Tag: M.W:100-200

7119-95-1, A common heterocyclic compound, 7119-95-1, name is 1-Nitropyrazole, molecular formula is C3H3N3O2, 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.

4-Nitro-lJH-pyrazoIe=N; [547] [Ref: Huettel, R. and Buechele, F., Chem. Ber. 1955, 88, 1586-1590] 1-Nitro-l/Z’-pyrazole (2.2g, 0.019 mol) was dissolved in sulfuric acid (lOmL) at-10¡ãC, and theresulting mixture was slowly warmed to rt overnight. The solution was added to ice (lOOg)dropwise, and the resulting white solid was collected by filtration and washed with water.The aqueous phase was extracted with EtOAc (3x30mL), the combined organic phases werewashed with brine (2x30mL), and dried over anhydrous sodium sulfate. Evaporation underreduced pressure provided an off-white solid, which was combined with the first solid anddried in vacua to provide the title compound. LC-MS (ES, Pos.): 1 14 [MH+]. ‘H NMR(DMSO-d6, 400 MHz): 8 = 8.27 (s, 1H), 8.90 (s, 1H), 13.96 (br s, 1H).

The synthetic route of 7119-95-1 has been constantly updated, and we look forward to future research findings.

402-61-9, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 402-61-9 name is 5-Methyl-1H-pyrazole-3-carboxylic acid, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.

EXAMPLE 13 beta-{4-[2-(5-Methylpyrazole-3-carboxamido)-ethyl]-phenyl}-propionic acid 1.27 ml. triethylamine and 0.85 ml. ethyl chloroformate are added at -10 C. to a solution of 1.12 g. of 5-methylpyrazole-3-carboxylic acid in 25 ml. anhydrous tetrahydrofuran. After 15 minutes, a further 1.27 ml. triethylamine is added and then 2.57 g. ethyl beta-[4-(2-aminoethyl)-phenyl]-propionate hydrochloride. The reaction mixture is stirred for 1 hour at +20 C., filtered with suction and the filtrate is evaporated and the residue taken up in methylene chloride. After extraction with 2N hydrochloric acid, 2N aqueous sodium hydroxide solution and neutralization, the solution is dried and evaporated. The crude ester thus obtained is heated under reflux for 1 hour with 0.6 g. sodium hydroxide in 30 ml. ethanol. After cooling, the precipitated sodium salt is filtered off with suction, dissolved in water and carefully acidified. The precipitate obtained is filtered off and recrystallized from 20% ethanol. There is obtained beta-{4-[2-(5-methylpyrazole- 3-carboxamido)-ethyl]-phenyl}-propionic acid in a yield of 22% of theory; m.p. 202-205 C.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 5-Methyl-1H-pyrazole-3-carboxylic acid, and friends who are interested can also refer to it.

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. 73616-27-0, name is 5-Amino-1-(2-hydroxyethyl)pyrazole, A new synthetic method of this compound is introduced below., 73616-27-0

To a solution of 5-AMINO-1-(2- hydroxyethyl) pyrazole (6.35 g) in a mixed solvent of ethanol (25 ml) and concentrated hydrochloric acid (0.035 ml) was added dropwise isoamyl nitrite (7.03 g). The mixture was stirred at room temperature for 17 hours. The crystalline residue was collected by filtration and dried in vacuo to give 5-amino-l- (2-hydroxyethyl)-4- nitrosopyrazole (4.0 g) as a solid. 1H-NMR (DMSO-d6) 8 3.68 (2H, t, J=5.5Hz), 3.94 (2H, t, J=5.5Hz), 4.89 (1H, br), 8.06 (2H, br), 8.53 (1H, s)

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.

A common compound: 5744-56-9, name is 1,3-Dimethyl-1H-pyrazole-5-carboxylic acid, belongs to pyrazoles-derivatives compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below. 5744-56-9

Scheme I 1,3-Dimethyl-4-nitro-pyrazole-5-carboxylic acid One-hundred twelve g concentrated sulfuric acid is added to 42 ml 90% nitric acid at 70-80 C., 39 g of 1,3-dimethylpyrazole-5-carboxylic acid is added in portions over one hour such that the temperature does not go over 90 C. After 2.5 hours the reaction mixture is cooled and poured over ice. The resulting percipitate was filtered, dried, and recrystallized in ethanol, mp 141-142 C.

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, 5744-56-9, other downstream synthetic routes, hurry up and to see.

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. 175137-46-9, name is 5-Cyclopropyl-1H-pyrazol-3-amine belongs to pyrazoles-derivatives compound, it is a common compound, a new synthetic route is introduced below. 175137-46-9

To a solution of (2J?)~2-[(2-chloro-5-nitro?yrimidin-4-yl)amino]-2-(4- fluoro?henyl)ethanol (Method 6; 300 mg, 0.96 mmol) in EtOH (4 ml) was added a solution of S-cyclopropyl-lH-pyrazol-S-amine (118 mg, 0.96 mmol) in EtOH (2 ml) and triethylamine (0.2 ml, 1.44 mmol). The reaction mixture was stirred at 45 0C for 18 hours. Solvent was removed and the residue was dissolved in EtOAc and was washed with water. The organic layer was concentrated. Flash chromatography on silica gel (EtOAc) gave the desired product as a yellowish solid (196 mg, 51%). NMR 0.64 (m, 2H), 0.92 (m, 2H), 1.83 (m, IH), 3.82 (m, 2H), 5.27 (m, 2H), 5.93 (m, IH), 7.12 (m, 2H), 7.39 (m, 2H), 8.95 (s, IH), 9.19 (s, IH), 10.54 (br s, IH), 12.11 (br s, IH).

The synthetic route of 175137-46-9 has been constantly updated, and we look forward to future research findings.

5932-27-4, 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. 5932-27-4, name is Ethyl 1H-pyrazole-3-carboxylate belongs to pyrazoles-derivatives compound, it is a common compound, a new synthetic route is introduced below.

b. 4-Iodo-1H-pyrazole-3-carboxylic acid ethyl ester (Intermediate 74b) A suspension of Intermediate 74a (5.00 g, 35.7 mmol) in acetonitrile (90 mL) was treated with iodine (9.10 g, 35.7 mmol) then ceric ammonium nitrate (19.6 g, 35.7 mmol) and the mixture was stirred at RT overnight. Another portion of iodine (2.28 g, 9.0 mmol) was added and the mixture was stirred for a further 24 h then treated with ice-cold aqueous sodium hydrogensulphite solution (5%, 100 mL). The mixture was filtered through Celite rinsing with EtOAc and water. The phases were separated and the aqueous phase was extracted with EtOAc (2*). The combined organic layers were washed with water and brine, dried (Na2SO4), filtered and evaporated in vacuo. The resulting solid was triturated with ether/cyclohexane, filtered off, washed with cyclohexane and dried at 50 C. in vacuo to give the title compound (3.70 g, 39%). LCMS (Method 3): Rt 2.88 min, m/z 267 [MH+] (weak).

The synthetic route of 5932-27-4 has been constantly updated, and we look forward to future research findings.

Adding a certain compound to certain chemical reactions, such as: 27258-33-9, name is 1-Methyl-1H-pyrazole-5-carbaldehyde, 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 27258-33-9, 27258-33-9

General procedure: Method B [34]: The reaction mixture of aldehyde (4 mmol), acetone (116 mg, 2 mmol) and K2CO3 (1.1 g, 4 mmol) in the mixed solvent of toluene-ethanol-water (10 mL 4.0 mL 2.0 mL) was stirred at 70 C for 12 h. After cooling down to room temperature, the solvent was evaporated in vacuo. The resulting residue was partitioned between dichloromethane and water. The aqueous phase was further extracted with dichloromethane twice. The combined organic extracts were rinsed with brine and dried over anhydrous magnesium sulfate. The organic solvent was removed under vacuum to give a residue, which was purified by preparativeTLC (5% methanol in dichloromethane) or column chromatography(2% methanol in dichloromethane).

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, 1-Methyl-1H-pyrazole-5-carbaldehyde, other downstream synthetic routes, hurry up and to see.

As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 5744-51-4 name is Ethyl 1,5-dimethyl-1H-pyrazole-3-carboxylate, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below. 5744-51-4

Ethyl 5-methyl-1-hydro-pyrazolecarboxylate (30.8 g, 200 mmol) was dissolved in 200 mL of dry tetrahydrofuran solution. Sodium hydride (4.8 g, 200 mmol) was slowly added under ice-cooling and sodium hydride was added completely. After the temperature was raised to 50C, the mixture was stirred for 1 hour and cooled to room temperature. Methyl iodide (28.2 g, 200 mmol) was then dissolved in 100 mL of tetrahydrofuran and slowly added dropwise to the reaction. The addition was complete and heating to 50C was continued for 2 hours. After the reaction is complete, cool to room temperature, remove tetrahydrofuran under reduced pressure, then add 100 mL of water, extract with ethyl acetate (100 mL x 3), combine the organic layers, dry, and remove the ethyl acetate under reduced pressure to give 5-methyl-1-carbonitrile. Ethyl 2-pyrazolecarboxylate 26.6 g, 85%.Lithium aluminum hydride (3.8 g, 100 mmol) was added to a dry three-necked flask, 200 mL of dry tetrahydrofuran, and then ethyl 5-methyl-1-methyl-pyrazolecarboxylate (16.8 g, 100 mmol) was dissolved in 100 mL of dry. Tetrahydrofuran was slowly added dropwise to the three-necked flask, and stirring was continued for 4 hours after completion of the addition. After the reduction is completed, absolute ethanol is added dropwise to remove the remaining lithium tetrahydroaluminum, the tetrahydrofuran is removed under reduced pressure, 500 mL of methanol is added, the pH is adjusted to neutral, the mixture is heated to reflux for 6 hours, and the filtrate is filtrated. The filtrate is concentrated and dissolved in 100 mL of dichloromethane. And washed twice with 50 mL of saturated aqueous sodium chloride, and the organic layer was dried and concentrated to give 5-methyl-1-methyl-pyrazolemethanol 8.8 g, 70%.5-methyl-1-carbonitrileThe base-pyrazole methanol (6.3 g, 50 mmol) was dissolved in 20 mL of methylene chloride. Thionyl chloride (6 g, 50 mmol) was slowly added dropwise. After the addition was complete, stirring was continued for 2 hours. After the reaction was complete, saturated sodium bicarbonate was added slowly. The aqueous solution was adjusted to pH neutral and then extracted with 200 mL of dichloromethane. The organic layers were combined, dried and concentrated to give 3-chloromethyl-1-methyl-5-methylpyrazole (6.5 g, 90%).In a 50 mL round bottom flask was added 3-chloromethyl-1-methyl-5-methylpyrazole (1.44 g, 10 mmol) and N-(2,4,6-trimethylphenyl)imidazole (1.86 g) (10 mmol), 20 mL of acetonitrile, and the mixture was heated under reflux for 6 hours, cooled to room temperature, and the solvent was distilled off under reduced pressure. The obtained solid was dissolved in water and filtered. The filtrate was saturated with aqueous solution of ammonium hexafluorophosphate, and the solid precipitated and was dried to give 3.8. g imidazolium salt ligand (HL1PF6), yield 88%.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, Ethyl 1,5-dimethyl-1H-pyrazole-3-carboxylate, and friends who are interested can also refer to it.

5334-40-7, The chemical industry reduces the impact on the environment during synthesis 5334-40-7, name is 4-Nitro-1H-pyrazole-3-carboxylic acid, I believe this compound will play a more active role in future production and life.

To a 250 mL round bottom flask was added 5 g (18.1 mmol) of crude I-f,Nitro-lH-pyrazole-3-carboxylic acid (3.1 g, 19.9 mmol)EDC ¡¤ HCl 4.1 g (21.7 mmol),HOBt 2.9 g (21.7 mmol) and anhydrous DMF 50 mL,Stir at room temperature for 24 hTLC detects the disappearance of the starting material (methanol: chloroform = 1:10).The reaction solution was poured into 200 mL of ice water,Precipitation of a large number of light yellow solid, standing,Consider the yellow solid,The crude product was recrystallized from a mixed solvent of ethyl acetate and methanol to give 4.7 g of (I-g)Yield 62.4%.

The chemical industry reduces the impact on the environment during synthesis 4-Nitro-1H-pyrazole-3-carboxylic acid. I believe this compound will play a more active role in future production and life.

A common heterocyclic compound, 5334-40-7, name is 4-Nitro-1H-pyrazole-3-carboxylic acid, molecular formula is C4H3N3O4, 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. 5334-40-7.

Preparation of 4-nitro-1H-pyrazole-3-carboxylic acid methyl ester 4-Nitro-1H-pyrazole-3-carboxylic acid (1.00 kg, 6.37 mol, 1.0 wt) and methanol (8.00 L, 8.0 vol) were charged to a flange flask equipped with a mechanical stirrer, condenser and thermometer. The suspension was cooled to 0 to 5 C. under nitrogen and thionyl chloride (0.52 L, 7.12 mol, 0.52 vol) was added at this temperature. The mixture was warmed to 15 to 25 C. over 16 to 24 hours. Reaction completion was determined by 1H NMR analysis (d6-DMSO). The mixture was concentrated under vacuum at 35 to 45 C. Toluene (2.00 L, 2.0 vol) was charged to the residue and removed under vacuum at 35 to 45 C. The azeotrope was repeated twice using toluene (2.00 L, 2.0 vol) to give 4-nitro-1H-pyrazole-3-carboxylic acid methyl ester (1.071 Kg, 98.3%) as an off white solid.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 4-Nitro-1H-pyrazole-3-carboxylic acid, its application will become more common.