Tag: M.W=100-200

Electric Literature of 63286-28-2,Some common heterocyclic compound, 63286-28-2, name is 2-Chloro-3-hydrazinylpyrazine, molecular formula is C4H5ClN4, 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.

(2) To a 100 mL eggplant flask were added the above slightly red oil of (S)-2-methylpiperidine-1-carbonylchloride (0.53 g), diisopropylethylamine (1.57 mL), and dichloromethane (20 mL), 2-chloro-3-hydrazinylpyrazine (0.44 g) was added thereto under argon gas flow with stirring at room temperature, and the resulting mixture was stirred at the same temperature for 24 hours. After the reaction was completed, water was added thereto, and the resulting mixture was extracted with dichloromethane. The resulting organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The resulting residues were subjected to Moritex medium pressure preparative (Purif-Pack, SI size 20 (10 g), hexane:ethyl acetate=70:30 to 0:100), the fractions comprising the title compound were collected, concentrated under reduced pressure, ethyl acetate and diisopropyl ethyl ether were added thereto, the precipitated solid was collected by filtration, and washed with diisopropyl ethyl ether to give the title compound (23.7 mg) (yield 2.9%) as a colorless solid. MS(DUIS) m/z: 270/272 [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 2-Chloro-3-hydrazinylpyrazine, its application will become more common.

Reference:
Patent; MITSUBISHI TANABE PHARMA CORPORATION; UBE INDUSTRIES, LTD.; NAKAJIMA, Tatsuo; HAYASHI, Norimitsu; ISHIZAWA, Kouhei; TSUZAKI, Yasunori; IWAMURA, Ryo; TSUBOIKE, Kazunari; US2019/185479; (2019); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 71257-38-0, 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. 71257-38-0 name is 1,2,3,4-Tetrahydropyrrolo[1,2-a]pyrazine, 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.

To a solution of 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (4.68 mmol) and 1,2,3,4-tetrahydro-pyrrolo[1,2-a]pyrazine (3.9 mmol) in methanol (15 ml) there was added, under nitrogen, at 25 C., a catalytic amount of acetic acid, followed by sodium cyanoborohydride (2.5 eq.). The resulting solution was stirred for 16 h at that temperature until the reaction was complete (TLC monitoring). Ice was added to the reaction mixture, and then concentration in vacuo was carried out. The residue was taken up in dichloromethane (100 ml) and washed with saturated sodium bicarbonate solution and with saturated sodium chloride solution. The organic phase was dried (Na2SO4), filtered, and concentrated in vacuo. The crude product so obtained was used directly in the following synthesis step. Yield: 40%.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 1,2,3,4-Tetrahydropyrrolo[1,2-a]pyrazine, and friends who are interested can also refer to it.

Reference:
Patent; Gruenenthal GmbH; US2008/153843; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 32974-92-8, The chemical industry reduces the impact on the environment during synthesis 32974-92-8, name is 1-(3-Ethylpyrazin-2-yl)ethanone, I believe this compound will play a more active role in future production and life.

(1) 10 mmol of 2-acetyl-3-ethylpyrazine was dissolved in 20 ml of methanol,Stirring at 60 C for 15 min to prepare a solution;(2) taking 10 mmol of 4-methylthiosemicarbazide dissolved in 20 ml of methanol,The solution prepared in the step (1) is dropwise added to a methanol solution containing 4-methylthiosemicarbazide, and the reaction mixture is stirred under reflux at 60 C for 24 hours to obtain a pale yellow precipitate.After the reaction, the mixture was cooled to room temperature, poured into a beaker and evaporated, and the resulting precipitate was filtered.Wash 3 times with absolute ethanol,After drying, the ligand L2 is obtained;Yield: 86.7%,

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, 1-(3-Ethylpyrazin-2-yl)ethanone, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Guangxi Normal University; Yang Feng; Cai Meiling; Li Wenjuan; Liang Hong; (15 pag.)CN109796497; (2019); A;,
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. 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows., SDS of cas: 36070-80-1

Oxalyl chloride (1.55 ml, 17.48 mmol), followed by DMF (2 drops), was added to a mixture of 5-chloropyrazine-2-carboxylic acid (2.31 g, 14.57 mmol) in DCM (40 ml). The reaction was stirred at RT for 2 hours after which time the volatiles were removed in vacuo. The residue was taken up DCM (40 ml) and azetidine (1.08 niL, 16.03 mmol) and triethylamine (4.46 ml, 32.06 mmol) added. The mixture was stirred at RT for 72 hours. The volatiles were removed in vacuo and ethyl acetate (100 ml) added to the residue. The organics were washed with water (100 ml), citric acid (50 ml), saturated sodium bicarbonate solution (50 ml), brine (50 ml), dried (MgSO4), filtered and the solvent removed in vacuo to give a yellow solid. The residue was chromatographed on silica, EPO eluting with a gradient of 50 -100% ethyl acetate in o-hexane, to give the desired compound as a yellow solid (2.38 g), 1H NMR delta (CDCl3): 2.35 – 2.42 (2H, m), 4.26 (2H, t), 4.67 (2H, t), 8.52 (IH, d), 9.09 (IH, d); m/z 198 (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 36070-80-1.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2006/125958; (2006); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 41110-33-2, name is Methyl 5-methylpyrazine-2-carboxylate, 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 41110-33-2, name: Methyl 5-methylpyrazine-2-carboxylate

EXAMPLE 3 The reaction is carried out, under nitrogen, in a 1 L¡Á4 neck flask equipped with a mechanical stirrer, water condenser (with gas inlet), and a thermocouple. The reactor is charged with 5-methylpyrazinecarboxylic acid, methyl ester (20.00 g), and methylene chloride (90 g). A solution of OXONE (84.67 g) in water (335 g) is added, and the mixture is vigorously stirred for 68 h at room temperature. The layers are separated, the organic layer is dried over magnesium sulfate, and gravity filtered. The aqueous layer is extracted with methylene chloride (3¡Á135 g). Each extract is poured through the filter containing the magnesium sulfate from above. The extracts are combined and the solvent is removed by distillation at 55 C. Residual solvent is removed under vacuum (25 inches of Hg at 55 C.) yielding 15.39 g (70%) of the n-oxide as an off-white solid).

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; ISP INVESTMENTS INC.; US2005/239803; (2005); 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. 19838-07-4, name is 3-Methylpyrazin-2(1H)-one, A new synthetic method of this compound is introduced below., Safety of 3-Methylpyrazin-2(1H)-one

To a solution of 3-methylpyrazin-2-ol (1.5 g, 13.62 mmol) in anhydrous DMF (20 mL) was added N-bromosuccinimide (2.67 g, 14.98 mmol) at 0 C. The reaction mixture was slowly warmed to room temperature and stirred overnight. The resulting mixture was poured into water, and extracted with IPA/DCM (1/5). The combined organics were dried over anhydrous Na2S04, filtered then concentrated. The residue was purified by column chomatography with 80% ethyl acetate/hexanes to give the title compound as white solid (1.97 g, 10.42 mmol, 77% yield).Exact mass calculated for C5H5BrN20: 188.0, found: LCMS m/z = 189.0 [M+H]+; lU NMR (400 MHz, DMSO-i ) delta ppm 2.27 (d, J = 0.5 Hz, 3H), 7.73 (s, 1H), 12.3 (s, 1H).

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; ARENA PHARMACEUTICALS, INC.; JONES, Robert M.; HAN, Sangdon; BUZARD, Daniel J.; LEHMANN, Juerg; NARAYANAN, Sanju; YUE, Dawei; WO2011/127051; (2011); A1;,
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 875781-43-4 as follows. Quality Control of 2-Bromo-5H-pyrrolo[2,3-b]pyrazine

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).

According to the analysis of related databases, 875781-43-4, the application of this compound in the production field has become more and more popular.

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

Application of 939412-86-9,Some common heterocyclic compound, 939412-86-9, name is (3-Chloropyrazin-2-yl)methanamine hydrochloride, molecular formula is C5H7Cl2N3, 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.

To a solution of (3S,7R,9aS)-3-methyl-4-oxooctahydropyrido[2,l- c][l ,4]oxazine-7-carboxylic acid (55 mg, 0.26 mmol) in anhydrous DCM (1 mL) was added oxalyl dichloride (0.068 mL, 0.77 mmol) in DCM (0.5 mL) at 0C under N2 atmosphere, and followed by 1 drop of DMF. The resulting mixture was stirred at 0C for 2 hrs. The reaction mixture was evaporated, dissolved with DCM (0.5 mL), and added to a solution of (3-chloropyrazin-2-yl)methanamine hydrochloride (56.1 mg, 0.31 mmol), and triethylamine (0.079 mL, 0.57 mmol) in DCM (1 mL), at 0C under N2 atmosphere, and the mixture was stirred for 12 hrs at 15 C.Then the mixture was diluted with DCM (5 mL), and H20 (5 mL). The organic layer was washed with brine (5 mL), dried over Na2S04, evaporated to get the crude product, which was then purified by prep-TLC (PE/THF=1 : 1) to give (3S,7R,9aS)-N-((3-chloropyrazin-2- yl)methyl)-3-methyl-4-oxooctahydropyrido[2, 1 -c] [ 1 ,4]oxazine-7-carboxamide (55 mg, yield: 62.9 %). 1H NMR (400MHz, CDC13) delta = 8.42 (d, J=2.5 Hz, IH), 8.29 (d, J=2.5 Hz, IH), 7.17 (br. s., IH), 4.76 – 4.57 (m, 2H), 4.16 (q, J=6.9 Hz, IH), 3.92 (dd, J=4.1 , 12.2 Hz, IH), 3.74 (dd, J=2.5, 12.0 Hz, IH), 3.37 – 3.25 (m, IH), 2.73 (t, J=12.3 Hz, IH), 2.42 (tt, J=4.0, 1 1.8 Hz, IH), 2.18 – 2.03 (m, 2H), 1.99 – 1.84 (m, IH), 1.79 – 1.68 (m, 2H), 1.44 (d, J=7.0 Hz, 3H).

The synthetic route of 939412-86-9 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MERCK SHARP & DOHME CORP.; WU, Hao; KIM, Ronald M.; LIU, Jian; GAO, Xiaolei; BOGA, Sobhana Babu; GUIADEEN, Deodialsingh; KOZLOWSKI, Joseph; YU, Wensheng; ANAND, Rajan; YU, Younong; SELYUTIN, Oleg B.; GAO, Ying-Duo; LIU, Shilan; YANG, Chundao; WANG, Hongjian; WO2014/114185; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 22047-25-2, 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.

To a solution of 5-methyl-2-furaldehyde (24.59 mmol) and 2-acetylpyrazine (24.59 mmol)was added 20 mL of ethanol. The mixture was dissolved first before addition of 2% ethanolicKOH (9.63 mL) at 0C and stirred for 24 hr at 25C. After the completion of reaction wasmonitored by TLC, crushed ice was added to the reaction mixture. The precipitate formedwas filtered, washed with cold water, dried, and recrystallized by absolute ethanol. of 3-(5-methylfuran-2-yl)-1-(pyrazin-2-yl)prop-2-en-1-one (5) Yellow crystal (77.4% yield) m.p. 113.4-115.7C, IR (cm-1): 3104 (C-H aromatic), 2923 (CHaliphatic), 1662 (C=O), 1598 (C=C olefinic), 1558 and 1518 (C=C aromatic). 1H NMR(400 MHz, CDCl3): Table 1); 13C NMR (100 MHz, CDCl3): Table 1; Found (ESI): 215.0815[M+ H+], (C12H11N2O2 requires 215.0821).

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, Acetylpyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Article; Mokhtar, Zakiah; Jamalis, Joazaizulfazli; Bohari, Siti Pauliena Mohd; Rosli, Mohd Mustaqim; Fun, Hoong-Kun; Molecular Crystals and Liquid Crystals; vol. 631; 1; (2016); p. 119 – 131;,
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. Application In Synthesis of 5,6,7,8-Tetrahydroimidazo[1,2-a]pyrazine

5.6.7.8-Tetrahydroimidazo[1 ,2-a]pyrazine(l17) (620 mg, 3.07 mmol) and diethylaminomethyl polystyrene (3071 mg, 9.83 mmol) were slurried in dichloromethane (DCM) (20 ml_). 2-Chloro-4-fluorobenzoyl chloride (622 mg, 3.22 mmol, commercially available from e.g. Sigma-Aldrich, Maybridge or Fluorochem) was added and the slurry stirred at 25 0C for 3 h. The resin was removed by filtration, washed with dichloromethane (50 ml) and the filtrate concentrated in vacuo to afford a crude oil. The crude product was purified by flash chromatography (Isolera, 100 g, 0-100% 2M ammonia in methanokdichloromethane (1 :9)/dichloromethane) to afford product. This was further purified by flash chromatography (Isolera, 50 g, 0-100% methanokdichloromethane (1 :9)/dichloromethane), to afford product. The oil was further purified by MDAP to afford clean product as the formate salt. The solid was loaded on to an SCX cartridge (Varian, 5g) and washed with methanol. The product was eluted with 2M ammonia methanol and the filtrate concentrated to afford desired product in 330 mg as a white solid.LC/MS = 280/282 (M+H)+, retention time = 0.52 minutes (2 minute).

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; GLAXO GROUP LIMITED; DEAN, David Kenneth; MUNOZ-MURIEDAS, Jorge; SIME, Mairi; STEADMAN, Jon Graham Anthony; THEWLIS, Rachel Elizabeth Anne; TRANI, Giancarlo; WALL, Ian David; WALTER, Daryl Simon; WO2010/125101; (2010); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem