Tag: M.W=100-200

A common heterocyclic compound, 33332-25-1, name is Methyl 5-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. 33332-25-1.

A round bottomed flask was charged with methyl2-chloropyrazine-5-carboxylate (Lonza, 4.83 g, 28 mmol), 1 -Boc-2(S)-ethyl- 5(R)-methylpiperazine free base (6.4 g, 28 mmol), cesium carbonate (Aldrich, 14 g, 42 mmol) and 1 ,4 dioxane (100 ml). The resulting suspension was stirred at 100 0C for 2 d and then filtered. The solid was washed with ethyl acetate (3X400 ml). The combined organic solutions were concentrated on a rotary evaporator to remove the solvent. The residue was purified by flash chromatography on silica gel using 1 % methanol (containing 10% ammonium hydroxide) in dichloromethane as an eluent to provide A21 (9.0 g, 90%), as a beige solid

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

Reference:
Patent; SCHERING CORPORATION; PHARMACOPEIA DRUG DISCOVERY, INC.; WO2006/91428; (2006); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

19745-07-4, 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. 19745-07-4, name is 2,5-Dichloropyrazine, A new synthetic method of this compound is introduced below.

2-(4-Benzyloxyphenyl)-5-(6-octyloxypyridin-3-yl)pyrazine STR50 Step 1 In accordance with scheme C-I, 30 g (201 mmol) of 2,5-dichloropyrazine and 45.92 g (201 mmol) of 4-benzyloxyphenylboronic acid are coupled analogously to Example 4a to give 2-chloro-5-(4-benzyloxyphenyl)pyrazine.

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:
Patent; Hoechst Aktiengesellschaft; US5512207; (1996); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-25-1, Adding some certain compound to certain chemical reactions, such as: 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate, 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 33332-25-1.

a) 5-r3-(4-Fluoro-phenyl)-5-methyl-3H-ri,2,31triazol-4-ylmethoxyl-pyrazine-2-carboxylic acid methyl esterTo a suspension of NaH (55% in oil, 116 mg, 2.7 mmol) in THF (4 mL) was added a solution of [3-(4-fluoro-phenyl)-5-methyl-3H-[l,2,3]triazol-4-yl]-methanol (500 mg, 2.4 mmol) in THF (6 mL) dropwise at 0 C and the reaction mixture was stirred at room temperature for 30 min. Then a solution of methyl 5-chloropyrazine-2-carboxylate (460 mg, 2.65 mmol) in THF (6 mL) was added dropwise at 0 C and the reaction mixture was stirred at room temperature for 16 h. The mixture was then poured into ice water and extracted with ethyl acetate and the combined organic extracts washed with brine, dried over sodium sulphate, filtered and evaporated.Purification by chromatography (silica, 0 to 50% ethyl acetate in heptane, then 0 to 5% methanol in dichloromethane) afforded the title compound (787 mg, 95%) as a white solid. MS: m/e = 344.3 [M+H]+.

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 33332-25-1.

Reference:
Patent; F. HOFFMANN-LA ROCHE AG; HERNANDEZ, Maria-Clemencia; LUCAS, Matthew C.; THOMAS, Andrew; WO2012/62687; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 5521-58-4, name is 5-Methylpyrazin-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. 5521-58-4

l-Chloro-N,N,2-trimethyl-l-propenylamine (0.11 mL, 0.80 mmol) was added to a solution of 3-{ [6-(azetidin- 1 -ylcarbonyl)pyridin-3-yl]oxy }-5-[((15)-2-{ [(1 , 1- dimethylethyl)(dimethyl)silyl]oxy}-l-methylethyl)oxy]benzoic acid (0.3 g, 0.62 mmol) in DCM (10 mL) and stirred for 1 hour. 2-Amino-5-methylpyrazine (135 mg, 1.23 mmol), then pyridine (0.1 mL, 1.23 mmol), were added and the mixture stirred for a further 30 mins before being reduced in vacuo and partitioned between ethyl acetate (50 mL) and water (50 mL). The aqueous layer was further extracted into ethyl acetate (50 mL) and the combined organics washed with water (50 mL), brine (50 mL), dried (MgSO4), filtered and reduced in vacuo. The crude oil was chromatographed on silica, eluting with 40-100% ethyl acetate in isohexane, to give the desired compound as a colourless oil (82 mg). 1H NuMR delta (CDCl3): 0.00 (s, 3H), 0.03 (s, 3H), 0.83 (s, 9H), 1.28 (d, 3H), 2.32 (quin, 2H), 2.53 (s, 3H), 3.64 – 3.77 (m, 2H), 4.22 (t, 2H), 4.47 – 4.51 (m, IH), 4.68 (t, 2H), 6.81 (t, IH), 7.10 (t, IH), 7.27 (t, IH), 7.33 – 7.35 (m, IH), 8.08 – 8.11 (m, 2H), 8.30 (d, IH), 8.37 (s, IH), 9.50 (d, IH); m/z 578 (M+H)+

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 5521-58-4.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2007/7041; (2007); 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. 27825-20-3, name is Methyl 3-Hydroxy-2-pyrazinecarboxylate, This compound has unique chemical properties. The synthetic route is as follows., 27825-20-3

1.52 g of methyl 3-hydroxy-2-pyrazinecarboxylate was suspended in 12.2 mL of 1,1,1,3,3,3-hexamethyldisilazane, and the suspension was heated under reflux for 1 hour. After standing to cool, the solvent was removed under reduced pressure, and the obtained residue was dissolved in 30 mL of dichloroethane under nitrogen atmosphere. 4.98 g of beta-D-ribofuranose-1-acetate-2,3,5-tribenzoate and 1.73 mL of tin(IV) chloride were successively added thereto, and the mixture was further stirred at room temperature for 14 hours. The reaction mixture was diluted with 30 mL of chloroform and 30 mL of a saturated sodium bicarbonate aqueous solution, and the precipitate was removed by filtration, so that the organic layer was obtained. The obtained organic layer was successively washed with water and then with a saturated saline solution. Thereafter, the layer was dried with anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography [eluant; n-hexane : ethyl acetate = 1 : 1], so as to obtain 3.4 g of a white solid, methyl 4-{(2R, 3R, 4R, 5R)-3,4-bis(benzoyloxy)-5-[(benzoyloxy)methyl]tetrahydro-2-furanyl}-3-oxo-3,4-dihydro-2-pyrazinecarboxylate. IR(KBr)cm-1: 1734, 16601H-NMR(CDCl3)delta: 3.96(3H,s), 4.71(1H,dd,J=4.0,12.4Hz), 4.8-4.9(2H,m), 5.8-5.9(2H,m), 6.45(1H,d,J=4.0Hz), 7.34(1H,d,J=4.2Hz), 7.3-7.6(9H,m), 7.70(1H,d,J=4.2Hz), 7.9-8.0(4H,m), 8.0-8.1(2H,m); Reference Example 20 [136.1] 50 mg of methyl 3-hydroxy-2-pyrazinecarboxylate was suspended in 1.6 mL of 1,1,1,3,3,3-hexamethyldisilazane, and the solution was heated under reflux for 1 hour under nitrogen atmosphere. After standing to cool, the solvent was removed under reduced pressure, and an acetonitrile solution containing 0.17 g of (2S, 3R, 4R, 5R)-2-(acetyloxy)-4-(benzoyloxy)-5-[2-(diethoxyphosphoryl)ethyl]tetrahydro-3-furanyl benzoate was added thereto. Thereafter, the solvent was removed under reduced pressure. The obtained residue was suspended in 2.00 mL of acetonitrile under nitrogen atmosphere, and thereafter, 67 muL of tin(IV) chloride was added thereto under ice cooling, followed by leaving at room temperature for 24 hours. 300 mg of methyl 3-hydroxy-2-pyrazinecarboxylate was treated in the same above manner, and the obtained reaction mixture was poured into a mixed solution of 50 mL of ethyl acetate, 50 mL of ice and 100 mL of a saturated sodium bicarbonate aqueous solution. The precipitate was removed by filtration, the organic layers were separated, and the aqueous layer was extracted with 50 mL of ethyl acetate. The organic layers were combined, and the obtained organic layers were washed with a saturated saline solution and then dried with anhydrous magnesium sulfate. The solvent was then removed under reduced pressure. The obtained residue was purified by silica gel column chromatography [eluant; ethyl acetate : methanol = 100 : 1], so as to obtain 0.76 g of a colorless oil product, methyl 4-{(2R, 3R, 4R, 5R)-3,4-bis(benzoyloxy)-5-[2-(diethoxyphosphoryl)ethyl]tetrahydro-2-furanyl}-3-oxo-3,4-dihydro-2-pyrazinecarboxylate. IR(neat)cm-1: 1734, 16701H-NMR(CDCl3)delta: 1.3-1.35(6H,m), 1.85-2.3(4H,m), 3.97(3H,s), 4.05-4.2(4H,m), 4.45-4.55(1H,m), 5.65(1H,t,J=6.5Hz), 5.74(1H,dd,J=3.6,5.9Hz), 6.24(1H,d,J=3.6Hz), 7.3-7.4(4H,m), 7.5-7.6(4H,m), 7.85-7.95(4H,m).

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:
Patent; TOYAMA CHEMICAL CO., LTD.; EP1417967; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Some common heterocyclic compound, 113305-94-5, name is 5-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. 113305-94-5

EXAMPLE 1E N-(2-{[tert-butyl(dimethyl)silyl]oxy}-5-chlorophenyl)-N’-(5-cyano-2-pyrazinyl)urea A mixture of Example 1B (0.84 g, 7 mmol) and Example 1D (2.0 g, 7.06 mmol) in toluene (20 mL) was heated to reflux for 48 hours, cooled to room temperature, and filtered. The filter cake was washed with hexanes (2*10 mL) to provide 1.66 g (58.5%) of the desired product. MS (ESI(-)) m/z 402 (M-H)-; 1H NMR (500 MHz, DMSO-d6) delta 10.99 (s, 1H), 9.33 (s, 1H), 9.00 (d, J=1.3 Hz, 1H), 8.82 (d, J=1.36 Hz, 1H), 8.07 (d, J=2.7 Hz, 1H), 7.07 (dd, J=2.7 and 8.8 Hz, 1H), 6.97 (d, J=2.71 Hz, 1H), 0.98 (s, 9H), 0.32 (s, 6H).

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

Reference:
Patent; Li, Goaquan; Li, Qun; Li, Tongmei; Lin, Nan-Horng; Mantei, Robert A.; Sham, Hing L.; Wang, Gary T.; US2004/34038; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

33332-25-1, 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. 33332-25-1, name is Methyl 5-chloropyrazine-2-carboxylate belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

3-Chloro-4,5-dimethyl-6-((R)-3-methyl-piperazin-1-yl)-pyridazine (1.20 g, 4.88 mmol), 5-chloro-pyrazine-2-carboxylic acid methyl ester (946 mg, 5.37 mmol), triethylamine (3.40 mL, 24.4 mmol), and 1,4-dioxane (10 mL) are combined in a 100 mL round-bottom flask fitted with a reflux condenser and heated to 80 C. for 24 h. The reaction is then allowed to cool to room temperature and stirred for 48 h. A beige solid precipitates during this time which is isolated by filtration, rinsing with H2O. The precipitate is dried in vacuo to afford the title compound (1.30 g, 71%).MS (m/z, MH+) meas. 377.3.

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

Reference:
Patent; Novartis AG; US2010/41663; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

274-79-3,Some common heterocyclic compound, 274-79-3, name is Imidazo[1,2-a]pyrazine, molecular formula is C6H5N3, 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.

Imidazo[1,2-a]pyrazine (420 mg, 3.53 mmol) was dissolved in acetonitrile (10 mL).N-bromosuccinimide (691 mg, 3.88 mmol) was added thereto, and the mixture was reacted at room temperature overnight.After the reaction is completed, a saturated sodium hydrogencarbonate solution is added thereto.Extract with dichloromethane, dry the organic phase with anhydrous sodium sulfate, filter, and then dry the solvent.The residue was purified by silica gel column chromatography to give a yellow solid,619mg.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Imidazo[1,2-a]pyrazine, its application will become more common.

Reference:
Patent; Shanghai Pharmaceutical Group Co., Ltd.; Wan Huixin; Li Chunli; Shi Chen; Liu Haiyan; Li Ping; Shen Jingkang; (50 pag.)CN104341425; (2018); B;,
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. 98-97-5, name is Pyrazine-2-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows., 98-97-5

[0535] Synthesis of methyl pyrazine-2-carboxylate: [0536] To a stirred solution of pyrazine-2-carboxylic acid (5 g, 40.29 mmol) in MeOH (20 mL) was added concentrated H2S04 (1 mL) drop-wise and stirred under reflux for 5 h. The reaction mixture was cooled to RT; volatiles were evaporated under reduced pressure. The residue was diluted with water and basified to pH~ 8.5 using NaHC03 and extracted with EtOAc. Combined organic layer was dried over sodium sulphate, filtered and concentrated in vacuo to afford methyl pyrazine-2- carboxylate (3.5 g, 63.63%) as an off-white solid. 1H-NMR (DMSO d6, 400 MHz): delta 9.21 (s, 1H), 8.91 (d, 1H), 8.82 (d, 1H), 3.92 (s, 3H); TLC: 50% EtOAc/Hexane (Rf: 0.4).

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:
Patent; ENVIVO PHARMACEUTICALS, INC.; RIPKA, Amy; SHAPIRO, Gideon; MCRINER, Andrew, J.; BURSAVICH, Matthew, Gregory; WO2013/142269; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

A common heterocyclic compound, 19745-07-4, name is 2,5-Dichloropyrazine, molecular formula is C4H2Cl2N2, 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. 19745-07-4.

Preparation 10 1-Benzoyl-3-{[(5-chloropyrazin-2-yl)oxy]methyl}azetidine-3-carboxylic acid Sodium hydride (95 mg, 2.38 mmol) was added to anhydrous dimethyl sulphoxide (4 mL) at room temperature and stirred, under a nitrogen atmosphere, for 30 minutes. 1-Benzoyl-3-(hydroxymethyl)azetidine-3-carboxylic acid (255 mg, 1.08 mmol) (Preparation 15) in dimethyl sulphoxide (1 mL) was added drop-wise and the resulting mixture was stirred, at room temperature, for 15 minutes. 2,5-Dichloropyrazine (194 mg, 1.3 mmol) was added and the mixture was stirred, at room temperature, for 3 hours. The reaction mixture was diluted with water (15 mL) and washed with diethyl ether (2*15 mL). The aqueous layer was acidified with aqueous hydrochloric acid (2M, 2 mL) and extracted with dichloromethane (2*15 mL). The combined dichloromethane layers were dried over magnesium sulphate and concentrated. The resulting residue was purified by chromatography on silica gel eluding with ethyl acetate:methanol:acetic acid (95:5:1) to give the title compound, as a colourless gum in 80percent yield, 305 mg. 1H NMR (400 MHz, CDCl3) : 4.32 (m, 2H), 4.54 (d, 1H), 4.75 (m, 3H), 7.4-7.56 (m, 3H), 7.65 (d, 2H), 8.04 (s, 1 H), 8.14 (s, 1H); LRMS APCI m/z 348 [MH]+

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

Reference:
Patent; Pfizer Inc; US2008/280877; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem