698-29-3Relevant articles and documents
Studies on the Thorpe-Ziegler-reaction. A new synthesis of the pyridine part of thiamine
Edenhofer,Spiegelberg,Oberhaensli
, p. 1230 - 1240 (1975)
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Fully continuous flow preparation method of 2-methyl-4-amino-5-aminomethylpyrimidine
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Paragraph 0006; 0045-0046; 0048-0061, (2021/07/17)
The invention discloses a fully continuous flow preparation method of 2-methyl-4-amino-5-aminomethylpyrimidine. The method comprises the following steps: mixing a mixed solution of cyanoacetamide, N, N-dimethylformamide and a catalyst with phosphorus oxychloride in a micro-mixer, and carrying out a continuous flow reaction in a micro-channel reactor to obtain (dimethyl aminomethylene) malononitrile; continuously quenching, continuously extracting and separating, concentrating an organic solution, mixing with a methanol solution, and continuously reacting with organic alkali to obtain 2-methyl-4-amino-5-cyanopyrimidine; continuously filtering the reaction mixed solution, dissolving the solid with methanol, conveying the dissolved solid and hydrogen to a fixed bed microchannel reactor through a micromixer, carrying out hydrogenation reaction, and concentrating, drying and purifying the product to obtain the 2-methyl-4-amino-5-aminomethylpyrimidine product. The method is mild in reaction condition, short in reaction time, high in product yield, low in energy consumption, green, safe and easy to industrially amplify and apply.
Fully Continuous Flow Synthesis of 5-(Aminomethyl)-2-methylpyrimidin-4-amine: A Key Intermediate of Vitamin B1
Chen, Fener,Huang, Huashan,Jiang, Meifen,Liu, Minjie
, p. 2331 - 2337 (2021/10/25)
Herein, we demonstrate an expeditiously fully continuous flow synthesis of 5-(aminomethyl)-2-methylpyrimidin-4-amine, a key intermediate for vitamin B1. The process is accomplished via three chemical transformations in six sequential continuous flow devices from an economical starting material, 2-cyanoacetamide. First, single step continuous flow synthesis is demonstrated in a certain type of flow reactor for each reaction step, with a yield of 94, 90, and 99%, respectively. Then, fully continuous flow synthesis of 5-(aminomethyl)-2-methylpyrimidin-4-amine is demonstrated in 84% total yield with a total residence time of 74 min and 0.92 g/h throughput.
Method for preparing 2-methyl-4-amino-5-cyanopyrimidine by Mannich reaction
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Paragraph 0041; 0042; 0043; 0044; 0045; 0046; 0047-0052, (2017/08/25)
The invention relates to a method for preparing 2-methyl-4-amino-5-cyanopyrimidine by Mannich reaction. According to the invention, ethylamidine hydrochloride, malononitrile and an aldehyde compound are used as raw materials and subjected to the Mannich reaction to obtain 2-methyl-4-amino-5-cyano-5,6-dihydropyrimidine hydrochloride that is then oxidized by an oxidizer to obtain the 2-methyl-4-amino-5-cyanopyrimidine. The raw materials malononitrile and ethylamidine hydrochloride used for the method for preparing 2-methyl-4-amino-5-cyanopyrimidine by Mannich reaction are high in stability under reaction conditions, thereby reducing side reactions of the malononitrile and free ethylamidine hydrochloride under an alkaline condition and providing guarantee for high yield and high purity of the product.