Tag: M.W=100-200

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. 16298-03-6, name is Methyl 2-aminopyrazine-3-carboxylate, This compound has unique chemical properties. The synthetic route is as follows., SDS of cas: 16298-03-6

Hydrazine hydrate (34 mL, 1.1 mol) was added portionwise to a stirred suspension of methyl 3-aminopyrazine-2-carboxylate 37 (21.3 g, 139 mmol) in ethanol (65 mL) at room temperature. The resulting slurry was stirred at 60 °C for 2 h, cooled to room temperature, and filtered. The solid was washed with cold ethanol (2 x 25 mL) and dried to a constant weight to afford 3-aminopyrazine-2-carbohydrazide (20.75 g, 97percent) as a beige solid. TBTU (5.77 g, 18.0 mmol) was added portionwise over 15 min to a stirred suspension of DIPEA (8.5 mL, 49 mmol), 1-methylcyclopropanecarboxylic acid (1.63 g, 16.3 mmol) and 3-aminopyrazine-2-carbohydrazide (2.50 g, 16.3 mmol) in acetonitrile (40 mL). The mixture was stirred at 80 °C for 20 min, and then cooled to 0 °C. DIPEA (8.5 mL, 49 mmol) followed by 4-methylbenzene-1-sulfonylchloride (9.34 g, 49 mmol) were added over a period of 15 min. The reaction mixture was brought to reflux and allowed to stir at room temperature for 14 h. The mixture was concentrated, and the residue was diluted with DCM, washed with water and brine, dried over magnesium sulfate and concentrated. The crude product was purified by flash chromatography on silica gel eluting with 0 to 40percent ethyl acetate in dichloromethane. After evaporation of the solvent, the resulting solid was triturated with diethyl ether, filtered, washed with the minimum of diethyl ether and dried to afford 3-(5-(1-methylcyclopropyl)-1,3,4-oxadiazol-2-yl)pyrazin-2-amine (2.12 g, 60percent). NBS (1.87 g, 10.5 mmol) was added portionwise to a solution of 3-(5-(1-methylcyclopropyl)-1,3,4-oxadiazol-2-yl)pyrazin-2-amine (2.08 g, 9.6 mmol) in THF (30 mL). The reaction mixture was stirred at room temperature for 16 h and concentrated. The residue was dissolved in dichloromethane (150 mL), washed with water (2 x 40 mL), brine, dried over magnesium sulfate and concentrated. After evaporation of the solvents, the crude product was purified by flash chromatography on silica gel eluting with 0 to 10percent ethyl acetate in dichloromethane. The solvent was evaporated to dryness to afford 5-bromo-3-(5-(1-methylcyclopropyl)-1,3,4-oxadiazol-2-yl)pyrazin-2-amine (2.50 g, 88percent) as a yellow solid. Bis(triphenylphosphine)palladium(II) chloride (59 mg, 0.08 mmol) was added in one portion to a stirred solution of 5-bromo-3-(5-(1-methylcyclopropyl)-1,3,4-oxadiazol-2-yl)pyrazin-2-amine (500 mg, 1.69 mmol) and hexamethyldistannane (0.49 mL, 2.4 mmol) dissolved in dioxane (8 mL) under argon. The resulting suspension was stirred at 80 °C for 1 h. The mixture was evaporated. The crude product was purified by flash chromatography on silica gel eluting with 10 to 30percent ethyl acetate in dichloromethane. The solvent was evaporated to dryness to afford 3-(5-(1-methylcyclopropyl)-1,3,4-oxadiazol-2-yl)-5-(trimethylstannyl)pyrazin-2-amine 38a (314 mg, 49percent) as a yellow crystalline solid.

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 16298-03-6.

Reference:
Article; Barlaam, Bernard; Cosulich, Sabina; Delouvrie, Benedicte; Ellston, Rebecca; Fitzek, Martina; Germain, Herve; Green, Stephen; Hancox, Urs; Harris, Craig S.; Hudson, Kevin; Lambert-Van Der Brempt, Christine; Lebraud, Honorine; Magnien, Francoise; Lamorlette, Maryannick; Le Griffon, Antoine; Morgentin, Remy; Ouvry, Gilles; Page, Ken; Pasquet, Georges; Polanska, Urszula; Ruston, Linette; Saleh, Twana; Vautier, Michel; Ward, Lara; Bioorganic and Medicinal Chemistry Letters; vol. 25; 22; (2015); p. 5155 – 5162;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 25911-65-3, name is 3-Aminopyrazine-2-carbonitrile, molecular formula is C5H4N4, 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. HPLC of Formula: C5H4N4

EXAMPLE 4 Synthesis of 3-Amino-6-bromopyrazine-2-carbonitrile (Intermediate 3) To a solution of intermediate 2 (1.7 g, 14 mmol) in acetic acid (40 mL) at RT was added bromine (0.95 mL, 19 mmol) slowly. The resulting mixture was heated at 60 C. for 30 min and then cooled to RT. The mixture was poured into ice water and the resulting solid filtered. After thoroughly washed with water, the title compound was obtained as a yellow solid (2.3 g, 83%). 1H NMR (500 MHz, DMSO-d6): delta 8.44 (s, 1H), 7.60 (br s, 2H). MS (ES+): m/z 199 (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 25911-65-3, its application will become more common.

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

Some common heterocyclic compound, 91476-80-1, name is 5,6,7,8-Tetrahydroimidazo[1,2-a]pyrazine, molecular formula is C6H9N3, 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. SDS of cas: 91476-80-1

6-chloro-2-(l,l-dimethylethyl)-l,3-benzoxazole-7-sulfonyl chloride (457 mg) was dissolved in 2.5 mL DCM and the solution was cooled to 0 0C. Triethylamine (0.41 mL) was added followed by 5,6,7,8-tetrahydroimidazo[l,2-alpha]pyrazine (201 mg) dissolved in 2.5 mL DCM. The reaction mixture was stirred at 0 0C to room temperature over night. The reaction was quenched with water and extracted with DCM (3×10 mL). The combined organic layers were dried Na2SOzI, filtered and the solvent was removed in vacuo. The crude product was purified by column chromatography eluting with a gradient of 0 to 20% MeOH in DCM yielding 409 mg of product. Rf: 0.57 (10% MeOH in DCM).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 91476-80-1, its application will become more common.

Reference:
Patent; SMITHKLINE BEECHAM CORPORATION; WO2007/124423; (2007); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 41110-28-5, name is 3-Methylpyrazine-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. category: Pyrazines

Example 1.1: Preparation of 3-methyl-pyrazine-2-carboxylic acid ethyl esterTo a solution of 3-methyl-pyrazine-2-carboxylic acid (10 g) (commercially available) and jV,7V-dimethylformamide (“DMF”) (1 drop) in dichloromethane (20 ml) at ambient temperature was added drop wise oxalyl chloride (2.57 ml). The reaction mixture was stirred at ambient temperature for 1 hour. The reaction mixture was concentrated and the residue dissolved in dichloromethane (20 ml). Triethylamine (4.04 ml) was added to this solution followed by drop wise addition of ethanol (10 ml). The reaction mixture was stirred at ambient temperature for one hour and then concentrated. The residue was purified by chromatography on silica gel (eluent: 0-10% v/v ethyl acetate in zso-hexane) to give 3- methyl-pyrazine-2-carboxylic acid ethyl ester (9.85 g). MH+ = 167, RT = 0.73 min (Method A). IH-NMR (400 MHz, CDCl3): 8.61 (d, IH), 8.54 (d, IH), 4.49 (q, 2H), 2.85 (s, 3H), 1.46 (t, 3H) ppm.

The synthetic route of 3-Methylpyrazine-2-carboxylic acid has been constantly updated, and we look forward to future research findings.

Reference:
Patent; SYNGENTA LIMITED; WILLETTS, Nigel, James; MULHOLLAND, Nicholas, Phillip; WORTHINGTON, Paul, Anthony; AVERY, Alaric, James; WO2010/130970; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 74290-67-8, 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. 74290-67-8 name is 2-Amino-5-bromo-3-methylpyrazine, 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.

A solution of 5-bromo-3-methyl-pyrazin-2-amine (1000 mg, 5.32 mmol), phenol (650 mg, 6.91 mmol), Cs2C03 (2600 mg, 7.98 mmol), Cul (203 mg, 1.06 mmol), and Nu,Nu-dimethylgly cine (110 mg, 1.06 mmol) in dioxane (5 mL) was degassed and heated to 90 C under N2 for 12 h. After cooling to room temperature, the mixture was diluted with EtOAc (100 mL) and water (100 mL) and the organic phase collected. The aqueous layer was extracted again with EtOAc (100 mL) and the combined organic layers were dried over anhydrous MgSC^ and concentrated to dryness. The residue was purified by flash column chromatography to give the title compound as a yellow oil (533 mg, 49.8% yield). MS (ESI): mass calcd. for CnHnN30, 201.1; m/z found, 202.1 [M+H]+.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 2-Amino-5-bromo-3-methylpyrazine, and friends who are interested can also refer to it.

Reference:
Patent; JANSSEN PHARMACEUTICA NV; ARORA, Nidhi; BACANI, Genesis M.; BARBAY, Joseph Kent; BEMBENEK, Scott D.; CAI, Min; CHEN, Wei; DECKHUT, Charlotte Pooley; EDWARDS, James P.; GHOSH, Brahmananda; HAO, Baoyu; KREUTTER, Kevin; LI, Gang; TICHENOR, Mark S.; VENABLE, Jennifer D.; WEI, Jianmei; WIENER, John J. M.; WU, Yao; ZHU, Yaoping; ZHANG, Feihuang; ZHANG, Zheng; XIAO, Kun; (1000 pag.)WO2017/100668; (2017); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 356783-16-9, A common heterocyclic compound, 356783-16-9, name is 3,6-Dichloropyrazine-2-carbonitrile, molecular formula is C5HCl2N3, 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 II-29 In 60 mL of dimethyl sulfoxide was dissolved 3.0 g of 3,6-dichloro-2-pyrazinecarbonitrile. After adding 3.0 g of potassium fluoride, the mixture thus obtained was stirred at 90-100 C. for 2 hours. The reaction mixture was returned to room temperature, to which were successively added 2.1 g of 2-methyl-1,3-cyclopentandione and 7.2 ml of triethylamine. The mixture thus obtained was stirred at room temperature for one hour. The reaction mixture was added to a mixture of 50 mL of ethyl acetate and 200 mL of water, and the organic layer was separated. The organic layer thus obtained was washed successively with water and saturated aqueous solution of sodium chloride and dried on anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. The residue thus obtained was purified by silica gel column chromatography [eluent: n-hexane:ethyl acetate=2:1] to obtain 1.7 g of 6-fluoro-3-[(2-methyl-3-oxo-1-cyclopenten-1-yl)oxy]-2pyrazinecarbonitrile as a yellow-colored solid product. IR (KBr) cm-1: 2238, 1707, 1676 1H-NMR (CDCl3) delta: 1.72(3H,t,J=1.8 Hz), 2.58-2.68(2H,m), 2.76-2.91(2H,m), 8.29(1H,d,J=8.1 Hz)

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; Toyama Chemical Co., Ltd.; US2003/130213; (2003); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 54608-52-5, name is 2-Hydrazinopyrazine, molecular formula is C4H6N4, 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. HPLC of Formula: C4H6N4

To a solution of 2-hydrazinylpyrazine (0.485 g, 4.40 mmol) in HOAc (6 mL) was added (2- (hydroxyimino)-l -phenylbutane-l ,3-dione (0.765 g, 4.00 mmol) in small portions over 2 minutes. The mixture was stirred for 5 minutes and the resulting light orange suspension was stirred at 60 C for 6 hours. EtOH (1 mL) was added and the mixture was heated at 60 C for an additional 6 hours. The resulting dark green suspension was cooled to ambient temperature and the mixture was diluted with H20 (30 mL). The green suspension was stirred for 1 hour and the solid was collected via vacuum filtration. The collected solid was washed with H20 and dried in vacuum. The solid was suspended in EtOH (25 mL) and concentrated HC1 (500 mu) was added. The mixture was heated at reflux for 20 hours, cooled to ambient temperature and diluted with chilled 0 (75 mL). The mixture was treated with 1M NaOH to pH=7 and was extracted with Et20 (3X). The combined extracts were washed with saturated NaCl and dried over MgS04. The dried solution was filtered through packed Celite and concentrated. The residual green-yellow solid was purified on a Si02 column using step gradient elution (25% CH2CI2, 50% EtOAc/hexanes) to furnish the title compound as a turquoise solid (325 mg, 31%). MS (apci) m/z = 266.1 (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 54608-52-5, its application will become more common.

Reference:
Patent; ARRAY BIOPHARMA INC.; ALLEN, Shelley; BLAKE, James F.; BRANDHUBER, Barbara J.; JIANG, Yutong; KOLAKOWSKI, Gabrielle R.; XU, Rui; WINSKI, Shannon L.; WO2014/78328; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 59489-32-6, These common heterocyclic compound, 59489-32-6, name is 5-Chloro-2,3-dimethylpyrazine, 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.

Description 86: 2,3-dimethyl-5-[(phenylmethyl)oxy]pyrazine (D86); Potassium tert-butoxide (413 mg, 3.68 mmol) was added to a solution of 5-chloro-2,3- dimethylpyrazine D85 (350 mg) and benzyl alcohol (0.638 ml, 6.14 mmol) in 1,4-Dioxane (12 ml). The resulting yellow suspension was stirred at 98 0C for 20 minutes and then the temperature was allowed to reach 23 0C. Water (5 ml) and EtOAc (20 ml) were added, the aqueous phase was extracted with EtOAc (3 x 10 ml) and the collected organic layers washed with brine (2 x 5 ml), dried over Na2SO4, filtered and evaporated under reduced pressure to give a yellow oil.This was purified by column chromatography on silica gel (SNAP KP-SiI 5Og; eluted with Cy/EtOAc 90:10) and an orange solid was obtained. It resulted to be not pure and it was further purified by silica gel chromatography (SNAP KP-SiI; eluted with n- hexane/Et2O 90:10). Evaporated fractions gave the title compound D86 as yellow solid(175 mg).UPLC (IPQC): rt = 1.10 minutes, peak observed: 215 (M+l) C13Hi4N2O requires 214.

Statistics shows that 5-Chloro-2,3-dimethylpyrazine is playing an increasingly important role. we look forward to future research findings about 59489-32-6.

Reference:
Patent; GLAXO GROUP LIMITED; AMANTINI, David; DI FABIO, Romano; WO2010/122151; (2010); A1;,
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. 768-05-8, name is Pyrazinoic acid hydrazide, This compound has unique chemical properties. The synthetic route is as follows., Formula: C5H6N4O

General procedure: 2.3. General procedure for the synthesis of N’-(2r,4c-diaryl-3-azabicyclo[3.3.1]nonan-9-ylidene)pyrazine-2-carbohydrazide(8-14)The quest for the synthesis of N’-(2r,4c-diaryl-3-azabicyclo[3.3.1]nonan-9-ylidene)pyrazine-2-carbohydrazide (8-14) wasaccomplished in two steps as outlined in Scheme 1. A mixture of2r,4c-diaryl-3-azabicyclo[3.3.1]nonan-9-one (1-7) (1 mmol),commercially available pyrazine-2-carbohydrazide (PZH)(1.5 mmol) in methanol and chloroform mixture (1:1 v/v), andcatalytic amount of acetic acid (0.1 mL) was added and refluxed for2-3 h. On the completion of reaction, a solid mass was formed.After cooling to room temperature, the precipitate was filtered offand washed with cold mixture of ethanol and water. The crude product was recrystallized from ethanol [16].

According to the analysis of related databases, 768-05-8, the application of this compound in the production field has become more and more popular.

Reference:
Article; Mangalam; Sebastian Antony Selvan; Sankar; Journal of Molecular Structure; vol. 1129; (2017); p. 305 – 312;,
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. 22047-25-2, name is Acetylpyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. Quality Control of Acetylpyrazine

Hydrobromic acid (33 wt% in AcOH, 3.1 mL, 17.1 mmol, 1.05 equiv) and bromine (0.85 mL, 16.5 mmol, 1.0 equiv) were sequentially, slowly added to a solution of 2-acetylpyrazine (2.0 g, 16.4 mmol, 1.0 equiv) in glacial acetic acid (18 mL) and the reaction was stirred for 4 h at 23 C. The yellow solid was collected, washed with glacial acetic acid (7 mL) and dried to afford crude 2-(2-bromo)acetylpyrazine hydrobromide 88b (3.3 g, 71% crude) as a colorless solid, which was used without further purification. To a solution of 2-(2-bromo)acetylpyrazine hydrobromide 88b prepared above (1.0 g, 3.55 mmol, 1.0 equiv) in 95% EtOH was added thiourea (0.33 g, 4.3 mmol, 1.2 equiv) and DIPEA (1.8 mL, 10.3 mmol, 2.9 equiv) and the brown suspension was heated at reflux for 3 h. After cooling to rt the solvent was evaporated and the residue washed with CH2Cl2. The solid was dried under reduced pressure to afford the title compound (0.60 g, 95%) as a yellow solid: Rf = 0.27 (9:1 CH2Cl2-MeOH); 1H NMR (600 MHz, CD3OD) delta 7.32 (s, 1H), 8.40 (d, J = 2.3 Hz, 1H), 8.51 (s, 1H), 9.01 (d, J = 1.2 Hz, 1H); 13C NMR (150 MHz, CD3OD) delta 109.5, 142.5, 143.0, 144.6, 147.5, 148.6, 170.4; HRMS (APCI+) calcd for C7H7N4S [M+H]+ 179.0386, found 179.0382 (error 2.2 ppm).

The synthetic route of 22047-25-2 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Meissner, Anja; Boshoff, Helena I.; Vasan, Mahalakshmi; Duckworth, Benjamin P.; Barry III, Clifton E.; Aldrich, Courtney C.; Bioorganic and Medicinal Chemistry; vol. 21; 21; (2013); p. 6385 – 6397;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem