Tag: M.W=100-200

Electric Literature of 912773-21-8,Some common heterocyclic compound, 912773-21-8, name is 2-Bromo-5-chloropyrazine, molecular formula is C4H2BrClN2, 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 mixture of 2-bromo-5-chloro-pyrazine (2 g, 10.34 mmol), 3-fluoro-5-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-2-(2,2,2-trifluoro-l,l- dimethyl-ethoxy)pyridine (3.61 g, 10.34 mmol), CS2CO3 (6.74 g, 20.68 mmol) andPd(dppf)Cl2 (1.13 g, 1.55 mmol) in l,4-Dioxane (80 mL) and Water (8 mL) was stirred at 55 C under N2 for 5 hours. The mixture was cooled to room temperature and concentrated to give a residue. To the residue was added water (50 mL) and extracted with EtOAc (50 mL x 2). The combined organic phase was washed with water (50 mL), brine (50 mL x 2), dried over anhydrous Na2S04, filtered and concentrated to give the crude product. The crude product was purified by flash chromatography column on silica gel (EtOAc in PE = 0% to 5% to 10%) to give the product (2.3 g, 5.45 mmol) as a solid. ‘H NMR (400 MHz, CDCI3) dH= 8.77 (d, 1H), 8.64 (d, 1H), 8.53 (d, 1H), 8.05 (dd, 1H), 1.88 (s, 6H). LCMS R, = 0.96 min in 1.5 min chromatography, MS ESI calcd. for Ci3HnClF4N30 [M+H]+336.0, found 335.9.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2-Bromo-5-chloropyrazine, its application will become more common.

Reference:
Patent; PRAXIS PRECISION MEDICINES, INC.; GRIFFIN, Andrew, Mark; MARRON, Brian, Edward; MARTINEZ BOTELLA, Gabriel; REDDY, Kiran; WITTMANN, Marion; (0 pag.)WO2019/232209; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 768-05-8,Some common heterocyclic compound, 768-05-8, name is Pyrazinoic acid hydrazide, molecular formula is C5H6N4O, 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: To a stirred solution of the acid hydrazide 5 (2mmol, 0.27g) in absolute ethanol (10ml), the appropriate heteroaromatic ketone or substituted pyrazolaldehyde (2mmol) was added in the presence of catalytic amount of glacial acetic acid (5 drops), the mixture was refluxed for 12-16h. The product obtained was filtered, washed with diethyl ether, dried and recrystallized from ethanol.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Pyrazinoic acid hydrazide, its application will become more common.

Reference:
Article; Hassan, Nayera W.; Saudi, Manal N.; Abdel-Ghany, Yasser S.; Ismail, Azza; Elzahhar, Perihan A.; Sriram, Dharmarajan; Nassra, Rasha; Abdel-Aziz, Marwa M.; El-Hawash, Soad A.; Bioorganic Chemistry; vol. 96; (2020);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 33332-25-1, A common heterocyclic compound, 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, molecular formula is C6H5ClN2O2, 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.

863 mg of 5-chloropyrazine-2-carboxylic acid methyl ester was dissolved in 13 ml of N, N-dimethylformamide, 0.67 ml of 1-methylpiperazine and 5 ml of N, N-diisopropylethyl The mixture was heated to 80 C under argon, and the mixture was heated for 2 hours. After heating, the reaction solution was diluted with 65 ml of water and extracted with ethyl acetate. The organic phases were combined and washed with saturated aqueous sodium chloride solution five times, Dried over sodium, filtered and concentrated, and the residue was subjected to column chromatography (dichloromethane: methanol = 99: 1-97: 3, v / v) to give 1.024 g of a yellowish solid in 86.7% yield.

The synthetic route of 33332-25-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Chinese Academy Of Sciences Shanghai Pharmaceutical Institute; Duan Wenhu; Geng Meiyu; Zhao Bin; Ding Jian; Ai Jing; Fan Jun; Peng Xia; Yan Wei; Chen Yi; (77 pag.)CN106146493; (2016); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 14667-55-1, A common heterocyclic compound, 14667-55-1, name is 2,3,5-Trimethylpyrazine, molecular formula is C7H10N2, 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.

EXAMPLE IV Preparation Of 1-(2,3,5-Trimethyl-6-pyrazinyl)-1-propanone STR8 The reaction of trimethylpyrazine and freshly distilled propionaldehyde is carried out as described in Example I on the same molar scale. Preparative thick layer chromatography (2000mu silica gel GF, developed in 5% acetone/hexane) of the crude reaction product gives a 48% yield of 1-(2,3,5-trimethyl-6-pyrazinyl)-1-propanone (mp 65-67 C.). An analytically pure sample for odor and flavor evaluation is obtained by preparative GLC (1/4″*15′ Carbowax 20M-TPA). The structure is verified by spectroscopy. Anal. calc. for C10 H14 N2 O: C, 67.39; H, 7.92; N, 15.72; Found: C, 67.24; H, 8.13; N, 15.62.

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; Philip Morris Incorporated; US4588813; (1986); A;,
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. 13924-95-3, name is Methyl 5-hydroxypyrazine-2-carboxylate, A new synthetic method of this compound is introduced below., COA of Formula: C6H6N2O3

Potassium carbonate (8.82 g) and sodium chlorodifluoroacetate (6.53 g) were added to a solution of methyl 5-hydroxypyrazine-2-carboxylate (3.3 g) in DMF (42.8 ml). The reaction solution was stirred at 100 C. for 30 minutes, and then saturated aqueous ammonium chloride was added, followed by extraction with ethyl acetate. The organic layer was washed with a saturated sodium bicarbonate solution and brine and then dried over magnesium sulfate. The drying agent was removed by filtration and then the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography to obtain the title compound (928 mg).1H-NMR (400 MHz, CDCl3) delta (ppm): 4.04 (s, 3H), 7.49 (t, J=71.2 Hz, 1H), 8.47 (d, J=0.8 Hz, 1H), 8.92 (d, J=0.8 Hz, 1H).

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; EISAI R&D MANAGEMENT CO., LTD.; US2010/93999; (2010); 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. 22047-25-2, name is Acetylpyrazine, A new synthetic method of this compound is introduced below., Formula: C6H6N2O

General procedure: To a stirred solution of aldehyde (10mmol) (4-(dimethylamino)benzaldehyde, 4-(1-piperidinyl)benzaldehyde, 4-(4-morpholinyl)benzaldehyde or 4-(diphenylamino)benz-aldehyde) in EtOH (75mL), ketone (20mmol) (2-acetylpyridine, 2-acetylthiazole or 2-acetylpyrazine) was added. Then KOH (1.54g, 27.5mmol) and NH3 (aq) (35mL) were added to the reaction mixture. The solution was stirred at room temperature for 24h. The solid was collected by filtration and washed with H2O. Recrystallization from ethanol (1, 4, 7, 10) or toluene (2, 3, 5, 6, 8, 9, 11, 12) afforded a crystalline solid.

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:
Article; Palion-Gazda, Joanna; Machura, Barbara; Klemens, Tomasz; Szlapa-Kula, Agata; Krompiec, Stanis?aw; Siwy, Mariola; Janeczek, Henryk; Schab-Balcerzak, Ewa; Grzelak, Justyna; Ma?kowski, Sebastian; Dyes and Pigments; vol. 166; (2019); p. 283 – 300;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

59489-71-3, name is 2-Amino-5-bromopyrazine, 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. Quality Control of 2-Amino-5-bromopyrazine

A mixture of 2-amino-5-bromopyrazine (0.5 g, 2.79 mmol) and [4-(methylsulfonyl)phenyl]boronic acid (0.57 g, 2.79 mmol) in 1,4-dioxane (10 mL) and MeOH (4 mL) was treated with 2M Na2CO3 (4 mL) and Pd(PPh3)4 (65 mg, 0.06 mmol). The reaction mixture was degassed with N2 and heated at 100 C. for 3 h. Most of 1,4-dioxane and MeOH was removed under reduced pressure. Water was added, and the mixture was extracted with EtOAc (50 mL×4). The combined organic extracts were washed with brine, dried over Na2SO4, filtered, and the filtrate was concentrated to a brown solid, which was triturated with CH2Cl2 to give 0.465 g (67%) of 5-[4-(methylsulfonyl)phenyl]-2-pyrazinamine as a yellow solid. The filtrate was washed with 1 N HCl (25 mL), and the aqueous layer was separated and basified with 4N NaOH. The mixture was extracted with EtOAc (50 mL×2) and the combined organic extracts were washed with brine, dried over Na2SO4, filtered, and the filtrate was concentrated to give additional 0.045 g (7%) of 5-[4-(methylsulfonyl)phenyl]-2-pyrazinamine as a yellow solid. 1H NMR (400 MHz, DMSO-d6): delta 8.63 (s, 1H), 8.15 (d, 2H, J=8.5 Hz), 7.97 (s, 1H), 7.91 (d, 2H, J=8.5 Hz), 6.81 (s, 2H), 3.20 (s, 3H); LRMS (ESI), m/z 250 (M+H).

The synthetic route of 59489-71-3 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; SMITH KLINE BEECHAM CORPORATION a corporation; US2010/29650; (2010); 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, Recommanded Product: 4858-85-9

A. Preparation of the intermediate compoundsA1. Preparation of intermediate compound 3 a) Preparation of intermediate compound 12,3-Dichloropyrazine (10 g, 62.12 mmol) and 1-(phenylmethyl)-4-piperidin- amine (13.73 ml_, 67.12 mmol) were dissolved in DMF (60 ml). Then Na2CO3 (10.09 g, 114.10 mmoi) was added. The reaction was stirred at 130 0C for 16 hours. The solid was filtered off, washed with AcOEt and the solvent was evaporated till dryness. The product was dissolved in AcOEt, washed with H2O and brine, dried with MgSO4 and evaporated under vacuum. The product was used without any further purification yielding 15 g of the desired intermediate compound 1 (74 %).

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; JANSSEN PHARMACEUTICA N.V.; WO2007/71639; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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 41110-33-2 as follows. category: Pyrazines

A solution of lithium aluminium hydride (164.0 mL, 0.164 mol, 1.0 M in THF, 0.5 equiv.) was added to a suspension of methyl 5-methylpyrazine-2-carboxylate (50 g, 0.328 mol, 1.0 equiv.) in anhydrous THF (750 mL) at -78 C. (The internal temperature was kept below -72 C during the addition of lithium aluminium hydride). Upon completion of addition, the reaction mixture was left, to stir at -78 C for a further 20 min and was then quenched with glacial AcOH (50.0 mL) at the same temperature. The resulting mixture was warmed to RT and the volatiles were removed by evaporation under pressure. The residue was dissolved in 1.5 N HCl (500 mL) and extracted with DCM (2 x 2 L). The extracts were combined, washed with saturated aqueous sodium hydrogen carbonate solution (2 x 500 mL), (Note: no product observed in HCl or aqueous sodium hydrogen carbonate solution) dried over anhydrous Na2SO4, and concentrated in vacuo, to yield the initial product as a brown oil. The residue was purified by column chromatography (silica gel 60-120 mesh) eluting with a gradient of 10% EtOAc in petroleum ether to provide the title compound as a pale yellow liquid (21.3 g, 53 %). TLC Info: (9.0/1.0 Petroleum ether/EtOAc). 1H NMR (400 MHz, CDCl3) delta 10.14 (s, 1H), 9.07 (d, J = 1.5 Hz, 1H), 8.63 (d, J = 1.4 Hz, 1H), and 2.70 (s, 3H). LCMS (ESI positive ion) m/z: 123 (M+H)+.

According to the analysis of related databases, 41110-33-2, the application of this compound in the production field has become more and more popular.

Reference:
Patent; AMGEN INC.; CHEN, Ning; CHEN, Yinhong; DEBENEDETTO, Mikkel V.; DRANSFIELD, Paul John; HARVEY, James S.; HEATH, Julie Anne; HOUZE, Jonathan; KHAKOO, Aarif Yusuf; LAI, Su-Jen; MA, Zhihua; NISHIMURA, Nobuko; PATTAROPONG, Vatee; SWAMINATH, Gayathri; YEH, Wen-Chen; KREIMAN, Charles; (308 pag.)WO2018/93579; (2018); 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. 19847-12-2, name is Pyrazinecarbonitrile, A new synthetic method of this compound is introduced below., SDS of cas: 19847-12-2

In a 250 mL round-bottomed flask, pyrazine-2-carbonitrile (10 g, 95.1 mmol), pyridine (2.26 g, 2.33 ml, 28.5 mmol), and 2-mercaptopropionic acid (10.1 g, 95.1 mmol) were combined to give a light yellow solution. The reaction mixture was heated to 100 C. and stirred for 2 h. Upon cooling, the thick yellow mixture was diluted with 100 mL ethanol and stirred for 30 min. The slurry was then filtered, and washed with diethyl ether (2*100 mL) to give 5-methyl-2-pyrazin-2-yl-thiazol-4-ol (17.86 g, 97.1%) as yellow solid which was used directly without further purification. Trifluoro-methanesulfonic acid 5-methyl-2-pyrazin-2-yl-thiazol-4-yl ester:

The synthetic route of 19847-12-2 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Alam, Muzaffar; Du Bois, Daisy Joe; Hawley, Ronald Charles; Kennedy-Smith, Joshua; Minatti, Ana Elena; Palmer, Wylie Solang; Silva, Tania; Wilhelm, Robert Stephen; US2011/71150; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem