for preparing 3 alpha, 7 alpha-dihydroxy-6 alpha-alkyl-5 beta-cholanic acid I and an intermediate thereof. The method requires no low-temperature reaction; reaction conditions are mild; a purification method is simple; and the method of the invention is suitable for industrial production.

The invention belongs to the field of medicine chemical industry and particularly relates to a preparation method for tedizolid phosphate. According to the preparation method provided by the invention, intermediates in the steps and the final product are high in purity. In addition, by using diiso-propylamido dibenzyl phosphite as a phosphorylation reagent, a dimerized product is further avoided, so that the preparation method provided by the invention is higher in yield. The preparation method provided by the invention is relatively short in route and mild in reaction condition, and further avoids use of toxic, irritant and strongly corrosive reagents, so that the preparation method is green and environmentally friendly. Meanwhile, ultralow temperature reaction is avoided, so that the preparation method is simple to operate, and the tedizolid phosphate is easy to prepare and high in production efficiency. Thereofe, the preparation method provided by the invention is suitable for industrial production.