Tag: M.W=100-200

Related Products of 16298-03-6,Some common heterocyclic compound, 16298-03-6, name is Methyl 2-aminopyrazine-3-carboxylate, molecular formula is C6H7N3O2, 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) Methyl 2-bromo-3-pyrazine carboxylate To a stirred mixture of 12.7 g. of methyl 2-amino pyrazine 3-carboxylate and 47 ml. of 48% hydrobromic acid there is added, dropwise, 12.6 ml. of bromine keeping the temperature at 0. A solution of 14.4 g. of sodium nitrite in 60 ml. of water is then added, dropwise, at 0 and the reaction mixture stirred for 15 minutes. The reaction mixture is basified to pH 8 with sodium bicarbonate and extracted with ethyl acetate and again with chloroform. The organic layers are dried over magnesium sulfate, filtered and concentrated to a yellow oil. Recrystallization from ether-hexane yields the product, m.p. 43-45 C.

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 2-aminopyrazine-3-carboxylate, its application will become more common.

Reference:
Patent; Schering Corporation; US4492702; (1985); 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. 33332-29-5, name is 2-Amino-5-chloropyrazine, This compound has unique chemical properties. The synthetic route is as follows., SDS of cas: 33332-29-5

5-CHLORO-2-PYRAZINAMINE (D47, Step 1) (2.41 g, 18.6 MMOL) was dissolved in concentrated hydrochloric acid (24 ML), cooled in an ice-acetone bath and treated with a solution of sodium nitrite (2.63 g, 38.1 MMOL) in water (18 ML) dropwise over a period of 1 hour. The mixture was cooled in an ice-water bath and left to stir for 1 hour. The mixture was allowed to warm to room temperature over 1 hour, neutralised by addition of sodium hydroxide solution (2M) and extracted with dichloromethane. The DICHLOROMETHANE layers were combined, dried under magnesium sulfate and evaporated in vacuo. The resulting residue was purified by column chromatography eluting with a mixture of ethyl acetate: pentane (1: 9) to afford the title compound (0.33 g);’H NMR (CDCI3) 8.40 (2H, s).

According to the analysis of related databases, 33332-29-5, the application of this compound in the production field has become more and more popular.

Reference:
Patent; GLAXO GROUP LIMITED; WO2004/56369; (2004); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 5521-58-4, 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. 5521-58-4 name is 5-Methylpyrazin-2-amine, 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.

Example 22; Synthesis of N-(5-methyl-pyrazin-2-yl l)-4-(3-{[5-(trifluoromethyl)pyridin-2-yl]oxy}benzylidene)piperidine-1-carboxamide; Step 1; Phenyl 5-methylpyrazin-2-ylcarbamate; 2-Amino-5-methyl-pyrazine (2.00 g, 21.25 mmol) was dissolved in THF (80 mL), cooled to 0 C., and treated with pyridine (1.77 g, 22.3 mmol) followed by the dropwise addition of phenylchloroformate (3.49 g, 22.3 mmol) in THF (30 mL). After stirring for 3 h, 100 mL of MeCN was added and the reaction mixture was reduced to a volume of 100 mL in vacuo. The title compound as white crystals was collected by filtration (2.5 g, 55%) and was used without further purification.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 5-Methylpyrazin-2-amine, and friends who are interested can also refer to it.

Reference:
Patent; FAY, Lorraine Kathleen; Johnson, Douglas S.; Kesten, Suzanne Ross; Lazerwith, Scott E.; Morris, Mark Anthony; Stiff, Cory Michael; Meyers, Marvin Jay; Wang, Lijuan Jane; US2008/261941; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Related Products of 109838-85-9, The chemical industry reduces the impact on the environment during synthesis 109838-85-9, name is (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, I believe this compound will play a more active role in future production and life.

The starting material, methyl 3-{6-[3-(5,6,7,8-tetrahydro-l,8-naphthyridin-2- yl)propyl]pyridin-3-yl}-L-alaninate was prepared as follows: To a solution of (2i?)-2-isopropyl-3,6-dimethoxy-2,5~dihydropyrazine (5 ml, 27.9 mmol) in THF (130 ml) was added at -78°C 1.6 M nBuLi (17.44 ml, 27.9 mmol). The mixture was stirred at -78°C for 10 min and treated with a solution of 2,5-dibromopyridine (7 g, 27.9 mmol) in THF ( 2 ml). After stirring for 2 hours, H2O ( 100 ml) was added and the mixture was allowed to warm up to ambient temperature. After extraction with ether and evaporation, the residue was purified by silica gel chromatography (10percent to 30percent ethyl acetate in petroleum ether) to afford (25r,5i?)-2-[(6-bromopyridin-3-yl)methyl]-5-isopropyl- 3,6-dimethoxy-2,5-dihydropyrazine (8.2g, 83percent); 1H NMR Spectrum:fDMSOd6) 0.58 (d, 3H), 0.92 (d, 3H), 2.06-2.15 (m, IH), 2.97 (dd, IH), 3.04 (dd, IH), 3.50 (t, IH), 3.61 (s, 3H), 3.66 (s, 3H), 3.34-3.39 (m, IH), 7.47 (dd, IH), 7.54 (d, IH), 8.11 (d, IH).

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, (R)-2-Isopropyl-3,6-dimethoxy-2,5-dihydropyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; ASTRAZENECA AB; ASTRAZENECA UK LIMITED; WO2008/93065; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reference of 33332-28-4, The chemical industry reduces the impact on the environment during synthesis 33332-28-4, name is 2-Amino-6-chloropyrazine, I believe this compound will play a more active role in future production and life.

(c) N-(6-Chloro-pyrazin-2-yl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide This compound was prepared from 4-hydroxy-2-methyl-N-ethyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide, 2-amino-6-chloro-pyrazine and p-toluenesulfonic acid analogous to Example 14. Yield: 68percent of theory. Melting point: 278°-279° C. (decomposition). C14 H11 ClN4 O4 S (366.79): Calc.: C–45.84percent; H–3.03percent; Cl–9.67percent; N–15.28percent; S–8.74percent. Found: C–45.62percent; H–3.11percent; Cl–9.70percent; N–15.04percent; S–8.59percent.

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-Amino-6-chloropyrazine, other downstream synthetic routes, hurry up and to see.

Reference:
Patent; Dr. Karl Thomae Gesellschaft mit beschrankter Haftung; US4533664; (1985); A;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Application of 939412-86-9, These common heterocyclic compound, 939412-86-9, name is (3-Chloropyrazin-2-yl)methanamine hydrochloride, 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 l-oxooctahydropyrido[l,2-c][l,3]oxazine-7-carboxylic acid (3.13 g, 15.7 mmol) in THF (100 mL) was added (3-chloropyrazin-2-yl)methanamine hydrochloride (2.8 g, 15.7 mmol), TEA (4.8 g, 47.2 mmol) and HATU (6 g, 15.7 mmol). The mixture was stirred at room temperature for 2 h. The reaction was complete detected by LCMS. The reaction mixture was treated with DCM and water, the organic layer was dried and concentrated. The residue was purified by column chromatography on silica gel eluted with DCM/THF = 5/1 to give N-((3-chloropyrazin-2-yl)methyl)-l- oxooctahydropyrido[l,2-c][l,3]oxazine-7-carboxamide (4.7 g, 92%).1H- NMR(CDC13,400 MHz) delta 1.40 – 1.49 (m, 1 H), 1.71 – 1.92 (m, 3 H), 2.04 – 2.26 (m, 2 H), 2.43 – 2.57 (m, 1 H), 2.81 – 2.97 (m, 1 H), 3.31 – 3.42 (m, 1 H), 4.13 – 4.27 (m, 2 H), 4.46 – 4.56 (m, 1 H), 4.64 (d, /= 4.70 Hz, 2 H), 8.29 (d, /= 2.35 Hz, 1 H), 8.44 (d, /= 2.35 Hz, 1 H).

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 19847-12-2,Some common heterocyclic compound, 19847-12-2, name is Pyrazinecarbonitrile, molecular formula is C5H3N3, 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.

General procedure: Synthesis of 5-(thiophen-3-yl)-1H-tetrazole (2a). 3-Thiophenecarbonitrile 1a (218 mg, 2 mmol), NaN3 (260 mg,4 mmol), CeCl3·7H2O (75 mg, 0.2 mmol), and 8 mL of a 3:1isopropanol/water mixture were added to a 30-mL Pyrexmicrowave vessel and capped. The microwave vessel wasthen placed in a multi-mode microwave reactor. The reactionwas magnetically stirred and heated for 1 hour at 160 C.The pressure in the vessel was not determined. The reactionwas monitored by TLC using an ether/hexane mixture (typically50/50) for development. After cooling, the reactionmixture was diluted with saturated aqueous sodium bicarbonate(20 mL) and washed with ethyl acetate (2 x 15 mL).The aqueous sodium bicarbonate layer was cooled with iceand acidified to a pH of 2 or less with concentrated hydrochloricacid, which was added drop-wise. The precipitateformed was extracted with ethyl acetate (3 x 15 mL). Thecombined organic layers were dried over anhydrous sodiumsulfate and decanted into a tared round bottom flask. Theorganic layer was concentrated under reduced pressure. Thetetrazole product was recrystallized from ethyl acetate andhexane. All reagents mentioned above were used unpurified.

The synthetic route of 19847-12-2 has been constantly updated, and we look forward to future research findings.

Reference:
Article; Dudley, Joshua; Feinn, Liana; Defrancesco, Heather; Lindsay, Erica; Coca, Adiel; Roberts, Elizabeth Lewis; Medicinal Chemistry; vol. 14; 6; (2018); p. 550 – 555;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthetic Route of 13924-94-2,Some common heterocyclic compound, 13924-94-2, name is Methyl 5-aminopyrazine-2-carboxylate, molecular formula is C6H7N3O2, 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. Methyl 5-((3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yI)amino)pyrazine-2- carboxylate (93). To a solution of 77 (1.1303 g, 4.02 mmol), 92 (0.5969 g, 3.90 mmol), CsCO3 (3.12 g, 9.58 mmol), rac-B1NAP (0.1868 g, 0.30 mmol) in toluene (4.5 mL) in a 100 mL round-bottomed flask was added Pd2(dba)3 (0.1780 g, 0.19 mmol). The solution was sparged with nitrogen for 5 mm., then a reflux condenser was fitted to the flask, the atmosphere was evacuated and back-filled with nitrogen (three times), and the reaction was heated to reflux with stirring in an oil bath (125- 120 C) for 22h. After cooling the reaction to room temperature, excess cesium carbonate and other solid particulates were filtered and washed with ethyl acetate, and the organic filtrate was concentrated in vacuo to give a crude product that was purified by column chromatography (150 mL Si02, 20% ethyl acetate:hexanes to 25% ethyl acetate: hexanes) to give 93 (0.8727 g, 63%) as a crystalline solid, m.p. 134.9-137.1 C: ?H NMR (400 MHz, CDC13)6 8.81 (d,J= 1.2, 1H), 8.08 (d,J = 1.6, 1H), 7.32 (s, 1H), 7.20 (s, 1H), 7.03 (br s, 1H), 3.95 (s, 3H), 2.22 (s, 3H), 1.68 (s, 4H), 1.28 (s, 6H), 1.24 (s, 6H); ?3C NMR (100.6 MHz, CDC13) 164.8, 154.3, 145.4, 144.1, 143.6, 132.8, 130.7,129.5, 129.3, 122.2, 52.3, 34.9, 34.8, 34.1, 33.9, 31.8, 31.7, 17.6; IR(neat) 3162, 2961, 1712, 1542, 1306, 1271, 1129 cm1 ES-MS (M+Na)+ calcd for C21H27N3O2Na 376.2001, found 376.2006.

The synthetic route of 13924-94-2 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; ARIZONA BOARD OF REGENTS ON BEHALF OF ARIZONA STATE UNIVERSITY; WAGNER, Carl; MARSHALL, Pamela; JURUTKA, Peter; WO2015/130973; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

These common heterocyclic compound, 312736-50-8, name is 3,5-Dichloropyrazine-2-carboxamide, 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. Safety of 3,5-Dichloropyrazine-2-carboxamide

A mixture of 3,5-dichloropyrazine-2-carboxamide (3b, 450 mg, 2.34 mmol), 3-(methanesulfonyl)aniline (441 mg, 2.58 mmol), DIPEA (408 muL, 2.34 mmol) and 1,4-dioxane (20 mL) was stirred 110 C for 60 h. After the mixture was cooled, water was added, and the resulting slurry was extracted with EtOAc. The organic layer was dried over anhydrous MgSO4, and concentrated in vacuo. The residue was purified by silica gel column chromatography (CHCl3/MeOH=100:0 to 50:1).The resulting product was washed with EtOAc to give 4b (425 mg,55%) as a pale yellow solid. 1H NMR (DMSO-d6): delta 3.24 (3H, s),7.55-7.77 (2H, m), 7.90-8.04 (1H, m), 8.06-8.36 (3H, m), 8.50 (1H, s),11.73 (1H, s); MS (FAB) m/z [M+H]+ 327.

The synthetic route of 3,5-Dichloropyrazine-2-carboxamide has been constantly updated, and we look forward to future research findings.

Reference:
Article; Iikubo, Kazuhiko; Kurosawa, Kazuo; Matsuya, Takahiro; Kondoh, Yutaka; Kamikawa, Akio; Moritomo, Ayako; Iwai, Yoshinori; Tomiyama, Hiroshi; Shimada, Itsuro; Bioorganic and Medicinal Chemistry; vol. 27; 8; (2019); p. 1683 – 1692;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Electric Literature of 5521-55-1, 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. 5521-55-1 name is 5-Methylpyrazine-2-carboxylic acid, 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.

Step 1: To a solution of 2-methylpyrazine-5-carboxylic acid (10 g, 72.4 mmol) and TEA (20 mL, 108 mmol) in t-butanol (156 mL) and dioxanes (100 mL) was added diphenyl phosphorylazide (23.4 mL, 108 mmol) and the resulting solution was warmed at 100 C. for 3 hours and then cooled to room temperature overnight. The crude reaction mixture was concentrated in vacuo. Purification by chromatography (silica 0-15% ethyl acetate/hexanes) following trituration of impure fractions with ether afforded (5-methyl-pyrazin-2-yl)-carbamic acid tert-butyl ester (10.6 g, 70%): 1H NMR (300 MHz, CHLOROFORM-d) delta ppm 1.56 (s, 9H) 2.51 (s, 3H) 8.02 (br. s., 1H) 8.07-8.14 (m, 1H) 9.18 (d, J=1.13 Hz, 1H).

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

Reference:
Patent; Brotherton-Pleiss, Christine E.; Walker, Keith A. M.; US2012/149718; (2012); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem