Synthetic Route 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.
[Reference Example 6] 1-(6-Methoxy-3-pyridyl)-5-(2-pyrazinyl)-1H-pyrazole-3-carboxylic acid [Show Image] [Show Image] Lithium bis(trimethylsilyl)amide (a 1.0 M solution in tetrahydrofuran, 11.0 mL) was added to a solution of 1-(2-pyrazinyl)-1-ethanone (1.22 g) in tetrahydrofuran (10 mL) under cooling to -78C, and the resultant mixture was stirred for 55 minutes. Diethyl oxalate (2.05 mL) was added thereto, and the mixture was slowly returned to room temperature, and stirred for 6.5 hours. An aqueous 1 N hydrochloric acid solution (11 mL), water and diethyl ether were added to the reaction solution, and the mixture was partitioned. Then, sodium chloride was added to the aqueous layer to be saturated, and then ethyl acetate was added for extraction. The organic layers were combined, and the solvent was evaporated under reduced pressure, to obtain a crude product of 4-(2-pyrazinyl)-2, 4-dioxobutanoic acid ethyl ester (1.83 g, 82%) as a solid. To a suspension of this crude product (1.58 g) in ethanol (20 mL), a solution formed from a suspension of 5-hydrazino-2-methoxypyridine hydrochloride (1.50 g) of Reference Example 1 in ethanol (80 mL) conditioned with triethylamine (1.9 mL), was added, and the mixture was heated to reflux for 19 hours. Acetic acid (5 mL) was further added to the reaction solution, and the mixture was heated to reflux for 1.5 days. After air cooling, ethyl acetate and a saturated aqueous solution of sodium hydrogen carbonate were added to the reaction solution, and the mixture was partitioned. The organic layer was dried over anhydrous sodium sulfate. After separation by filtration, a residue obtained by evaporating the solvent under reduced pressure was purified by silica gel column chromatography (ethyl acetate-hexane), to obtain 1-(6-methoxy-3-pyridyl)-5-(2-pyrazinyl)-1H-pyrazole-3-carboxylic acid ethyl ester (1.05 g, 45%) as a solid. To a solution of this obtained 1H-pyrazole-3-carboxylic acid ethyl ester product (1.05 g) in ethanol (30 mL), an aqueous 1 N sodium hydroxide solution (10.0 mL) was added, and the mixture was stirred for 16 hours at room temperature. An aqueous 1 N hydrochloric acid solution (15 mL), water and ethyl acetate were added to the reaction solution, and the mixture was partitioned. The organic layer was dried over anhydrous magnesium sulfate. After separation by filtration, the solvent was evaporated under reduced pressure, to obtain a crude product of the title compound (0.883 g, 92%) as a solid. This product was supplied to the subsequent reaction without being purified.
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:
Patent; DAIICHI PHARMACEUTICAL CO., LTD.; EP1785418; (2007); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem