Month: May 2021

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 4858-85-9 as follows. Formula: C4H2Cl2N2

A mixture 2,3-dichloropyrazine (50 g, 0.34 mmol) and concentrated aqueous ammonium hydroxide (200 mL) was stirred at 85 C. in a closed pressure vessel for 4 days. The mixture was cooled to 25 C., water (200 mL) was added, and the mixture was filtered. The solid was washed with water (400 mL), then with dichloromethane (400 mL) and dried under vacuum. Compound 100 was isolated as a white solid 32.5 g (73%). 1H NMR (400 MHz, DMSO-d6 delta 7.93 (d, 1H), 7.55 (d, 1H), 6.79 (bs, 2H).

According to the analysis of related databases, 4858-85-9, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Schering Corporation; US2007/105864; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 912773-24-1, These common heterocyclic compound, 912773-24-1, name is 6-Bromoimidazo[1,2-a]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 6-bromoimidazo[l,2-a]pyrimidine (2.4 g, 12.1 mmol) in DMF, were sequentially added (4-methylpiperazin-r-yl)(4-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2- yl)phenyl)methanone (80% of 4.1 g, 12.1 mmol), a solution of NaHC03 (3.1g, 36.3 mmol) in water (30 mL), water (3 mL) and (A-Phos)2PdCl2 (400 mg, 0.60 mmol). The reaction mixture was heated at 90 C for 4 h, then was diluted with water (100 mL) and extracted with EtOAc (3><100 mL). The combined organic layer was dried over Na2S04, filtered and concentrated under reduced pressure.. The residue was purified by flash column chromatography (silica gel, eluent CHCl3/MeOH 95 :5 to 85 : 15) to afford of (4-(imidazo[ 1 ,2-a]pyrazin-6-yl)phenyl)(4- methylpiperazin-l-yl)methanone (1.5 g, 65%). 1H NMR (400 MHz, CDC13) delta 8.60 (d, J~ 2,0 Hz, 1 H), 8.10 (d, J= 4.0, 1 H), 7.80 (d, J= 8.0 Hz, 1 H), 7.58 (m, 4 H) 7.39 (d, J= 8.0, 1 H), 3.84 (br s, 2 H), 3.50 (br s, 2 H), 2.40 (br s, 4 H), 2.35 (s, 3 H); MS (ESI) m/z 322 [M+1] Statistics shows that 6-Bromoimidazo[1,2-a]pyrazine is playing an increasingly important role. we look forward to future research findings about 912773-24-1. Reference:
Patent; AGENCY FOR SCIENCE, TECHNOLOGY AND RESEARCH; NACRO, Kassoum; DURAISWAMY, Athisayamani, Jeyaraj; CHENNAMANENI, Lohitha, Rao; WO2013/147711; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 2423-65-6, name is Pyrazine 1-oxide, 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 2423-65-6, Formula: C4H4N2O

Conditions: The N-oxide (2 equiv.), aryl halide, Pd(OAc)2 (5 mol %), Pt-Bu3-HBF4 (15 mol %), K2CO3 (2 equiv.) and the additive (if indicated, 2 equiv.) were added to a round bottom flask followed by the addition of dioxane and heating to 110 C.; Initial reaction screens with N-oxides 60, 70 and 80 under previously described conditions lead to disappointing results, probably due to the fact that the N-oxides were only sparingly soluble in toluene. The reaction conditions were reinvestigated. These efforts lead to the discovery that dioxane provides superior conversions with N-oxides 60 and 80 giving the cross coupled products 81 and 82 in 75% and 72% yields respectively (Table 3, entries 1 and 2). These two substrates actually exhibit superior reactivity compared to pyridine N-oxide as demonstrated by a competition experiment between 80 and pyridine N-oxide which results in exclusive arylation of 60 (Table 3, entry 4). In contrast to the excellent results obtained with 60 and 80, pyrimidine N-oxide 70 reacts in low yield (Table 3, entry 3).

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

Reference:
Patent; University of Ottawa; US2008/132698; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 1458-16-8, 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. 1458-16-8, name is Methyl 3-amino-6-iodopyrazine-2-carboxylate, This compound has unique chemical properties. The synthetic route is as follows.

Example 3b 3-amino-6-iodopyrazine-2-carboxamide 30 ml of ammonia in water is added under magnetic stirring to 15 g (53 8 mmol) of a solution of methyl 3-amino-6-iodopyrazine-2-carboxylate in 150 ml of methanol. The reaction medium is stirred at 25 C. for 48 hours. After evaporation of the solvents, the precipitate obtained is filtered, rinsed with water and then dried at 50 C. to yield 12.50 g of 3-amino-6-iodopyrazine-2-carboxamide (88%) in the form of a beige solid. LCMS (EI, m/z): (M+1) 265.02 1H NMR: deltaH ppm (400 MHz, DMSO): 8.35 (1H, s, CHarom), 7.85 (1H, bs, NH), 7.60 (3H, bs, NH), 3.25 (3H, s, CH3)

The chemical industry reduces the impact on the environment during synthesis Methyl 3-amino-6-iodopyrazine-2-carboxylate. I believe this compound will play a more active role in future production and life.

Reference:
Patent; PIERRE FABRE MEDICAMENT; KALOUN, El Bachir; BEDJEGUELAL, Karim; RABOT, Remi; KRUCZYNSKI, Anna; SCHMITT, Philippe; PEREZ, Michel; RAHIER, Nicolas; US2013/85144; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 768-05-8, These common heterocyclic compound, 768-05-8, name is Pyrazinoic acid hydrazide, 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.

pyrazine-2-carbonvl azide.; pyrazine-2-carbohydrazide (11.1 g, 80 mmol) was dissolved in 140 mL of water and charged with 6N HC1 (13.3 mL, 80 mmol) and cooled to 0C. To the stirred reaction mixture was added a solution of sodium nitrite (8.3 g, 120 mmol) in 80 mL of water was added slowly over a period of 15-30 minutes using an addition funnel. After the addition was complete the reaction was warmed to room temperature and stirred for an additional 5h. The solution was the neutralized by the careful addition of solid NaHC03 and then extracted with CHC13 (3x). The pooled organic fractions were dried over Na2SO4, filtered, concentrated and dried under high vacuum overnight to yield 2.5 g (21%) the title acyl azide. The product was used in subsequent steps without purification. IH NMR (d6-DMSO 8 9.30, d, 1H; 8 9.03, d, 1H; 8 8.90, dd, 1H).

Statistics shows that Pyrazinoic acid hydrazide is playing an increasingly important role. we look forward to future research findings about 768-05-8.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2005/66163; (2005); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 36070-79-8, These common heterocyclic compound, 36070-79-8, name is 6-Chloropyrazine-2-carboxamide, 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: 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

Related Products 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.

Description 65: 2-bromo-5-iodopyrazine (D65); In a 1000 ml, ice bath cooled round-bottomed flask was dissolved 5-bromo-2-pyrazinamine D64 (11.3 g) in Acetonitrile (125 ml)/water (188 ml). In the mixture HI 67% water solution (45 ml, 401 mmol) was added. To the solution was added dropwise during 150 minutes a solution of sodium nitrite (31.4 g, 455 mmol) in water (125 ml). After the addition the reaction mixture was sealed, was let to warm-up to room temperature and was heated at 50 0C for 30 hours. After cooling the mixture was poured into 800 ml of 20% NaOH and was extracted with Et2O (3 x 800 ml). Gathered Et2O layers were washed with Na2S2Os saturated solution, dried over Na2SO4 and the solvent was evaporated. The crude was purified by Silica Chromatography (Biotage SP – column size 34Og) using DCM 100% to DCM/MeOH 90: 10 as eluent. It was recovered the title compound D65 (896 mg) as yellow powder. 1H NMR (400 MHz, CHLOROFORM-d) delta ppm 8.49 – 8.56 (m, 1 H) 8.65 (d, 1 H)

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:
Patent; GLAXO GROUP LIMITED; AMANTINI, David; DI FABIO, Romano; WO2010/122151; (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. 1245644-42-1, name is 6-Bromo-3-iodoimidazo[1,2-a]pyrazine, A new synthetic method of this compound is introduced below., category: Pyrazines

To a solution of 6-bromo-3-iodoimidazo[1,2-a]pyrazine (3 g, 9.26 mmol) in DMF (50 mL), were added 4-cyanophenylboronic acid 3 (1.632 g, 11.1 mmol), K3PO4 (4.91 g, 23.15 mmol), Pd(PPh3)4 (0.534 mg, 0.46 mmol) and water (5 mL). The reaction mixture was heated at 90 C. for 1 h and water was added to the mixture to induce precipitation. The precipitate was isolated by filtration and was purified by column chromatography (silica gel, eluent petroleumether/EtOAc 1:1) to afford of 4-(6-bromoimidazo[1,2-a]pyrazin-3-yl)benzonitrile (2.5 g, 90%) as an off-white solid. 1H NMR (400 MHz, DMSO-d6) delta 9.88 (s, 1H), 8.90 (s, 1H), 8.27 (s, 1H), 8.05-7.99 (m, 4H); MS (ESI) m/z 301.1 [C13H7BrN4+2]+.

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; Agency for Science, Technology and Research; Nacro, Kassoum; Duraiswamy, Athisayamani Jeyaraj; Rao, Lohitha; US2014/371199; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 27825-21-4, A common heterocyclic compound, 27825-21-4, name is Methyl 3-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.

Example 16 3-[4-(2,3-Dihydroxypropyl)piperazin-1-yl]pyrazine-2-carboxylic acid methyl ester dihydrochloride Grams 20.5 of 1-(2,3-dihydroxypropyl)piperazine and 11 g of 3-chloropyrazine-2-carboxylic acid methyl ester in 100 ml dioxane were refluxed for one hour. The reaction mixture was cooled and settled, the solvent evaporated and the obtained residue dissolved in concentrated hydrochloric acid and the solution diluted with isopropanol until incipient precipitation. After resting, 12.7 g of 3-[4-(2,3-dihydroxypropyl)piperazin-1-yl]pyrazine-2-carboxylic acid methyl ester dihydrochloride melting at 195-197C (with decomposition), were obtained.

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; DOMPE’ FARMACEUTICI S.p.A.; EP230402; (1993); B1;,
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. 4774-14-5, name is 2,6-Dichloropyrazine, A new synthetic method of this compound is introduced below., category: Pyrazines

To a solution of tert-butyl azetidin-3-ylcarbamate hydrochloride (LXIV) (2 g, 9.58 mmol) in dry DMF (19.2 mL) was added DIPEA (8.37 ml, 47.9 mmol). To this mixture was added 2,6-dichloropyrazine (LXV) (1.428 g, 9.58 mmol) and the reaction was stirred at 95C for 3 hours. The reaction was quenched with water (20 mL) and extracted with EtOAc. The organic layer was dried over anhydrous Na2SO4, filtered and concentrated. The residue was purified by silica gel column chromatography (40g) (100%) hexanes?hexanes:EtOAc 1 : 1) to yield tert-butyl (1-(6- chloropyrazin-2-yl)azetidin-3-yl)carbamate (LXVI) (2.2882 g, 8.04 mmol, 83.9% yield) as a white solid. ESIMS found for C12H17CIN4O2 m/z 285.1 (M+H).

The synthetic route of 4774-14-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; SAMUMED, LLC; KC, Sunil Kumar; WALLACE, David Mark; CAO, Jianguo; CHIRUTA, Chandramouli; HOOD, John; (322 pag.)WO2016/40193; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem