pyrazoles-derivatives

1621-91-6, 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. 1621-91-6, name is 1H-Pyrazole-3-carboxylic acid, A new synthetic method of this compound is introduced below.

Sulfuric acid (5.8 mL) was added dropwise to a stirred solution of 1H-pyrazole-3-carboxylic acid (1 g, 8.92 mmol) in MeOH (65 mL) at 0 C. After the addition was completed the mixture was allowed to warm to room temperature and stirred for 18 hours. The mixture was concentrated in vacuo and the residue was dissolved in water and basified with NaHCO3 (aq. sat. solution). The mixture was extracted with AcOEt. The organic layer was separated, dried (MgSO4), filtered and the solvents evaporated in vacuo to yield 1H-pyrazole-3-carboxylic acid methyl ester (0.7 g, 62% yield) as a white solid which was used in the next step without further purification.

If you are interested in these compounds, you can also browse my other articles.Thank you for taking the time to read this article. I hope you enjoyed 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.

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.

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.

288-13-1, 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.

Reference Production Example 1-1 1H-pyrazole-1-ylmethanol The mixture of 2.04 g of pyrazole, 2.00 g of paraformaldehyde and 1 ml of triethylamine was stirred at 130 C for 10 hours. After the reaction mixture was cooled to room temperature, acetone was added to the reaction mixture, and then the mixture was filtered. The filterate was concentrated under reduced pressure. Hexane was added to the residue, and then crystalline was formed. The crystalline was collected to obtain 3.10 g of 1H-pyrazole-1-ylmethanol. 1H-NMR(CDCl3,TMS,delta(ppm)):5.51(2H,s),6.30(1H,t),7.58-7.61(2H, m)

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.

39806-90-1, The chemical industry reduces the impact on the environment during synthesis 39806-90-1, name is 4-Iodo-1-methyl-1H-pyrazole, I believe this compound will play a more active role in future production and life.

e-2) Preparation of [0250] [0251] N2 atmosphere. A mixture of intermediate (62) (0.004 mol), 4-iodo-1-methyl-1H-pyrazole (0.0035 mol), 1,4-dioxane (25 ml) and Cs2CO3 (1.6 g) in Xantphos (0.1 g) was degassed. Pd2(dba)3 (0.13 g) was added and the reaction mixture was degassed again. The reaction mixture was stirred at 80-90 C. for 2 hours. After cooling, the reaction mixture was filtered over dicalite. The filtrate was concentrated and the residue was purified on silica gel using DCM/CH3OH (from 100% to 96/4) as eluent. The product fractions were collected and evaporated to dryness. The residue was used as such in the next reaction, yielding 0.14 g of intermediate (64).

The chemical industry reduces the impact on the environment during synthesis 39806-90-1. I believe this compound will play a more active role in future production and life.

Adding a certain compound to certain chemical reactions, such as: 17635-44-8, name is 3,4,5-Tribromopyrazole, 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 17635-44-8, 17635-44-8

EXAMPLE 1 Preparation of Ethyl 3,4,5-Tribromopyrazole-1-acetate A quantity (92 gm., 0.3 mole) 3,4,5-tribromopyrazole was added with vigorous stirring to a solution of 7.1 gm. sodium (0.31 mole) in 300 ml. absolute ethanol. After the mixing was complete, 100 gm. (0.6 mole) ethyl bromoacetate was added dropwise while stirring was continued. The mixture was diluted with 200 ml. absolute ethanol and this reaction mixture was stirred at about 25 C. for about 18 hrs. After removing most of the ethanol by evaporation under reduced pressure, 100 ml. of 6 N hydrochloric acid was added to the residue, and this aqueous acid mixture was made alkaline with solid sodium carbonate. The aqueous layer was separated and extracted with three 60-ml, portions of ether. The ether extracts were combined, washed with three 40-ml. portions of water, and dried with anhydrous magnesium sulfate. After removing the ether by evaporation under reduced pressure, there was obtained a white solid. Recrystallization from technical hexane (Skellysolve B, a mixture of isomeric hexanes having a boiling range between 61 C. and 69 C.) gave 96.0 gm. of ethyl 3,4,5-tribromopyrazole-1-acetate having a melting point at 101 to 103 C. Analysis: Calc’d. for C7 H7 Br3 N2 O2: C, 21.51; H, 1.81; N, 7.17; Br, 61.33. Found: C, 21.79; H, 1.62; N, 6.96; Br, 61.56.

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, 3,4,5-Tribromopyrazole, other downstream synthetic routes, hurry up and to see.

139756-02-8, These common heterocyclic compound, 139756-02-8, name is 4-Amino-1-methyl-3-N-propyl-1H-pyrazole-5-carboxamide, 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.

Step 8 2-Methyl-4-(2-propoxybenzoylamino)-5-propyl-2H-pyrazole-3-carboxamide: A solution of 2-propoxybenzoic acid (13.7 g, 76.1 mmol) and thionyl chloride (36.2 g, 304.4 mmol) in dry dichloromethane (80 mL) was heated for 3 hours at reflux. The solvent and excess thionyl chloride were distilled off under reduced pressure. The residue was taken up in dry dichloromethane (60 mL) and reacted with a solution of 4-amino-2-methyl-5-propyl-2H-pyrazole-3-carboxamide (12.6 g, 69.2 mmol), dry triethylamine (7 g, 69.2 mmol) and 4-(N,N-dimethylamino)pyridine (84.5 mg, 0.7 mmol) in dry dichloromethane (200 mL) at 0 C. Stirring was maintained for 1 hour, and the reaction mixture was successively washed with water (150 mL), saturated aqueous sodium carbonate solution (200 mL) and saturated brine (200 mL). The organic layer was dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated to about 60 mL, and then hexane (150 mL) was added to give precipitate product as a white solid (22 g, 92%). 1H NMR (300 MHz, CDCl3) delta 9.47 (s, 1H), 8.28 (d, 1H, J=7.8 Hz), 7.87 (br.s, 1H), 7.57-7.52 (m, 1H), 7.16-7.05 (m, 2H), 5.53 (s, 1H), 4.20 (t, 2H, J=6.6 Hz), 4.09 (s, 3H), 2.54 (t, 2H, J=7.5 Hz), 1.97-1.85 (m, 2H), 1.69-1.26 (m, 2H), 1.07 (t, 3H, J=7.2 Hz), 0.95 (t, 3H, J=7.5 Hz). LC-MS: m/z=345 (M+H)+

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 139756-02-8.

The chemical industry reduces the impact on the environment during synthesis 2075-46-9, name is 4-Nitro-1H-pyrazole, I believe this compound will play a more active role in future production and life. 2075-46-9

Into a 250 mL round-bottom flask, was placed a solution of compound 28.1 (5 g, 44.22 mmol, 1.00 equiv) in CH3CN (100 mL), 2-bromoethan-1- ol (11 g, 88.02 mmol, 2.00 equiv) and potassium carbonate (18.5 g, 133.85 mmol, 3.00 equiv). The resulting solution was stirred overnight at 95C in an oil bath. The reaction was then quenched by the addition of water and extracted with 3 x 100 mL of ethyl acetate. Organic layers were combined and concentrated under vacuum. The product crude was purified using flash column chromatography to furnish 3.5 g (50%) of intermediate 28.2 as yellow oil.

The chemical industry reduces the impact on the environment during synthesis 2075-46-9. I believe this compound will play a more active role in future production and life.

4522-35-4, The chemical industry reduces the impact on the environment during synthesis 4522-35-4, name is 3-Iodo-1H-pyrazole, I believe this compound will play a more active role in future production and life.

NaH (60% dispersion in mineral oil, 143 mg, 3.57 mmol) was added to a stirred solution of 3-iodo-lH-pyrazole [4522-35-4] (659 mg, 4.00 mmol) in DMF (20 mL) at 0 C under N2 atmosphere. The mixture was stirred at room temperature for 30 min. 2- (Trimethylsilyl)ethoxymethyl chloride [76513-69-4] (0.66 mL, 3.74 mmol) was added at 0 C and the reaction mixture was stirred at room temperature for 16 h. The mixture was diluted with water and extracted with EtOAc. The organic layer was dried (MgS04), filtered and the solvents were evaporated in vacuo. The crude product was purified by flash column chromatography (silica; EtOAc in heptane, gradient from 0/100 to 10/90). The desired fractions were collected and concentrated in vacuo to afford a mixture of 1-188 and 1-189 (965 mg, 86%).; Cul (28.3 mg, 0.15 mmol), N,N?-dimethylcyclo hexane- 1, 2-diamine (46.9 uL, 0.30 mmol) and K2C03 (411 mg, 2.98 mmol) were added to a solution of 1-188 and 1-189 (965 mg, 2.98 mmol) in l,4-dioxane (10 mL) in a sealed tube while nitrogen was bubbling. After 10 min, 4-chloro-lH-pyrrolo[3,2-c]pyridine [60290-21-3] (227 mg, 1.49 mmol) was added. The reaction mixture was stirred at room temperature for 10 min, and at 100 C for 20 h. The mixture was diluted with water and extracted with EtOAc. The combined organic extarcts were dried (MgS04), filtered and the solvents were evaporated in vacuo. The crude product was purified by flash column chromatography (silica; EtOAc in heptane, gradient from 0/100 to 15/85). The desired fractions were collected and concentrated in vacuo to afford a mixture of 1-190 and I- 191 (270 mg, 51%).; Pd2dba3 (39.1 mg, 42.6 pmol), XantPhos (61.7 mg, 0.11 mmol) and CS2CO3 (521 mg, 1.60 mmol) were added to a solution of 1-190 and 1-191 (372 mg mg, 1.07 mmol) in anhydrous DMF (12 mL) in a sealed tube while nitrogen was bubbling. After 10 min, 2,6-dichloro-4-fluoroaniline [344-19-4] (249 mg, 1.39 mmol) was added. The reaction mixture was stirred at room temperature for 10 min, and at 100 C for 20 h. The mixture was filtered over a pad of Celite and the filtrate was concentrated in vacuo. The crude product was purified by flash column chromatography (silica; EtOAc in heptane, gradient from 0/100 to 100/0).). The desired fractions were collected and concentrated in vacuo to afford a mixture of I- 192 and 1-193 (376 mg, 71 %).

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