Tag: M.W=100-200

Application of 59489-71-3, 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. 59489-71-3, name is 2-Amino-5-bromopyrazine, This compound has unique chemical properties. The synthetic route is as follows.

2-amino-5-bromopyrazine (5.25g, 30mmol,1 eq.) and phenyl- boronic acid (5.5 g, 45mmol, 1.5 eq.) were dissolved in toluene (100 mL) and stirred at room temperature. Ethanol (20 mL) and 1 M Na2CO3 aq. (48 mL) were added to the reaction mixture. After vacuum deaeration and argon gas protection, bis-(triphenylphosphine) palladium(II) chloride (300 mg, 0.43 mmol, 5.5% of 2-amino-5-bromopyrazine) in 10 mL of toluene was added to the solution and the mixture was deaerated again and stirred for 2 hours at 105 C under argon atmosphere. After cooling to room temperature, the solution was filtered through a diatomite pad to remove the palladium catalyst. The solution was extracted with ethyl acetate, and the brown organic phase was washed with water and brine, dried over Na2SO4 and evaporated.The resulting residue was purified by silica gel column chromatography using petroleum ether/ethyl acetate 1/1, v/v , affording 2-amino-5-phenylpyrazine (7) as a yellow solid (4.8g, 92.8%).1HNMR (DMSO-d6, 300 MHz): delta8.50 (s, 1H), 7.97 (s, 1H), 7.90 (d, 2H,J=7.8Hz), 7.44-7.39 (t, 2H), 7.32-7.28 (t, 1H), 6.55 (s,2H); ESI-MS calcd. for C10H9N3: 171.1, found: 173.2 (M+2H+).

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

Reference:
Article; Yuan, Ming-Liang; Jiang, Tian-Yu; Du, Lu-Pei; Li, Min-Yong; Chinese Chemical Letters; vol. 27; 4; (2016); p. 550 – 554;,
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. 17231-51-5, name is 3-Amino-6-bromopyrazine-2-carbonitrile, This compound has unique chemical properties. The synthetic route is as follows., Application In Synthesis of 3-Amino-6-bromopyrazine-2-carbonitrile

Step 2: synthesis of 3,6-dibromopyrazine-2-carbonitrile (15) To a solution of copper(ii) bromide (1.432 g, 6.41 mmol) and tert-butylnitrite (0.769 mL, 6.41 mmol) in acetonitrile (40 mL) was added 3-amino-6-bromopyrazine-2-carbonitrile 14 (1.16 g, 5.83 mmol) in portions (in 2 h). The reaction was stirred for 2 h at 50 C. Quenched with 2N HCl solution and the resulting precipitate was collected. Purification by chromatography (CH2Cl2) gave pure 3,6-dibromopyrazine-2-carbonitrile 15 (820 mg, 53.5%). 1H-NMR (400 MHz, CDCl3) 8.66 (s, 1H). (m/z)=261, 263 and 265 (M+H)+.

According to the analysis of related databases, 17231-51-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Folmer, Brigitte Johanna Bernita; Man, de Adrianus Petrus Antonius; Gernette, Elisabeth Sophia; Corte Real Goncalves Azevedo, Rita; Ibrahim, Hemen; US2013/79341; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 14508-49-7, name is 2-Chloropyrazine, 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 14508-49-7, Recommanded Product: 2-Chloropyrazine

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, 2-Chloropyrazine, 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 914452-71-4, 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 914452-71-4 as follows.

To a solution of 2-bromo-6-methylpyrazine (3 g, 17.3 mmol) in carbon tetrachloride (30 ml) were added at r.t. under an argon atmosphere N-bromo succinimide (3.39 g, 19.1 mmol) and benzoyl peroxide (420 mg, 1.73 mmol). The mixture was stirred for 24 fir, while a 75 W lamp was shining on the orange reaction mixture). The mixture was filtered, washed with CC14 and concentrated. The residue was dissolved in EtOAc, washed with sat aq NaHC03, brine, dried over MgS04, filtered and concentrated. The crude product was purified by silica gel chromatography using a heptane/EtOAc gradient as eluent, providing the title compound (1.88g, 43%) as brown solid.

According to the analysis of related databases, 914452-71-4, the application of this compound in the production field has become more and more popular.

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; HOFFMANN-LA ROCHE INC.; FLOHR, Alexander; GROEBKE ZBINDEN, Katrin; KOERNER, Matthias; LERNER, Christian; WO2013/178569; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

36070-79-8, name is 6-Chloropyrazine-2-carboxamide, belongs to pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows. COA of Formula: C5H4ClN3O

General procedure: 150 mg (0.952 mmol) of 5-Cl-PZA (1) or 6-Cl-PZA (2) was dissolved in ethanol together with triethylamine (1 eq., 96 mg, 0.952 mmol). Three equivalents of corresponding alkylamine were added to the reaction mixture and refluxed in ethanol generally for 6 hours. The completion of the reaction was checked by TLC chromatography (eluent: hexane/ethyl acetate, 1:2). The crude product was absorbed on silica by solvent evaporation and purified by flash chromatography (hexane/ethyl acetate gradient elution).

The synthetic route of 36070-79-8 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Servusova, Barbora; Paterova, Pavla; Mandikova, Jana; Kubicek, Vladimir; Kucera, Radim; Kunes, Jiri; Dolezal, Martin; Zitko, Jan; Bioorganic and Medicinal Chemistry Letters; vol. 24; 2; (2014); p. 450 – 453;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 113305-94-5, A common heterocyclic compound, 113305-94-5, name is 5-Aminopyrazine-2-carbonitrile, molecular formula is C5H4N4, 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.

A solution of (S)-tert-butyl 2-((2-chloro-5-(4-methoxyphenyl)pyridin-4- ylamino)methyl)morpholine-4-carboxylate (0.036 g, 0.083 mmol), 2-amino-4- cyanopyrazine (0.014 g, 0.116 mmol), Xantphos (0.008 g, 0.013 mmol), cesium carbonate (0.054 g, 0.166 mmol), tris(dibenzylideneacetone)dipalladium chloroform complex (0.007 g, 0.008 mmol) in dioxane (0.7 mL) was stirred at room temperature under nitrogen for 10 min then heated under microwave irradiation for 60 min at 150 0C. The reaction mixture was purified by ion exchange on SCX-II acidic resin (1 g), eluting with methanol / dichloromethane (1 / 1), then 2M ammonia-methanol. The basic fractions were combined and the solvent was removed in vacuo. The crude product was purified by preparative thin layer chromatography, eluting with ethyl acetate / hexane (1 / 1), to give the title compound as a yellow solid (0.014 g, 32%).1H NMR (CDCI3, 500 MHz) delta 8.81 (s, 1 H), 8.51 (s, 1 H), 7.79 (s, 1 H), 7.30 (d, 2H, J = 8.5 Hz), 7.06 (s, 1 H), 7.02 (d, 2H, J = 8.5 Hz), 4.95 (t, 1 H, J = 5.2 Hz), 3.87 (s, 3H), 3.88-3.84 (m, 1 H), 3.65-3.60 (m, 1 H), 3.52-3.48 (m, 2H), 3.33-3.20 (m, 2H), 2.97-2.90 (m, 1H), 2.76-2.67 (m, 1 H), 1.47 (s, 9H). LCMS (4)Rt = 2.17 min; m/z (ESI+) 518 [MH+].

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; CANCER RESEARCH TECHNOLOGY LIMITED; WO2009/44162; (2009); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 486460-20-2, name is 3-(Trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyrazine, A new synthetic method of this compound is introduced below., Recommanded Product: 486460-20-2

A solution of 5.0 g (26.6 mmol) of 3- (trifluoromethyl) -1,2,4-triazolo [4,3-a] pyrazine 3.0 g and a mass fraction of5% by weight of palladium on charcoal was charged into a 100 ml three-necked flask containing 50 ml of absolute ethanol and hydrogen gas was bubbled at 30 C under magnetic stirring,Atmospheric hydrogenation 20H, after the reaction is filtered, the filtrate by activated carbon decolorization, the column chromatography, yellow-brown liquid 3.5G, the yield 68.5%.

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; Nankai University; Wang, Baolei; Li, Zhengming; Zhang, Yan; (13 pag.)CN106749262; (2017); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

138588-41-7, name is Pyrazine-2-carboximidamide hydrochloride, belongs to pyrazines compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows. Safety of Pyrazine-2-carboximidamide hydrochloride

A stirred mixture of 5-(bromo-p-fluorophenyl-acetyl)-1-isopropyl-3-methyl-1, 3- dihydro-benzoimidozol-2-one (8) (0.5 g, 1.23 mmol), pyrazine-2-carboxamidine hydrochloride (0.395 g, 2,49 mmol), cesium carbonate (1.22 g, 3.74 mmol) and DMF (4.0 mL) was heated to 60 C. After 1 hour, the reaction was determined to be complete by LCMS. The reaction was cooled to room temperature and diluted with water (40 mL). After stirring for 1 hour, the crude suspension was filtered and the solids were purified by flash chromatography (diethyl ether, followed by ethyl acetate to afford 40 mg of the title compound (MAPKi No.2) as a light tan solid.

The synthetic route of 138588-41-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; PFIZER PRODUCTS INC.?; WO2005/60967; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 109838-85-9, A common heterocyclic compound, 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, molecular formula is C9H16N2O2, 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 (2R)-(-)-2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazine(0.61 g, 4.36 mmol) in THF (8 mL) was added n-BuLi (2.5 M in hexane, 1.8 mL, 4.58 mmol) at -78 °C. After allowed to stir for 0.3 hours, Compound Int-15a (2.75 g, 6.98 mmol) in 2 mL of THF was added and the mixture was allowed to stir at the temperature for 4 hours. The reaction was quenched by saturated aqueous H4C1 solution and the organic layers were extracted with EtOAc. The combined organic solution was washed with brine solution, dried (Na2S04), and concentrated in vacuo. The residue obtained was purified using an ISCO 40 g column (gradient from 0percent to 2.5percent ether in hexane) to provide Compound Int-15b, 783 mg (44percent). 1H MR (CDC13) delta 4.05 (m, 1H), 3.96 (t, J= 3.4 Hz, 1H), 3.72 (s, 3H), 3.71 (s, 3H), 3.49 (dd, J= 2,8, 0.4 Hz, 1H), 3.26 (dd, J= 6, 9.4 Hz, 1H), 2.30 (m, 1H), 1.96 (m, 1H), 1.60 (m, 2H), 1.37-1.17 (m, 3H), 1.08 (d, J= 6.9 Hz, 3H), 0.99-0.86 (m, 2H), 0.72 (d, J= 6.6 Hz, 3H), 0.49 (dd, J= 11.0, 14.4 Hz, 1H), 0.35 (dd, J= 11.0, 14.2 Hz, 1H), 0.16 (s, 6H)

The synthetic route of 109838-85-9 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MERCK SHARP & DOHME CORP.; KOZLOWSKI, Joseph, A; ROSENBLUM, Stuart, B; COBURN, Craig, A; SHANKAR, Bandarpalle, B; ANILKUMAR, G, Nair; CHEN, Lei; DWYER, Michael, P; JIANG, Yueheng; KEERTIKAR, Kartik, M; LAVEY, Brian, J; SELYUTIN, Oleg, B; TONG, Ling; WONG, Michael; YANG, De-Yi; YU, Wensheng; ZHOU, Guowei; WU, Hao; HU, Bin; ZHONG, Bin; SUN, Fei; JI, Tao; SHEN, Changmao; WO2012/40923; (2012); A1;; ; Patent; SCHERING CORPORATION; COBURN, Craig, A.; LAVEY, Brian, J.; DWYER, Michael, P.; KOZLOWSKI, Joseph, A.; ROSENBLUM, Stuart, B.; WO2012/50848; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 4744-50-7,Some common heterocyclic compound, 4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, molecular formula is C6H2N2O3, 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.

General procedure: A mixture of an appropriate cyclic imides 1-14 (5.0 mmol), 4-(hydrazinecarbonyl)benzenesulfonamide (15) (1.08 g, 5.0 mmol), and anhydroussodium acetate (0.69 g, 5.0 mmol) in glacial acetic acid(20 mL) was heated under reflux for 12 h. After cooling the reactionmixture, the precipitate obtained was filtered, washed with water, driedand re-crystallised from acetic acid.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2,3-Pyrazinecarboxylic anhydride, its application will become more common.

Reference:
Article; Abdel-Aziz, Alaa A.-M.; El-Azab, Adel S.; Ghiaty, Adel H.; Gratteri, Paola; Supuran, Claudiu T.; Nocentini, Alessio; Bioorganic Chemistry; vol. 83; (2019); p. 198 – 204;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem