Electric Literature of 5521-55-1, The chemical industry reduces the impact on the environment during synthesis 5521-55-1, name is 5-Methylpyrazine-2-carboxylic acid, I believe this compound will play a more active role in future production and life.
General procedure: Under argon, a stirred solution of appropriate carboxylic acid (0.37 mmol, 1.0 eq.) and Et3N (0.48 mmol, 1.3 eq.) in dry THF (7 mL) was cooled to -10 C. Ethyl chloroformate (0.55 mmol, 1.5 eq.) was dropwise added and the resulting mixture was stirred for 2 h. Afterward, a solution of sodium azide (0.63 mmol, 1.7 eq.) in water (2 mL) was added in one portion. After 1 h at -10 C, the reaction was found to be complete (TLC) and was quenched into iced water (5 mL). The mixture was extracted with EtOAc (3 * 10 mL) and the combined organic layers were successively dried over MgSO4, filtered and evaporated under reduced pressure. The crude acyl azide was placed in dry toluene (20 mL) and the mixture heated at reflux for 1 h to give the corresponding crude isocyanate. The latter was dissolved in dry dioxane (7 mL) prior to adding the amine 4 (0.37 mmol, 1.0 eq.). The solution was heated at reflux for 24 h. The reaction mixture was cooled to room temperature and the volatiles were removed to dryness in vacuum at 40 C. The dark residue was purified by silica gel chromatography column (CH2Cl2/MeOH 99/1) to afford the desired valmerins.
In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 5-Methylpyrazine-2-carboxylic acid, other downstream synthetic routes, hurry up and to see.