Month: November 2020

33332-25-1, 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 33332-25-1 as follows.

Methyl 5-[(oxan-4-yl)amino]pyrazine-2-carboxylate Methyl 5-chloro-2-pyrazinecarboxylate (507 mg, 2.94 mmol), Et3N (1.08 mL, 7.64 mmol) and 4-aminotetrahydropyran (395 uL, 3.82 mmol) were dissolved in dioxane (5 mL) and heated in a microwave reactor at 100 C. for 20 min. Water (50 mL) and brine (25 mL) were added and the reaction mixture was extracted into EtOAc (2*100 mL), dried (MgSO4) and concentrated in vacuo to give the title compound (236 mg, 33.9%) as a yellow oil. LCMS (ES+): 238.2 [MH]+.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 33332-25-1, and friends who are interested can also refer to it.

Reference:
Patent; Proximagen Limited; Espensen, Max; Savory, Edward; US2015/258101; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

875781-43-4,Some common heterocyclic compound, 875781-43-4, name is 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, molecular formula is C6H4BrN3, 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: 2-Bromo-5H-pyrrolo[3,2-b]pyrazine(4; 0.471 g,2.39 mmol), 4-pyridylboronic acid (0.58 g, 4.72 mmol), dichloro 1,1′-bis(diphenylphosphino)ferrocenepalladium (II) dichloromethane adduct (0.097 g, 0.12 mmol), acetonitrile(3 mL) and 1M sodium carbonate (3 mL) were placed in a 10 mL CEM microwavevial. The vial was capped and irradiated in a CEM microwave reactor for 30minutes at 150 C.Water (3 mL) and ethyl acetate (9 mL) were added the layers were partitioned. Theaqueous layer was extracted with ethyl acetate (2 x 10 mL). The combined organicextracts were washed with saturated sodium chloride (5 mL), dried over MgSO4and concentrated under reduced pressure. The residue was purified by preparativereverse phase HPLC to give 2-(pyridin-4-yl)-5H-pyrrolo[2,3-b]pyrazine(14; 0.28 g,60%) as an off white solid: 1H NMR (400 MHz, DMSO-d6) delta 12.24 (s, 1H), 9.00(s, 1H), 8.69 (dd, J = 4.5, 1.6 Hz, 2H), 8.12 (dd, J = 4.5, 1.6Hz, 2H), 7.98 (d, J = 3.6 Hz, 1H), 6.74 (d, J = 3.6 Hz, 1H); ESMSm/z 197.1 (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 2-Bromo-5H-pyrrolo[2,3-b]pyrazine, its application will become more common.

Reference:
Article; Burdick, Daniel J.; Wang, Shumei; Heise, Christopher; Pan, Borlan; Drummond, Jake; Yin, Jianping; Goeser, Lauren; Magnuson, Steven; Blaney, Jeff; Moffat, John; Wang, Weiru; Chen, Huifen; Bioorganic and Medicinal Chemistry Letters; vol. 25; 21; (2015); p. 4728 – 4732;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-29-5, A common compound: 33332-29-5, name is 2-Amino-5-chloropyrazine, belongs to Pyrazines compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below.

To a solution of 5-chloropyrazin-2-amine (2.5 g, 19.3 mmol) in IPA (25 mL) was added 2-chloroacetaldehyde (5.68 g, 28.95 mmol). The resulting mixture was stirred at 100 C for 16 hours to give a black suspension. The reaction solution was cooled to room temperature and concentrated to give a residue. The residue was dissolved in EtOAc (150 mL) and K2C03 aqueous (60 mL). After separatation, the organic layer was washed with brine (50 mL x 2), dried over anhydrous Na2504, filtered and concentrated to give a crude product. The crudeproduct was purified by silica gel column with EtOAc in PE = (10% to 50%) to give 6- chloroimidazo[1,2-alpyrazine (1000 mg, 33% yield) as a solid. ?H NMR (400 MHz, CDC13) oe11 8.94 (s, 1H), 8.20 (s, 1H), 7.88 (s, 1H), 7.73 (s, 1H). LCMS R = 0.174 mm in 1.5 mm chromatography, MS ESI calcd. for C6H5C1N3 [M+H1 154.0, found 153.8.

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, 2-Amino-5-chloropyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; PRAXIS PRECISION MEDICINES, INC.; REDDY, Kiran; MARTINEZ BOTELLA, Gabriel; GRIFFIN, Andrew Mark; MARRON, Brian Edward; (168 pag.)WO2018/98500; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

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. 4858-85-9 name is 2,3-Dichloropyrazine, 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. 4858-85-9

The product from Example 6 was dissolved in DMF (150 kg) at [25C.] The solution in the 1200 L reactor was cooled to [20C] to [25C] and transferred into the 1200 L receiver with a DMF rinse (30 kg). Anhydrous [K2CO3] (103 kg) was added to the 1200 L reactor. The solution in the 1200 L receiver was transferred to the 1200 L reactor with a DMF rinse (30 kg). The 2,3-dichloropyrazine (48.5 kg) was added with a DMF rinse (4 L). The 1200 L reactor was heated to reflux at [127C] to [133C.] Samples were taken every 12-18 h and monitored by GC. The reaction was complete in 41.5 h. The contents of the 1200 L reactor were cooled to [35C] to [45C] and transferred onto a 48″Nutsche filter sending the filtrate sent to the 1200 L receiver. [MTBE] rinses [(2X200] kg at [35C] to [45C)] of the 1200 L reactor were transferred onto the 48″Nutsche filter sending the rinses to the 1200 L receiver. The filtrate in the 1200 L receiver was transferred to the 1200 L reactor with a [MTBE] rinse (50 kg). The solution in the 1200 L reactor was concentrated under vacuum to remove MtBE and DMF. MgS04 was added to a 48″Nutsche (181 kg) and the 1200 L receiver (45 kg). MtBE (625 kg) was added to the 1200 L reactor, heated to [40C] to [45C,] and stirred to dissolve the title compound. The solution was cooled to [15C] to [30C] and transferred into the 1200 L receiver with a [MTBE] rinse (100 kg). The slurry in the 1200 L receiver was stirred for 3.5 h and filtered onto the 48″Nutsche filter sending the filtrate into the 1200 L reactor. The 1200 L receiver was rinsed with [MTBE] (2×250 kg at [15C] to [30C)] and transferred to the 48″ Nutsche filter sending the rinses into the 1200 L reactor. The filtrate in the 1200 L reactor was distilled under vacuum to afford the title compound of 87.83% GC purity. The yield was quantitative. [‘H] NMR (400 MHz, [D6-DMSO] at [87C)] : [6] 8.18 (1H, d, J = 2. 5 Hz), 7.89 (1H, d, J = 2.1 Hz), 7.47 (6H, d, J = 7. 6 Hz), 7.31 (6H, 5, [J = 7. 6 HZ),] 7.18 (3H, t, [J = 7. 4 HZ),] 4.31-4. 26 [(1H,] m), 3.66 [(1H,] ddd, [J = 12.] 4,9. 9,2. [5HZ),] 3.48 [(1H,] brd, J = 127 Hz), 2.72 (1H, brd, J = 11. 2 Hz), 2.59 [(1H,] br d, J [= 10.] 7 Hz), 2.49 (d6-DMSO, reference), 2.14 [(1H,] br dd, J = 11. 2,2. 0 Hz), 1.89 [(1H,] [BR T, J 9. 9 HZ),] 1.37 (3H, d, [J = 6. 6 HZ).] [3C] NMR (100 MHz, d6-DMSO at [87C)] : 3 153.85 (s), 141.51 (s), 139.79 (d), 134.86 (d), 128.57 (d), 127.02 (d), 135.60 (d), 76.07 (s), 52.09 (t), 50.84 (d), 47.68 (t), 44.40 (t), 39.52 (d6-DMSO, reference), 15.39 (q). IR (diffuse reflectance) 2963 (s), 2350 (w), 2317 (w), 1959 (w), 1921 (w), 1906 (w), 1501, 1488,1465, 1443 (s), 1411 (s), 1143 (s), 1022,744, 708 (s), [CM”.] HRMS (FAB) calcd for [C28H27CLN4 +HL] 455.2002, found 455.2004. [[A] D =-36] (c 0.98, [CH2CL2).] Anal. Calcd for [C28H27CLN4] : C, 73. [91] ; H, 5.98 ; N, 12. [31] ; Cl, 7.79. Found: C, 74.26 ; H, 6.84 ; N, 10.74.

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; BIOVITRUM AB; WO2004/829; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

767340-03-4, These common heterocyclic compound, 767340-03-4, name is (2Z)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazine-7(8H)-yl]-1-(2,4,5-trifluorophenyl)but-2-en-2-amine, 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.

Into a 500 ml flask were charged chloro (1, 5-cyclooctadiene) rhodium (I) dimer { [Rh (cod) Cl] 2} (292 mg, 1.18 mmol) and (R, S) t-butyl Josiphos (708 mg, 1.3 mmol) under a nitrogen atmosphere. Degassed MeOH was then added (200 mL) and the mixture was stirred at room temperature for 1 h. Into a 4 L hydrogenator was charged the enamine amide 2-4 (118 g, 0.29 mol) along with MeOH (1 L). The slurry was degassed. The catalyst solution was then transferred to the hydrogenator under nitrogen. After degassing three times, the enamine amide was hydrogenated under 200 psi hydrogen gas at 50 C for 13 h. Assay yield was determined by HPLC to be 93% and optical purity to be 94% ee. The optical purity was further enhanced in the following manner. The methanol solution from the hydrogenation reaction (18 g in 180 mL MeOH) was concentrated and switched to methyl t-butyl ether (MTBE) (45 mL). Into this solution was added aqueous H3PO4 solution (0.5 M, 95 mL). After separation of the layers, 3N NaOH (35 mL) was added to the water layer, which was then extracted with MTBE (180 mL + 100 mL). The MTBE solution was concentrated and solvent switched to hot toluene (180 mL, about 75 C). The hot toluene solution was then allowed to cool to 0 C slowly (5-10 h). The crystals were isolated by filtration (13 g, yield 72%, 98-99% ee); m. p. 114.1-115. 7 C. 1H NMR (300 MHz, CD3CN) : 8 7.26 (m), 7. 08 (m), 4.90 (s), 4.89 (s), 4.14 (m), 3.95 (m), 3.40 (m), 2.68 (m), 2.49 (m), 1.40 (bs). Compound 2-5 exists as amide bond rotamers. Unless indicated, the major and minor rotamers are grouped together since the carbon-13 signals are not well resolved: 13C NMR (CD3CN) : 8 171.8, 157.4 (ddd, JCF = 242.4, 9.2, 2.5 Hz), 152.2 (major), 151.8 (minor), 149.3 (ddd; JCF = 246.7, 14.2, 12.9 Hz), 147.4 (ddd, JCF = 241.2, 12.3, 3.7 Hz), 144.2 (q, Jcp= 38. 8 Hz), 124.6 (ddd, JcF = 18.5, 5.9, 4.0 Hz), 120.4 (dd, JCF = 19.1, 6.2 Hz), 119.8 (q, JcF = 268. 9 Hz), 106.2 (dd, JCF = 29.5, 20.9 Hz), 50.1, 44.8, 44.3 (minor), 43.2 (minor), 42.4, 41.6 (minor), 41.4, 39. 6, 38. 5 (minor), 36. 9.

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 767340-03-4.

Reference:
Patent; MERCK & CO., INC.; WO2005/72530; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-29-5, Name is 2-Amino-5-chloropyrazine, 33332-29-5, 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.

(c) 2-Amino-5-chloropyrazine (1.7 g) was dissolved in chloroform (190 ml) and pyridine (1.3 ml) was added under an argon atomosphere. The flask and its contents were protected from light and a solution of bromine (0.7 ml) in chloroform (85 ml) was added over a period of 1 hour. After stirring for 2 hours more bromine (0.07 ml) in chloroform (8.5 ml) was added. After stirring for 30 minutes, pyridine (0.2 ml) was added. The reaction mixture was stirred for a further 30 minutes then washed with water (50 ml) and the organic phase was separated. Volatile material was removed by evaporation and and the residue was purified by chromatography through a bed of silica (90 g), eluding with hexane (200 ml), followed by dichloromethane. Dichloromethane fractions containing the product were evaporated to give 2-amino-3-bromo-5-chloropyrazine (1.68 g); 1 H NMR (d6 -DMSO): 6.94 (br s, 2 H), 8.09 (s, 1 H); mass spectrum (+vc CI): 208 (M+H)+.

Statistics shows that 2-Amino-5-chloropyrazine is playing an increasingly important role. we look forward to future research findings about 33332-29-5.

Reference:
Patent; Zeneca Limited; US5866568; (1999); 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. 123-32-0, name is 2,5-Dimethylpyrazine, A new synthetic method of this compound is introduced below., 123-32-0

Preparation of 3,6-dimethyl-2- (3-methoxy) benzoyl pyrazine, comprising the steps of:(1) 2,5-dimethyl pyrazine take 0.2mmol, 3- methoxybenzoyl acid 0.4mmol, silver phosphate 0.02mmol, potassium persulfate 0.4mmol, 1.4mL was added dichloromethane, 0.6mL of distilled water was added, and the reaction mixture was placed in a 5mL tube and placed in an oil bath at 40 heated, reaction 24h, cooled to room temperature to obtain a reaction solution;(2) The step (1) the resulting reaction mixture was directly concentrated to give a concentrate, the concentrate with ethyl acetate / petroleum ether = 1/2 (v / v) as the developing solvent, separation by thin layer chromatography to give 32mg target The product, in 66% yield.

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; Henan Agricultural University; Wu Zhiyong; Zhao Mingqin; Li Yuan; (10 pag.)CN108101856; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common compound: 6705-33-5, name is Pyrazin-2-ylmethanol, belongs to Pyrazines compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below. 6705-33-5

General procedure: In a typical reaction, a suspension of amine (1.0 mmol) and alcohol (1.0 mmol) was added to a mixture of magnetic catalyst (0.04 g) with 1.5 ml distilled water. The resulting mixture was heated to 40 C for an appropriate time under aerobic conditions. In the case of exposure by EMF, the resulting mixture was transferred to a Helmholtz cylinder permanent magnet and exposed with 362 muT intensity for an appropriate time. Progress of the reaction was monitored by TLC. After completion of the reaction, the mixture was cooled to room temperature, and the catalyst was separated from the product solution using an external magnet, washed with deoxygenated distilled water, dried in a desiccator at room temperature, and used for the next reaction cycle without any pre-treatment. Solvent of the reaction mixture was evaporated to generate the crude product. The product was concentrated and purifiedby column chromatography on silica-gel using EtOAc/heptane (1:4) as eluent.

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, 6705-33-5, other downstream synthetic routes, hurry up and to see.

Reference:
Article; Rafiee, Ezzat; Joshaghani, Mohammad; Abadi, Parvaneh Ghaderi-Shekhi; Research on Chemical Intermediates; vol. 44; 4; (2018); p. 2503 – 2522;,
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 13301-04-7 as follows. 13301-04-7

A solution of methyl 3,6-dibromopyrazine-2-carboxylate (500 mg, 1.690 mmol, 1 equiv), (3S,4S)-3-methyl-2-oxa-8-azaspiro[4.5]decan-4-amine dihydrochloride (493.05 mg, 2.028 mmol, 1.2 equiv) and DIEA (1091.88 mg, 8.448 mmol, 5.0 equiv) in DMA (10 mL) was stirred for 2 at 55 C. Di-tert-butyl dicarbonate (552.33 mg, 2.531 mmol, 1.5 equiv) was then added and the resulting mixture was stirred for 2 h at room temperature. The reaction mixture was diluted with water and extracted with EtOAc. The organic layer was washed with water and brine, dried over anhydrous Na2S04 and concentrated. The residue was purified by silica gel column chromatography, eluted with PE/EtOAc =1 : 1 to afford the title compound (615 mg, 2 steps yield 75%) as yellow oil.

According to the analysis of related databases, 13301-04-7, the application of this compound in the production field has become more and more popular.

Reference:
Patent; NIKANG THERAPEUTICS, INC.; FU, Jiping; LOU, Yan; HE, Yigang; (0 pag.)WO2020/61101; (2020); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 23688-89-3, name is 6-Chloropyrazine-2-carboxylic acid, 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. 23688-89-3

Preparation of compound 8a: 6-Chloropyrazine-2-carbonyl chloride A mixture of 2-chloro-6-carboxy-pyrazine (1000 mg, 6.3 mmol) in ACN (20 ml_) was treated with thionyl chloride (800 uL). The resulting mixture, which became homogeneous upon heating, was refluxed for 2 h. The solvent was removed under reduced pressure which gave an oil. The crude product was used in the next step.

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 23688-89-3.

Reference:
Patent; PFIZER INC.; NINKOVIC, Sacha; BRAGANZA, John Frederick; COLLINS, Michael Raymond; KATH, John Charles; LI, Hui; RICHTER, Daniel Tyler; WO2010/16005; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem