35 results about "Pyrazinecarboxylic acid" patented technology

The invention relates to a new method for preparing telaprevir, which comprises the following steps: 1) orderly coupling the following 5 substances according to a Fmoc solid-phase synthetic method with a resin as a carrier to obtain peptide resin: amino acid Fmoc-P-OH, Fmoc-octahydrocyclopenta[c]pyrrole-1-carboxylic acid, Fmoc-L-tertiary leucine, Fmoc-2-cyclohexyl glycine, and 2-pyrazinecarboxylic acid; 2) allowing the peptide resin to react with a cyclopropylamine solution to obtain the telaprevir. The Fmoc is 9-fluorenylmethyloxycarbonyl, and is connected with an amino, or with a nitrogen atom on a carbon atom connected with a carboxyl. The method for preparing telaprevir of the invention is simple in operation, low in cost, and high in yield.

The invention relates to a 1-naphthoic acid and 2-pyrazinecarboxylic acid mixed ligand containing rare earth metal complex as well as a preparation method and an application of the1-naphthoic acid and 2-pyrazinecarboxylic acid mixed ligand containing rare earth metal complex. The complex has the chemical formula as follows: [Ln(mu3-OH)(NA)(pyzc)], wherein Ln is a lanthanide rare earth ion Dy(III), Gd(III) or Yb(III), NA<-> is the univalent anion of 1-naphthoic acid, and pyzc<-> is the univalent anion of 2-pyrazinecarboxylic acid. The complex is prepared by using a solvothermal method and is relatively high in yield and good in repeatability. A fluorescent material of the complex is the first 1-naphthoic acid and 2-pyrazinecarboxylic acid mixed ligand containing rare earth metal complex, can emit an emission peak with a rare earth ion characteristic or an emission peak of a ligand in a solid state and can be used as a molecular-based fluorescent material to exert a huge application value in the field of material science.

The invention provides a method for preparing 5-methylprazine-2-carboxylic acid. The preparation method comprises the steps: using 5-methyl-2and3- pyrazine 2-carboxylic acid as raw material, carrying out photophobism reaction in a saturated saline solution, and obtaining 5-methylprazine-2-carboxylic acid as a final product. The preparation method optimizes the process from the source on the basis of the principle of water decarboxylation, thereby being a method for effective decarboxylation in a saline solution at lower temperature. Moreover, in the preparation method, no organic solvent is added in the chemical reaction, no pollution is generated, the condition is mild, the reaction in the whole technological process has no high temperature, high selectivity and few by-products, thus the preparation method is a simple and available pollution-free method which has the capability of large-scale production.

The invention discloses a method for synthesis of favipiravir. The method comprises an esterification reaction of 3-aminopyrazine-2-carboxylic acid and an alcohol, a bromination reaction, a diazotization reaction, an ammonolysis reaction, a chlorination-dehydration reaction, a one-pot series connection aromatic ring fluorination reaction, a cyan-hydrolysis reaction, an aromatic ring hydroxyl substitution reaction, and purification treatment so that favipiravir is obtained. The method utilizes 3-amino-2-carboxypyrazine as a raw material to synthesize favipiravir through 8-step reactions and has a total yield of 26%. The key intermediates 3 and 6 in the method are purified by recrystallization so that column chromatography separation in the literature is avoided. The final three reactions are finished by a one-pot method so that the operation is simplified. The synthesis method improves a yield, realizes a low cost and green economy and is conducive to industrial production.

The invention provides a method for preparing 2-methyl-5-pyrazinecarboxylic acid. The method provided by the invention is characterized in that potassium permanganate which is more harmful to the environment is not used, a target compound 2-methyl-5-pyrazinecarboxylic acid can be prepared from cheap and easily available methylglyoxal and 2-amino malonamide taken as raw materials through four stepsof cyclization, hydrolysis, chlorination and reduction, the yield of the reaction route is high, the amount of byproducts is small, and products are purer.

The invention discloses a Cu-Nd heterometallic coordination polymer and a preparation method thereof. The chemical formula of Cu‑Nd heterometallic coordination polymer is {[Nd(L 1 ) 2 Cu(L 2 )(H 2 O) 2 ]·3H 2 O} n , the molecular formula is: C 15 h 15 CuN 6 NdO 15 , Molecular weight: 727.10. (1) Dissolve neodymium perchlorate hexahydrate and copper acetate in distilled water; (2) Dissolve 3,5‑pyrazoledicarboxylic acid and 2‑pyrazinecarboxylic acid in DMF; (3) Dissolve step (1 ), (2) mixed the prepared solutions, adjusted the pH with ethylenediamine, filtered, and dried to obtain Cu‑Nd heterometallic coordination polymer, L 1 To represent 3,5-pyrazole dicarboxylic acid to remove two carboxyl hydrogen atoms, with two units of negative charge; L 2 It represents the removal of a carboxyl hydrogen atom from 2‑pyrazinecarboxylic acid. The invention has simple process and good repeatability.

The invention relates to a new method for preparing telaprevir, which comprises the following steps: 1) orderly coupling the following 5 substances according to a Fmoc solid-phase synthetic method with a resin as a carrier to obtain peptide resin: -amino acid Fmoc-P-OH, -Fmoc-octahydrocyclopenta[c]pyrrole-1-carboxylic acid, -Fmoc-L-tertiary leucine, -Fmoc-2-cyclohexyl glycine, and -2-pyrazinecarboxylic acid; 2) cracking the peptide resin to obtain deprotected peptide; 3) allowing the deprotected peptide to react with cyclopropylamine under a liquid-phase condition to obtain the telaprevir; wherein the Fmoc is 9-fluorenylmethyloxycarbonyl, and is connected with an amino, or with a nitrogen atom on a carbon atom connected with a carboxyl. The method for preparing telaprevir of the invention is simple in operation, low in cost, and high in yield.

The invention discloses a method for purifying crude 5-methylpyrazine-2-carboxylic acid. The method utilizes a vacuum sublimation and desublimation process to prepare high-purity 5-methylpyrazine-2-carboxylic acid. The preparation process is followed by dehydration of the crude product, heating up and vacuuming to open nitrogen for sublimation, cooling and desublimation, opening the tank, and receiving the material. The 5-methylpyrazine-2-carboxylic acid white transparent solid with a total yield of more than 80% and a purity of more than 99% can be obtained. The method is simple in process, does not need to use organic solvents, has no waste water, is more environmentally friendly, has low cost, high product purity and high yield, and is suitable for industrial production.

The invention belongs to the field of chemical synthesis and particularly relates to a reparation method of 6-bromine-3-hydroxyl-2-pyrazinamide. The method comprises the steps of converting 3-hydroxyl-2-pyrazinecarboxylic acid methyl ester which is taken as an initial material into 6-bromine-3-hydroxyl-2-pyrazinecarboxylic acid methyl ester, and then carrying out ammonolysis, so that the 6-bromine-3-hydroxyl-2-pyrazinamide can be prepared with high yield by simple and convenient operations. The preparation method has the advantages that the 3-hydroxyl-2-pyrazinecarboxylic acid methyl ester which is cheap in price, and convenient to purchase in markets is taken as the initial material, the method is simple and convenient and easy to implement, the selected solvent range is wide, a solvent is easy to remove, the yield is high, and the method can be applicable to industrial production.

The invention discloses a synthesis method of zopiclone impurity pyrazine-2-carboxylic acid (5-chloro-pyridine-2-yl)-amide, and the method comprises the following steps: 1) pyrazine-2-formic acid and 2-amino-5-chloropyridine are subjected to a reaction in a solvent; 2) separating reaction products; 3) purifying; wherein the solvent in the step 1) is selected from alkyl halide and thionyl chloride. The alkyl halide is selected from any one or a combination of dichloromethane, trichloromethane, 1, 1-dichloroethane and 1, 2-dichloroethane.

The invention discloses a phase-separating device for the production of 2-methyl-5-pyrazinecarboxylic acid, relates to the technical field of phase-separating equipment, and comprises a fixing frame, and a mounting hole is opened in the middle of the top of the fixing frame, and the mounting hole is A centrifugal cylinder is fixed on the inner wall of the centrifugal cylinder, and a drum is arranged inside the centrifugal cylinder. A fixed ring plate is fixed on the top position of the inner peripheral wall of the centrifugal cylinder, and a rotating ring plate is installed on the inner ring of the fixed ring plate. The inner ring of the rotating ring plate is fixed on the outer peripheral wall of the rotating shaft. When the extraction time set by the single-chip microcomputer of the present invention is reached, the second electromagnetic valve is opened and the first electromagnetic valve is closed. At this time, the light phase liquid gradually flows out, and the inert gas slowly returns to the anti-permeation rubber sleeve, and the anti-infiltration rubber sleeve gradually expands. Then continuously push the light phase tube to move gradually so that it can be in contact with the light phase liquid all the time until the light phase liquid flows out completely, which can increase the collection rate of the light phase liquid and reduce waste.

The invention discloses a conjugated polymer based on pyrazine-2-carboxylate unit, which has the following general structure: this type of copolymer can be used as an active layer material in organic semiconductor devices such as organic solar cells and organic field effect transistors, Applications in organic electroluminescent devices, organic thermochromic components, and organic field effect transistors, which have better solar light harvesting capabilities, hole transport capabilities, and thermal stability.