Month: May 2021

Synthetic Route of 5780-66-5,Some common heterocyclic compound, 5780-66-5, name is Pyrazine-2-carbaldehyde, molecular formula is C5H4N2O, 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.

Method 54; Pvrazine-2-carboxaldehyde oxime A IN solution of lithium aluminium hydride in THF (73. 8ml, 73.8mmol) was added to a suspension of methyl pyrazine-2-carboxylate (20g, 145mmol) in anhydrous THF (300. 0ml) at-78°C keeping the reaction temperature below-72°C. On completion of addition the reaction mixture was left to stir at-78°C for a further 20 minutes and then quenched with glacial acetic acid (20. 0ml). The resulting mixture was warmed to room temperature and the volatiles removed by evaporation. The residue was dissolved in 3N hydrochloric acid (116ml) and extracted with DCM. The extracts were combined, washed with saturated aqueous sodium hydrogen carbonate solution and the solvent evaporated. The residue was purified by chromatography on silica gel eluting with DCM/diethylether (100: 0 then 80: 20 and then 0: 100) to give pyrazine-2-carboxaldehyde (15.67g, 100percent). This was immediately dissolved in chloroform (200ml) cooled to 0°C and hydroxylamine mono-hydrochloride (11. 02g, 159. 5mmol) and triethylamine (24. 2ml, 117. 4mmol) were added. The reaction mixture was then stirred at ambient temperature for 0.5 hour, and the solvent removed by evaporation. The residue suspended in diethylether (500ml) and the insolubles removed by filtration. The filtrate was evaporated and the residue purified by chromatography eluting with DCM/diethylether (100: 0 then 80: 20 and then 0: 100) to give the title compound (5. 5g, 31percent) as a solid. NMR (DMSO-d6) : 8.15 (s, 1H), 8.62 (dd, 2H), 8. 99 (s, 1H).

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

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2005/40159; (2005); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 14508-49-7, 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. 14508-49-7, name is 2-Chloropyrazine belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below.

General procedure: 2-Aminoethanethiol hydrochloride (1.1-1.2 equiv) was suspended in dry HMPA (1-4 mL). NaH (dry, 95%) (2.4-2.6 equiv) was added portion-wise over 10-20 min while the reaction mixture was cooled in an ice-cold water bath under a nitrogen atmosphere. The mixture was stirred for 10 min at ambient temperature before portion-wise addition of the desired halogenated heterocycle (1.22-17.5 mmol, 1 equiv) over 10 min. The reaction mixture was stirred at ambient temperature for 2 h-2 days. Water was added slowly to quench the reaction then the aqueous layer was extracted with CH2Cl2, and the combined organic extract dried (MgSO4), filtered and solvent removed in vacuo to give the crude product. TLC on silica using CH2Cl2/MeOH/NH3 in MeOH, 9:0.8:0.2 showed the products with Rf values in the range 0.15-0.20.

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

Reference:
Article; Mountford, Simon J.; Campi, Eva M.; Robinson, Andrea J.; Hearn, Milton T.W.; Tetrahedron; vol. 67; 2; (2011); p. 471 – 485;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

870787-06-7, name is 3-(Trifluoromethyl)pyrazine-2-carboxylic acid, 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. Recommanded Product: 3-(Trifluoromethyl)pyrazine-2-carboxylic acid

Example 2. Production of N-[2-(2,4-dichlorophenyl)-1-methylethyl]-2-trifluoromethylpyrazine-3-carboxamide (compound No. 3-43) To a solution of 2-trifluoromethylpyrazine-3-carboxylic acid (0.25 g, 1.3 mmol), [2-(2,4-dichlorophenyl)-1-methylethyl]amine (0.27 g, 1.3 mmol) and 4-dimethylaminopyridine (0.19 g, 1.6 mmol) in chloroform (10 ml) was added 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (0.3 g, 1.6 mmol) and the mixture was stirred at room temperature for 12 hrs. After adding water and chloroform, the mixture was partitioned, and the organic layer was washed successively with water and saturated brine and dried over anhydrous sodium sulfate. The mixture was concentrated under reduced pressure and the residue was purified by silica gel column chromatography (hexane:ethyl acetate=2:1) to give a desired compound (yield; 0.31 g, 63%). property; melting point 163-164C

The synthetic route of 870787-06-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; NIHON NOHYAKU CO., LTD.; EP1997800; (2008); 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 113305-94-5 as follows. Recommanded Product: 5-Aminopyrazine-2-carbonitrile

Into a flask, purged with an inertatmosphere of nitrogen, was placed 5-aminopyrazine-2-carbonitrile (0.69 ml, 8.33mmol) and EtOH (36.2 ml). To this was added 2-bromo-1 ,1-diethoxyethane (2.58 ml, 16.6 mmol) and HBr in water (6.59 mL, 58.3 mmol). The mixture was warmed at 85C for 4 h. Upon completion, the reaction was diluted with EtOAc (50 mL), cooled to 0C, and slowly quenched with satd. aq. NaHCO3 until the pH was adjusted to 9. Theresulting solution was extracted with EtOAc (3x), and the organic layers were combined and dried over anhyd. Na2SO4. The solid was filtered, and the filtrate was concentrated in vacuo to dryness. The crude mixture was triturated with DCM:hexanes (1:1). The liquid was decanted and the solid was dried to afford the title compound.

According to the analysis of related databases, 113305-94-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; MERCK SHARP & DOHME CORP.; GARFUNKLE, Joie; ORNOSKI, Olga; PARKER, Dann, L., Jr.; RAGHAVAN, Subharekha; XU, Libo; YANG, Zhiqiang; (96 pag.)WO2016/191335; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 4744-50-7,Some common heterocyclic compound, 4744-50-7, name is 2,3-Pyrazinecarboxylic anhydride, molecular formula is C6H2N2O3, 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.

In a 100 mL flask, 2,3-pyrazinedicarboxylic anhydride 12 (0.7505 g, 5 mmol) was reacted with 2 (1.0511 g, 5 mmol) in dry THF (10 mL) stirred overnight at rt. The mixture was transferred to a separatory funnel and extracted with CH 2 Cl 2 (3 x 10 mL) and NaOH (1N) (10 mL). The organic phase was separated and HCl (1N) (10 mL) was added to the aqueous phase until a pH=2 was reached and a precipitate formed. The solid was filtered and washed with water (20 mL), and concentrated under reduced pressure to provide 13 (1.73 g, 4.8 mmol, 96%), as a yellow solid. 1 H NMR (400 MHz, DMSO-d 6 ) delta 1.33 (3H, t, J = 7.02 Hz), 2.51 (4H, d, J = 1.59 Hz), 4.46 (2H, q, J = 7.01 Hz), 7.21 (1H, t, J = 7.52 Hz), 7.47 (1H, t, J = 7.66), 7.59 (1H, d, J = 4.10 Hz), 7.61 (1H, d, J = 3.48 Hz), 7.73 (1H, d, J = 7.27 Hz), 8.58 (1H, s), 8.63 (2H, s); 13 C NMR (100 MHz, DMSO-d 6 ) delta 14.2, 37.5, 109.4, 109.7, 110.95, 119.1, 119.7, 120.6, 122.3, 122.6, 126.2, 131.8, 136.8, 140.5, 141.8, 144.8, 145.8, 164.3. LC/MS (ESI) m/z 361.1292 [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 2,3-Pyrazinecarboxylic anhydride, its application will become more common.

Reference:
Article; Vlaar, Cornelis P.; Castillo-Pichardo, Linette; Medina, Julia I.; Marrero-Serra, Cathyria M.; Velez, Ericka; Ramos, Zulma; Hernandez, Eliud; Bioorganic and Medicinal Chemistry; vol. 26; 4; (2018); p. 884 – 890;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 16298-03-6, The chemical industry reduces the impact on the environment during synthesis 16298-03-6, name is Methyl 2-aminopyrazine-3-carboxylate, I believe this compound will play a more active role in future production and life.

A solution of methyl 3-aminopyrazine-2-carboxylate (3.0 g, 19.6 mmol) and BS (3.5 g, 23.5 mol) in MeCN (70 mL) was stirred at 70C for 5 h. Then the mixture was concentrated and extracted with EtOAc. The organic layer was washed with a2S03 (a.q.) and brine, dried over Na2S04 and concentrated in vacuo. The crude product of methyl 3-amino-6- bromopyrazine-2-carboxylate (3.0 g, yield: 92%) was used for next step without further purification. -NMR (CDC13, 400 MHz) delta 8.18 (s, 1H), 6.54-6.93 (m, 2H), 3.86 (s, 3H). MS (M+H)+: 232 / 234.

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, Methyl 2-aminopyrazine-3-carboxylate, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; MERCK SHARP & DOHME CORP.; DAI, Xing; LIU, Hong; PALANI, Anandan; HE, Shuwen; NARGUND, Ravi; XIAO, Dong; ZORN, Nicolas; DANG, Qun; MCCOMAS, Casey, C.; PENG, Xuanjia; LI, Peng; SOLL, Richard; WO2014/209727; (2014); 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. 27398-39-6, name is 3-Chloropyrazine-2-carboxylic acid, This compound has unique chemical properties. The synthetic route is as follows., SDS of cas: 27398-39-6

3-Cl-POA (1.0 g, 6.3 mmol) was dispersed in dry toluene (approx. 50 mL) with thionyl chloride (1.4 mL, 18.9 mmol, 3 equiv.) and a catalytic amount (1-2 drops) of N,N-dimethylformamide (DMF). The reaction mixture in round bottomed flask was stirred and heated in an oil bath under a condenser at 95 °C for approximately 1 h. Solvents were evaporated in vacuo and the residue was azeotroped with dry toluene (3 × 20 mL) to remove the unreacted SOCl2 to yield crude acyl chloride [43] as brown solid, which was used without further purification.

According to the analysis of related databases, 27398-39-6, the application of this compound in the production field has become more and more popular.

Reference:
Article; Semelkova, Lucia; Konecna, Klara; Paterova, Pavla; Kubicek, Vladimir; Kunes, Jiri; Novakova, Lucie; Marek, Jan; Naesens, Lieve; Pesko, Matus; Kralova, Katarina; Dolezal, Martin; Zitko, Jan; Molecules; vol. 20; 5; (2015); p. 8687 – 8711;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 16298-03-6, 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 16298-03-6 as follows.

1.5 equivalents of N-iodosuccinimide are added at room temperature to 5 g (32.7 mmol) of a methyl 3-aminopyrazine-2-carboxylate solution in 25 ml of dimethylformamide. The reaction medium is heated at 65C for 1 hour, added together with 0.5 equivalents of N-iodosuccinimide and maintained at 65C for 24 hours. After returning to room temperature, the solvent is evaporated and then the product is extracted several times with dichloromethane. The organic phases are combined, washed with 10% sodium bisulfite solution, dried on magnesium sulfate and concentrated to yield 8 g (88%) of methyl 3-amino-6-iodopyrazine-2-carboxylate in the form of a yellow solid. LCMS (EI, m/z): (M+1) 280 1H NMR: deltaH ppm (400 MHz, DMSO): 8.50 (1H, s, CHarom), 7.50 (2H, bs, NH2), 3.20 (3H, s, CH3)

According to the analysis of related databases, 16298-03-6, the application of this compound in the production field has become more and more popular.

Reference:
Patent; PIERRE FABRE MEDICAMENT; Sokoloff, Pierre; Cachoux, Frederic; EP2689778; (2014); 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 41270-66-0 as follows. Computed Properties of C16H11ClN2

In one embodiment of the preparation method of the sirepag intermediate of the present invention, the preparation method of the siriparg intermediate according to the present embodiment is: in a reaction bottle equipped with a reflux tube, a drying tube and a thermometer, adding 5- Chloro-2,3-diphenylpyrazine (30.0 g, 0.11 mol, 1.0 eq.), 4-(isopropylamino)-1-butanol (18.5 g, 0.14 mol, 1.25 eq.), 1, 4-Dioxane 150 mL, stir and dissolve, and then add Pd (dba)2(2.4g, 4.2mmol), P(o-tolyl)3(1.69 g, 8.3 mmol), sodium tert-butoxide (13.0 g, 0.135 mol), heated to 120 C., and incubated for 1.8 hours. The reaction was complete by TLC and the reaction was stopped.The mixture was cooled to room temperature and filtered. The filtrate was adjusted to pH 6.5-7.5 with 1N hydrochloric acid, extracted with ethyl acetate (150 mL x 2), washed with 150 mL of brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure with the residue being ethanol: The mixture was recrystallized with 300 mL of n-hexane = 1:15 mixed solvent and dried in an oven to obtain 39.0 g of a white solid. The yield was 96%, and the liquid purity was 97.1%.

According to the analysis of related databases, 41270-66-0, the application of this compound in the production field has become more and more popular.

Reference:
Patent; Guangdong Saifeng Pharmaceutical Technology Co., Ltd.; Feng Wenzhou; Chen Rongmin; Ding Xiaoming; Zheng Yuchun; Bao Changxiao; Gong Zihua; (9 pag.)CN107652243; (2018); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 74290-65-6, 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 74290-65-6 as follows.

To 3-bromo-5-methylpyrazin-2-amine (850 mg,4.52 mmol) was added ethoxycarbonyl isothiocyanate (0.51ml., 4.52 mmol) followed by toluene (1 mL). The mixturewas placed in a preheated 100 C. oil bath, and within aminute, all the solids had dissolved. After 15 min, all hadseized to a solid mass. After an additional 15 minutes, methanol(-5 mL) was added and the mixture refluxed to digest thesolids. The mixture was cooled to rt after 5 minutes and thesolids collected by filtration, washing with methanol to giveethyl 6-methylthiazolo[5,4-b]pyrazin-2-ylcarbamate (680mg, 2.85 mmol, 63.1% yield).

According to the analysis of related databases, 74290-65-6, the application of this compound in the production field has become more and more popular.

Reference:
Patent; BRISTOL-MYERS SQUIBB COMPANY; COOK II, JAMES H; MCDONALD, IVAR M; KING, DALTON; OLSON, RICHARD E; WANG, NENGHUI; IWUAGWU, CHRISTIANA I; ZUSI, F.CHRISTOPHER; MACOR, JOHN E; (330 pag.)JP5714745; (2015); B2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem