These common heterocyclic compound, 95-89-6, name is 3-Chloro-2,5-dimethylpyrazine, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. name: 3-Chloro-2,5-dimethylpyrazine
Ammonia in water (3 mL, 48.5 mmol) was added to 3-chloro-2,5-dimethylpyrazine (0.121 mL, 1 mmol) and the mixture heated by microwaves to 165 C. for 7 hours. Following LCMS analysis, the reaction was then reheated to 165 C. for a further 16 hours, by microwaves. After cooling, the solvent was removed under a stream of nitrogen and the crude redissolved in dichloromethane (20 mL). Water (25 mL) was added and the mixture basified to pH14 using sodium hydroxide solution (18 N). The organic layer was removed and the aqueous layer extracted with dichloromethane (5¡Á25 mL). The organic phases were combined and dried using a hydrophobic frit, then evaporated in vacuo to give the title product (109 mg). This was used directly in the next step with no further purification. LCMS (2 min, high pH) Rt 0.47 min, m/z (ES+) 124 (M+H). 1H NMR (400 MHz, CHLOROFORM-d) delta ppm 7.73 (s, 1H), 4.42 (br. s., 2H), 2.37 (s, 3H), 2.35 (s, 3H).
The synthetic route of 3-Chloro-2,5-dimethylpyrazine has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Glaxo Group Limited; Birault, Veronique; Campbell, Amanda Jennifer; Harrison, Stephen; Le, Joelle; Shukla, Lena; US2015/65507; (2015); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem