Month: December 2020

Reference of 78342-42-4, A common heterocyclic compound, 78342-42-4, name is (S)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine, molecular formula is C9H16N2O2, 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.

To a solution of 3.32 g (18 mmol) of commercially available (2S)-2, 5- dihydro-3,6-dimethoxy-2-isopropylpyrazine in 100 mL of tetrahydrofuran at-70 ¡ãC was added 12 mL (19 mmol) of a 1.6M solution of butyllithium in hexanes. After stirring at this temperature for 20 min, 5 g (19.5 mmol) of 2-fluoro-4- trifluoromethylbenzyl bromide in 20 mL of tetrahydrofuran was added and stirring was continued for 3 h before warming the reaction to ambient temperature. The reaction was quenched with water, concentrated in vacuo, and extracted with ethyl acetate. The combined organic phase was washed with brine, dried, and concentrated in vacuo. Purification by flash chromatography (silica gel, 0-5percent ethyl acetate in hexanes) afforded 5.5 g of the title compound. [1H NMR] (500 MHz, [CDCL3)] [8] 7.33- 7.25 (m, 3H), 4.35-4. 31 (m, 1H), 3.75 (s, 3H), 3.65 (s, 3H), 3.60 (t, [1H,] J = 3.4 Hz), 3.33 (dd, 1H, J = 4.6, 13.5 Hz), 3.03 (dd, [1H,] J = 7,13. 5 Hz), 2.25-2. 15 (m, [1H),] 1.0 (d, 3H, J = 7 Hz), 0.66 (d, 3H, J = 7 Hz).

The synthetic route of 78342-42-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MERCK & CO., INC.; WO2004/7468; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 5521-58-4, A common heterocyclic compound, 5521-58-4, name is 5-Methylpyrazin-2-amine, molecular formula is C5H7N3, 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.

3-{[5-(Azetidin-1-ylcarbonyl)pyrazin-2-yl]oxy}-5-[(1S)-2-methoxy-1-methylethoxy]-N-(5-methylpyrazin-2-yl)benzamide To a flask fitted with overhead stirrer, condenser, thermometer and nitrogen line was added 3-{[5-(azetidin-1-ylcarbonyl)pyrazin-2-yl]oxy}-5-[(1S)-2-methoxy-1-methylethoxy]benzoic acid (1.0 eq), and acetonitrile (10 vols) followed by pyridine (3 eq) under a nitrogen atmosphere. Thionyl chloride (1.2 eq) as a solution in acetonitrile (0.225 vols) was added slowly, drop-wise via syringe pump over at least 2 hours. 5-Methylpyrazin-2-amine (1.2 eq) was added to the mixture as a solid. After 2.5 hours the reaction was quenched by adding toluene (10 vols) and 1.0M sodium carbonate solution (2.5 eq). The layers were separated. The organic layer was retained in the flask, then 1.0M hydrochloric acid (1.94 eq) was added. The mixture was agitated for 15 minutes then separated. The organic layer was washed with two aliquots of water (5 vols) then the solvent was removed on the rotary evaporator. Toluene (5 vols) was added to the residue, and warmed to 45 C. Isohexane (1.7 vols) was added, the mixture was seeded, and allowed to cool to ambient temperature overnight. The mixture was cooled to 0 C. for 4 hours, and then cooled to -10 C. for 3 hours. The solid was isolated by filtration then washed with isohexane (2.5 vols). After drying in the vacuum oven at 40 C. overnight, the desired product was obtained as a solid (corrected yield 85%).

The synthetic route of 5521-58-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; AstraZeneca AB; US2010/210621; (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. 54608-52-5, name is 2-Hydrazinopyrazine, This compound has unique chemical properties. The synthetic route is as follows., Formula: C4H6N4

In a 3-L, 3-necked, round-bottomed flask were charged 60.0 gr (Z)-3-(3-(3,5- bis(trifluoromethyl)phenyl)- 1 H- 1,2, 4-triazol- 1 -yl)acrylic acid (SLN- 105, prepared according to examples 27), Ethyl acetate (0.42 lit, 7V) and Acetonitrile (0.3 lit,5V) at 20-25C. Charged 2-hydrazino pyrazine (19.8 gr, 1.05 eq) then cooled to 0 to 5C. Charged EDC .HC1 (1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride) (49. lgr 1 .Seq) at 0 to 5C. The reaction mass was stirred for 3hrs and monitored by HPLC (till SLN-105 NMT 1.0%). Once the reaction completes, charge water (0.2lit, 2V) and stirred for 15-30 mm at 15-20C, settled and separated the organic layer. Collected the organic layer and washed with sodium bicarbonate solution (0.Slit, SV). Finally washed the organic layer with water (0.2lit, 2 V) and combined the collected organic layer containing the product. The solvent is distilled off under vacuum at 50 to 60C for 30 mm. To the obtained solid, added absolute Ethanol (0.6lit, 1OV) and stirred for 30mm at 20-25C then cooled to 0-5C and stirred for 1 hr at 0-5C. Filtered the compound under vacuum at 20-25C and washed with Ethanol (0.2lit, 2V). The wet cake was dried at 55-60C under vacuum (600 to 700 mm Hg) for 4 hrs. (Yield 83%).

According to the analysis of related databases, 54608-52-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; WATSON LABORATORIES INC.; MUTHUSAMY, Anantha Rajmohan; KANNIAH, Sundara Lakshmi; RAVI, Akash; DAS, Tonmoy Chitta; CHEMATE, Rajendra Popat; SINGH, Anil Kumar; WAGH, Yogesh Dhananjay; (60 pag.)WO2018/129227; (2018); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 78342-42-4, A common heterocyclic compound, 78342-42-4, name is (S)-2,5-Dihydro-3,6-dimethoxy-2-isopropylpyrazine, molecular formula is C9H16N2O2, 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 1 Production of (2R,5S)-2-(2-(diethoxy-phosphoryl)ethyl)-2,5-dihydro-3,6-dimethoxy-5-isopropyl pyrazine 0.52 mol of (S)-2,5-dihydro-3,6-dimethoxy-2-isopropyl pyrazine are solved in 400 ml of absolute THF under argon and are cooled to -78¡ã C. Under stirring, 200 ml of a 2.7 M solution of butyl lithium (in heptane) (0.54 mol) are added in drops and slowly. Subse-quently, a solution of 0.52 mol of diethyl-(2-bromoethyl) phosphonate in 300 ml of absolute THF is added in drops and slowly during stirring, and the mixture is stirred for further 3 h at -78¡ã C. Then, 11.7 ml (about 0.2 mol) anhydrous acetic acid are added slowly. The reaction mixture is allowed to warm up slowly to room temperature. The solvent is removed, and the residue is solved in 600 ml of diethyl ether and washed with 200 ml of water. The aqueous phase is still extracted three times with each 100 ml of diethyl ether. The combined ether phases are dried over MgSO4, filtered and the solvent is removed in vacuo. The residue is solved in a mixture of diethyl ether and hexane (1:10) and filtered over a bed of silica gel. Thereby, first it is eluted with diethyl ether and hexane (1:5). Yield: about 70percent of a yellow liquid. 1H-NMR (CDCl3): 0.71, 1.04 (d, 6H, CH(CH3)2), 1.33 (t, 6H, P(O)(OCH2CH3)2), 1.68-2.25 (m, 4H, CHCH2CH2P), 3.65, 3.67 (s, 6H, OCH3), 4.02 (m, 1H), 4.10-4.20 (m, 4H, P(O)(OCH2CH3)2).

The synthetic route of 78342-42-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Lindhorst, Thomas; Werner, Birgit; Bock, Holger; US2010/22478; (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. 69214-33-1, name is 8-Chloroimidazo[1,2-a]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., Recommanded Product: 69214-33-1

A solution of 8chioroimidazo[i,2a1pyrazine (730 mg, 4.8 mrnol) and NCS (955 mg, 7,2mrnol) in MeCN/DCE (10 rnL/5 rnL ) was heated to 90 C overnight. After LCMS indicated thatstarting material disappeared, the mixture was poured into water (20 mL) and extracted with DCM (20 mL x 3). The combined organic layer was washed with water (20 rnL) and brine (20 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo, The residue was purified by chromatography on silica (3% FtOAc in petroleum ether) to give the title compound(700 mg) as a yellow solid. LRMS miz (M+H) 188.1, 190.1 found, 188.1, 190.1 required.

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 69214-33-1.

Reference:
Patent; MERCK SHARP & DOHME CORP.; LIVERTON, Nigel; KUDUK, Scott D.; BESHORE, Doug C.; MENG, Na; LUO, Yunfu; (127 pag.)WO2016/101119; (2016); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Adding a certain compound to certain chemical reactions, such as: 1174321-06-2, name is 5-(Difluoromethyl)pyrazine-2-carboxylic acid, 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 1174321-06-2, Application In Synthesis of 5-(Difluoromethyl)pyrazine-2-carboxylic acid

Step 6: tert-Butyl ((4aS,5SJaS)-7a-(5-(5-(difluoromethyl)pyrazine-2-carboxamido)-2- fluorophenyl)-3-ethyl-4-oxo-5-(trifluoromethyl)-3,4,4a,5JJa-hexahvdrofuror3,4- dlpyrimidin-2-yl)carbamate N-Ethyl-N-(propan-2-yl)propan-2-amine (190 muL, 1.1 mmol) was added to a stirred mixture of tert-butyl ((4aS,5S,7aS)-7a-(5-amino-2-fluorophenyl)-3-ethyl-4-oxo-5- (trifluoromethyl)-3,4,4a,5,7,7a-hexahydrofuro[3,4-d]pyrimidin-2-yl)carbamate (100 mg, 0.21 mmol), 5-(difluoromethyl)pyrazine-2-carboxylic acid (57 mg, 0.33 mmol) and (lH-benzotriazol-l-yloxy)(tripyrrolidin-l-yl)phosphonium hexafluorophosphate (170 mg, 0.33 mmol) in dry DCM (1 mL) at RT under nitrogen. The reaction was stirred at this temperature for 16 h, and then partitioned between DCM and NaHCO3 (aq.). The aqueous layer was extracted with DCM (x2). The combined extracts were dried by passing through a hydrophobic frit and then evaporated. The residue was purified by column chromatography (normal phase, 1Og, Biotage SNAP cartridge KP-SiI, 12mL per min, gradient 5% to 30% EtOAc in n-hexane) to give the title compound (118 mg, cream foam). 1H NMR (400 MHz, CDCl3-d) delta ppm 1.14 (t, J=7.07 Hz, 3H) 1.56 (s, 9H) 3.96 – 4.15 (m, 3H) 4.39 (d, J=9.60 Hz, IH) 4.50 (dd, J=9.73, 2.91 Hz, IH) 4.53 – 4.62 (m, IH) 6.81 (t, J=54.60 Hz, IH) 7.22 (dd, J=10.74, 8.97 Hz, IH) 7.76 (dd, J=6.69, 2.65 Hz, IH) 7.79 – 7.84 (m, IH) 8.93 (s, IH) 9.52 (s, IH) 9.65 (s, IH) 10.64 (s, IH).

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 5-(Difluoromethyl)pyrazine-2-carboxylic acid, and friends who are interested can also refer to it.

Reference:
Patent; EISAI R&D MANAGEMENT CO., LTD; CASTRO PINEIRO, Jose, Luis; HALL, Adrian; MADIN, Andrew; VO, Ngoc-Tri; WO2011/9897; (2011); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 41270-66-0, A common heterocyclic compound, 41270-66-0, name is 5-Chloro-2,3-diphenylpyrazine, molecular formula is C16H11ClN2, 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.

A mixture of 5-Chloro-2,3-diphenyl-pyrazine (10.00 g, 37.5 mmol) and a 70% solution of isopropylamine in water (44.32 g, 74.9 mmol) in isopropanol (100 ml) was heated at 150 C for 24 h in a autoclave with 200-400 psi pressure. The reaction progress was monitored by HPLC and after completion of reaction; resulting mass was cooled to 25-30 C and concentrated. The residue was diluted with water and extracted with dichloromethane, after which the extract was distilled completely to obtain solid (5,6-diphenyl- pyrazin-2-yl)-isopropyl-amine (7.0g, 76%) as pale yellowish solid. [Yleld= 7g]

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; MEGAFINE PHARMA (P) LTD.; MATHAD VIJAYAVITTHAL THIPPANNACHAR; DODDAPPA PRALHAD ANEKAL; KARDILE PRITESH BHIMRAJ; PADAKI SANTHOSH AMBADAS; GAIKWAD BAPUSAHEB SHRIHARI; SHINDE GORAKSHANATH BALASAHEB; (63 pag.)WO2017/42828; (2017); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

762240-92-6, name is 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine hydrochloride, 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. SDS of cas: 762240-92-6

Preparation-1: Preparation of (R)-tert-butyl 4-oxo-4-(3-(trifluoromethyl)-5,6- dihydro-[l,2,4]triazolo[4,3-a]pyrazin-7(8H)-yI)-l-(2,4,5-trifluorophenyl) butan-2-ylcarbamate (0089) In 2 L three necked round bottom flask equipped with mechanical stirrer, thermometer and an addition funnel, were added 400 mL DMF, 100 g (3i?)-N- (tert-butoxycarbonyl)-3-amino-4-(2,4,5-trifluorophenyl) butanoic acid and 72 g 3- (trifluoromethyl)-5,6,7,8-tetrahydro-l,2,4-triazolo-[4,3-a]pyrazine hydrochloride. The reaction mixture was cooled to 0 to 5C and 106 g TBTU was added. 116.3 g DIPEA was added to the reaction mixture and stirred for 1 hour. After the completion of reaction, 1 L water and 600 mL 1% NaHC03 was added. The reaction mixture was stirred for 1 hour at 25C to 35C. The precipitates were filtered and washed with water. The product was dried under vacuum at 60C for 4 hours to obtain 151.9 g of title compound.

The synthetic route of 762240-92-6 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; CADILA HEALTHCARE LIMITED; DWIVEDI, Shri Prakash Dhar; KHERA, Brij; SINGH, Kumar Kamlesh; SOLANKI, Kirtipalsinh Sajjansinh; WO2015/114657; (2015); A2;,
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. 912773-24-1, name is 6-Bromoimidazo[1,2-a]pyrazine, This compound has unique chemical properties. The synthetic route is as follows., Formula: C6H4BrN3

Example 17-8 Synthesis of 6-bromo-3-iodo-imidazo[1,2-a]pyrazine 6-Bromoimidazo[1,2-a]pyrazine 16* (1.98 g, 0.01 M) was added to N-iodosuccinimide (2.46 g, 0.011 M) in acetonitrile (50 ml). The resulting mixture was heated at reflux overnight. The solvent was evaporated in vacuo and the residue was treated with sodium carbonate solution and extracted with ethyl acetate (3 x 200 ml). The combined extracts were dried over magnesium sulphate and evaporated in vacuo to give a pale brown solid. The solid was washed with ethyl acetate (10 ml) to give 2.23 g of the desired product. 1H-NMR (400 MHz, CDCl3): delta = 7.88 (1 H, s, ArH), 8.25 (1 H, s, ArH), 8.81 (1 H, s, ArH).

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 912773-24-1.

Reference:
Patent; Max-Planck-Gesellschaft zur Foerderung der Wissenschaften e.V.; Ullrich, Axel; Falcenberg, Mathias; EP2818471; (2014); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 33332-29-5, 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. 33332-29-5, name is 2-Amino-5-chloropyrazine belongs to Pyrazines compound, it is a common compound, a new synthetic route is introduced below.

General procedure: Method B is a modification of Method A and was performed under nitrogen atmosphere andwith extended work-up. Substituted benzoyl chloride (1.5 mmol, 1.2 equiv) was placed into the askunder nitrogen, diluted with dry DCM (5 mL) and dry pyridine (400 mg, 5 mmol, 4 equiv) was added.The mixture was mixed for 5 min under nitrogen. Then, 5-chloropyrazin-2-amine (162 mg, 1.25 mmol,1 equiv) dissolved in DCM (10 mL) was added dropwise over 10 min under nitrogen ow. The askwas closed by septum and stirred for additional 6 h. After reaction, the mixture was diluted with DCMto the final volume of 40 mL and washed with water (1 30 mL), 5% (m/m) aqueous NaHCO3 solution(1 30 mL), and brine (1 30 mL). The organic layer was dried over anhydrous Na2SO4 and adsorbedon silica (4 g) by evaporating the solvents under reduced pressure. Automated flash chromatographywas run using same conditions as described in Method A. If needed, the products were recrystallizedfrom hot EtOH (crystallization initiated by cooling and dropwise addition of cold water).

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

Reference:
Article; Zitko, Jan; Mindlova, Al?b?ta; Vala?ek, Ond?ej; Jand’ourek, Ond?ej; Paterova, Pavla; Janou?ek, Ji?i; Kone?na, Klara; Dole?al, Martin; Molecules; vol. 23; 9; (2018);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem