Category: 57097-81-1

Reference of 57097-81-1,Some common heterocyclic compound, 57097-81-1, name is 3-Bromo-5-methyl-1H-pyrazole, molecular formula is C4H5BrN2, 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.

INTERMEDIATE 63 4-(3-bromo-5-methyl-lH-pyrazol-l-yl)-2-(trifluoromethyl)pyrimidine To a solution of 3-bromo-5-methyl-lH-pyrazole (100 mg, 0.621 mmol) in anhydrous DMSO (2 mL) was added NaH (27.3 mg, 0.683 mmol) at 0 C. The mixture was stirred for 30 min at 0 C, followed by the addition of 4-chloro-2- (trifluoromethyl)pyrimidine (113 mg, 0.621 mmol) in DMSO (1 mL). The resulting mixture was stirred at room temperature overnight. The mixture was quenched with water (5 mL) and extracted EtOAc (10 mL x 3). The organic layer was collected and dried over Na2S04. The solvent was removed in vacuo to give the crude product. This was purified by flash chromatography (ISCO Combiflash, 10 g, Biotage Si column, ~30 mL/min, 100% hexanes 5 min, gradient to 100% EtOAc in hexanes 15 min) to afford 4-(3-bromo-5-methyl-lH-pyrazol-l-yl)-2-(trifluoromethyl)pyrimidine. LCMS calc. = 308.98; found = 308.91 (M+H)+.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 3-Bromo-5-methyl-1H-pyrazole, its application will become more common.

Reference:
Patent; MERCK SHARP & DOHME CORP.; MOCHIDA PHARMACEUTICAL CO., LTD.; SMITH, Cameron, James; TAN, John, Qiang; ZHANG, Ting; BALKOVEC, James; GREENLEE, William, John; GUO, Liangqin; XU, Jiayi; CHEN, Yi-heng; CHEN, Yili; CHACKALAMANNIL, Samuel; HIRABAYASHI, Tomokazu; NAGASUE, Hiroshi; OGAWA, Kouki; WO2014/120346; (2014); A1;,
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 57097-81-1 as follows. Recommanded Product: 57097-81-1

General procedure: The properly substituted pyrazole (1.0 equiv) was dissolved in anhyd pyridine. DMAP (0.1 equiv) was added, and the reaction mixture was stirred under N2 for 30 min. The appropriate isocyanate (1.1-1.5 equiv) was then added, and the resulting mixture was stirred for 12 h. The solvent was evaporated under reduced pressure and the crude was purified by silica gel column chromatography, eluting with a mixture cyclohexane/EtOAc.

According to the analysis of related databases, 57097-81-1, the application of this compound in the production field has become more and more popular.

Reference of 57097-81-1, A common heterocyclic compound, 57097-81-1, name is 3-Bromo-5-methyl-1H-pyrazole, molecular formula is C4H5BrN2, 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 solution of 3-bromo-5-methyl-1H-pyrazole (from Ark Pharm, 6.4 g, 40 mmol) in tetrahydrofuran (263 mL) at 0 C. was added sodium hydride (3.2 g, 80 mmol). After stirring for 30 min, [beta-(trimethylsilyl)ethoxy]methyl chloride (8.4 mL, 48 mmol) was added and the reaction mixture was allowed to warm to room temperature over 2 h. The reaction mixture was diluted with ethyl acetate and water. The aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated. The crude was purified with flash chromatography (eluting with a gradient of 0-15% ethyl acetate in hexanes) to give the desired product as colorless oil (12 g, 100%). LCMS calculated for C10H20BrN2OSi (M+H)+: m/z=291.1. Found: 291.0

The synthetic route of 57097-81-1 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. 57097-81-1, name is 3-Bromo-5-methyl-1H-pyrazole, A new synthetic method of this compound is introduced below., Quality Control of 3-Bromo-5-methyl-1H-pyrazole

Step A: 5-(3-Bromo-5-methyl-lH-pyrazole-l -yl)-3-chloropyridazine To a solution of 3-bromo-5-methylpyrazole (0.4 g, 2.48 mmol) in DMF (5 mL) at room temperature was added KOtBu (0.279 g, 2.48 mmol) in one portion. To this mixture was added a solution of 3, 5-dichloropyridaine (0.37 g, 2.48 mmol) in DMF (5 mL). The reaction mixture was heated at 100 C for 1 h. The reaction mixture was cooled to room temperature, diluted with EtOAc (50 mL), washed with satd aq. NaHC03 (10 mL) and water (100 mL), the aqueous layers were separated and extracted with EtOAc (3 x 50 mL). The combined organic layers were washed with water (100 mL), brine (100 mL), dried over Na2S04, filtered and concentrated. The crude solid was purified by PTLC (50% EtOAc in hexanes) to afford 5-(3-bromo-5- methyl-lH-pyrazole-l -yl)-3-chloropyridazine, as a white solid. LCMS calc. = 272.95; found – 272.88 (M+H)+.

The synthetic route of 57097-81-1 has been constantly updated, and we look forward to future research findings.