Tag: M.W=100-200

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.

1) Preparation of 2-Iodo-3-methoxypyrazine To 20 ml of an anhydrous THF solution of 1.3 g of diisopropylamine was added 4.8 ml (2.5 M hexane solution) of n-butyllithium at -78 C., and the mixture was stirred at that temperature for 20 minutes. To the reaction mixture was added 10 ml of a THF solution of 1.1 of 2-methoxypyrazine, followed by stirring at -78 C. for 1 hour. To the reaction mixture was further added 10 ml of a THF solution of 4.0 g of iodine, followed by stirring for 4 hours while gradually elevating the temperature to room temperature. The reaction mixture was diluted with ethyl acetate, washed successively with a saturated sodium thiosulfate aqueous solution and a saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate. The solvent was evaporated, and the residue was subjected to silica gel column chromatography using chloroform as a developing solution. The fraction containing the desired compound was concentrated to give 0.49 g of the title compound. 1H-NMR (CDCl3) delta: 4.02 (s, 3H), 7.94 (d, 1H, J=2.5 Hz), 7.99 (d, 1H, J=2.5 Hz).

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

Reference:
Patent; Daiichi Pharmaceutical Co., Ltd.; US6169086; (2001); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application 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.

Synthesis of 4-bromo-A, -(pyrazin-2-yl)benzohydrazide (15): 4-Bromohcnzoic acid (0.5 g, 2.4 mmol) was dissolved in dichloromethane (20 mL) and cooled to 0 C. 2- Hydrazinylpyrazine (0.32 g, 2.9 mmol), EDCI (0.55 g, 2.9 mmol), HOBt (0.39 g, 2.9 mmol) and DIPEA (0.96 g, 7.4 mmol) were added at 0 C. The reaction mixture was allowed to warm to room temperature and stirred for 4 h. The reaction mixture was transferred into water (100 mL) and extracted with CH2C12 (3 x 25 mL). The combined organic layers were washed with brine, dried over anhydrous Na2S04 and concentrated under reduced pressure to give crude product, which was purified by silica gel chromatography (0-5% MeOH in CH2C12) to obtain 4-bromo-N’-(pyrazin-2-yl)benzohydrazide (15). (Yield: 0.15 g, 20%). LCMS: m/z 295. 18 [M+2], = 1.8 min.

The synthetic route of 54608-52-5 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; KARYOPHARM THERAPEUTICS INC.; BALOGLU, Erkan; SHACHAM, Sharon; SENAPEDIS, William; MCCAULEY, Dilara; LANDESMAN, Yosef; GOLAN, Gali; KALID, Ori; SHECHTER, Sharon; WO2015/3166; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

4858-85-9, name is 2,3-Dichloropyrazine, 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. Application In Synthesis of 2,3-Dichloropyrazine

2,3-Dichloropyrazine (2 mL, 13 mmol) was dissolved in 95% ethanol (4 mL) and to this was added, dropwise and with stirring, hydrazine anhydrous (2 mL, 67 mmol). During the addition of the hydrazine the solution became warm and yellowish. Following cooling of this mixture in an ice bath, the resulting material was isolated by filtration, washed with cold aqueous 95% ethanol to riled 1-(3-chloropyrazin-2-yl)hydrazine (1.42 g, 73% yield) as white crystals. No further purification was done. MS m/z: 145.0 (M+1).

The synthetic route of 4858-85-9 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Amgen Inc.; US2010/120774; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 74290-69-0, name is 5-Bromo-6-methylpyrazin-2-amine, 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 74290-69-0, Computed Properties of C5H6BrN3

Compound 9 was prepared by reacting compound 7 (3.18 g;11 mmol) with compound 8 (1.88 g; 10 mmol) in the presence of Pd(PPh3)4 (250 mg) and Na2CO3 (6.36 g; 60 mmol) in THF (120 mL containing10% water) for 12 h at 343 K. Compound 9 was purified bycolumn chromatography on silica gel using petroleum ether/ethyl acetate(15:1, v/v) as eluent. A yellow solid was obtained with 90% yield.M.p.: 454-455 K. 1H NMR (400 MHz, DMSO-d6 TMS), delta (ppm): 7.78 (s,1H), 7.43 (d, J 8.4 Hz, 2H), 7.30 (t, J 7.6 Hz, 4H), 7.04 (d,J 8.0 Hz, 4H), 7.03 (d, J 5.2 Hz, 2H), 6.99 (d, J 8.4 Hz, 2H), 6.35 (s, 2H), 2.36 (s, 3H). 13C NMR (101 MHz, DMSO-d6, TMS) delta (ppm):153.6, 147.3, 147.1, 146.1, 139.4, 133.6, 129.7, 129.5, 128.8, 124.0,123.0, 122.5, 22.6. ESI-MS (ESI, m/z): [M] calcd of C23H20N4, 352.1;found, 353.2, [M H].

If you are interested in these compounds, you can also browse my other articles.Thank you for taking the time to read this article. I hope you enjoyed it.

Reference:
Article; Shi, Fu; Cui, Shiqiang; Liu, Hongling; Pu, Shouzhi; Dyes and Pigments; vol. 173; (2020);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, 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. Application In Synthesis of Methyl 5-chloropyrazine-2-carboxylate

To a solution of methyl-5-chloropyrazine-2-carboxylate (120 mg, 0.70 mmol) in a mixture of acetonitrile (2 mL) and DMF (1 mL) was added lithium chloride (295 mg, 6.95 mmol). The suspension was heated to 160C for 5 mins in a Smith creator microwave after which time the reaction was diluted with water (10 mL). Saturated sodium bicarbonate solution (20 mL) was added and the aqueous layered extracted twice with ethyl acetate (30 mL). The combined organics were discarded and the aqueous layer adjusted to pH 4 with IN hydrochloric acid. The aqueous phase was extracted twice with ethyl acetate (20 mL) and the combined organics washed with water (2 x 20 mL), brine (10 mL) and dried (MgSO4). The volatiles were removed to give the title compound as a colourless solid (68 mg). 1H NMR delta (CDCl3): 7.20 (IH, br s), 8.72 (IH, s), 9.21 – 9.21 (IH, m); m/z 157 (M-H)+.

The synthetic route of Methyl 5-chloropyrazine-2-carboxylate has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2007/7041; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 27398-39-6, These common heterocyclic compound, 27398-39-6, name is 3-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.

1.59 g (10 mmol) of 3-chloropyrazine-2-carboxylic acid was dissolved in 20 mL of dichloromethane solvent, 2.54 g (20 mmol) of oxalyl chloride, 2 drops of DMF,After stirring at reflux for 5 h, the solvent and excess oxalyl chloride were evaporated under reduced pressure.Obtained a purplish red oil; it was dissolved in 20 mL of dichloromethane.Add 0.92g (5mmol)Ethyl 5-(methylaminomethyl)-1H-imidazole-4-carboxylate and1.52 g (15 mmol) of triethylamine,After stirring at room temperature until the reaction was completed, it was poured into 50 mL of saturated sodium bicarbonate solution, and extracted with dichloromethane (20 mL ¡Á 4).After filtration, the solvent was evaporated under reduced pressure to give ethyl 5-((3-chloro-N-methylpyrazine-2-carboxamido)methyl)-1H-imidazole-4-carboxylate.Ethyl 5-((3-chloro-N-methylpyrazine-2-carboxamido)methyl)-1H-imidazole-4-carboxylate was dissolved in 20 mL of acetonitrile.Add 3.26 g (10 mmol) of cesium carbonate,The mixture was stirred under reflux until the reaction was completed, and the solvent was evaporated under reduced pressure.It was dissolved in 20 mL of dichloromethane.Wash with distilled water (30 mL ¡Á 2), dry over anhydrous sodium sulfate,After filtration, the solvent was evaporated under reduced pressure.Column chromatography (EtOAc, 1percent Et3N),A white solid was obtained in a two step yield of 55percent.

The synthetic route of 27398-39-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; The Chinese People’s Liberation Army Military Academy Of Medical Sciences Poison Pharmaceutical Institute; Beijing Normal University; Yu Gang; Zhang Zhanbin; Cao Yanqing; Su Ruibin; Zheng Zhibing; Zhou Xinbo; Li Yi; Xiao Guiying; (16 pag.)CN109206428; (2019); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 36070-79-8, name is 6-Chloropyrazine-2-carboxamide, 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 36070-79-8, Computed Properties of C5H4ClN3O

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).

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, 6-Chloropyrazine-2-carboxamide, other downstream synthetic routes, hurry up and to see.

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

Electric Literature of 17231-51-5, 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 17231-51-5 as follows.

Step 1 [0188] A 50 mL RBF equipped with magnetic stir bar was charged with 1.0 g (1.0 eq.) Bromo amine, 1 .6 g (2.2 eq.) methyl Iodide, and 3.7 g (2.2 eq.) CsC03 in 25 ml DMF. The reaction was stirred at RT. The reaction mixture got dark and was let to stir overnight. LC/MS looks like previous runs. The reaction was partionned between EA and aq. Citric. The organics were washed with satd. bicarb, brine, dried and concentrated in vacuo to crude. Purification was done by Flash Chromatography (20 – 50 % EA-H). The fractions containing visible yellow product (even if some had some long wave impurities) were combined and concentrated then vacuum dried to afford 940 mgs of crystalline solid.

According to the analysis of related databases, 17231-51-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; MALLINCKRODT LLC; FRESKOS, John, N.; WO2013/39851; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 4774-14-5,Some common heterocyclic compound, 4774-14-5, name is 2,6-Dichloropyrazine, molecular formula is C4H2Cl2N2, 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 4; 6-Chloro-N-phenylpyrazin-2-amine A solution of 2,6-dichloropyrazine (1 g, 6. 7 mrnol) and anitine (1. 25 g, 13.4 mmol) in ethoxyethanol (20 mE) containing DIPEA (2.5 mL, 13. 4 minor) was heated at reflux for 3 days under Na. The solution was concentrated under reduced pressure and the residue dissolved in EtOAc (50 mL) and washed successively with H20 (50 mL), 1M HC1 (2 x 50 mL), H20 (50 mL) and brine (50 mL). After drying (Na2SO4) the solvent was removed under reduced pressure and the residue chromatographed cluting with EtOAc-hexane (20:80-50:50) to separate pure product from the lower fractions (230 mg, 17%).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2,6-Dichloropyrazine, its application will become more common.

Reference:
Patent; CYTOPIA RESEARCH PTY LTD; WO2005/66156; (2005); 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. 21279-62-9, name is 3-Chloropyrazine-2-carboxamide, This compound has unique chemical properties. The synthetic route is as follows., SDS of cas: 21279-62-9

General procedure: The starting compound (1.27 mmol) was treated with 18 aliphatic amines, alicyclic amines or saturated heterocycles containing at least one nitrogen atom (2.54 mmol). Four reactions were completed by conventional heating methods. The conditions were 110 C, toluene as a solvent and pyridine (1.27 mmol) as a base. The reaction time was set to one hour. Then the reactions were completed using the microwave reactor with focused field and conditions used for syntheses were 140 C, 30 min,120 W, methanol used as a solvent and pyridine (1.27 mmol) as a base. They were set experimentally with respect to prior experience. The progress of reaction was monitored with TLC in system hexane/ethyl acetate (1:1). Then the mixture was separated by flash column chromatograph using gradient elution. Mobile phases were hexane and ethyl acetate again.

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 21279-62-9.

Reference:
Article; Jandourek, Ondrej; Dolezal, Martin; Kunes, Jiri; Kubicek, Vladimir; Paterova, Pavla; Pesko, Matus; Buchta, Vladimir; Kralova, Katarina; Zitko, Jan; Molecules; vol. 19; 7; (2014); p. 9318 – 9338;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem