Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 5521-55-1, name is 5-Methylpyrazine-2-carboxylic acid, A new synthetic method of this compound is introduced below., Product Details of 5521-55-1
Step 1. tert-butyl 5-methylpyrazin-2-ylcarbamate To solution 5-methylpyrazine-2-carboxylic acid (2.5 g, 18.1 mmol), tert-butanol (6.92 mL, 72.4 mmol), Et3N (3.78 mL, 27.1 mmol) in 1,4-dioxane (12.5 mL) at 95 C. was dropwise added diphenylphosphoryl azide (DPPA, 3.23 mL, 18.1 mmol), and the reaction was heated at 95 C. for 1.5 h, followed by a 2nd portion of DPPA (1 mL, 5.6 mmol) and heated for additional 1.5 h. The reaction mixture was cooled down, concentrated and the residue was diluted with EtOAc (50 mL), washed with water (30 mL), 3 M NaOH (30 mL), sat. NaHCO3 (30 mL) and brine (30 mL), dried over Na2SO4, and concentrated. The residue was purified by flashed chromatography on silica gel eluting with gradient EtOAc/CH2Cl2 (0-20%) to afford tert-butyl 5-methylpyrazin-2-ylcarbamate as white solid. LCMS (m/z): 210.1 (MH+), 0.69 min; 1H NMR (400 MHz, CDCl3) delta ppm 9.17 (s, 1H), 8.09 (s, 1H), 7.75 (br. s., 1H), 2.51 (s, 3H), 1.56 (s, 9H).
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; Novartis AG; Bagdanoff, Jeffrey T.; Ding, Yu; Han, Wooseok; Huang, Zilin; Jiang, Qun; Jin, Jeff Xianming; Kou, Xiang; Lee, Patrick; Lindvall, Mika; Min, Zhongcheng; Pan, Yue; Pecchi, Sabina; Pfister, Keith Bruce; Poon, Daniel; Rauniyar, Vivek; Wang, Xiaojing Michael; Zhang, Qiong; Zhou, Jianguang; Zhu, Shejin; (366 pag.)US9242996; (2016); B2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem