Category: 2075-45-8

Synthetic Route of 2075-45-8, These common heterocyclic compound, 2075-45-8, name is 4-Bromo-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.

To a mixture of 4-bromo- lH-pyrazole (500 mg, 3.40 mmol) in DCM (10 mL) was added Boc20 (0.790 mL, 3.40 mmol) and Et3N (0.948 mL, 6.80 mmol). The mixture was stirred at 25 C for 1 h. The mixture was concentrated to afford fert-butyl 4-bromo- lH-pyrazole-l-carboxylate (800 mg, 2.91 mmol, 86% yield). TLC (PE/EA = 2: 1, Rf = 0.6): lH NMR (400 MHz, CD3OD) delta 8.31 (s, 1H), 7.77 (s, 1H), 1.63 (s, 9H). ES-LCMS m/z 148.0 (M-Boc+H).

Statistics shows that 4-Bromo-1H-pyrazole is playing an increasingly important role. we look forward to future research findings about 2075-45-8.

Reference:
Patent; GLAXOSMITHKLINE INTELLECTUAL PROPERTY DEVELOPMENT LIMITED; EIDAM, Hilary Schenck; DEMARTINO, Michael P.; GONG, Zhen; GUAN, Amy Huiping; RAHA, Kaushik; WU, Chengde; YANG, Haiying; YU, Haiyu; ZHANG, Zhiliu; CHEUNG, Mui; WO2014/141187; (2014); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Reference of 2075-45-8, The chemical industry reduces the impact on the environment during synthesis 2075-45-8, name is 4-Bromo-1H-pyrazole, I believe this compound will play a more active role in future production and life.

4-bromopyrazole (15.6 g, 0.1 mol), ethyl iodide (10.9 g, 0.1 mol), tetrabutylammonium iodide (3.7 g, 0.01 mol) at room temperature,Dissolved in 5 ml of dimethyl sulfoxide (DMSO), and added with sodium hydroxide solution [sodium hydroxide solution: a solution obtained by dissolving 4.4 g (0.11 mol) of sodium hydroxide in 5 ml of water],The reaction is exothermic. After the addition is completed, it is stirred at room temperature overnight, diluted with water and diluted with dichloromethane.Drying, concentration and distillation under reduced pressure gave 16.8 g of 1-ethyl-4-bromo-1H-pyrazole.The yield was 96.0%.

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, 4-Bromo-1H-pyrazole, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Changsha Luxing Biological Technology Co., Ltd.; Tan Yongjun; (16 pag.)CN108863936; (2018); A;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

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 2075-45-8 as follows. name: 4-Bromo-1H-pyrazole

Step 1 : 4-(Methylthio)-1H-pyrazole A suspension of 4-bromopyrazole (4 g, 27 mmol) in tetrahydrofuran (68 mL) was cooled to 0C and n-butyllithium (2.5 M in hexanes, 35.9 mL, 90 mmol) was added dropwise over a period of 20 min. The reaction mixture was stirred at room temperature for 1 h and then was cooled to 0C. 1 ,2-Dimethyldisulfide (2.66 mL, 30.0 mmol) was added dropwise. The reaction mixture was stirred at 0C for 1.5 h. The reaction mixture was poured into water (150 mL) and then it was acidified to pH~8 with a saturated aqueous solution of ammonium chloride and a solution of aqueous hydrochloric acid (1 N). The mixture was extracted with ethyl acetate (150 mL x 3) and the combined organic layers were dried over sodium sulfate, filtered and concentrated under reduced pressure to afford 4-(methylthio)-1 H-pyrazole (3300 mg). 1H NMR (500 MHz, CDCI3) delta 2.36 (s, 3H), 7.63 (s, 2H).

According to the analysis of related databases, 2075-45-8, the application of this compound in the production field has become more and more popular.

Reference:
Patent; PFIZER INC.; AHN, Kay; BOEHM, Markus; CABRAL, Shawn; CARPINO, Philip A.; FUTATSUGI, Kentaro; HEPWORTH, David; KUNG, Daniel W.; ORR, Suvi; WANG, Jian; WO2013/150416; (2013); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Synthetic Route of 2075-45-8,Some common heterocyclic compound, 2075-45-8, name is 4-Bromo-1H-pyrazole, molecular formula is C3H3BrN2, 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-Bromo-1H-pyrazole, 5.00 g (34.0 mmol), di-tert-butyl dicarbonate, 8.17 g (37.4 mmol), and triethylamine, 7.57 g (74.8 mmol), were added into 50 mL of dichloromethane. The resulting mixture was stirred at room temperature for overnight. The resulting mixture was purified by silica gel column chromatography to give 8.00 g (93%) of the product as an off-white solid. MS (ESIpos): m/z = 247 [M+H]+. LC-MS [method 4, gradient starting with water (0.1 %HCOOH)-Acetonitrile, 10%B]: Rt = 1.75 min.

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

Synthetic Route of 2075-45-8, These common heterocyclic compound, 2075-45-8, name is 4-Bromo-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.

1-{[2-(trimethylsilyl)ethoxy]methyl}-1H pyrazole-4-carbaldehyde was prepared as follows: To a solution of 4-bromo pyrazole (16.90 g, 115 mmol) in THF (400 mL) under N2 at 0 C was added NaH ( 3.31 g, 138 mmol) and stirred for 15 min. Neat SEM-Cl (21.10 g, 126.46 mmol) was added drop wise to the reaction mixture and stirred overnight at rt. The reaction was quenched with water (200 mL) and excess THF was removed in vacuo. The residue was extracted with EtOAc (2×500 mL), dried over MgS04 and removed in vacuo to give crude 4- bromo- 1 – ( [2-(trimethylsilyl)ethoxy]methyl) – lH-pyrazole (36 g) as a yellow oil. The crude material was used in next step without further purification. To a solution of 4-bromo-l-{[2-(trimethylsilyl)ethoxy]methyl}-IH-pyrazole (35.83 g, 129.35 mmol) in THF (750 mL) at at -78 C under N2 was added n-BuLi (67.26 mL, 168.16 mmol, 2.5 M) slowly. After the reaction mixture was stirred for 3 h at -78 C, DMF (50 mL) was added at -78 C and warmed to rt overnight. It was cooled to -30 C, quenched with 1 N HCl (120 mL) and stirred at 0 C for 30 min and 30 min at rt. The extraction was carried out with EtOAc (2×500 mL) and washed with brine (2×150 mL). The combined organic layers were dried over MgS04, filtered and removed in vacuo. The crude material was purified on silica gel and eluted with EtOAc/hexanes (from 5% to 20%) to yield 1-{[2- (trimethylsilyl)ethoxy]methyl]-1H pyrazole-4-carbaldehyde (12.34 g, 34%) as brown oil

The synthetic route of 2075-45-8 has been constantly updated, and we look forward to future research findings.

Application of 2075-45-8, A common heterocyclic compound, 2075-45-8, name is 4-Bromo-1H-pyrazole, molecular formula is C3H3BrN2, 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 1: Preparation of tert-butyl 4-bromo-lH-pyrazole-l-carboxylate B [00161] Boc anhydride (2.34 niL, 10.2 mmol) was added to a solution of 4-bromo-lH- pyrazole (1 g, 6.8 mmol), triethylamine (3.3 raL, 23.8 mmol) and 4-dimethylaminopyridine (0.166 g, 1.36 mmol) in acetonitrile (20 mL) at 0 C and the reaction mixture was stirred at room temperature for 2 h. The reaction mixture was diluted with water and extracted with ethyl acetate (100 niL x 3). The combined organic extract was washed with water (100 mL), brine (100 raL), dried over anhydrous sodium sulfate and evaporated. The crude material was purified by combiflash purifier using 10% ethyl acetate in hexane to afford the title compound tert-butyl 4- bromo-1 H-pyrazole- 1 -carboxylate (1.65 g, 98% yield) as a colorless liquid. FontWeight=”Bold” FontSize=”10″ H NMR (400 MHz, CDCls) delta 8.09 (s, 1H), 7.66 (s, 1H), 1.65 (s, 9H).

The synthetic route of 2075-45-8 has been constantly updated, and we look forward to future research findings.

Each compound has different characteristics, and only by selecting the characteristics of the compound suitable for a specific situation can the compound be applied on a large scale. 2075-45-8, name is 4-Bromo-1H-pyrazole, This compound has unique chemical properties. The synthetic route is as follows., Computed Properties of C3H3BrN2

[0001187] To a solution of 4-bromo-lH-pyrazole (2.92 g, 20.0 mmol) in anhydrous DMF (50 mL) was added 2-bromopropane (3.69 g, 30.0 mmol) and potassium carbonate (6.90 g, 50 mmol) at room temperature. The reaction mixture was stirred for 10 h. The mixture was diluted with water (100 mL) and extracted with ethyl acetate (150 mL x 3). The combined organic extracts were washed with brine (150 mL x 2) and dried over anhydrous sodium sulfate. After filtration, the solvent was removed in vacuo and the residue was purified with flash column chromatography on silica gel to give Compound 330A.

According to the analysis of related databases, 2075-45-8, the application of this compound in the production field has become more and more popular.

Reference of 2075-45-8, These common heterocyclic compound, 2075-45-8, name is 4-Bromo-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.

Synthesis of intermediate compound 1: 4-bromopyrazole (4410 mg, 30.00 mmol, 1.00 equiv), cuprous iodide (571 mg, 3.00 mmol, 0.10 equivalent) was added sequentially to a dry three-necked flask with a reflux condenser and a magnetic rotor.L-valine (691 mg, 6.00 mmol, 0.20 equivalent),Potassium carbonate (8292 mg, 60.00 mmol, 2.00 equivalent) was purged three times with nitrogen.Then m-iodoanisole (12640 mg, 54.00 mmol, 1.80 eq.) and re-distilled dimethyl sulfoxide (10 mL). The reaction mixture was stirred at 100 C for 2 days, and was monitored by TLC thin-layer chromatography to afford 4-bromopyrazole. The reaction was quenched by the addition of water (100 mL), filtered, and then ethyl acetate (50 mL) was washed thoroughly, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered and evaporated. The obtained crude product was separated and purified by silica gel column chromatography, eluent (petroleum ether/ethyl acetate=20:1-10:1),Compound 1, a colorless viscous liquid of 7441 mg, yield 98%.

Statistics shows that 4-Bromo-1H-pyrazole is playing an increasingly important role. we look forward to future research findings about 2075-45-8.

Reference of 2075-45-8, 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. 2075-45-8 name is 4-Bromo-1H-pyrazole, 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.

4-Bromo-1-(1-ethoxyethyl)-1H-pyrazole (11-II-a)To a solution of 4-bromo-1H-pyrazole (3 g, 20.4 mmol), ethyl vinyl ether (1.76 g, 24.5 mmol) in DCM (30 mL) was added HCl (4M in dioxane, 0.16 mL), and the reaction mixture was stirred for 3 h at RT. After completion of the reaction (monitored by TLC), the reaction was neutralized with saturated NaHCO3 solution and extracted with DCM (3×100 mL). The combined organic layers were dried over anhydrous Na2SO4 and concentrated in vacuo to afford 11-II-a (4.46 g, 89%) as colorless liquid; TLC: 30% EtOAc/Hexane (Rf: 0.7); 1H-NMR (CDCl3, 200 MHz): delta 7.60 (s, 1H), 7.46 (s, 1H), 5.46 (q, J=6.0 Hz, 1H), 3.55-3.25 (m, 2H), 1.63 (d, J=6.0 Hz, 3H), 1.15 (t, J=7.2 Hz, 3H); Mass: 221 [M++2].

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 4-Bromo-1H-pyrazole, and friends who are interested can also refer to it.

Reference of 2075-45-8,Some common heterocyclic compound, 2075-45-8, name is 4-Bromo-1H-pyrazole, molecular formula is C3H3BrN2, 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 solution of 4-bromo-lH-pyrazole (21.6 g, 147 mmol) in dichloromethane (400 mL) from Step 1 was added HCl (4 N in dioxane) (2.204 mL, 8.82 mmol )And ethoxyethylene (12.72 g, 176 mmol). After stirring the mixture for 30 min at rt, the reaction was quenched with aqueous NaHCO3 (30 mL), stirred at rt for 1 h, and the two layers were separated. The organic layer was washed with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford 28 g of crude product. The material was purified by flash chromatography using silica gel using a hexane / ethyl acetate mixture as a solvate. A portion of the main product containing the uv activity was combined and concentrated in vacuo to afford 13.2 g (41%) of the desired product as a clear oil

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