3-HYDROXYPYRAZINE-2-CARBOXAMIDE synthesis
- Product Name:3-HYDROXYPYRAZINE-2-CARBOXAMIDE
- CAS Number:55321-99-8
- Molecular formula:C5H5N3O2
- Molecular Weight:139.11
131543-46-9
62009-47-6
55321-99-8
The general procedure for the synthesis of 3-hydroxypyrazine-2-carboxamide from the compound (CAS:131543-46-9) and 2-aminomalonamide was carried out as follows: firstly, diethylaminomalonate (in the form of hydrochloric acid) was dissolved in water, and pH was adjusted by adding sodium bicarbonate to a value greater than 7. Subsequently, an extraction operation was carried out, and the organic phase was evaporated under reduced pressure. The product obtained was quantitatively converted to aminodicarbonamide by treating the product with an aqueous ammonia solution at 80 °C overnight. The product obtained in this step does not require further purification and can be directly dissolved in water for the next reaction. Next, glyoxal sodium bisulfite hemihydrate was added to this aqueous solution and the reaction mixture was stirred at 90°C for 3 hours. After completion of the reaction, the reaction mixture was adjusted to alkaline with 58% NH4OH solution. A 30% H2O2 solution was added dropwise to the rapidly stirred cold solution at 0°C. The reaction mixture was allowed to stand at room temperature to induce precipitation of 2-hydroxy-3-carboxamide pyrazine. Finally, the solid product was collected in 63% yield and purified by partial recrystallization. References: [J. Med. Chem. 1983, 26, 283-86], [J. Heterocyclic Chem. 1979, 16, 193].
131543-46-9
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Yield:55321-99-8 91.2%
Reaction Conditions:
with sodium hydroxide in water at -10 - 22; for 4.67 h;
Steps:
1 Example 1: Preparation of compound III
In the reaction flask, add 220 ml of 20% sodium hydroxide aqueous solution, cool to -10°C, and then add 100 g of 2-aminomalonamide to suspend it in the solution. Then, 149.4 g of 40% glyoxal aqueous solution was added dropwise, and the addition was completed in about 40 minutes. After the dropwise addition, the reaction mixture was stirred at -5°C for 1 hour, heated to 22°C, and stirred for another 3 hours. After the reaction is completed, it is cooled to below 5°C, the reaction compound is adjusted to pH 12 by adding 1 mol/l sodium hydroxide, and a solution is made again. The solution was then adjusted to pH 2 by adding 6 mol/l hydrochloric acid. The deposited crystals were collected by filtration and washed with water and 50% (w/w) ethanol successively to obtain 108.6 g of compound II with a yield of 91.2%.
References:
CN111349049,2020,A Location in patent:Paragraph 0044-0048