Month: September 2021

Some common heterocyclic compound, 123-32-0, name is 2,5-Dimethylpyrazine, molecular formula is C6H8N2, 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. 123-32-0

(b) 3,6-Dimethylpyrazin-2-amine A mixture of 2,5-dimethylpyrazine (14 g, 0.13 mol) in N,N-dimethylaniline (50 mL) was heated to 170 C. and NaNH2 (22 g, 0.56 mol) was added in portions. The reaction mixture was stirred at 170 C. for 1 h, and the solvent was removed. The product was purified by silica gel column chromatography to give 3,6-dimethylpyrazin-2-amine as a brown solid (1.6 g, yield 10%). ESI MS: m/z 124 [M+1]+.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 123-32-0, its application will become more common.

Reference:
Patent; Sunovion Pharmaceuticals Inc.; US2012/178748; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 54608-52-5, These common heterocyclic compound, 54608-52-5, name is 2-Hydrazinopyrazine, 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 3 Hydrazinopyrazine (6.2 g, 57 mmol) and 1-(2-chloropyridin-4-yl)-2-(4-fluorophenyl)ethanone (14 g, 57 mmol) were suspended in benzene (250 ml) and p-toluenesulfonic acid monohydrate (0.68 g) was added. The reaction mixture was then refluxed with azeotropic removal of water via Dean Stark trap. After 2 h, the benzene was removed in vacuo and di-ethylene glycol was added. The reaction mixture was heated at reflux. After 2 h, the reaction mixture was poured into ether with vigorous stirring. Water was added and the product was extracted into ether. The organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo. Methanol was added and the solid was filtered off to give 6-(2-chloropyridin-4-yl)-7-(4-fluorophenyl)-5H-pyrrolo[2,3-b]pyrazine (4.9 g) as a solid.

The synthetic route of 54608-52-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Syntex (U.S.A.) LLC; US6316464; (2001); B1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 41110-29-6, The chemical industry reduces the impact on the environment during synthesis 41110-29-6, name is Methyl 3-methylpyrazine-2-carboxylate, I believe this compound will play a more active role in future production and life.

a) 3-Methyl-4-oxy-pyrazine-2-carboxylic acid methyl ester To a solution of 2.0 g (13.14 mmol) 3-methyl-pyrazine-2-carboxylic acid methyl ester in 40 ml CHCl3 was added 3.24 g (13.14 mmol) meta-chlorperoxybenzoic acid and the resulting mixture was heated to reflux for 1.5 h. The reaction mixture was basified with saturated aqueous NaHCO3 and extraced with CHCl3, the combined organic layers were dried with Na2SO4 and evaporated. The residue was purified by chromatography on silica gel (DCM to DCM/MeOH 9:1) to provide the title compound as colorless solid. HPLC: RtH11=0.40 min; ESIMS [M+H]+=169; 1H NMR (600 MHz, DMSO-d6): 8.56 (d, 1H), 8.48 (d, 1H), 3.33 (s, 3H).

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 3-methylpyrazine-2-carboxylate, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; NOVARTIS AG; US2012/172359; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 356783-16-9, These common heterocyclic compound, 356783-16-9, name is 3,6-Dichloropyrazine-2-carbonitrile, 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.

REFERENTIAL EXAMPLE II-12 In 25 mL of dimethylformamide was dissolved 2.5 g of 3,6-dichloro-2-pyrazinecarbonitrile. After adding 3.2 g of 4-(benzyloxy)phenol and 3.0 g of potassium carbonate, the mixture was stirred at room temperature for one hour. A mixture of 25 ml of ethyl acetate and 100 mL of water was added to the reaction mixture, and the organic layer was separated. The organic layer thus obtained was washed successively with water and saturated aqueous solution of sodium chloride and dried on anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. Diisopropyl ether was added to the residue, the insoluble matter was filtered off, and the filtrate was concentrated. The residue thus obtained was washed with n-hexane to obtain 3.84 g of 3-[(4-(benzyloxy)phenoxy)]-6-chloro-2-pyrazinecarbonitrile as a light brown-colored solid product. R (KBr) cm-1: 2238 H-NMR (CDCl3) delta: 5.12(2H,s), 7.03-7.48(9H,m), 8.65(1H,s)

Statistics shows that 3,6-Dichloropyrazine-2-carbonitrile is playing an increasingly important role. we look forward to future research findings about 356783-16-9.

Reference:
Patent; Toyama Chemical Co., Ltd.; US2003/130213; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 4858-85-9, name is 2,3-Dichloropyrazine, belongs to pyrazines 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 4858-85-9, category: Pyrazines

A mixture 2,3-dichloro-pyrazine (5.0 g, 34 mmol), 1-isopropylpiperazine (6.5 g, 51 mmol) and potassium carbonate (7.0 g, 51 mmol) in acetonitrile (100 mL) was stirred at ambient temperature for 2 h. Addition of hexane, followed by filtration and concentration of the filtrate gave 9.5 g of crude material as an orange liquid. Purification by filtration through silica using heptane/EtOAc (3: 1), followed by EtOAc/acetone (1: 1), provided 6.5 g (79%) of the title compound as a yellow oil which solidified upon cooling. HPLC purity: 98%. MS m/z 241 (M+H) +. HRMS m/z calcd for C11H17ClN4 (M) + 240.1142, found 240.1138.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 2,3-Dichloropyrazine, and friends who are interested can also refer to it.

Reference:
Patent; BIOVITRUM AB; WO2004/9586; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 21279-62-9, 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. 21279-62-9, name is 3-Chloropyrazine-2-carboxamide belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

General procedure: The starting compound (1.27 mmol) was treated with 18 aliphatic amines, alicyclic amines or saturated heterocycles containing at least one nitrogen atom (2.54 mmol). Four reactions were completed by conventional heating methods. The conditions were 110 C, toluene as a solvent and pyridine (1.27 mmol) as a base. The reaction time was set to one hour. Then the reactions were completed using the microwave reactor with focused field and conditions used for syntheses were 140 C, 30 min,120 W, methanol used as a solvent and pyridine (1.27 mmol) as a base. They were set experimentally with respect to prior experience. The progress of reaction was monitored with TLC in system hexane/ethyl acetate (1:1). Then the mixture was separated by flash column chromatograph using gradient elution. Mobile phases were hexane and ethyl acetate again.

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-Chloropyrazine-2-carboxamide, other downstream synthetic routes, hurry up and to see.

Reference:
Article; Jandourek, Ondrej; Dolezal, Martin; Kunes, Jiri; Kubicek, Vladimir; Paterova, Pavla; Pesko, Matus; Buchta, Vladimir; Kralova, Katarina; Zitko, Jan; Molecules; vol. 19; 7; (2014); p. 9318 – 9338;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 113305-94-5, The chemical industry reduces the impact on the environment during synthesis 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, I believe this compound will play a more active role in future production and life.

Reflux a solution of 2.24 g (18.65 mmol) of 5-aminopyrazine-2-carbonitrile and 9.45 mL (74.40 mmol) of boron trifluoride etherate in 50 mL of methanol for 2 h. Concentrate the reaction mixture under reduced pressure and take up the residue obtained in 200 mL of EtOAc and 10 mL of a saturated aqueous solution of NaHCO3. Dry the organic phase over Na2SO4 and concentrate under reduced pressure. Purify the residue obtained by silica gel column chromatography, eluding with a cyclohexane/EtOAc 1:1 mixture. After concentration under reduced pressure, we obtain 1.4 g of methyl 5-aminopyrazine-2-carboxylate in the form of oil. Yield=49%

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, 5-Aminopyrazine-2-carbonitrile, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Sanofi Aventis; US2009/318473; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 121246-96-6, 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. 121246-96-6 name is 3-Chloropyrazine-2-carbaldehyde, 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.

Preparation 1; 4-Methyi-3,4,5,6-tetrahydro-2H-[1,2’lbip(at)rrazinyl-3′-carbaldehyde; n-BuLi (56 mmol, 22.4 mL, 2.5 M in hexanes) was added to tetrahydrofuran (300 mL) cooled to-78 C followed by the addition of 2,2-6,6-tetramethylpiperidine (52 mmol, 8.71 mL). The solution was removed from the cooling bath and stirred for 30 minutes and then cooled back to -78C. 2-chloropyrazine (40 mmol, 3.65 mL) was added dropwise, and the solution turned a reddish-brown color. After stirring 30 minutes, methylformate (60 mmol, 3.7 mL) was added and the reaction mixture was stirred for 2.25 hrs at -78C. Acetic acid (8 mL) was added and the mixture was warmed to 0C, was washed 3 times with 1: 1 brine-water, dried over sodium sulfate, and then concentrated in vacuo. The residue was dissolved in 1,4- dioxane (250 mL) and 1-methylpiperazine (60 mmol, 6.6mL) and potassium carbonate solution (8.28g in 60 mL of water) were added and the mixture was heated at 100C for 1.5 hours. After cooling to room temperature, the mixture was filtered through a Celite pad which was then washed with chloroform. The filtrate was concentrated in vacuo and purified by silica gel chromatography (100: 1:1 chloroform-methanol-ammonium hydroxide) to yield 3.3 g (40% yield for two steps) of 4-methyl-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl-3′-carbaldehyde; ¹3C NMR (100 MHz, CDC13) d 191.7,154.3, 145.3,134.5, 133.2, 55.1, 48.7, 46.3; MS (AP/CI) 207.2 (M+H)+.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-Chloropyrazine-2-carbaldehyde, and friends who are interested can also refer to it.

Reference:
Patent; PFIZER PRODUCTS INC.; WO2005/113535; (2005); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 76537-18-3, 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. 76537-18-3, name is 3-Bromo-5-chloropyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows.

Intermediate C75-Chloro-3-( I ,3-dimethyl-I H-pyrazol-4-yl)-pyrazi n-2-ylam me To a solution of 3-bromo-5-chloropyrazin-2-amine (3.75 g, 18.01 mmol) in DME (90 mL) wasadded 1 ,3-dimethyl-4-(4,4,5,5-tetramethyl-1 ,3,2-dioxaborolan-2-yl)-1 H-pyrazole (4 g, 18.01 mmol), bis(triphenylphosphine)palladium(ll) chloride (0.632 g, 0.901 mmol) and Na2003 (aq.2.OM) (27.0 mL, 54.0 mmol). The reaction was heated to 90C overnight. The reaction was added to water (250m1) and the product was extracted into EtOAc (2 x 230m1). The organic phase was washed with brine, dried over MgSO4. The solids were removed by filtration, washed with EtOAc and the filtrate concentrated under vacuum. The crude product was purified by flash column chromatography, eluting with 0-10% gradient of (2M NH3 in MeOH)in DCM on a 80g Si-column, loading with DCM to give the product (2.5g)LCMS: Rt 0.81 mins; MS mlz 224.0 [M+H]+; Method 2minLowpHvol

The chemical industry reduces the impact on the environment during synthesis 3-Bromo-5-chloropyrazin-2-amine. I believe this compound will play a more active role in future production and life.

Reference:
Patent; NOVARTIS AG; BELLENIE, Benjamin Richard; BLOOMFIELD, Graham Charles; BRUCE, Ian; CULSHAW, Andrew James; HALL, Edward Charles; HOLLINGWORTH, Gregory; NEEF, James; SPENDIFF, Matthew; WATSON, Simon James; (395 pag.)WO2015/162459; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 61655-72-9, name is 6-Chloro-N,N-dimethylpyrazin-2-amine, This compound has unique chemical properties. The synthetic route is as follows., Application In Synthesis of 6-Chloro-N,N-dimethylpyrazin-2-amine

B. 2-(2-Dimethylaminoethylamino)-6-dimethylaminopyrazine. Following the process of Example 3A using 2-chloro-6-dimethylaminopyrazine there is obtained, 2-(2-dimethylaminoethylamino)-6-dimethylaminopyrazine.

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 61655-72-9.

Reference:
Patent; Merck & Co., Inc.; US4144338; (1979); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem