Category: 57381-43-8

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. 57381-43-8, name is Methyl 2,5-dibromobenzoate, A new synthetic method of this compound is introduced below., HPLC of Formula: C8H6Br2O2

General procedure: Method A:16,17 A two-necked round-bottomed flask equipped with a reflux condenser and a magnetic stir bar was charged with the 2-bromobenzoic acid (20mmol) and freshly distilled methanol (25mL). The solution was heated in a hot water bath, conc. H2SO4 (8mmol) was added slowly and the reaction mixture was refluxed for 24h. After cooling to room temperature around half of the amount of the solvent was removed in vacuo and the residue was partitioned between water (50mL) and diethyl ether (70mL). The organic layer was separated and washed with saturated NaHCO3 (2×50mL), water (50mL) and brine (50mL), dried over anhydrous MgSO4 and the volatiles were removed under reduced pressure. The crude product thus obtained was purified by flash chromatography on silica gel to afford the alkyl-2-halobenzoate. (0023) In a two-necked round-bottomed flask equipped with a reflux condenser and a magnetic stir bar the alkyl 2-halobenzoate (22.5mmol) was dissolved in freshly distilled dry THF (30mL) under argon. The solution was cooled to 0°C using an ice bath and NaH (60percent in mineral oil, 15mmol) was added portionwise. After stirring for 15min a solution of the alkyl acetate (15mmol) in dry THF (30mL) was added dropwise to the reaction mixture at 0°C. The mixture was warmed up, stirred at room temperature for 2h and heated under reflux for 24h. After cooling to room temperature around half of the amount of the solvent was removed in vacuo and the reaction mixture was diluted with toluene (50mL). The resulting mixture was washed with 2N HCl (50mL), saturated NH4Cl (50mL), dried over anhydrous MgSO4 and the volatiles were removed under reduced pressure. The crude product was purified by flash column chromatography on silica gel to afford the alkyl 3-(2?-halophenyl)-3-oxo-propanoate 1.

The synthetic route of 57381-43-8 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Weischedel, Heike; Sudheendran, Kavitha; Mikhael, Alevtina; Conrad, Juergen; Frey, Wolfgang; Beifuss, Uwe; Tetrahedron; vol. 72; 24; (2016); p. 3454 – 3467;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Application of 57381-43-8, 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 57381-43-8 as follows.

Step 3: Preparation of 5-Bromo-2-r3-cyclopropyl-l-(3-methyl-pyridin-2-yl)-lH-pyrazol-5- ylaminol-benzoic acid methyl ester; To a mixture of 3-cyclopropyl-l-(3-methyl-pyridin-2-yl)-lH-pyrazol-5-amine (1.0 g, 4.667 mmol) and 2,5-dibromo-benzoic acid methyl ester (1.25 g, 4.243 mmol) in toluene (20 mL) was added BINAP (0.264 g, 0.424 mmol), followed by Pd2(dba)3 (0.233 g, 0.255 mmol). To the mixture was added cesium carbonate (1.94 g, 5.94 mmol) and the suspension was heated at 118 ¡ãC overnight and cooled to rt. The cooled reaction mixture was diluted with ethyl acetate and filtered through Celite and concentrated. The product (0.61 g, 31percent) was isolated by column chromatography (25percent ethyl acetate/ hexanes), then on the HPLC (20 to 90 percent acetonitrile). MS m/z 427.1 (M+); HPLC RT (min) 4.06 {method (A)}.

According to the analysis of related databases, 57381-43-8, the application of this compound in the production field has become more and more popular.

Reference:
Patent; BAYER PHARMACEUTICALS CORPORATION; WO2007/27842; (2007); A1;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

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. 57381-43-8, name is Methyl 2,5-dibromobenzoate, A new synthetic method of this compound is introduced below., COA of Formula: C8H6Br2O2

To a dried 25 mL flask was introduced 3-tert-butyl-1-(2-methylphenyl)-1 H-pyrazol-5-amine (220 mg, 0.96 mmol), methyl 2,5-dibromobenzoate (235 mg, 0.80 mmol), Pd2(dba)3 (36.6 mg, 0.04 mmol), BINAP (49.8 mg, 0.08 mmol), and Cs2CO3 (365 mg, 1.12 mmol). The flask was degassed followed by addition of toluene (1 mL), and the mixture was then heated to 110¡ãC for 20 h. The mixture was cooled to rt, and diluted with ethyl acetate. The solid was filtered off, and the solvent was removed under reduced pressure. The residue was redissolved in methanol/THF (4: 1, v/v) and filtered though a C8-silica plug. HPLC purification using a gradient elution from 10percent to 90percent acetonitrile in water afforded 110 mg (31 percent) of the title compound. 1H NMR (300 MHz, CD2Cl2) No. 9.21 (s, 1 H), 7.41 (d, 1 H), 7.20-7.30 (m, 5 H), 7.10 (d, 1 H), 6.09 (s, 1 H), 3.72 (s, 3 H), 2.04 (s, 3 H), 1.30 (s, 9 H). ES-MS m/z 444.1 (MH+); HPLC RT (min) 4.30.

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.

Reference:
Patent; BAYER PHARMACEUTICALS CORPORATION; WO2005/112923; (2005); A2;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

57381-43-8, Adding a certain compound to certain chemical reactions, such as: 57381-43-8, name is Methyl 2,5-dibromobenzoate, belongs to esters-buliding-blocks 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 57381-43-8.

[150] To a dried 25 mL flask was introduced 3-tert-butyl-1-(2-methylphenyl)-1H-pyrazol- 5-amine (intermediate C, 220 mg, 0.96 MMOL), methyl 2,5-dibromobenzoate (235 mg, 0.80 MMOL), Pd2 (dba) 3 (36.6 mg, 0.04 MMOL), BINAP (49.8 mg, 0.08 MMOL), and CS2CO3 (365 mg, 1.12 MMOL). The flask was degassed followed by addition of toluene (1 mL), and the mixture was then heated to 110¡ãC for 20 h. The mixture was cooled to rt, and diluted with ethyl acetate. The solid was filtered off, and the solvent was removed under reduced pressure. The residue was redissolved in METHANOL/THF (4: 1, V/V) and filtered though a CB-SILICA plug. HPLC purification using a gradient elution from 10percent to 90percent acetonitrile in water afforded 110 MG (31 percent) of the TITLE COMPOUND.APOS;H NMR (300 MHZ, CD2CI2) 5 9.21 (s, 1 H), 7.41 (d, 1 H), 7.20-7. 30 (m, 5 H), 7.10 (d, 1 H), 6.09 (s, 1 H), 3.72 (s, 3 H), 2.04 (s, 3 H), 1.30 (s, 9 H). ES-MS M/Z 444.1 (MH+) ; HPLC RT (min) 4.30.

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, Methyl 2,5-dibromobenzoate, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; BAYER PHARMACEUTICALS CORPORATION; WO2004/50650; (2004); A1;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Some common heterocyclic compound, 57381-43-8, name is Methyl 2,5-dibromobenzoate, molecular formula is C8H6Br2O2, 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. 57381-43-8

General procedure: A mixture of magnesium turnings (0.036g, 1.5mmol), bromobenzene (0.15g, 1mmol), tri-n-butyltin chloride (0.49g, 1.5mmol) and 1,2-dibromoethane (0.094g, 0.5mmol) as initiator in dry THF (5mL) was sonicated for 1h in an ultrasonic cleaning bath at around 35¡ãC, with monitoring of the reaction by TLC. Once the reaction finished, aqueous saturated NH4Cl solution (40mL) was added and extracted with ethyl acetate (3¡Á20mL). The combined extracts were washed with brine (60mL) and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure and the product was isolated by column chromatography with silica gel doped with 10percent of KF to retain tri-n-butyltin halides formed during the reaction. 4 (0.286, 0.78mmol, 78percent) eluted with 98:2 (hexane/diethyl ether).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 57381-43-8, its application will become more common.

Reference:
Article; Gerbino, Dario C.; Fidelibus, Pablo M.; Mandolesi, Sandra D.; Ocampo, Romina A.; Scoccia, Jimena; Podesta, Julio C.; Journal of Organometallic Chemistry; vol. 741-742; 1; (2013); p. 24 – 32;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics