Month: May 2021

Electric Literature of 6164-79-0, The chemical industry reduces the impact on the environment during synthesis 6164-79-0, name is Methyl 2-pyrazinecarboxylate, I believe this compound will play a more active role in future production and life.

Example 21.1Pyrazine-2-carbohydrazide To the title compound of Example 19.1 (1.28 mg, 9.3 mmol) in ethanol (10 mL) was added hydrazine hydrate (0.54 mL, 11.1 mmol) and then heated at 78 C. overnight. The reaction mixture was cooled and concentrated in vacuo. The residue was triturated with ethyl acetate, filtered and dried to give the title product as a yellow solid (870 mg, 68%).1H NMR (300 MHz, (CD3)2SO): delta (ppm) 10.16 (broad s, 1H), 9.13 (s, 1H), 8.84 (s, 1H), 8.70 (s, 1H), 4.65 (broad s, 2H).

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

623565-14-0, name is 2-Ethyl 5-(4-nitrobenzyl) 6,7-dihydropyrazolo[1,5-a]pyrazine-2,5(4H)-dicarboxylate, 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. COA of Formula: C17H18N4O6

Step 4: 2-Hydroxymethyl-6. 7-dihvdro-4H-pyrazolo1, 5-alpyrazine-5-carboxylic acid 4-nitrobenzvl ester; LiBH4 (640 mg) and MeOH (1.2mL) was added to the THF (267 mL) solution of 6, 7-dihydro-4H-pyrazolo [1,5-a] pyrazine-2, 5-dicarboxylic acid 2-ethyl ester 5- (4- nitrobenzyl) ester (10 g) under a nitrogen atmosphere at room temperature and stirred for 3 h at 40 C. Additional LiBH4 (523 mg) and MeOH (1.0 mL) was added to the solution and stirred for 1 h at 40 C and 1 h at 50 C. The mixture was acidified with 3 mol/L HCI to pH 2 and stirred for 1 h at room temperature, then solid K2CO3 was added to the solution to adjust pH to 8. The insoluble material was filtered off and the filtrate was extracted with AcOEt. The organic layer was dried (K2CO3), and concentrated under reduced pressure. The residue was purified with silica gel column chromatography (CHCI3/MeOH =49/1-19/1) to afford titled compound as pale yellow crystals (8.44 g, 95%). 1H NMR (CDCI3) 8 1. 69 (br, 1 H), 3.98 (t, 2H, J = 5.5 Hz), 4.19 (t, 2H, J = 5.5 Hz), 4.65 (s, 2H), 4.75 (s, 2H), 5.28 (s, 2H), 6.08 (s, 1H), 7.53 (d, 2H, J = 8.7 Hz), 8.24 (d, 2H, J=8. 7Hz).

The synthetic route of 623565-14-0 has been constantly updated, and we look forward to future research findings.

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. 330786-09-9, name is Methyl 3,5-dichloropyrazine-2-carboxylate belongs to pyrazines compound, it is a common compound, a new synthetic route is introduced below. HPLC of Formula: C6H4Cl2N2O2

Step 1: [0443] Dichloropyrazine S1.1 (synthesized as described in Yamada, K.; Mastuki, K.; Omori, K.; Kikkawa, K. US Patent Application 2004/0142930A1) (0.46 g, 2.7 mmol) was diluted with 10 mL of acetonitrile. To this was then added DIPEA (0.52 mL, 3.0 mmol) and cyclopropylamine (0.19 mL, 2.7 mmol) and the reactions stirred at rt overnight. The following day the reaction was concentrated by rotary evaporation and the resulting syrup diluted with water and stirred until a filterable precipitate formed. The solid was isolated by filtration and washed with water affording the desired product as a bright yellow solid containing regioisomers S1.2 and S1.3. Step 2: [0444] The mixture of regioisomers S1.2 and S1.3 (0.42 g, 1.9 mmol) were diluted with 20 mL of dioxane and 2.0 mL of 1M LiOH. The reaction was stirred at rt until all starting material had been consumed. The reaction was then acidified to pH=2 with 1M HCl and diluted with water to a total volume of 70 mL. The resulting solid was isolated by filtration affording the major isomer, S1.4, as a yellow solid (107 mg, 26%). Upon sitting, a precipitate formed in the filtrate which was then isolated and identified as regioisomer S1.5 (0.17 g, 42%).

The synthetic route of 330786-09-9 has been constantly updated, and we look forward to future research findings.

These common heterocyclic compound, 23611-75-8, name is Methyl 6-chloropyrazine-2-carboxylate, 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. Quality Control of Methyl 6-chloropyrazine-2-carboxylate

Step 3: Preparation of (6-chloropyrazin-2-yl)methanol. To a solution of methyl 6- chloropyrazine-2-carboxylate (2.0 g, 11.6 mmol) in water (20 mL) at 0 C was added NaBH4 (2.3 g, 58.0 mmol) portionwise. The reaction mixture was warmed to r.t. and stirred for 30 mm, followed by addition of satd. aq. K2C03 (40 mL) and EtOH (20 mL). The resulting mixture was stirred for another 1 hr and extracted with EA (2 x 20 mL). The combined organic layers were dried over anhydrous Na2SO4and concentrated and purified by standard methods to afford (6- chloropyrazin-2-yl)methanol. LC-MS: m/z 145.0 (M+H).

The synthetic route of Methyl 6-chloropyrazine-2-carboxylate has been constantly updated, and we look forward to future research findings.

Reference of 369638-68-6,Some common heterocyclic compound, 369638-68-6, name is tert-Butyl (5-methylpyrazin-2-yl)carbamate, molecular formula is C10H15N3O2, 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.

tert-butyl 5-methylpyrazin-2-yl carbamate (6.27 g, 30.0 mmol) was weighed and dissolved in 30 mL dichloromethane, and in an ice water bath, 20 mL trifluoroacetic acid was added slowly. It was moved to react at room temperature for 1 hour, rotate evaporated to dryness to remove the solvent, and was used for the next step directly.

The synthetic route of 369638-68-6 has been constantly updated, and we look forward to future research findings.

Electric Literature of 23688-89-3, 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 23688-89-3 as follows.

(R)-(2,2-dimethyl-1,3-dioxolan-4-yl)methanol (2.50 g, 18.93 mmol) was added to a room temperature suspension of NaH 60 wt% (833.0 mg, 20.82 mmol) in THF (50 mL). The reaction mixture was stirred at room temp for 30 min and a solution of 6-chloropyrazine-2-carboxylic acid (1.0 g, 6.31 mmol) in THF (20 mL) was added. The reaction mixture was stirred at room temp for 30 min then heated at reflux for 2 h. After cooling to room temp, the pH was adjusted to 3 by the addition of 3 N HCl (4 mL). The mixture was poured into brine and extracted with EtOAc. The combined organics were dried and concentrated. The crude product was recrystallized from pentane/EtOAc to give (R)-6-((2,2-dimethyl-1,3-dioxolan-4-yl)methoxy)pyrazine-2-carboxylic acid (764.0 mg, 48% yield). MS (ESI) calcd for C11H14N2O6 (m/z): 254.09; found: 255 [M+H].

According to the analysis of related databases, 23688-89-3, the application of this compound in the production field has become more and more popular.

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 33332-28-4 as follows. SDS of cas: 33332-28-4

To a solution of 2-amino-6-chloropyrazine (1 g, 7.72 mmol) in anhydrous acetonitrile (10 mL) was gradually added NBS (4.12 g, 23.16 mmol, 3 equiv.) at 0°C. The reaction mixture was slowly warmed up to r.t. and stirred overnight then diluted with water and extracted with Et20. Combined organic layers were washed with water and brine, then dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The crude material was purified byflash chromatography on silica eluting with Hexane/EtOAc (1:1)to give the title compound (1.55 g, 5.39 mmol, 70percent) as a pale yellow solid. ESI-MS: 287.90 [M+H]+.

According to the analysis of related databases, 33332-28-4, the application of this compound in the production field has become more and more popular.

Synthetic Route of 312736-49-5, 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. 312736-49-5 name is 3,5-Dichloropyrazine-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.

(2) A mixture of 2-carboxy-3,5-dichloropyrazine (prepared in the above (1)) 226 g, sodium hydrogen carbonate 118 mg, methyl iodide 0.5 ml and dimethylformamide 1.8 ml is stirred at room temperature for 14 hours. The mixture is diluted with a 10% aqueous citric acid solution and extracted with ethyl acetate. The combined organic layer is washed with water and an aqueous saturated sodium chloride solution, dried over sodium sulfate and concentrated in vacuo to give 2-methoxycarbonyl-3,5-dichloropyrazine as a pale brown crystalline powder 245 mg. mp 60-63 C., MS(m/z): 206(M+)

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3,5-Dichloropyrazine-2-carboxylic acid, and friends who are interested can also refer to it.

Electric Literature of 33332-29-5,Some common heterocyclic compound, 33332-29-5, name is 2-Amino-5-chloropyrazine, molecular formula is C4H4ClN3, 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 5-chloropyrazin-2-amine (25 g, 192.98 mmol) in DCM (250 mL) was added NBS (34.35 g, 192.98 mmol). The resulting mixture was stirred at 40 C for 1 hour. After cooling to room temperature and concentrated, water (200 mL) was added to give residue, extracted with EtOAc (150 mL x 2). The combined organic phase was washed with brine (150 mL), dried over Na2S04, filtered and concentrated to give the crude product. The crude product was purified by chromatography column on silica gel (EtOAc in PE = 0% to 15% to 30%) to give the product (31 g, 148.72 mmol, 77% yield) as a solid. ‘H NMR (DMSO-cL, 400MHz) 5H = 8.09 (s, 1H), 6.96 (s, 2H).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2-Amino-5-chloropyrazine, its application will become more common.

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. HPLC of Formula: C6H8ClF3N4

2,4,5-Trifluorophenylacetic acid (2-1) (available from several commercial suppliers) (0.25 g, 1.32 mol), Meldrum’s acid (0.21 kg, 1.45 mol), and DMAP (12.9 g, 0.11 mol) were charged into a 5 L three-neck flask. Acetonitrile (750 mL) was added in one portion at room temperature. N,N-diisopropylethylamine (492 mL, 2.83 mol) was added in one portion at room temperature while maintaining the temperature below 40 C. Pivaloyl chloride (178 mL, 1.45 mol) was added dropwise over 1 to 2 h while maintaining the temperature below 50 C. The reaction was aged at 45-50 C for 2-3 h. Triazole hydrochliride 1-4 (0.30 kg, 1.32 mol) was added in one portion at 45-50 C. Trifluoroacetic acid (30.3 mL, 0.39 mol) was added dropwise, and the reaction solution aged at 50-55 C for 6 h. Without further work-up, the crude reaction mixture containing 2-3 can be used directly for conversion inrto DP-IV inhibitors. The isolated solution yield was 88-90%.

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