100643-27-4Relevant articles and documents
Green Microwave-assisted Multicomponent Route to the Formation of 5,8-Dihydropyrido[2,3-d]pyrimidine Skeleton in Aqueous Media
Saraev, Vyacheslav E.,Zviagin, Ievgen M.,Melik-Oganjanyan, Rafael G.,Sen'ko, Yulia V.,Desenko, Sergey M.,Chebanov, Valentin A.
, p. 318 - 324 (2017)
Three-component synthesis of 5-substituted 6-acetyl-2-amino-7-methyl-5,8-dihydropyrido[2,3-d]pyrimidines was brought to facile energy-efficient and environmental-friendly conditions using multicomponent reaction, microwave field as an activation method and hot water as a solvent. A series of the target compounds was synthesized using the developed procedure.
Preparation methods of 2,4-diamido-5-nitroso-6-hydroxypyridine and guanine
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Paragraph 0053; 0054; 0055; 0056; 0057; 0063; 0064-0066, (2018/10/19)
The invention discloses a preparation method of 2,4-diamido-5-nitroso-6-hydroxypyridine. The preparation method comprises the following steps: (1) in a sodium methoxide methanol solution, carrying outa ring-closure reaction between methyl cyanoacetate and guanidine salt; (2) adding recycled absolute methanol to be diluted, filtering and recycling byproduct sodium nitrate; (3) concentrating a filter liquor, and recycling absolute methanol; (4) adding water to destroy excessive sodium methoxide, concentrating and recycling water-containing methyl alcohol; (5) in a diluted methane acid solution,carrying out a nitrosation reaction among an obtained concentrate, sodium nitrite and a nitrosation mother liquor; (6) after the reaction ends, carrying out cooling crystallization, filtering, takinga filter liquor as the nitrosation mother liquor to be used indiscriminately, and drying an obtained filter cake to obtain the 2,4-diamido-5-nitroso-6-hydroxypyridine. According to the preparation method, indiscriminate use of the nitrosation mother liquor and recycling of sodium nitrate and methyl alcohol are realized, and simultaneously the diluted methane acid solution is used for replacing concentrated sulfuric acid used, in the prior art, to carry out the nitrosation reaction, so that the recycling of a solvent and a reagent is facilitated, and the displacement of waste water is reduced.
