Month: June 2021

Electric Literature of 21279-64-1, 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. 21279-64-1 name is 5-Chloropyrazine-2-carboxamide, 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.

5-[18F]F-PZA was synthesized via a halogen exchange reaction, similar to the method used tosynthesize 5-F-PZA (Fig 2). 2960 MBq (80 mCi) of aqueous [18F]fluoride in ddH2O was purchasedfrom PETNET Solutions Inc. The [18F]fluoride was placed in a vial containing Kryptofix2.2.2 (5 mg, 13 mumol) and potassium carbonate (1 mg, 7 mumol) and the solution was thendried by azeotropic distillation. The solid residue was then re-solubilized with 0.2±0.3 mL ofacetonitrile containing 1±2 mg 5-chloropyrazinamide (5-Cl-PZA). The reaction mixture washeated in a securely capped 2 mL reaction vial at 105C for 8 min, and subsequently quenchedwith 0.8 mL water. The reaction mixture was filtered through a vented 0.22 um Millipore filterusing a 1 mL syringe and then purified by HPLC with an isocratic mobile phase of 8% acetonitrile/92% 0.02Maqueous ammonium acetate with 5% acetic acid (Phenomenex Luna PFP,250 × 10, 5 mum, 4 mL/min). The radioactive product eluted at the same retention time as the5-F-PZA standard (10 to 12 min). The solvent was removed by rotary evaporation. The residuewas re-solubilized in sterile phosphate buffered saline and the pH of the solution was adjustedto 7.4 by the addition of 2M NaOH. The solution was filtered through an Acrodisc 13 mmsyringe filter equipped with a 0.2 mum Supor membrane (Pall Corporation) into a sterile vial.Radiochemical purity was determined by reverse-phase analytical HPLC (Phenomenex PFP,250 × 4.6, 5 mum, 1 mL/min, 8% acetonitrile/92% 0.02Maqueous ammonium acetate with 5%acetic acid mobile phase).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 5-Chloropyrazine-2-carboxamide, and friends who are interested can also refer to it.

Reference:
Article; Zhang, Zhuo; Ordonez, Alvaro A.; Smith-Jones, Peter; Wang, Hui; Gogarty, Kayla R.; Daryaee, Fereidoon; Bambarger, Lauren E.; Chang, Yong S.; Jain, Sanjay K.; Tonge, Peter J.; PLoS ONE; vol. 12; 2; (2017);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 98-97-5,Some common heterocyclic compound, 98-97-5, name is Pyrazine-2-carboxylic acid, molecular formula is C5H4N2O2, 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.

Pyrazinecarboxylic acid (2.72 g, 21.9 mmol) was added to a solution of L- cyclohexylglycine methyl ester (4.13 g, 19.9 mmol) in CH2CI2 (100 ml) at room temperature under N2, forming a white suspension. Triethylamine (6.33 ml, 4.62 g, 45.8 mmol) was added, followed by benzotriazol-l-yloxy-tris-(dimethylamino)- phosphonium hexafluorophosphate (BOP; 9.69 g, 21.9 mmol), which turned the reaction mixture from purple to an orange solution. After two days of stirring at room temperature the reaction mixture was washed two times with 50 ml saturated Na2CC>3, followed by the washing of the aqueous layers with CH2CI2 (2 chi 50 ml). The organic layers were collected and dried with MgSC , followed by concentration in vacuo. Purification by silica gel flash chromatography (c-Hex:EtOAc = 2: 1 with 0.5% triethylamine) afforded 9 (5.28 g, 19.03 mmol, 96%) as a yellow oil that solidified upon standing to give a white solid.[a f = +42.5 (c= 1.13, CHC13); *H NMR (250.13 MHz, CDCI3) delta = 9.39 (d, J= 1.25 Hz, 1H), 8.76 (d, J = 2.5 Hz, 1H), 8.57 (t, J = 1.5 Hz, 1H), 8.25 (d, J = 8.8 Hz, 1H), 4.74 (dd, J= 5.5, 9.3 Hz, 1H), 3.78 (s, 3H), 1.96 (m, 1H), 1.77 (m, 5H), 1.24 (m, 5H); 13C NMR (62.90 MHz, CDCI3): delta= 172.0 (C), 162.8 (C), 147.4 (CH), 144.5 (CH), 144.1 (C), 142.7(CH), 57.0 (CH), 52.3 (CH3), 41.2 (CH), 29.7 (CH2), 28.4 (CH2), 26.0 (CH2); IR (neat): v^cm ) = 3374 (m), 2920 (s), 2845 (w), 1740 (s), 1665 (s); HRMS (ESI, 4500 V): m/z calcd. for Ci4Hi9N303Na+ ([M + Na]+) 300.1319, found 300.1319.

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

Reference:
Patent; VERENIGING VOOR CHRISTELIJK HOGER ONDERWIJS, WETENSCHAPPELIJK ONDERZOEK EN PATIENTENZORG; RUIJTER, Eelco; ORRU, Romano; ZNABET, Anass; POLAK, Marloes; TURNER, Nicholas; WO2011/103932; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 313340-08-8, name is 3,5-Dichloro-6-ethylpyrazine-2-carboxamide belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. Computed Properties of C7H7Cl2N3O

Preparation Example 238 A mixture of 3,5-dichloro-6-ethylpyrazine-2-carboxamide (630 mg), 2-methyl-4-(morpholin-4-yl)aniline (500 mg), diisopropylethylamine (900 muL), and N-methylpyrrolidone (5 mL) was stirred at 110 C. overnight. The reactant was left to be cooled, and then water was added thereto, followed by extraction with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and then the solvent was evaporated under reduced pressure. The obtained residue was purified by silica gel column chromatography (eluent; hexane:ethyl acetate=8:2?5:5) to obtain 5-chloro-6-ethyl-3-{[2-methyl-4-(morpholin-4-yl)phenyl]amino}pyrazine-2-carboxamide (660 mg) as an orange solid.

The synthetic route of 313340-08-8 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ASTELLAS PHARMA INC.; Matsuya, Takahiro; Kondoh, Yutaka; Shimada, Itsuro; Kikuchi, Shigetoshi; Iida, Maiko; Onda, Kenichi; Fukudome, Hiroki; Takemoto, Yukihiro; Shindou, Nobuaki; Sakagami, Hideki; Hamaguchi, Hisao; US2014/323463; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

54013-06-8, name is Ethyl 5-aminopyrazine-2-carboxylate, 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. SDS of cas: 54013-06-8

Chloroacetaldehyde (9.5 mL of a 50 wt% solution in water) was added to a mixture of aminopyrazine (2.00 g, 12.0 mmol), sodium bicarbonate (2.00 g, 23.8 mmol) and absolute ethanol (100 mL). The reaction was heated to 90 C for 16 hours. After cooling to room temperature, the reaction was concentrated and purified by flash chromatography (silica, 0-10% methanol/chloroform) to give pure 1-1 as a tan colored solid. 1 H NMR (400 MHz, CDCI3) delta 9.18 (s, 1 H), 9.01 (d, J= 1.4, 1 H), 7.93 (d, J= 1 .1 , 1 H), 7.84 (s, 1 H), 4.51 (q, J= 7.1 , 3H), 1 .46 (t, J = 7.1 , 4H).

The synthetic route of 54013-06-8 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; IRM LLC; NOVARTIS AG; CHATTERJEE, Arnab Kumar; NAGLE, Advait Suresh; PARASELLI, Prasuna; LEONG, Seh Yong; ROLAND, Jason Thomas; MISHRA, Pranab Kumar; YEUNG, Bryan KS; ZOU, Bin; WO2014/78813; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 1049026-49-4, These common heterocyclic compound, 1049026-49-4, name is 2-Bromo-5-(methylthio)pyrazine, 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 1: To a solution of 2-bromo-5-(methylthio)pyrazine (CAS1049026-49-4, 5 g) in (0432) N,N-dimethylacetamide (10 ml) were added ethane- 1,2-diol (7.57 g) and potassium carbonate (5.05 g). The mixture was stirred at room temperature for 18 h. The mixture was heated to 60 C for 8 h and stirred at room temperature for 3 days. The mixture was heated to 90 C for 1.5 h. The temperature was raised to 100 C and the mixture was stirred for 2 h. After cooling to room temperature, water was added and the mixture was extracted with EtOAc. The organic layers were dried (MgS04), filtered and concentrated in vacuo.The crude material was purified by flash chromatography (Si02, 0% to 50% EtOAc in n-heptane) to give 2-((5-(methylthio)pyrazin-2- yl)oxy)ethanol (2.88 g) as colorless solid. MS: m/z = 187.1 [M+H]+.

Statistics shows that 2-Bromo-5-(methylthio)pyrazine is playing an increasingly important role. we look forward to future research findings about 1049026-49-4.

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; HOFFMANN-LA ROCHE INC.; SIENA BIOTECH S.P.A.; GUBA, Wolfgang; HAAP, Wolfgang; OBST SANDER, Ulrike; PETERS, Jens-Uwe; WOLTERING, Thomas; (81 pag.)WO2016/1266; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 3149-28-8, A common heterocyclic compound, 3149-28-8, name is 2-Methoxypyrazine, molecular formula is C5H6N2O, 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 lithium 2,2,6,6-tetra-methylpiperidide (2.6 mmol, 0.5 M in THF) at -78 C was added a solution of 2-methoxypyrazine (220 mg, 2.0 mmol) in THF (5 mL). The reaction mixture was stirred at -78 C for 30 min. Ethyl formate (167 mg, 0.18 mL, 2.3 mmol) was added and stirring was continued for 30 min at -78 C. A mixture of hydrochloric acid (35% aq, 1 mL), ethanol (1 mL) and THF (4 mL) was added and the resulting mixture was warmed to room temperature, neutralized with NaHCO3 (satd, 5 mL) and evaporated to near dryness. The residue was extracted with dichloromethane (3×25 mL). The organic extract is dried (MgSO4) and reduced in vacuo. The crude residue was purified by flash column chromatography using n-hexanes/ethyl acetate (3:1) as eluent to give the title compound as a yellow solid (193 mg, 1.4 mmol, 70%); mp 47-49 C (lit.10 mp 66-67 C); numax (neat)/cm-1 2955, 2797, 1710, 1534, 1468, 1365, 1305, 1072, 954, 762; deltaH (400 MHz, CDCl3) 10.27 (1H, s, CHO), 8.37 (1H, d, J 2.4, CH), 8.35 (1H, d, J 2.4, CH), 4.13 (3H, s, Me); deltaC (100 MHz, CDCl3) 190.1 (CHO), 160.5 (C), 145.7 (CH), 137.5 (CH), 136.3 (C), 54.5 (Me); m/z (ESI) 161 (100%, [M+Na]+); HRMS (ESI, [M+Na]+) found 161.0322. [C6H6N2NaO2]+ requires 161.0321.

The synthetic route of 3149-28-8 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Wang, Christy; Sperry, Jonathan; Tetrahedron; vol. 70; 21; (2014); p. 3430 – 3439;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 24241-18-7,Some common heterocyclic compound, 24241-18-7, name is 2-Amino-3,5-dibromopyrazine, molecular formula is C4H3Br2N3, 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 suspension of 2-amino-3,5-dibromopyrazine (2 g, 7.91 mmol) in water (25 mL) was added 2-bromo-1,1-dimethoxyethane (0.96 mL, 8.15 mmol, 1.03 equiv.) and the reaction mixture was heated at 100C for 2h. The reaction mixture was then cooled down to r.t. and the resulting precipitate was collected by filtration and dried under reduced pressure overnight to afford the title product as a beige solid (2 g, 7.22 mmol, 91 %) that was used without further purifi25 cation. ESI-MS: 275.95/277.95/279.95 [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 2-Amino-3,5-dibromopyrazine, its application will become more common.

Reference:
Patent; SELVITA S.A.; BOBOWSKA (NEE WITKOWSKA), Aneta; GALEZOWSKI, Michal; NOWAK, Mateusz; COMMANDEUR, Claude; SZEREMETA-SPISAK, Joanna; NOWOGRODZKI, Marcin; OBARA, Alicja; DZIELAK, Anna; LOZINSKA, Iwona; DUDEK (NEE SEDLAK), Marcelina; JANIGA, Anita; REUS, Jacek; WRONOWSKI, Marek; ZASTAWNA, Magdalena; RADZIMIERSKI, Adam; SWIRSKI, Mateusz; ZACHMANN, Julian; FABRITIUS, Charles-Henry; PORTER, Rod; FOGT, Joanna; (276 pag.)WO2019/2606; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 622392-04-5, 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. 622392-04-5, name is 2-Bromo-5-iodopyrazine, This compound has unique chemical properties. The synthetic route is as follows.

In a 5 mL round bottomed flask were mixed: 1,1-dimethylethyl 1-piperazinecarboxylate (110 mg, 0.590 mmol, available from Fluke), 2-bromo-5-iodopyrazine (140 mg, 0.491 mmol, available from Apollo) and Dipea (0.112 mL, 0.639 mmol) in Tert-Butanol (2 mL). The reaction was stirred and heated under reflux at 100 C. for 40 hr. The reaction mixture was partitioned between EtOAc (20 mL) and water (20 mL) and the organic layer washed with brine (20 mL) before being dried through an hydrophobic frit and concentrated. The samples were dissolved in 1:1 MeOH:DMSO 2×1 mL and purified by MDAP. The solvent was evaporated in vacuo to give the required product 1,1-dimethylethyl 4-(5-iodo-2-pyrazinyl)-1-piperazinecarboxylate (98.6 mg) LCMS (Method C): Rt=1.20, MH+=391

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

Reference:
Patent; Demont, Emmanuel Hubert; Garton, Neil Stuart; Gosmini, Romain Luc Marie; Hayhow, Thomas George Christopher; Seal, Jonathan; Wilson, David Matthew; Woodrow, Michael David; US2012/208798; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature 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.

General procedure: p-methylbenzenesulfonic acid (1.7 mg, 0.01 mmol) was added to pyrrole-2-carboxaldehyde derivative 3a (50 mg, 0.406 mmol) and 1-(pyrazin-2-yl)hydrazine (44.7 mg, 0.406 mmol) in 1,2-dichloroethane (50 mL). The reaction mixture was refluxing for 4 h. Then, 0.5 ml of NEt3 was added into the mixture. The reaction mixture was stirred for 10 minutes before subsequent addition of BF3*OEt2 (0.5 mL), and the reaction was left stirring at refluxing condition for 4 h. After cooling to room temperature, the reaction mixture was added CH2Cl2 (50 mL) and poured into water (50 mL). The organic phase was isolated and the corresponding water phase was extracted twice with CH2Cl2 (30 mL). Organic layers were combined, washed with water, dried over anhydrous sodium sulfate, filtered. After solvent removal by evaporation, the crude product was purified by silica gel column chromatography (CH2Cl2/n-hexane = 2:1) to afford 2a (51.7 mg, 41%) as yellow solids.

Statistics shows that 2-Hydrazinopyrazine is playing an increasingly important role. we look forward to future research findings about 54608-52-5.

Reference:
Article; Jiang, Xindong; Yue, Shuai; Chen, Kepeng; Shao, Zhumei; Li, Chen; Su, Yajun; Zhao, Jianzhang; Chinese Chemical Letters; vol. 30; 12; (2019); p. 2271 – 2273;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 16298-03-6, 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. 16298-03-6, name is Methyl 2-aminopyrazine-3-carboxylate belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

EXAMPLE 2 Synthesis of 3-Aminopyrazine-2-carboxamide (Intermediate 1) A solution of 3-amino-pyrazine-2-carboxylic acid methyl ester (5.0 g, 33 mmol) in concentrated ammonium hydroxide solution (30 mL) was heated at 60 C. for 3 h. The mixture was cooled to RT and the resulting solid filtered. After thoroughly washed with water followed by ether, the title compound was obtained as a brown solid (3.7 g, 82%). 1H NMR (500 MHz, DMSO-d6): delta 8.19 (d, J=2.4 Hz, 1H), 8.07 (br s, 2H), 7.80 (d, J=2.4 Hz, 1H), 7.59 (br s, 2H). MS (ES+): m/z 139 (M+H)+.

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

Reference:
Patent; TargeGen, Inc.; US2007/259876; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem