- Efficient Halogenation of 2-Aminopyrazine
-
2-Aminopyrazine was halogenated with NIS, NCS, and NBS under different reaction conditions. Chlorination and bromination were achieved with good yields by using acetonitrile as the solvent. However, iodination was only obtained in poor yields. Undoubtedly, the best conditions for both mono-and dihalogenation were the use of NBS, acetonitrile, and microwave assistance for short periods. 3,5-Dibromo-2-Aminopyrazine is an excellent functionalized starting material for the synthesis of nitrogen heterocycles.
- Grima, Josep,Lizano, Enric,Pujol, M. Dolors
-
p. 2000 - 2003
(2019/10/22)
-
- Synthesis method of 2-amino-5-iodopyrazine
-
The invention belongs to the field of organic synthesis, and particularly relates to a synthesis method of 2-amino-5-iodopyrazine. The synthesis method of 2-amino-5-iodopyrazine comprises the following steps: carrying out a reaction on 2-aminopyrazine and N-iodosuccinimide which serve as raw materials under the action of a proper solvent at proper temperature for hours to generate 2-amino-5-iodopyrazine, and carrying out purification to obtain pure 2-amino-5-iodopyrazine. The synthesis method of 2-amino-5-iodopyrazine has the beneficial effects that the reaction raw materials are readily available and reasonable in price; the reaction conditions are mild; the synthesis method is easy to operate and control; post-treatment is simple; the product quality is stable; and the purity is high.
- -
-
Paragraph 0009-0011; 0012-0014; 0015-0016
(2017/08/28)
-
- MEDICAMENT FOR REDUCTION OF BLOOD LDL CHOLESTEROL
-
PROBLEM TO BE SOLVED: To provide a medicament which makes it possible to reduce blood LDL. SOLUTION: A medicament for reduction of blood LDL comprises a compound represented by general formula (I), or salt thereof, or solvate thereof as an active ingredient. COPYRIGHT: (C)2015,JPOandINPIT
- -
-
Paragraph 0083; 0084
(2016/10/09)
-
- Chemical synthesis of coelenterazine and its analogs: New route by four segment-couplings
-
A novel and improved synthetic route includes four segment-couplings toward coelenterazine and its analogs as luminescent molecules. Regio- and chemo-selective cross coupling reactions using palladium catalysts with 5-iodo-3-bromo-2-aminopyrazine have enabled providing various aminopyrazine derivatives having different substituents. The improved synthesis of coelenterazine and its analogs employed advanced condensation with the aminopyrazines using various keto-acetal segments, which resulted in much higher yields to give the final imidazopyrazinone heterocycles than the previous method using keto-aldehydes.
- Chou, Chun-Ming,Tung, Yu-Wen,Lin, Meng-I,Chan, Diana,Phakhodee, Wong,Isobe, Minoru
-
p. 1323 - 1339
(2013/08/15)
-