Day: October 30, 2020

In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 1072-68-0 as follows. 1072-68-0

To a solution of 1,4-dimethyl-1H-pyrazole (52 g, 541 mmol) in anhydrous THF (1.0 L) was added dropwise n-BuLi (0.22 L, 2.5 M, 550 mmol) at -78 C with stirring over 2 h. Then, a solution of (RS)-4 (110 g, 396 mmol) in anhydrous THF (1.0 L) was added dropwise to the above solution over 1 h at the same temperature. The resulting mixture was stirred at -78 C for 1.5 h. TLC (PE-EtOAc, 1:2) showed (RS)-4 was completely consumed. The mixture was poured into sat. aq NH4Cl (1 L) and extracted with EtOAc (3 ¡Á 0.8 L). The combined organic extracts were washed with brine (1 L), dried (Na2SO4), and concentrated to give the crude product. Purification by column chromatography on silica gel (PE-EtOAc, 20:1 ? 5:1) gave 8i as a yellow oil, and 7i as a yellow solid when the column was continuously eluted with PE-EtOAc(5:1 ? 2:1).

According to the analysis of related databases, 1072-68-0, the application of this compound in the production field has become more and more popular.

These common heterocyclic compound, 6076-12-6, name is Ethyl 4-methyl-1H-pyrazole-3-carboxylate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 6076-12-6

Ethyl 4-methyl-1 H-pyrazole-3-carboxylate (Intermediate 33) (1.0 g, 6.49 mmol) was dissolved in DMF : H20 (9.0 mL : 1.0 mL) and K20O3(3.58 g, 25.9 mmol) and sodium 2-chloro-2,2-difluoroacetate (Intermediate 35) (3.94 g, 25.9 mmol) were added at 0 C and then the mixture was heated at 130 C for 20 min. The reaction mixture was cooled to RT and ice-cold water was added. The aqueous layer was extracted with EtOAc (3 x 50 mL) and the combined organic layer was washed with brine solution, dried over Na2S04, filtered and concentrated. The residue was purified by column chromatography (Normal-Phase 60-120 mesh silica gel, 25 % EtOAc in hexanes) to give ethyl 1- (difluoromethyl)-4-methyl-1 /-/-pyrazole-3-carboxylate (325 mg, 25 %) as a solid.LCMS (System 3, Method D): m/z 205 (M+H)+(ESI +ve), at 3.77 min, 202 nm.

Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 6076-12-6.

These common heterocyclic compound, 288-13-1, name is 1H-Pyrazole, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 288-13-1

Pyrazole (8.5 g) and cold concentrated nitric acid (18 cm3, d = 1.4 g/mL) were added to concentrated sulfuric acid (15 cm3) that had been cooled to 0 C using an ice-salt bath.The reaction mixture was heated under reflux for 3 h. The reaction mixture was cooled toroom temperature, and additional nitrating mixture (6 cm3 of concentrated sulfuric acid and 6 cm3 of nitric acid) was added dropwise. The mixture was heated under reflux for a further 3 h, cooled and left to stand overnight. The obtained solution was poured onto ice (80 g), and the precipitate was filtered under reduced pressure, washed with cold water and cold ethanol, and crystallized from toluene. 4-Nitropyrazole (56 % yield) was obtained as a white solid.

Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 288-13-1.

14521-80-3, Adding some certain compound to certain chemical reactions, such as: 14521-80-3, name is 3-Bromo-1H-pyrazole, can increase the reaction rate and produce products with better performance than those obtained under traditional synthetic methods. Here is a downstream synthesis route of the compound 14521-80-3.

General procedure: To a solution of pyrazole 1-5 (1 equiv.) and triethylamine (1.5 equiv.) in dichloromethane (for 0.05mol of pyrazole – 50 mL of dichloromethane were user) Di-tert-butyl dicarbonate (1.2 equiv) wereadded at room temperature and left to stir overnight. Dichloromethane was washed with saturatedNaHCO3 solution (1¡Á25 mL – for 50 mL of dichloromethane) then with deionized H2O (1 ¡Á 25mL). Organic layer was dried with anhydrous Na2SO4, and evaporated under reduced pressure.

Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 14521-80-3.

31037-02-2, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 31037-02-2, name is Ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate belongs to pyrazoles-derivatives compound, it is a common compound, a new synthetic route is introduced below.

Alternative preparation according to Process B: 540g (2.26 mmol) of 2-fluoro-4-methyl-5-[(2,2,2-trifluoroethyl)sulphanyl]aniline are initially charged in dry dichloromethane.The flask is flushed with argon, and 2.5 ml of a 2Msolution of trimethylaluminium in toluene are added dropwise.The reaction mixture is stirred at room temperature for30min, and405 mg (2.39 mmol) ofethyl5-amino-1-methyl-1H-pyrazole-4-carboxylate are then added. The mixture isstirred at room temperature overnight, and a 1 0% strengthpotassium/sodium tartrate solution is then added. The organicphase is separated off and the aqueous phase is extractedtwice with dichloromethane. The combined organic phasesare dried over sodium sulphate and the mixture is applied toRP(C-18) material. Removal of the solvents is followed bypurification by means of MPLC on an RP(C-18) columnusing water/acetonitrile. This gives 577 mg (1 00% pure, 71%of theory) of the title compound.

The synthetic route of 31037-02-2 has been constantly updated, and we look forward to future research findings.

Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 288-13-1, name is 1H-Pyrazole, A new synthetic method of this compound is introduced below., 288-13-1

4-nitro-1H-pyrazole Pyrazole (10 g, 147 mmol), was added to concentrated sulfuric acid (100 mL), in portions, while maintaining the internal reaction temperature below 50 C. via an ice water bath. Concentrated nitric acid (10 mL) was then added, dropwise, maintaining the internal reaction temperature below 50 C. via an ice water bath. The ice water bath was removed and the reaction was heated to 60 C. and stirred for 4 hours. The reaction was cooled via an ice water bath and made basic, to ?pH 8, with 18 N aqueous NaOH solution (150 mL). The product, which precipitated as a white solid, was collected by filtration, washed with H2O, and dried under high vacuum to afford 4-nitro-1H-pyrazole (7 g, 42%) as a white solid. 13C NMR (100 MHz, CDCl3): delta 126.4, 137.0.

The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.

35344-95-7, A common heterocyclic compound, 35344-95-7, name is 1H-Pyrazole-4-carbaldehyde, molecular formula is C4H4N2O, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

To a stirred solution of 1H- pyrazole-4-carbaldehyde 13-4 (220 mg, 2.29 mmol) in DMF (5 mL) was added cesium carbonate (1.86 g, 5 72 mmol) and cyclohexyl methanesulfonate 13-3 (489.74 mg, 2.75 mmol). The reaction mixture was heated at 60C for 16 hours. The reaction mixture was quenched with cold water and extracted with ethyl acetate. The organic layer was washed with a saturated aqueous solution of NaHCCb, dried over NaiSCh and concentrated under reduced pressure to afford crude which was purified by column chromatography to afford l-cyclohexylpyrazole-4-carbaldehyde 13-5 (220 mg, 1.23 mmol, 53.91 % yield) as gummy liquid. LC MS: ES+ 179.

The synthetic route of 35344-95-7 has been constantly updated, and we look forward to future research findings.

A common heterocyclic compound, 27258-33-9, name is 1-Methyl-1H-pyrazole-5-carbaldehyde, molecular formula is C5H6N2O, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 27258-33-9.

To a mixture of compound OI-5a (2 g, 18.2 mmol, 1.0 eq) in DMF (20 mL) was added NBS (4.86 g, 27.3 mmol, 1.5 eq). The mixture was stirred at room temperature for 16 h under nitrogen atmosphere. Then the mixture was filtered and extracted with water and ethyl acetate. The organic phase was dried over anhydrous Na2SO4 and concentrated under reduced pressure. The residue was purified by silica gel chromatography to afford compound OI-5b (2.3 g, 67%).

The synthetic route of 1-Methyl-1H-pyrazole-5-carbaldehyde has been constantly updated, and we look forward to future research findings.

Adding a certain compound to certain chemical reactions, such as: 1128-54-7, name is 3-Methyl-1-phenyl-1H-pyrazole, belongs to pyrazoles-derivatives compound, can increase the reaction rate and produce products with better performance than those obtained under traditional synthetic methods. Here is a downstream synthesis route of the compound 1128-54-7, 1128-54-7

To the reaction flaskwas added 3-methyl-1-phenyl -1H- pyrazole (0.50 g, 0.003 mol), 5 ml of toluene,heated to 70 C, the reaction solution was added N- bromosuccinimide (0.40 g,0.003 mol), azobisisobutyronitrile (catalytic amount), plus Was completed, thereaction solution was warmed to reflux, the reaction was refluxed for 1 hour.After the reaction was cooled to below 30 C, the reaction solution was pouredinto 50 ml Liters of water with 3 ¡Á 50 ml of ethyl acetate and extracted, theresultant organic phase was washed with saturated aqueous sodium bicarbonate(50 ml), saturated After aqueous sodium chloride solution (50 ml), dried overanhydrous magnesium sulfate, and concentrated under reduced pressure, theresidue was purified by column chromatography (Eluent: ethyl acetate: petroleumether = 1: 100) to give 0.40 g of 3-bromo-1-phenyl -1H- pyrazole as a yellowoil, yield 56 %.

In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 3-Methyl-1-phenyl-1H-pyrazole, other downstream synthetic routes, hurry up and to see.

16034-46-1, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 16034-46-1, name is 1-Methyl-1H-pyrazole-5-carboxylic acid belongs to pyrazoles-derivatives compound, it is a common compound, a new synthetic route is introduced below.

A mixture of 1-methyl-1 H-pyrazole-5-carboxylic acid (1.0 g, 7.93 mmol), BH3. DMS (39.6 mL, 79 mmol) in THF (40 mL) was stirred at reflux overnight. The mixture was diluted with MeOH (30 mL) and stirred for 30 min, and the mixture was concentrated in vacuo. The residue was purified by silica gel column chromatography, eluting with CH2Cl2/MeOH. The residue was dissolved in DCM (20 mL) and to the solution was added SOCl2(5 mL, 68.5 mmol) at room temperature. The mixture was stirred for 3 h then concentrated to afford the product as an oil which was used in the next step without further purification. MS (ESI) calc? d for (C5H7ClN2) [M+H]+, 131.0, found, 131.0

The synthetic route of 1-Methyl-1H-pyrazole-5-carboxylic acid has been constantly updated, and we look forward to future research findings.